KR20080038081A - Audiovisual Signal Routing and Distribution System - Google Patents

Abstract

The audiovisual signal is converted from the raw format into a digitized, packetized compatible format and transmitted between the capture node and the display node via a switch. The display node converts the audiovisual signal from the compatible format to the display format to cause the display of the audiovisual signal. The use of switches for video routing and distribution enables one-to-one, one-to-many, many-to-one, and many-to-many distributions. The use of independent compatible format devices allows simultaneous distribution of several heterogeneous audiovisual signals.

Description

AUDIOVISUAL SIGNAL ROUTING AND DISTRIBUTION SYSTEM}

The present invention relates to a routing and distribution system for audiovisual signals, and more particularly, to an efficient and flexible system for routing and distributing audiovisual signals of various different formats.

There are a number of advanced video routing and distribution systems at present. An example is the Optima system of AutoPatch ^™ from XN Technologies, Inc. of Washington Cheney. This configuration system can handle various audio and video signals.

Such video routing and distribution systems are often referred to as video switches and are slowed down as more video formats are available. Conventional video switches support a number of available video formats, but as a specific problem, the variety of video formats is increasing and not all video formats can be supported. Except for standard television formats such as NTSC, PAL, and SECAM, the image format may be analog or digital, interlaced or progressive scan, various resolutions, various aspect ratios, various frame rates, and the like. Analog formats include, for example, composite video, S-picture, YUV, and RGB. Currently used video resolutions include, for example, 640 × 480, 800 × 600, 1024 × 768, 1280 × 1024, 1280 × 720, 1400 × 1050, 1600 × 1200, 1920 × 1080, and 2048 × 1536. Aspect ratios currently used include, for example, 4: 3, 5: 4 and 16: 9. In addition, frame rates currently used include, for example, 24 Hz, 25 Hz, 29.97 Hz, 30 Hz, 50 Hz, 59.94 Hz, 60 Hz, 72 Hz, and 85 Hz.

Various combinations of these and other parameters of the video signal can be hundreds or even thousands, with new formats being added at an alarming frequency. Although the image switch can support all of these formats currently implemented, the inevitable introduction of the new format inevitably enriches such image switches so that the new format cannot be supported.

In addition to supporting both currently available image formats and new formats that may be employed in the future, current image switches have other drawbacks. For example, current video switches transmit one incoming video signal to multiple destinations, while current video switches transmit multiple input audiovisual signals to the same output device (e.g., picture-in-picture or picture-in-picture). There is a lack of ability to simultaneously transmit audio-visual signals of different formats by sending them to picture-beside-picture (PBP), receive audio-visual signals of one format, and deliver these audio-visual signals to display devices of other formats. .

It can control multiple input signals of various formats simultaneously so that all received signals can be displayed on any display device, and can receive audiovisual signals of one format and distribute the audiovisual signals to display devices of different formats. There is a need for an efficient and flexible audiovisual signal routing and distribution system.

According to the invention, the capture node and the display node cooperate to digitally transmit the audiovisual signal. The capture node captures the audiovisual signal in its native format and converts the audiovisual signal into a interchange format. The capture node converts the audiovisual signal from a compatible format into a display format that is optimal for a self-contained display device, making the audiovisual signal a displayable signal. Capture, transmission and display of audiovisual signals take place in real time.

The capture node and the display node cooperate to select a number of mutually supported highest quality compatible formats without exceeding the available bandwidth at the data connection between the capture node and the display node. To minimize overuse of bandwidth, compatible formats generally do not include a modification to the raw format, which can increase the data rate of the video signal. In other words, the selected compatible format is the highest quality format of the mutually supported compatible format that does not exceed the available bandwidth allocated to the audiovisual signal. As a result, only processes that can reduce the data rate of the audiovisual signal are performed by the capture node. All necessary processes that can increase the data rate of an audiovisual data stream are performed by the display node when the audiovisual data stream no longer has a limitation on the data rate past the data connection.

Consider a case where a capture node captures a video signal in a frame of 1024 × 768 size. When the target display device displays a frame of 1600 × 1200, an increase in the frame size at the capture node increases the data rate, because more pixels are required to describe the 1600 × 1200 frame. Thus, since such frame upscaling is performed at the display node, excessive data rate and excessive consumption of communication bandwidth are prevented. Conversely, when the display node displays a frame of 640x480 size, the reduction of the frame size reduces the data rate, so downscaling of the frame is performed at the capture node. Since the frame size is performed and reduced at the capture node rather than the display node with concomitant degradation of image quality, the reduction of the frame size reduces the data rate of the image signal transmitted from the capture node to the display node, and thus finally displayed. It reduces the bandwidth consumed without any sacrifice of the image signal quality in the image signal.

To select compatible formats, the capture and display nodes exchange information about compatible formats supported by each. Suggestions of compatible formats are exchanged, rejected and calculated, and finally one proposal is allowed by both the capture node and the display node.

By using a digital compatible format, audiovisual signals are packetized, routed, and distributed through conventional digital packet switches. Switches supporting gigabyte / secondary and higher throughput rates are increasingly available and employable. At this high data rate, a wide variety of audiovisual signals can be handled without using lossy compression. In addition, these switches support one-to-one, one-to-many, many-to-one, many-to-many routing models, which are considerably more advanced than the one-to-one and one-to-many models supported by currently available video switches.

Another major advantage is in heterogeneous image distribution. The raw format received by the capture node and the displayable format generated by the display node need not be identical. Indeed, conversion to or from a negotiation compatible format is a very simple and secondary format conversion between source and display. In addition, the heterogeneous nature of the audiovisual signals distributed in this way applies to multiple image sources and multiple displays. In particular, a single switch can route audiovisual signals of various different native formats to display devices requiring various different displayable formats.

Another major benefit lies in the adaptability of this system. If a new native format is created and routing and distribution of the audiovisual signal of this new native format is required, a new capture node is created that supports the same negotiation compatible format as the new native format. The compatible formats are negotiated in the same way, and by creating a compatible format that is allowed by existing display nodes, no change to any other capture node and any display is required. Similarly, support of a new displayable format does not require any capture node or changes to existing display nodes, and new display nodes are created that support negotiation compatible formats and new displayable formats.

Another major advantage is the ease of installation. Since audiovisual signals are routed as packetized digital signals, conventional convenient, inexpensive copper digital cables (Cat5, Cat5E, Cat6 UTP, etc.) or optical fibers may be used.

Another major advantage is that high quality video and high quality multi-channel sound can be carried in one cable, and is easy to install.

1 is a block diagram illustrating a video stream distribution system in accordance with the present invention.

FIG. 2 is a detailed block diagram of the capture node of FIG.

3 is a block diagram illustrating in detail the display node of FIG.

4 is a transaction flow diagram illustrating transmission of an audiovisual signal in a compatible format in accordance with the present invention.

5 is a logical flow diagram illustrating selection of a compatible format in accordance with the present invention.

FIG. 6 is a block diagram showing details of the audiovisual signal converter of FIG. 2. FIG.

FIG. 7 is a block diagram illustrating in detail the outgoing bit-stream of FIG. 6; FIG.

8 is a block diagram showing details of a frame header packet of FIG.

9 is a block diagram showing details of the scan line packet of FIG.

FIG. 10 is a detailed block diagram of the audiovisual signal converter of FIG. 3; FIG.

Figure 11 is a block diagram illustrating a video stream distribution system including multiple capture nodes, multiple display nodes, and one switch, in accordance with the present invention.

12 and 13 illustrate display devices each having a divided screen capable of simultaneously displaying several image signals.

In accordance with the present invention, the capture node 102 (FIG. 1) and the display node 104 may produce an audiovisual signal in accordance with one or more digital audiovisual data formats, often referred to herein as audiovisual compatible formats, for the image source 106. Cooperate to transmit data from and to the display device 108. Capture node 102 receives the audiovisual signal from source 106 in its native format and converts the audiovisual signal into a selected image compatible format for transmission to display node 104. The display node 104 receives a digital audiovisual signal in a selected image compatible format, converts the audiovisual signal into a displayable format supported by the display device 108, and converts the audiovisual signal into a displayable format to the display device 108. Send.

As used herein, a "node" can be any device or logic that is communicated over a network.

To aid in the understanding of the following description, various audiovisual signal formats referred to herein are briefly described. Image source 106 generates an audiovisual signal in a "raw format," and capture node 102 receives it. The native format may be analog or digital.

The display node 104 generates an audiovisual signal in a "displayable format", and the display device 108 receives and displays it. The displayable format may be analog or digital, and may be the same or different format as the raw format. Native and displayable formats externally limit or define the tasks to be performed by capture node 102 and display node 104. In particular, the audiovisual signal from the image source 106 is displayed by the display device 108 with as little fidelity loss as possible, which is the task of the capture node 102 and the display node 104.

Through the data connection 110, the capture node 102 transmits the audiovisual signal in a "compatible format" and the display node 104 receives it. The compatible format is digital. Capture node 102 and display node 104 each support multiple compatible formats. In the manner described below, capture node 102 and display node 104 cooperate to select a particular compatible format, referred to as " selected compatible format, " whereby capture node 102 and display node 104 are selected. ) Transmits the audiovisual signal through the data connection unit 110.

As discussed above, capture node 102 captures an audiovisual signal from image source 106. Capture node 102 represents a captured audiovisual signal in digital form that is a compatible format that most accurately represents the audiovisual signal in its native format. The format of the captured audiovisual signal is often referred to as a "raw compatible format." The native compatible format is the compatible format prioritized by the capture node 102.

As discussed above, display node 104 generates an audiovisual signal in a displayable format for display by display device 108. Display node 104 generates an audiovisual signal from a compatible format that most accurately represents a displayable format into a displayable format, which is often referred to as a "displayable compatible format." The displayable compatible format is the compatible format that is prioritized by the display node 104.

Thus, the flow of the entire audiovisual signal is as follows. Image source 106 generates an audiovisual signal in a raw format. The capture node 102 captures an audiovisual source in a native compatible format, transmits an audiovisual signal in the selected compatible format via the data connection 110, and selects a compatible format selected from the native format if the selected compatible format is different from the raw format. To convert the audiovisual signal. The display node 104 receives the audiovisual signal and converts the displayable compatible format into the displayable compatible format if the displayable compatible format is different from the selected compatible format. Display node 104 converts an audiovisual signal from a displayable compatible format to a displayable format for playback by display device 108.

Capture, conversion, transmission, reception, conversion and display of audiovisual signals are all in real time. As used herein, “real time” means that a slight amount of time is required from the user's point of view before the audiovisual signal is transmitted from the image source 106 to the display device 108, for example, a few seconds. It is desirable that this amount of time be minimal, but “real time” can be seen that the audiovisual signal represented by the display device 108 appears immediately in response to a user's control input to the image source 106. In order to transmit an audiovisual signal in real time, capturing, converting, transmitting, receiving, converting and displaying the audiovisual signal occurs simultaneously.

It should be noted that the native format generated by the image source 106 may be different from the displayable format required by the display device 108. As long as there are common compatible formats supported by both capture node 102 and display node 104, any format received by capture node 102 may be in any format generated by display node 104. Can be displayed. Capture node 102 and display node 104 may be coupled to each other by data connection 110 as described in detail below.

The capture node 102 and the display node 104 may be easy to implement, such as an appliance. For example, capture node 102 supports only one raw image format, i.e., the raw image format generated from image source 106. Similarly, display node 104 is not required to support all conventional display formats, only the displayable formats required to drive a display on display device 108. Other native and displayable formats may be implemented by different instances of capture node 108 and display node 104, respectively.

In more detail with reference to FIG. 11, the data connection 110 may be routed through a switch 1102 allowing multiple capture nodes and multiple display nodes to be interconnected. As shown, the system includes three basic capture nodes and two display nodes. The capture node includes one for the SDTV signal, one for the HDTV signal, and one for the computer-generated progressive scan RGB signal. Display nodes include one for SDTV monitors and one for fixed scans for progressive scan and RGB-driven monitors. The compatible format is in digitized and packetized form, and the audiovisual signal can be routed through the switch 1102. In more detail below, any of the three source audiovisual signals may be routed to either of the two display devices. In fact, any source signal can be routed to multiple display devices simultaneously, and any display device can simultaneously receive and show multiple audiovisual signals.

Thus, the system collectively implemented by the capture node 102 and the display node 104 is flexible. Indeed, the logic required for capture node 102 and display node 104 to implement audiovisual signal interchange in accordance with the present invention is simple enough, which is included in an image source, such as image source 106. The display node 104 may be implemented with logic included in a display device such as the display device 108.

The selected compatible format accommodates various kinds of audio and video signal characteristics to be controlled. Specifically, the picture component of the compatible format is represented by the following characteristics.

1. Interlaced or progressive scan;

2. frames / fields per second;

3. Resolution of each frame / field: pixels per line and lines per frame / field;

4. Color model: RGB, YCrBc etc .;

5. ratio of color samples (4: 4: 4, 4: 2: 2, 4: 2: 0, etc.); And

6. Color depth (bits per color sample)

The voice component of the compatible format is represented by the following characteristics.

1. Number of channels: 1-8;

2. Sample rates: 32 kHz, 44.1 kHz, 48 kHz, 96 kHz;

3. sample depth at bits per sample: 12, 16, 20, 24; And

4. Encoding: LPCM, compacted, compressed:

Compression method: MPEG1 / Layer I, II, III, AC-3;

Companding technology: A-law, μ-law.

Capture node 102 is shown in detail in FIG. Capture node 102 includes audiovisual capture logic 202 that receives raw audiovisual signals in raw format from an external device such as a computer, camera, prerecorded video player, or the like. In addition, the raw audiovisual signal captured by the audiovisual capture logic 202 may be a raw video signal or a raw audio signal or a combination of video and audio. The audiovisual capture logic 202 converts the audiovisual signal from the raw format into a digital representation of the raw format in which the pixels are organized as a frame having a frame size and frame rate defined in the raw format. The audio portion of the audiovisual signal is similarly captured as a series of digital samples. The video and audio portions of the captured signal are time stamped at regular intervals for synchronized playback. This digital representation of the native format is also referred to herein as the native compatible format. Audiovisual capture logic is commonly known and may include signal conditioning elements to capture the signal in its optimally feasible form.

Assume that image source 106 is a standard defined image camera that generates an analog YUV signal with NTSC timing characteristics. Capture node 102 recognizes this format, which is 59.94 fields / second, each containing 240 visible lines. Recognition of various analog video signal formats is a conventional technique and will not be described in detail herein. The continuous field represents 29.97 frames / second of 480 interlaced lines. The complete, deinterlaced frame has an aspect ratio of 4: 3.

Since the captured video signal is in analog form, it does not include a specific number of pixels per line, but the audiovisual capture logic 202 of the capture node 102 samples 640 captured video signals during the display portion of each line. Square pixels and 640x480 frame resolution are generated to match the conventional frame aspect ratio 4: 3.

The display portion of each line is a portion of an analog image signal representing luminance and chrominance to be displayed, for example, in a video monitor capable of displaying analog YUV signals having NTSC timing characteristics. The blank portion of each line of the signal is considered a non-displayable portion of the line and is ignored.

The audiovisual signal capture logic 202 performs sampling using a conventional 4: 2: 2 method with one luminance and one color difference sample at each pixel. In this illustrative example, audiovisual capture logic 202 uses 8-bits to indicate respective luminance and chrominance values. Therefore, the net data rate of the signal obtained in bits per second is 147 Mb / sec, which is the product of 640 pixels / line, 240 lines / field, 59.94 fields / sec, 8 bits / sample, and 2 samples / pixel. In this illustrative example, the bandwidth of the data connection 110 is 1 Gb / sec, so approximately 90% is available for valid data. In this example, only 16% of the available effective bandwidth is required for the data stream, so there is no need to worry about bandwidth.

The captured digital format, which includes 59.94 fields of 240 lines of 640 pixels of YUV (4: 2: 2) data, each second having 8 bits per sample, is a native compatible format in this exemplary embodiment. While the capture node 102 receives an analog image YUV signal with NTSC timing characteristics, this digital format is a direct representation of the analog signal, and thus a representation that is prioritized by the capture node 102.

Capture node 102 includes an audiovisual signal converter 204, which receives the captured audiovisual signal from audiovisual capture logic 202 and performs the necessary conversion from the native compatible format to the selected compatible format. This conversion requires changes to various parameters of the native compatible format, including frame size (ie, number of pixels per line and number of lines per frame), frame rate, color depth, aspect ratio, and the like. The audiovisual signal converter 204 may apply a data rate reduction technique to the audiovisual signal in a manner described in detail below. If the native compatible format is the selected compatible format, the audiovisual signal converter 204 leaves the audiovisual signal unchanged.

In one embodiment, the audiovisual signal converter 204 performs a scale operation to produce a frame size and frame rate within a continuous range. Thus, a particular image compatible format supported by the audiovisual signal converter 204 may be represented as including a feature range. An example includes supporting frames in the range of 1.0 to 100 frames per second. In an alternative embodiment, the audiovisual signal converter 204 performs only a very simple operation that limits all other pixels and all other scanlines to reduce the frame size by an integer ratio such as 2: 1, 3: 1, and so on. In this alternative embodiment of the audiovisual signal converter 204, the supported image compatible format is represented as including discrete and discrete values of the supported characteristics. One example only includes supported frame sizes of 640 × 480, 320 × 240 and 160 × 120.

Capture node 102 includes an audiovisual stream controller 206 that forms a series of digital data packets representing audiovisual signals for delivery to display node 104. As used herein, a "packet" can be any set of data to be transmitted together and includes data defining an intended destination. Details of the series of packets will be described below. The audiovisual stream controller also interacts with the display node 104 (FIG. 1) via the data connection 110 to control successive packets and send a series of packets to the display node 104. Capabilities identify video compatible formats supported by capture node 102 by storing data identification range values and / or individual discrete values of various characteristics of the video compatible format. In addition, the capability 208 identifies any high-level signal that handles the capabilities of the capture node 102, such as, for example, deinterlace. The cooperation between the audiovisual stream controller 206 and the display node 104 for the delivery of an audiovisual signal in a video compatible format, in agreement with the video compatible format, is described below.

The display node 104 is shown in detail in FIG. Display node 104 includes an audiovisual stream controller 302, an audiovisual signal converter 304, and display logic 306. The audiovisual stream controller 302 selects a compatible format through the data connection 110 and cooperates with the audiovisual stream controller 206 of the capture node 102 to achieve an audiovisual data stream. The audiovisual stream controller 302 de-packetizes and transmits the received audiovisual data stream to the audiovisual signal converter 304, and the audiovisual signal converter 304 sends the received audiovisual data stream to the display logic 306. Convert the form into a format suitable for processing by a display format, ie displayable compatible format. This conversion involves the reversal of any data rate reduction technique applied by the capture node 102 and the conversion of the received audiovisual signal from the selected image compatible format to the displayable compatible format—for example, frame size, frame rate, color depth and Including changing parameters such as aspect ratio. The audiovisual signal converter 304 may support a range of various characteristic values of the audiovisual data stream, and may be limited to specific discrete values of these characteristics in the manner described above for the audiovisual signal converter 206. This conversion can be removed if the selected compatible format is also a displayable compatible format.

Display logic 306 may drive an audiovisual signal in a displayable format to be displayed on display device 108. Such driving may require converting a digital audiovisual signal in a displayable compatible format into an analog signal including a timing signal. The timing signal may be a timing signal removed by the audiovisual capture logic 202 or regenerated from the image source 106, or may be a different timing signal depending on the nature of the displayable image format required by the display device 108. . This conversion from the digital video format to the analog video format may be performed by video circuitry in a personal computer.

In addition, the display logic 306 reconstructs the speech signal from the digitized speech portion of the audiovisual signal and synchronizes the reproduction of the speech signal according to the timestamp included in the audiovisual signal as described above.

The display node 104 supports the range and / or discrete values of the disparity characteristics of the video compatible format supported by the audiovisual signal converter 306 and used by the audiovisual stream controller 302 to negotiate which video compatible format to use. Including capability 308 to indicate. Capability 308 is also a displayable compatible format of display node 104, i.e., a compatible format that is preferred by display node 104, and sometimes the closest compatible displayable format required by display device 108. Represents a format. The capability 308 may be fixed, to be set during the initial configuration of the display node 104, or to obtain the VESA's Display Data Channel / Extended Display Identification Data (EDID) to obtain the operating limits of the display device. It can be found at least in part from the display device 108 using conventional plug-and-play device discovery processes such as use. The display node 104 selects an optimal support characteristic of the display device 108-that is, image format and timing, and the display node 104 drives and selects a displayable compatible format according to this characteristic. In addition, the capability 308 identifies any high level signal processing capabilities of the display node 104, such as deinterlacing.

The interaction between the capture node 102 (FIG. 1) and the display node 104 is shown by a transaction flow diagram (FIG. 4). In step 402, the capture node 102 and the display node 104 detect the presence of each other via the data connection 110. In this exemplary embodiment, the data connection 110 is a 1000BaseT connection and includes a CAT-5E cable RJ45 connector for convenience. Capture node 102 and display node 104 detect a counterpart by applying a signal to data connection 110 and detecting a signal from the other end of data connection 100.

At step 404, capture node 102 and display node 104 exchange information about their respective capabilities. For example, the audiovisual stream controller 206 (FIG. 2) transmits data representing the native compatible format and data indicating the firmware version and / or creation date of the capture node 102, etc. It can be determined whether it has the latest negotiation protocol as implemented by each in step 406A-B. The audiovisual stream controller 302 similarly transmits data representing the capability 308, a displayable format, and data representing the firmware version and / or creation date.

In this embodiment, the audiovisual stream controller 302 transmits data indicative of a displayable compatible format. This negotiates a compatible format that allows the capture node 102 and display node 104 to preserve the quality of the transmitted audiovisual signal without exceeding the available bandwidth of the data connection 110. The selection of compatible formats by the audiovisual stream controllers 206 and 302 is described in detail below.

In steps 406A-B, capture node 102 and display node 104 independently and simultaneously select the desired compatible format according to the capabilities 208,308, native compatible format, and displayable compatible format. Capture node 102 selects the compatible format that was prioritized by capture node 104 in step 406A, and display node 104 selects the compatible format that was prioritized by display node 104 in step 406B.

Preferred compatible formats are generateable by capture node 102 and displayable by display node 104, to provide the desired display quality without unnecessarily consuming or exceeding the available bandwidth of data connection 110. It is an optimized format. In short, the preferred compatible format is a compatible format provided by the source signal as represented in the native compatible format, or providing a maximum fidelity that the display device can use efficiently beyond the bandwidth limit.

The primary concern in the selection of compatible formats is to extend the preservation of the quality of the audiovisual signal to the maximum possible. Such conversion is preferably performed by the capture node 102 in that any characteristic of the audiovisual signal can be changed to reduce the data rate (eg, down-scale of the frame size). This reduces the amount of data bandwidth required for the data connection 110. Conversely, such conversion is preferably performed by the display node 104 in that any characteristic of the audiovisual signal can be changed to increase the data rate (eg, up-scale of the frame size). This prevents excessive consumption of the band width of the data connection 110. However, unlike most other systems, it should be noted that avoiding excessive use of bandwidth is not a major concern. When (i) the audiovisual signal in the selected compatible format exceeds the available bandwidth, or (ii) which of the capture node 102 and the display node 104 will perform a particular component of digital signal processing, It is usually of interest (i).

Thus, as a general rule, the required down-scale is performed by the capture node 102 and the required up-scale is performed by the display node 104. One way to implement this general rule is to limit the nature of compatible formats to smaller native and display compatible formats. By not exceeding the nature of the native compatible format, any change in the audiovisual signal that increases the data rate of the audiovisual signal is performed by the display node 104 after the signal has been transmitted through the data connection 110 and thus the data. Unnecessary use of bandwidth through the connection 110 is avoided. Any changes in the audiovisual signal that reduce the data rate of the audiovisual signal by not exceeding the characteristics of the displayable compatible format are performed by the capture node 102 before the signal is transmitted through the data connection 110. Therefore, unnecessary use of the data bandwidth of the data connection 110 is similarly avoided.

Under some circumstances, this part is described below. It is assumed that the compatible format selected in the above manner will exceed the data connection 110, so that successful transmission of the audiovisual signal through the data connection 110 will eventually fail. If the preferred compatible format is estimated to exceed the available bandwidth of the data connection 110, the preferred compatible format is modified by applying the data rate reduction technique described in detail below. In this exemplary embodiment, the available bandwidth for the data payload of the data connection 110 is a predetermined percentage (eg, 90%) of the total available bandwidth of the data connection 110. For example, data connection 110 is set to 1 gigabyte per second, and the available bandwidth of connection 110 to capture node 102 and display node 104 is 900 megabytes per second.

In the given embodiment above, the native compatible format represents a YUV signal with NTSC timing characteristics and contains 59.54 fields of 240 lines of 640 pixels of YUV (4: 2: 2) with 8 bits per sample. If the display device 108 is a standard regulatory television monitor and accepts interlaced YUV signals, the displayable compatible format is the same as the native compatible format and also the selected compatible format. Further signal processing does not improve the fidelity of the audiovisual signal transmitted through capture node 102 and display node 104.

If the display device 108 is a progressive-scan computer monitor with an XGA native resolution (1024 × 768), the displayable format—the format preferred by the display node 104—is 60 frames per second, 24 bits each. It is the format most similar to the native display characteristics of XGA computer monitors, each with 768 lines of 1024 pixels in RGB representation. The audiovisual signal is converted to match the characteristics of the monitor to either the capture node 102 or the display node 104. The data stream is converted from (i) interlaced signal to progressive scan signal, (ii) YUV to RGB, and (iii) upscale of frame size from 640x480 to 1024x768. In terms of signal fidelity, either the capture node 102 or the display node 104 can be changed to perform such conversion. In terms of bandwidth conversion, this means performing these conversions at the destination, ie within the display node 102. In particular, upscale should be performed by display node 104 and not capture node 102 because there is no advantage in upscaling at capture node 102.

Deinterlacing and color-space conversion may be performed by either capture node 102 or display node 104. In one embodiment, (i) most display devices (and all digital displays: LCD, plasma, LCoS, DLP) are essentially progressive scan and RGB, and (ii) many types of format conversions, especially frame size scales. Since ring, and frame rate conversions are often performed on progressive scan image data, the compatible formats are both progressive scan and RGB. In an alternative embodiment, interlace compatible format is supported because deinterlacing is a virtually complex operation that includes motion detection and compensation in most implementations. Also, since the deinterlacing by the capture node 102 is twice the amount of bandwidth of the data connection 110 consumed by the audiovisual signal, the display node 104 as a whole if the display device 108 displays the interlaced signal. There is no particular benefit compared to the performance of deinterlacing or deinterlacing described above.

De-interlacing doubles the data rate (from 29.97 to 59.94 frames / second), using 24-bit RGB to increase the data rate by 50% over the others, and consequently the data rate in this example embodiment is 442 Mb / second, It is still at the available bandwidth. In addition, the importance of the impact of the deinterlacing complexity and the overall signal quality is an increase in the data transfer rate at the capture node 102 provided that the capture node 102 includes a good embodiment of the deinterlacing relative to the deinterlacing of the display node 102. It is believed to be justification for.

If the image content is made as a film and is essentially 24 frames / second, it is obvious that the deinterlacing may eventually reduce the data rate, and the deinterlacing process will detect the situation and the output will be 24 frames / second. As an interlaced video signal, each frame is different from the preceding frame (since each represents a different field, even or odd) and is not detected by a simple redundancy avoidance technique. However, frame deinterlacing makes their redundancy clear. Since there is no need to transmit the same frames, the 36 redundant frames per second generated may be missing. As will be described in detail below, this may occur automatically by the application of redundancy removal as implemented by capture node 102.

Referring to Fig. 4, step 406B is similar to step 406A, and the following description of step 406A is equally applicable to step 406B as is performed by display node 104. Step 406A is shown in detail in logic flow diagram 406A (Figure 5). Loop step 502 and next step 508 define a loop, in which each of the various characteristics specified in capabilities 208 and 308 are processed in accordance with step 504. Such features include the aforementioned list of video and audio components in compatible formats. For each of those features, processing moves from loop step 502 to step 504.

In step 504, capture node 102 determines the value of the subject characteristic for the desired compatible format. As briefly described above, the preferred compatible format is a compatible format that delivers optimal fidelity that the native compatible format can provide or display efficiently, without exceeding the bandwidth limit. In this exemplary embodiment, consideration of bandwidth is deferred to steps 512-514, which is described below. Thus, a concern at step 504 is the specific value of the characteristic that delivers the optimal fidelity that the native compatible format provides or can be used efficiently without the displayable compatible format exceeding the bandwidth limit.

This decision depends largely on the nature of the property under consideration. Some characteristics are obviously objectivity. For example, the frame or field size represents the number of scanlines and the number of pixels per scanline. The maximum fidelity of a native compatible format is a frame or field size of exactly the same dimensions. If the displayable compatible format can include every pixel and every pixel of a frame or field of this size, the dimensions of the native compatible format are used for the desired compatible format. Conversely, if the displayable compatible format cannot display all pixels of a frame or field of that size, the frame or field size of the preferred compatible format does not include pixels that cannot be represented in the displayable compatible format. Specifically, if the frame size of the displayable compatible format is smaller than the frame size of the native compatible format, the preferred compatible format uses the frame size of the displayable compatible format. Other objective characteristics include frame rate and color depth.

Other characteristics are not directly known in this way. For example, the color model may be RGB or YCrCb, among others. If the native compatible format represents a color using the YCrCb model and the displayable compatible format represents a color using the RGB color model, the audiovisual signal performs color model conversion. However, this color model transformation is less clear even if performed best by the capture node 102 or display node 104. This problem can be solved in several ways. For example, the capabilities 208 and 308 indicate that only the display node 104 can do this color model conversion. In this case, the preferred compatible format represents pixels in the YCrCb color model because the capture node 102 cannot convert the color model to RGB. One feature that requires significant processing is de-interlacing. For cost savings, it is useful to implement deinterlacing in only one of the capture node 102 and the display node 104. Although the preferred compatible format includes interlaced or progressive scan video that depends on the native compatible format, the displayable compatible format and its nodes 102-104 may perform deinterlacing.

This same principle of preserving most of the parity of the native compatible format to extend the displayable compatible format can be effectively used so that the parity can be applied along each characteristic of the desired compatible format of the loop of steps 502-508.

Once all the features have been processed according to the loops of steps 502-508, processing according to the loops of steps 502-508 is complete. At this point in time, the capture node 102 determines the preferred compatible format so that each selected characteristic is representative of the data that cannot be effectively used by the display node 104 and through the data connection 110 an audiovisual signal without the use of unnecessary bandwidth. You can make the best choice to preserve quality.

Following the loop of steps 502-508, processing following logic flow diagram 406A moves to step 510. In step 510, capture node 102 measures the data rate associated with the selected compatible format according to the loop of steps 502-508. Data rate measurements include (i) frame rate (frames per second) (ii) resolution (pixels per frame) (iii) pixel depth (bits per pixel), time stamps, frame start and scanline start markers, and It can be as simple as a product with the same arbitrary data overhead and packet data overhead. The result is a data rate measured in bits per second.

In test step 512, capture node 102 determines whether the measured data rate exceeds the bandwidth available through data connection 110. In this exemplary embodiment, the data connection 110 is a 1000BaseT connection and can support up to 1 gigabit data throughput per second. However, the actual usable bandwidth over data connection 110 may be slightly less than 1 gigabit per second.

In addition, the available bandwidth between the capture node 102 and the display node 104 is smaller when the display node 104 receives audiovisual data flows from multiple capture nodes of other embodiments, described in more detail below. In this case, display node 104 assigns a data rate to capture node 102 and reports the assigned data rate to capture node 102.

If the measured data rate of the selected compatible format exceeds the available throughput of the data connection 110, processing moves to step 514. In step 514, capture node 102 adjusts the configuration characteristics of the selected compatible format. In one embodiment, the capture node 102 reduces the frame rate of the video compatible format by half to reduce the measured data rate of the video compatible format. Of course, more complex mechanisms can be used to reduce the data rate of video compatible formats. In another embodiment, data rate reduction is achieved according to the particular choice of a given implementation. For example, image clarity can be excellent for certain implementations, and the default method can take resolution reduction and frame rate reduction of lossy compression. In other implementations, the smoothness of motion video may be excellent, and the default method may take a lot of compression with a loss of resolution reduction and / or frame rate reduction. Other data rate reduction techniques include audio and video signal degradation and capture nodes 102 that are transmitted using lossless compression (eg, run length encoding) and frame-to-frame redundancy avoidance. Or reduce the data rate of the video compatible format without the particularly complex logic requirements of both display modes 104. This data rate reduction technique is described more fully below.

In test step 512, if capture node 102 determines that the evaluated bit rate does not exceed the available bandwidth of switch 104, step 514 is passed because no bit rate reduction is necessary. After steps 512 to 514, processing according to logic flow diagram 406A and step 406A (Figure 4) are completed.

After steps 406A-406B, both capture node 102 and display node 104 arrive independently of the desired compatible format. In steps 408-410, capture node 102 and display node 104 determine to arrive at the same time, taking into account the selected compatible format. Various decision techniques are used to arrive at this same time, but this particular mechanism is sufficient. At step 408, capture node 104 transmits the provided compatible format to display node 104. In step 410, the display node 104 corresponds to both accepting or rejecting the provided compatible format and counter-provided compatible format if the provided compatible format is rejected. The display node 104 differs from (i) that the provided compatible format is selected by the display node 104 of step 406B and (ii) the firmware version and / or the date of creation of the nodes 102-104 is displayed in the display node 104. Is a newer version than capture node 102 and therefore implements a new one, thus rejecting the provided compatible format if a version of the compatible format selection is desired. In one embodiment more fully described below, display node 104 implements a graphical user interface using an on-screen display of display device 108, such that a user can specify a data rate reduction selection. This choice preserves, for example, image sharpness and color depth at the expense of smooth motion loss, preserves motion smoothing and color depth at perhaps cost of image sharpness, and image sharpness and motion smoothing possibly color depth. It may include maintaining at the expense of. In such an embodiment, the display mode 104 has the ultimate right to the selected compatible format to influence the user's selection.

In this exemplary embodiment, according to the compatible format provided when display node 104 is accepted in step 410 or in accordance with the format for counter-provided exchange when display node 104 responds to rejection in step 410. Respond immediately by the start of audiovisual signal transmission in step 412. In another embodiment, capture node 102 confirms the format for successful receipt, matching, counter serving exchange prior to step 412.

In step 412, capture node 102 transmits a data packet representing an audiovisual signal of the selected compatible format. The data packet is constituted by an audiovisual stream controller 206. Despite all the changes in the compatible format that can be maintained by the capture node 102 and the display node 104, these changes have a number of general characteristics. Each is essentially a series of frames or fields and includes a pixel array. In particular, the video signal received by the capture node 102 includes horizontal and vertical blanking periods and has a timing suitable for the initially planned display device. For example, an NTSC tuner can omit a video signal with the proper pixel ratio of the previous frame and the horizontal and vertical blanking periods driving a standard NTSC monitor. In the context of the audiovisual exchange system described herein, this inherent time is mostly inadequate because video content, ie its pixels, can be displayed on a display device with completely different temporal characteristics. Thus, the time characteristic required by the display device 108 is generated by the display node 104. Compatible formats used in the exchange system described herein include only the edges of pixels and lines, the end of frames and the end of field markers. Since the blanking period of the video signal is omitted, the data rate required to represent the video signal is significantly reduced.

The audiovisual signal converter 204 (FIG. 2) of the capture node 102 is shown in greater detail in FIG. The audiovisual signal converter 204 includes a frame re-formatter 602 that receives digitized pixel lines from the audiovisual capture logic 202. The audiovisual capture logic 202 captures a video signal and immediately converts the captured signal into a digital format, a native format in the manner described above. As described above, the audiovisual capture logic 202 captures an analog video signal having NTSC time characteristics in a interchangeable format that includes a 59.94 field of 240 lines of 640 pixels for each second video portion of the audiovisual signal. Of course, in other embodiments, capture node 102 may capture video according to different formats having different characteristics.

Frame reformatter 602 reformats the digitized pixel lines according to the characteristics of the selected compatible format. Such reformatting may include, for example, frame size reduction by deinterlacing, cropping and / or reduction, color depth reduction, frame rate reduction, and the like. Cropping can be used to remove some scan lines and noise at the top and bottom, overscan or any anomalies at the edges of the video image, and to determine the amount of data required to represent the video signal. It can be used to slightly but definitely reduce it. As discussed above, processing that increases the data rate is generally performed by the display node 104, while processing that reduces the data rate is generally performed by the capture node 102. In this exemplary embodiment, the deinterlacing is performed by the capture node 102 despite the increase in the data transfer rate as a result of the deinterlacing. The result of the processing by frame reformatter 602 is the current frame 604, which is suitable for the agreed video compatible format.

Some processing performed by frame reformatter 602 requires information of the content of the previous frame. Such processing may include, for example, increasing the frame rate including frame to frame redundancy removal and / or inserted frames. Upon completion of the new current frame 604, the previous content of the current frame 604 is stored as the previous frame 606. In another embodiment, the individual scan lines move from the current frame 604 to the previous frame 606 to minimize latency since the scan line wrapper 608, which is described more fully below, processes the individual scan lines. .

The audiovisual signal converter 204 includes a scan line wrapper 608. The scan line wrapper 608 constructs a data packet representing the current frame 604 and sends this packet to the inclusion of the output bit stream 612. At the same time that the data rate reduction due to the reduction of the characteristics of the video compatible format such as frame rate, frame size or color depth is carried out by the frame reformer 602, the scan line wrapper 608 reduces the other data rate and the data. Perform redundancy cancellation techniques of packet configuration. This technique is described more fully below.

The audiovisual signal converter 204 includes a header packer 610 that constitutes a data packet representing header information and includes such a packet of the output bit stream 612. The audiovisual signal converter 204 also includes an audio packer 614 that constitutes an audio frame for the contents of the audio content of the output bit stream 612. The audiovisual signal converter 204 includes an output bit stream 612. Is transmitted to the audiovisual stream controller 206, which implements the data transfer protocol using the audiovisual stream controller 302 (FIG. 3) of the display node 104 to output the output bit stream 612 (FIG. 6). Data packet is coupled to the display node 104.

The output bit stream 612 is shown in great detail in FIG. 7 and includes a frame header 702A, multiple scanline packets 704A-B, an audio frame packet 706A, another frame header 702B, and a frame header 702B. A plurality of scan line packets 704C corresponding to < RTI ID = 0.0 > In particular, each frame is represented by a frame header (e.g., frame header 702A) followed by a number of scan line packets (e.g., scan line packets 704A-B) corresponding to the frame header.

The audio frame packet (eg, audio frame packet 706A) is included in the output bit stream 612 but need not correspond to the current frame. There are some aspects of the audio signal that require different processing from that of the video signal. For example, as soon as the video signal is added or dropped, the playback of the audio portion of the audiovisual signal is preferably not interrupted. The audio and video streams are thus time stamped independently. Processing the video portion of an audiovisual signal is often quite complex and requires significantly more resources than processing the audio portion of the same audiovisual signal. In addition, people naturally compensate for delayed audio for their visible target material due to the relative speed of voice and light. However, the delayed visible target material for that audio is less sensitive than the human eye / ear. Thus, a delay is required in the audio portion of the audiovisual signal to avoid pre-playing of the audio portion relative to the video portion.

Frame header 702A is shown in great detail in FIG. 8 and represents a particular frame of an audiovisual signal in a matched video compatible format. This particular frame is often referred to as the target frame in the context of FIGS. 8-9. The frame sequence field 802 indicates the consecutive number of the target frame and assists the display node 104 in frame sequencing and subsequent scan line packet combining with the appropriate frame. The vertical blank time stamp 804 indicates the date and time, the target frame is captured and (i) the appropriate time of delivery of the target frame by the display node 104, (ii) the punishment of frame transmission by the correct reporting time between the frames. You can help with speed conversion and (i) target frame playback and audio synchronization. In particular, when the captured audiovisual signal is captured and stored for later playback, the vertical blank time stamp 804 may also be used to synchronize the reproduction of multiple audiovisual signals captured simultaneously. The storage of such captured audiovisual signals is described more fully below.

The frame type field 806 identifies the type of the target frame as standard, compressed or descent. The drop frame is only indicated by the header identifying the frame and indicates that the frame content was not transmitted. The compression indicated in the frame type field 806 may indicate a form of compression that includes, for example, run-length encoding, redundancy removal, and the like. The standard frame is one of (i) presence (not falling) and (ii) uncompressed.

Scan line 704 is shown in great detail in FIG. 9 and represents a particular line of target pixels, i.e., a target scan line. The frame sequence field 902 identifies the frame to a scan line belonging to the sequence number of the frame as shown in the frame sequence field 802 (FIG. 8). Line number field 904 (FIG. 9) indicates the sequence number of the target scan line and specifies the relative position of the target scan line within the target frame. The data type field 906 specifies one of the format numbers of the pixel data as shown in the data field 908. If the data type field 906 indicates that the pixel data is "row," the data field 908 stores the entire scan line of pixels representing the selected compatible format, e.g., the format specified in 24-bit color. If data type field 906 indicates a compression type, such as run length encoding, data field 908 stores the entire scan line of the pixels represented in the indicated compression format. If data type field 906 indicates that the target scan line does not change in the same scan line of the previous frame, data field 908 specifies the number of scan lines that say no change to the previous frame. Compression, e.g., run length encoding and avoiding scan line transmission unchanged from the previous frame, avoids redundancy and reduces the data rate of the audiovisual signal in a matched video compatible format.

The audio frame packet 706A includes the correlation data stamp appropriate to the target frame and the audio data itself. If the audio frame packet 706A corresponds to a particular frame of an audiovisual signal, the audio frame packet 706A may include a frame sequence number in addition to or in place of a time stamp.

The audiovisual signal converter 204 transmits the output bit stream 612 to the audiovisual stream controller 206 for transmitting the display node 104 through the data connection 110. The audiovisual stream controller 206 constructs the output bit stream from (i) the packet of the desired size from the bit stream 612, and (ii) sends any required address information for direct delivery of the packet to the display node 104. Apply a header to the packet to include, (i) add redundancy checks that circulate in the packet so that the display node 104 can evaluate the accuracy and completeness of each packet, and (i) the display node 104 And measures and transmits a packet that can be properly adjusted by an intermediate network device such as switch 1102 (FIG. 11).

In this exemplary embodiment, the audiovisual stream controller 206 is a packet of any desired size, such as a half of the bit stream accommodation buffer capacity of the display node 104, or any intermediate network, such as a switch 1102 (FIG. 11). Configure the device. One embodiment including a switch such as switch 1102 is described more fully below. The capture node 102 can have information regarding the miniature buffer between the capture node 102 and the display node 104 in a number of ways. Display node 104 may be configured to report the acceptance buffer size as part of capability 308 (FIG. 3). The minimum buffer size, for example 16 kilobytes (kB), may be specified as a prerequisite for any network device coupled between capture node 102 and display node 104. Thus, the minimum buffer size may be smaller than a predetermined required buffer size, for example 16 kB or the buffer size of the display node 104. To construct a packet of the desired size, the audiovisual stream controller 206 collects enough of the output bit stream 612 to fill the desired size of the paid packet and collects small data records or divides large data records as needed. And the aforementioned header and CRC.

To avoid overwhelming buffers at the display node 104 or any intermediate network device between the capture node 102 and the display node 104, the audiovisual stream controller 206 measures the transmission of packets, i. Restrict In particular, the audiovisual stream controller 206 determines the time interval over which packets of the output bit stream 612 are transmitted. To determine this time interval, the audiovisual stream controller 206 divides the desired packet size by the available bandwidth between the capture node 102 and the display node 104 to reach the peck interval.

As mentioned above, the usable bandwidth is a predetermined part of the connection speed in this exemplary embodiment. In addition, a portion of the available bandwidth may be allocated to multiple audiovisual data streams that further reduce the amount of bandwidth allocated to output bit stream 612. For example, video from two separate capture nodes may be sent to a single display node via switch 1102. The bandwidth allocated to each of the capture nodes is limited to the fact that the sum of the bandwidths must be within the total bandwidth available to the display node. The buffer in switch 1102 has a finite size, and even if a simple burst, if both capture nodes are sent at full bandwidth, the buffer for data sent to the display node may be overwhelmed and one of the video signals Or cause loss of part of all. Thus, it is important to limit the video signal transmission rate to avoid the possibility of exceeding the bandwidth available to the display node even if each capture node is instantaneous.

In this example, for a given capture node, for example capture node 102, we have a usable bandwidth of 0.6 gigabytes (Gb) per second and a packet size of 4 kilobits (kb). Thus, the packet transmission interval is about 5.7 ms, which allows the capture node 102 to transmit data for 4.0 ms and the capture node 102 waits for 1.7 ms. 4.0 ms of transmission or 1.7 ms of waiting need not be contiguous. Each period need not be evenly distributed within the packet transmission interval of 5.7 ms. Importantly, the ratio 4.0: 1.7 of the transmission time zone latency is maintained within an arbitrary 5.7 ms interval.

In order to measure the packet, the audiovisual stream controller 206 starts transmitting a packet of 4 kb every 5.7 ms. In doing so, the audiovisual stream controller 206 can avoid exceeding the available bandwidth, and a short burst that overflows the buffer at the display node 104 or intermediate network device between the capture node 102 and the display node 104. Even it can avoid exceeding the available bandwidth.

The measured packets of the audiovisual stream controller 206 make up the packet strip 210 received by the audiovisual stream controller 302 (FIG. 3). The audiovisual stream controller 302 checks for the accuracy and completeness of the packetized data using the CRC included by the audiovisual stream controller 206 and checks the bit stream 612 (FIG. 6) for the incoming bit stream 1002. Reconstruct with (Fig. 10) and send the incoming bit stream 1002 to the audiovisual signal converter 304. The scan line parser of the audiovisual signal converter 302 receives the incoming bit stream 1002, stores the currently received frame like the current frame 1006, and moves the previously received frame to the previous frame 1008. Reconstruct the frame from stream 1002. The scan line parser 1004 reverses any compression and / or redundancy removal performed by the scan line packer 608 (Figure 6). For example, this exemplary embodiment scan line parser 1004 reverses any compression indicated in the data type field 906 and scans if the data field 906 indicates no change in one or more scan lines. The line parser 1004 reuses the scan line from the previous frame 008.

Once reconstructed by the scan line parser 1004, the current frame 1006 is reformatted by the frame reformer 1010. In particular, frame reformatter 1010 composes a frame of a compatible format that can be displayed from a frame of the selected compatible format. This includes changes in frame size, frame rate, color depth, and the like. Upon increasing the frame from the video compatible format to the displayable format, the frame reformatter 1010 can use the previous frame 1008 for the current frame 1006 and frame interpolation.

The frame reformatter 1010 transmits a frame, such as the size, ratio, color depth, of the displayable compatible format, to the display logic 306, displays the logic 306, and the display expected by the display device 108. Add the blanking signal and time characteristic needed to produce a possible format.

Audio packets of the incoming bit stream 1002 are received by the audio parser 1012, which transmits the received audio to the display logic 306 for inclusion in a displayable audiovisual format.

A particularly useful benefit of using data packets to move an audiovisual signal from a video source to a display device is a digital switch that routes audiovisual signals from multiple video sources 106 and 106B-106C to multiple display devices 108 and 108B. For example, the usability of switch 1002 (FIG. 11). Packet switching is well known and is not described in detail here. A switch, such as switch 1002, may route data packets from any node 102, 102B-C, 104 to any other node 102, 102B-C, 104,104B.

In the embodiment of Figure 11, the data packet described above is simply addressed to the intended destination, for example display node 104. Such packets can also be addressed to both display nodes 104 and 104B, thereby enabling one-to-many audiovisual signal distribution. If the same compatible format can be used for both destinations, multicast forwarding (a characteristic of many packet switches) can be used to send a copy of the packet to multiple destinations. In FIG. 11, the audiovisual data stream from the capture node 102 is displayed as a picture in picture view of the picture view of the display device 108B as the main view 1108 of the display device 108. In this case, capture node 10 will send one high resolution video stream to display node 104 for display as a high resolution image on main view 1108. Capture node 102 also transmits the reduced video stream to display node 104B for display in small picture-in-picture view 1110.

Packets from multiple source devices, for example capture nodes 102 and 102C, may be addressed to a single destination via switch 1102, for example display node 104, and may be picture-in-picture, split (FIG. 12). And FIG. 13), or any other simultaneous display of multiple audiovisual signals by the display device, ie a many-to-one video distribution model. In the illustrative example of FIG. 11, the main view 1108 of the display device 108 displays the audiovisual data stream of the capture node 102 from the video source 106, and the picture in picture view 1108C is the video source. Display the audiovisual data stream of capture node 102C from 106C. With one channel between the switch 1102 and the display node 104, the collection of these video streams occurs within the switch 1102 as a matter of routine data packet routing.

At the same time, for example, one or both audiovisual signals from capture nodes 102 and 102B can be simultaneously routed to display node 104B for display by display device 108B, ie a many-to-many video distribution model. . The primary view 1110B of the display device 108B displays the audiovisual data stream received from the capture node 102B, and the picture-in-picture view 1110 displays the audiovisual data stream received from the capture node 102. In sum, each display node 104, 104B may receive any number or combination of audiovisual signals from capture nodes 102, 102B-C, and each capture node 102, 102B-C may only Transmit to any number or combination of display devices 104, 104B limited only by the bandwidth of the switch 1102. As gigabit / second data switches become more useful, such switches are becoming a viable medium for high quality audio and video distribution and routing.

Upon receiving a large number of audiovisual data, display node 104 limits each audiovisual data stream to conserve bandwidth for another. In the example of FIG. 12, views 1108, 1108C are shown in an array divided side by side than the picture-in-picture arrangement of FIG. In the example of FIG. 12, display node 104 limits the transmission rate of each incoming audiovisual data stream via switch 1102 to one half of the total available bandwidth. Switch 1102 is empirically determined to maintain reliable delivery of 0.9 gigabit data streams per second. The total amount of data can be received by the display node 104 via the switch 1102 is therefore 0.9 Gb / s. Accordingly, display node 104 is assigned 0.45 Gb / s to each incoming audiovisual data stream, and reports a restriction to capture nodes 102 and 102C during each video compatible format negotiation. 13 shows a display device 108 having four segmented views with a 16: 9 aspect ratio as configured by the display node 104. In the example of FIG. 13, display node 104 allocates one quarter of the available bandwidth to each of the four incoming audiovisual data streams.

In another embodiment, the bandwidth allocation is not evenly distributed among the multiple audiovisual data streams. For example, in the example of FIG. 13, one of the four audiovisual signals displayed by the display device 108 may feel more important than the other audiovisual signals, and the display node 104 is more than the portion assigned to the other audiovisual signals. And a larger available bandwidth between switch 1102. Similarly, smaller critical audiovisual signals are allocated to a relatively small portion of the available bandwidth. In the example of FIG. 13, one audiovisual signal may be allocated sufficient bandwidth to represent fewer frames per second while another audiovisual signal may be allocated to sufficient bandwidth of 60 frames per second.

In the picture-in-picture arrangement of FIG. 11, display node 104 uses only a small portion of the audiovisual data stream of capture node 102C for picture-in-picture view 1108C. Accordingly, display node 104 allocates only a small portion of the bandwidth to the audiovisual data stream of capture node 102C, for example the remaining 10% of the available bandwidth is allocated to the audiovisual data stream of capture node 102. .

The bandwidth from the capture node, such as capture node 102, to switch 1102 is similarly limited. In the example of FIG. 11, the audiovisual signal transmitted by the capture node 102 is addressed to both display nodes 104 and 104B. If the capture node 102 can send the same audiovisual data stream to both display nodes 104 and 104B, then the capture node 102 is a capture node because a typical data switch can route a single data stream to multiple destinations. The full bandwidth between 102 and switch 1102 can be used. However, in some circumstances, capture node 102 may not transmit the same audiovisual signal to multiple display nodes, and multiple discrete signals require capture node 102.

To illustrate this, it is helpful to consider the situation where a capture node, such as capture node 102, is required for an HDTV quality audiovisual signal and an SDTV quality audiovisual signal from two separate display nodes. As the display device 108B is for displaying four SDTV signals in a divided arrangement as shown in Fig. 13, a display node requesting an SDTV signal, for example, the display node 104B, may limit the bandwidth for the signal. Consider that To generate an HDTV quality audiovisual signal, capture node 102 requires all or almost all available bandwidth between capture node 102 and switch 1102. If display node 104B does not limit the bandwidth for signals received from capture node 102, capture node 102 may transmit full quality audiovisual signals to both display nodes 104 and 104B. However, since display node 104 has allocated 1/4 of the available bandwidth to audiovisual signals of capture node 102, display node 104B cannot receive full quality audiovisual signals and is still capable of segmented displays. Receive different audiovisual signals for different compartments.

Capture node 102 may adjust conflicting demands for various versions of its audiovisual signals in a number of ways. In one embodiment, capture node 102 satisfies all such needs of transmitting as many display nodes as a single audiovisual signal of a particular compatible format to minimize the number of generated audiovisual streams. For the generated audiovisual stream, capture node 102 allocates a proportional portion of the total bandwidth available for each audiovisual stream. As new streams are added and individual streams drop, capture node 102 reassigns bandwidth proportionally and renegotiation of the compatible format receives a signal requiring this and is executed by capture node 102.

In another embodiment, capture node 102 is simply rejected to generate any additional audiovisual streams that already produce one or more audiovisual signals consuming available bandwidth between capture node 102 and switch 1002.

Another particular useful benefit of using a matched compatible format is that the audiovisual signal processed in the system of Figure 11 is non-uniform. For example, in the example of FIG. 1, video source 106 generates an SDTV format audiovisual signal, such that video source 106 is the native format and capture node 102 of video source 106. Video source 106 generates computer generated digital video signals, such as SXGA and analog audio signals, as a result of which they are the native formats of video source 106B and capture node 102B. Video source 106C then generates an HDTV format audiovisual signal, such that video source 106C is the native format and capture node 102C of video source 106C. Similarly, display devices 108 and 108B are different from each other. At the same time as the display device 108B receives a computer compatible video signal, such as an XGA and an analog audio signal played back through the built-in speaker, the display device 108 receives audiovisual content conforming to the HDTV format. However, because all nodes are connected to each other according to a number of predetermined and mutually supported digital and packetized audiovisual signal formats, the nonuniform nature of each unique and displayable format may result in effective coordination between the nodes as described above. No connection

The interaction of process flow diagram 400 (FIG. 4) is accurately described in the embodiment shown in FIG. 11 with two important exceptions. First, the data packet is addressed to a particular node for proper routing via the switch 1102 described above. Second, the mutual discovery of step 402 is more complicated and involves the selection of one or more available audiovisual signals. In the description that follows, the capture nodes 102, 102B, 102C are directly similar to each other except where they stand out, and the display nodes 104, 104B are directly connected to each other except where they stand out. similar.

Display logic 306 (FIG. 3) of display node 104 implements an on screen display (OSD) graphical user interface (GUI) such that a human user can capture one or more capture nodes 102, 102B. , 102C). For example, display node 104 may be a set-top box, or may include a remote control to send a signal to display node 104 to influence the user's selection, including remote control, and display device 108 (Fig. 11) is used as a display medium in which GUI messages are displayed to the user. In addition, since the display node 104 is integrated into the display device 108, the display node 104 is affected from other GUI configurations installed in the display device 108.

In order to show the user a video source list from the selection, the display node 104 first finds all the capture nodes available for selection. Display node 104 finds this by broadcasting a request for device information via switch 1102. Audiovisual stream controller 206 (FIG. 2) of capture node 102 is configured to respond to this request for confirmation. In response to this request, the audiovisual stream controller 206 transmits one or more data packets collectively comprising a data confirmation capture node 102. Such data includes, for example, data specifying the manufacturer, model number, serial number, and firmware release number of capture node 102. The discovery of similar information for the video source 106 up to the scope of the capture node 102 is possible, or has such stored information, and the capture node 102 includes similar information for the video source 106. In one embodiment, the user has a GUI mechanism to cause additional acknowledgment information sent from the display node 104 via the switch 1002 to the capture node 102 for storage, such as information about the video source 106. Are provided. This additional information may include text designated for assistance by the user in the video source selected later. For example, the user may have the capture nodes 102, 102B, 102C store each of the following descriptive text: "video camera", "computer" and "digital satellite".

Audiovisual stream controllers 206 and 302 (FIGS. 2 and 3) implement the discovery state of this interaction. This discovery can operate with known available Simple Network Management Protocol (SNMP). Once display node 104 determines relative confirmation information about all capture nodes 102, 102B, 102C, display node 104 provides this information on display device 108 for selection by the user.

Using each descriptive text, display node 104 can provide a simple list of available video sources from which the user can select. Many set-top boxes generally follow user input controls as buttons on the remote control, allowing the user to issue user input commands such as up, down, left, right and enter. Using this controller available to the user, the navigation of the list of available sources is directly communicated to the user and selected by the user to select a source for viewing.

Such remote controls often have one or more buttons to launch the picture in picture view. In response to a request by the user, for example to display a picture-in-picture view using this button, the display node 104 provides the same list of available sources, from which the user can use the above-described manner, for example. For example, use the UP, DOWN, LEFT, RIGHT and ENTER buttons on the remote control of the set-top box.

When multiple views are visible as shown in Figures 11-13, for example, a configuration by the user to change which source feeds a video signal to a particular window is (i.e., window 1108). 2, or selecting window 1108C, and (ii) selecting the source for the window in the manner described above.

Upon selection by the user, the display node 104 and the selected capture node, for example the capture node 102, are each capable and unique displayable format in the manner described above with respect to step 404 (FIG. 4). Begins with exchange data on. The rest of the interaction is where all data packets are addressed for proper routing through switch 1102, display node 104 maps pixel data from source coordinates to display coordinates and the process window is different from one blurred source pixel. Same as described above in the context of FIG. 1 except for overlapping in pixels as the source. This mapping and blurring behavior is called "compositing". Synthesis is described more fully in US Patent Application No. 10/795/088 "Compositing Multiple Full Motion Video Streams for Display on a Video Monitor," filed March 4, 2004. The entire contents are reflected here.

The determination by the capture node 102 of the selected compatible format may be somewhat different. In this embodiment, capture node 102 may transmit audiovisual data signals to multiple display nodes, and capture node 102 may ignore the displayable compatible format because there are multiple displayable compatible formats, The video compatible format can be limited to the most effective fidelity use of the native compatible format by all displayable compatible formats up to the capture node 102 transmitting the audiovisual data stream. Restricting the video compatible format to the most effective fidelity use of the native compatible format by all displayable compatible formats is desirable if the new display node combines with a set of display nodes that receive audiovisual data streams from the capture node 102. May require renegotiation.

Another benefit of distributing non-uniform audiovisual signals through switches such as switch 1102 is the ability to attach additional elements to provide additional functionality. For example, timer 1104 is attached to a port of switch 1102 and provides a system wide clock signal. In one embodiment, each capture node 102, 102B, 102C is configured to detect the presence of timer 1104 and to synchronize an internal clock with timer 1104 when timer 1104 is present. It is composed. Internal clock synchronization of multiple capture nodes allows the display node to synchronize multiple audiovisual signals from multiple capture nodes by comparison of timestamps included in the audiovisual stream in the manner described above.

Another attached element is the digital signal processor 1106. The digital signal processor 1106 may perform complex tasks such as filtering, smoothing and / or reducing noise on the other node side shown in FIG. 11, such as high quality deinterlacing, edge detection, motion detection and sharpening. For purposes of explanation, it will be helpful to consider examples of interlaced audiovisual signals captured by capture node 102 and deinterlaced audiovisual signals expected by display node 104B. Consider a capture node 102 that generates only interlaced signals and a display node 104 that receives only progressive scan signals. Upon selecting the selected compatible format, capture node 102 and display node 104B determine that there are no commonly supported compatible formats. A capture node (rather than indicating that the agreement to the compatible format failed to reach) has failed. 102 or display node 104 may request a deinterlacing service from digital signal processor 1106. Accordingly, the digital service processor 1106 may receive a video signal of one compatible format and transmit the video signal to various compatible formats. In addition, the digital signal processor 1106 may apply the video in the same compatible format to process the video signal content by applying noise reduction to filtering, smoothing and / or the video signal itself, for example, edge detection, motion detection and sharpening. Receive and transmit signals. Edge detection, motion detection and filtering are known and are not described here.

The digital signal processor 1106 operates by acting as both (i) a display node that receives the interlaced audiovisual signal from the capture node 102 and (ii) a capture node that generates a deinterlaced audiovisual signal for the display node 104B. Perform the service.

The timer 1104 and the digital signal processor 1106 illustrate the modularity of the video distribution system described herein. Each capture node may be limited to maintaining only one or very few unique formats of the audiovisual signal, and each display node may be limited to maintaining only one or very few displayable formats. However, these capture nodes and display nodes (i) maintain a very wide variety of native displayable formats, (ii) convert each native format into any displayable format, and (i) And can be combined to transmit audiovisual signals to multiple display devices, (i) display multiple audiovisual signals on each display device, and (iii) attach additional nodes to add functionality.

The network topology described here is particularly simple. Figure 1 shows the simplest topology in which one capture node is connected to one display node by a single link. Figure 11 shows multiple capture nodes and multiple display nodes interconnected by a single link through a single switch. More complex topologies can be planned with multiple interconnected switches, with each switch having many capture nodes and display nodes attached. These interconnected switches may be in the same room or separated miles or thousands of miles to provide a comprehensive means for acquiring, distributing and displaying audiovisual signals.

In addition, for capture and display nodes that require very large bandwidth, the second or third link can add twice or triple the amount of data that can be adjusted. For example, to double the bandwidth between switch 1102 (FIG. 11) and display node 104, two 1.0 gigabit connections may connect switch 1102 and display node 104 to each other. Similarly, capture node 102C may couple to switch 1102 using two 1.0 gigabit connections to effectively double the available bandwidth between capture node 102C and switch 1102.

The foregoing is merely illustrative and is not limiting. Instead, the invention is defined only by their corresponding full scope and claims.

Claims (149)

An image capture node for use in a video signal distribution system, The node is, Capture logic for receiving an image signal in a native format; Signal format conversion logic operatively coupled to the capture logic for converting a video signal from the native format to a compatible format; A signal operatively coupled to the signal format conversion logic to transmit a video signal of the compatible format to a remote display node so that the display converts the video signal from the compatible format to a displayable format to display the video signal. Image capture node containing the transfer logic. 2. The image capture node of claim 1 further comprising negotiation logic for selecting the compatible format in accordance with the image processing capability of a display node operatively coupled to the signal format conversion logic. The method of claim 1, And negotiation logic for selecting the compatible format in accordance with the image processing capability of the display device, operatively coupled to the signal format conversion logic. The image capture node of claim 1, wherein the reception by the capture logic, the conversion by the signal conversion logic, and the transmission by the signal transmission logic are performed simultaneously in succession to each other. The method of claim 1, wherein the transmitting comprises transmitting the video signal of the compatible format to the display node, wherein the display node converts the video signal from the compatible format to a displayable format to display the video signal in real time. Image capture node. The display apparatus of claim 1, wherein the signal transmission logic transmits an image signal of the compatible format to a second remote display node so that the second display node converts the image signal from the compatible format to a second displayable format. An image capture node comprising signal transfer logic to display a signal. The method of claim 1, wherein the signal format conversion logic converts a video signal from a raw format into a second compatible format, Additionally, the signal transmission logic transmits the video signal of the second compatible format to a second remote display node so that the second display node converts the video signal from the compatible format to a second displayable format to convert the video signal. Display image capture node. The method of claim 1, wherein the converting comprises converting the video signal from a native format to two or more compatible formats, In addition, the transmission transmits a video signal of the compatible format to the one or more display nodes for each of the two or more compatible formats so that each of the one or more display nodes can respectively display the video signal from the compatible format. And an image capture node converting the format to display the image signal. The image capture node of claim 1, wherein the compatible format comprises a timestamp. 2. The method of claim 1, wherein the transmitting comprises transmitting the video signal of the compatible format to an intermediate signal processing node, wherein the intermediate signal processing converts the video signal from the compatible format to a second compatible format; And transmitting the video signal of the second compatible format to a remote display node, wherein the display node converts the video signal from the second compatible format to a displayable format and displays the video signal. The method of claim 1, wherein the transmitting comprises transmitting the video signal of the compatible format to an intermediate signal processing node. The intermediate signal processing processes the video signal to form an enhancement video signal; An image capture node for transmitting an enhancement video signal in the compatible format to a remote display node, wherein the display node converts the enhancement video signal from the compatible format to a displayable format and displays the enhancement video signal. 2. The image capture node of claim 1, wherein the transmitting comprises transmitting the compatible format video signal to the display node via at least two separate communication channels. A video display node for use in a video signal distribution system, The node is, Communication logic for receiving a video signal in a compatible format from which the video signal is converted from a native format by the remote capture node; Signal format conversion logic for converting a video signal from the compatible format into a displayable format operatively coupled to the communication logic; And display drive logic for displaying an image signal by the display device, the display drive logic being operatively coupled to the signal format conversion logic. 14. The video display node of claim 13 further comprising negotiation logic for selecting the compatible format according to the image processing capabilities of the capture node, operatively coupled to the signal format conversion logic. The video display node of claim 13, wherein the display comprises transmitting the video signal to the external display device for display by an external display device. The video display node of claim 13, wherein the receiving comprises receiving the video signal of the compatible format through a packet switch. 14. The video display node of claim 13 wherein the receiving comprises receiving the video signal in the compatible format through at least two packet switches. The image display node of claim 13, wherein the reception by the communication logic, the conversion by the signal format conversion logic, and the display by the display driving logic are performed simultaneously in succession to each other. The image display node of claim 13, wherein the reception by the communication logic, the conversion by the signal format conversion logic, and the display by the display driving logic are performed in real time. 14. The method of claim 13, further comprising: (1) receiving data indicative of one or more predetermined compatible formats executed by the capture node, operatively coupled to the signal format conversion logic, and (2) of the predetermined compatible format. And negotiation logic that determines that one or more supported ones are to be executed locally, and (3) selects one of the supported predetermined compatible formats as the compatible format. 21. A video display node in accordance with claim 20, wherein said supported predetermined compatible format selectively represents a range of supported values of a characteristic of a video signal. 21. The method of claim 20, wherein the negotiation logic is further to receive data indicative of the raw format; The negotiation logic may further include at least one of the supported predetermined compatible formats, taking into account the amount of fidelity loss of at least one predetermined supported compatible format relative to the native format; Taking into account the excess signal amount of at least one predetermined supported compatible format for the displayable format; A video display node that selects the compatible format by considering the amount of signal bandwidth for the remote display node. The method of claim 13, The communication logic receives a second video signal in the second compatible format that is converted from a second raw format by a second remote capture node; The signal format conversion logic further converts the second video signal from the second compatible format to the displayable format; And the display driving logic to display the second image signal. 14. The method of claim 13, wherein the receiving comprises receiving a video signal from an intermediate signal processing node; The intermediate signal processing node receives a video signal from a remote capture node in a first compatible format; And a video display node for converting the video signal from the first compatible format to the compatible format. 15. The video display node of claim 13 wherein the receiving comprises receiving the video signal of the compatible format from the capture node via at least two separate communication channels. Video signal distribution system, Capture logic for receiving video signals in native format, First signal format conversion logic for converting a video signal from the raw format to a compatible format, operatively coupled to the capture logic; A capture node operatively coupled to the first signal format conversion logic, the capture node comprising communication logic for transmitting the video signal in the compatible format; Second signal format conversion logic, operatively coupled to the communication logic, for converting a video signal from the compatible format to a displayable format; A display node comprising display drive logic operatively coupled to the second signal format conversion logic, the display drive logic to transmit an image signal of the displayable format to a display device such that the display device displays the image signal. Video distribution system. 27. The apparatus of claim 26, wherein the capture node further comprises negotiation logic operatively coupled to the signal format conversion logic; In addition, the display node includes negotiation logic operatively coupled to the second format conversion logic, Further, the negotiation logic of the capture node and the negotiation logic of the display logic to cooperatively select the compatible format according to the image processing capability of the capture node. 27. The apparatus of claim 26, wherein the capture node further comprises negotiation logic operatively coupled to the signal format conversion logic; In addition, the display node includes negotiation logic operatively coupled to the second format conversion logic, Additionally, the negotiation logic of the capture node and the negotiation logic of the display logic cooperatively select the compatible format according to the image processing capability of the display node. 27. The apparatus of claim 26, wherein the capture node further comprises negotiation logic operatively coupled to the signal format conversion logic; In addition, the display node includes negotiation logic operatively coupled to the second format conversion logic, Additionally, the negotiation logic of the capture node and the negotiation logic of the display logic cooperatively select the compatible format according to the image processing capability of the display device. 27. The system of claim 26, wherein the compatible format is a digital representation of the raw format. 27. The system of claim 26, wherein the reception by the capture logic, conversion of the video signal by the first format conversion logic from the raw format to the compatible format, by the communication logic, the displayable format from the compatible format And the conversion by the second format conversion logic and the transmission by the display driving logic are performed simultaneously in succession to each other. 27. The system of claim 26, wherein the reception by the capture logic, conversion of the video signal by the first format conversion logic from the raw format to the compatible format, by the communication logic, the displayable format from the compatible format An image display node, wherein the conversion by the second format conversion logic to the second format conversion logic is performed in real time. The method of claim 26, further comprising:  Third signal format conversion logic operatively coupled to the communication logic, for converting a video signal from the compatible format to a second displayable format; Second display driving logic operatively coupled to the third format conversion logic to transmit an image signal of the second displayable format to a second display device such that the second display device displays the image signal And a second remote display node comprising a. 27. The apparatus of claim 26, wherein the first signal format conversion logic is further configured to convert a video signal from the raw format into a second compatible format; In addition, the communication logic transmits the video signal of the second compatible format to a second remote display node so that the second display node converts the video signal from the second compatible format to a second displayable format to convert the video signal. Display distribution system. 27. The method of claim 26, wherein the converting comprises converting the video signal from a native format to two or more compatible formats, Additionally, the transmission transmits the video signal of the compatible format to the one or more display nodes for each of the two or more compatible formats so that each of the one or more display nodes can display the video signal separately from the compatible format. And a video distribution system converting the format to display the video signal. The method of claim 26, further comprising: Second capture logic for receiving a video signal in a second native format; A second capture node operatively coupled to the capture logic and the communication logic, the second capture node including a third signal format conversion logic for converting a second video signal from the second raw format to a second compatible format; ; The communication logic transmits a second video signal in the second compatible format from the second capture node to the display node, And the second signal format conversion logic converts the second video signal from the second compatible format into the displayable format to display the second video signal. 27. The system of claim 26, wherein the transmission comprises transmitting the video signal of the compatible format to the display node via at least two separate communication channels. A video signal distribution system for displaying a video signal, Capture logic for receiving video signals in native format, First signal format conversion logic for converting a video signal from the original format to a first compatible format operably coupled to the capture logic; A capture node operatively coupled to the first signal format conversion logic, the capture node comprising first communication logic for transmitting the video signal in the first compatible format; An intermediate node comprising first signal format conversion logic for converting a video signal from the first compatible format to a second compatible format operatively coupled to the first communication logic; Second communication logic for transmitting a video signal of the second compatible format, operatively coupled to the second signal format conversion logic; Third signal format conversion logic operatively coupled to the communication logic, for converting a video signal from the second compatible format to a displayable format; A display node comprising display driving logic operatively coupled to the third signal format conversion logic, the display driving logic to transmit an image signal of the displayable format to a display device such that the display device displays the image signal. Video distribution system. 14. The image capture node of claim 1 or the image display node of claim 13, wherein the compatible format is a digital representation of the raw format. 27. The image capture node of claim 1 or the image distribution system of claim 26, wherein the receiving comprises receiving a video signal from an external video source. 27. The video capture node of claim 1 or the video display node of claim 13 or the video distribution system of claim 26, wherein the compatible format comprises a digital packet that can be transmitted via a packet switch. 27. The video capture node of claim 1 or the video display node of claim 13 or the video distribution system of claim 26, wherein the transmitting comprises transmitting the video signal of the compatible format through a packet switch. 27. The video capture node of claim 1 or the video display node of claim 13 or the video distribution system of claim 26, wherein the transmission comprises transmitting the video signal of the compatible format through two or more packet switches. 27. The image capture node of claim 1 or the image display node of claim 13 or the image distribution system of claim 26, wherein the raw format is different from the displayable format. 27. The video capture node of claim 1 or the video distribution system of claim 26, wherein the transform omits one or more frames of the video signal such that the frame rate of the video signal in the compatible format is less than the frame rate of the video signal in the raw format. dropping). 27. The video capture node of claim 1 or the video distribution system of claim 26, wherein the transformation downscales a frame of the video signal to result in a frame size of the video signal in the compatible format that is less than the frame size of the video signal in the raw format. Including the step of 27. The image capture node of claim 1 or the image distribution system of claim 26, wherein the transformation comprises changing a color space representation of a pixel of the image signal. 27. The image capture node of claim 1 or the image distribution system of claim 26, wherein the transformation comprises interlacing a frame of an image signal. 27. The image capture node of claim 1 or the image distribution system of claim 26, wherein the transformation comprises de-interlacing a frame of the image signal. The video display node of claim 13 or the video distribution system of claim 26, wherein the conversion adds one or more frames of the video signal to result in a frame rate of the video signal in the displayable format that is greater than the frame rate of the video signal in the compatible format. including the step of adding. The video display node of claim 13 or the video distribution system of claim 26, wherein the transform upscales a frame of the video signal such that the frame size of the video signal of the displayable format is greater than the frame size of the video signal of the compatible format. including upscaling). The video display node of claim 13 or the video distribution system of claim 26, wherein the transformation comprises changing a color space (color space) representation of a pixel of the video signal. The video display node of claim 13 or the video distribution system of claim 26, wherein the transformation comprises interlacing a frame of the video signal. The video display node of claim 13 or the video distribution system of claim 26, wherein the transforming comprises de-interlacing a frame of the video signal. The image capture node of claim 1 or the image distribution system of claim 26, wherein (1) receive data describing one or more predetermined compatible formats executed by the display node, operatively coupled to the signal format conversion logic. Negotiation logic, (2) determining that one or more supported ones of the predetermined compatible format are to be executed locally, and (3) selecting one of the supported predetermined compatible formats as the compatible format. more logic). 56. The method of claim 55, wherein the supported predetermined compatible format selectively represents a range of supported values of a characteristic of a video signal. 56. The method of claim 55, wherein the negotiation logic is further configured to: consider one of the supported predetermined compatible formats, taking into account the amount of fidelity loss of at least one predetermined supported compatible format relative to the native format; Taking into account the excess signal amount of at least one predetermined supported compatible format for the displayable format; Selecting the compatible format by considering the amount of signal bandwidth for the remote display node. 27. The image capture node of claim 1 or the image distribution system of claim 26, wherein the negotiation for selecting the compatible format according to the amount of bandwidth available to the display node, operatively coupled to the signal format conversion logic. An image capture node or image distribution system further comprising an edition logic. 59. The method of claim 58, wherein the selection comprises the steps of: determining the required bandwidth for the video signal of the compatible format; Comparing the required bandwidth with the amount of available bandwidth. 60. The image capture node or image distribution system of claim 59, wherein the negotiation logic further determines that the required bandwidth exceeds an amount of available bandwidth. 61. The image capture node or image distribution system of claim 60, wherein the negotiation logic also employs a compatible format to reduce the bandwidth required by signals in the compatible format. 62. The apparatus of claim 61, wherein the negotiation logic is further configured to configure the compatible format such that the transformation comprises one or more frames of the video signal including a frame rate less than the frame rate of the raw format. Image capture node or image distribution system adopting the format. 62. The method of claim 61, wherein the negotiation logic comprises configuring the compatible format such that the transformation comprises a color depth less than the color depth of the raw format, so that the transformation comprises reducing the color depth of the image signal. An image capture node or image distribution system by employing the compatible format. 62. The image capture node or image distribution system of claim 61, wherein the negotiation logic adopts the compatible format by configuring a compatible format to include a color space that is different from the color space of the native format. 62. The apparatus of claim 61, wherein the negotiation logic is further configured to configure the compatible format such that the transformation comprises downsizing a frame of the video signal, including a frame size less than the frame size of the raw format. Image capture node or image distribution system adopting the format. 62. The image capture node or image distribution system of claim 61, wherein the signal format conversion logic applies lossless compression techniques to the image signal. 62. The image capture node or image distribution system of claim 61, wherein said signal format conversion logic applies lossy compression techniques to an image signal. 27. The video capture node of claim 1 or the video distribution system of claim 26, wherein the transmission comprises determining a maximum amount of data; Determining a minimum time interval, And transmitting at least a maximum amount of data of the video signal during a time interval not shorter than the minimum time interval. 69. The image capture node or image distribution system of claim 68, wherein the maximum amount of data is determined according to a buffer of a minimum size at which an image signal moves to the display node. 69. The image capturing node or image distribution system of claim 68, wherein the maximum amount of data is determined in accordance with other traffic moving through at least one buffer as the image signal travels to the display node. 69. The image capture node or image distribution system of claim 68, wherein the maximum amount of data and the minimum time interval are determined in accordance with the amount of bandwidth available to the display node. 37. A video display node of claim 23 or a video distribution system of claim 36, wherein the user interface for selecting the video signal and the second video signal from one or more available video signals operatively coupled to the communication logic. An image display node or image distribution system further comprising user interface logic to provide. 73. The video display node or video distribution system of claim 72, wherein displaying the video signal and displaying a second video signal comprise synthesizing the video signal and the second video signal into a combined video display. 74. The image display node or image distribution system of claim 73, wherein said composite image display combines said image signal and said second image in a picture in picture configuration. 74. The image display node or image distribution system according to claim 73, wherein said composite image display combines said image signal and said second image in a picture beside picture configuration. 74. The image display node or image distribution system of claim 73, wherein said composite image display combines said image signal and said second image in a picture over picture configuration. 27. The video capture node of claim 1, the video display node of claim 13, or the video distribution system of claim 26, wherein the compatible format includes a timestamp associated with the video signal. 78. The image capture node of claim 77 wherein the signal transmission logic inserts a time stamp into a speech signal associated with the video signal, the time stamp of the speech signal being related to a time stamp of the video signal. 79. The video display node or video distribution system of claim 78, wherein the display comprises synchronizing playback of the video signal and the audio signal in accordance with timestamps of both the video and audio signals. 27. The video display node of claim 1 or the video distribution system of claim 26, further comprising user interface logic to provide a user interface for selecting an image from one or more available video signals, operatively coupled to the communication logic. An image display node or image distribution system. A method for displaying a video signal, Receiving a video signal in a native format; Converting a video signal from the raw format into a compatible format; Transmitting the video signal of the compatible format to a remote display node so that the display converts the video signal from the compatible format to a displayable format to display the video signal. 84. The method of claim 81, wherein the receiving, converting, and transmitting are performed in succession one after another. 83. The method of claim 82, wherein the transmitting comprises transmitting the video signal of the compatible format to the display node, wherein the display node converts the video signal from the compatible format to a displayable format to display the video signal in real time. Way. 84. The method of claim 81, wherein the transmitting comprises transmitting the video signal of the compatible format to an intermediate signal processing node, The intermediate signal processing converts a video signal from the compatible format to a second compatible format; And transmitting the video signal of the second compatible format to a remote display node so that the display node converts the video signal from the second compatible format to a displayable format. 84. The method of claim 81, wherein the transmitting comprises transmitting the video signal of the compatible format to an intermediate signal processing node. The intermediate signal processing processes the video signal to form an enhancement video signal; Transmitting an enhancement video signal in the compatible format to a remote display node, wherein the display node converts the enhancement video signal from the compatible format to a displayable format to display the enhancement video signal. As a method for displaying an image, Receiving a video signal of a compatible format into which the video signal is converted from a native format by the remote capture node; Converting a video signal from the compatible format into a displayable format; Transmitting to a display device to display an image signal in the displayable format. As a method for displaying an image, Receiving a video signal in a native format to a capture node; Converting the video signal from the original format into a compatible format; Transmitting the video signal of the compatible format from the capture node to a display node; Converting the video signal from the compatible format into a displayable format; Transmitting to a display device to display an image signal in the displayable format. 88. The method of claim 81 or 87, further comprising selecting the compatible format according to the image processing capability of the display node. 88. The method of claim 81 or 87, wherein the receiving comprises receiving the video signal from an external video source. 88. The method of claim 81 or 87, wherein the compatible format is a digital representation of the native format. 88. The method of claim 81, 86 or 87, further comprising selecting the compatible format according to the image processing capability of the display device. 88. The method of claim 81, 86, or 87, wherein the compatible format includes a digital packet that can be transmitted through a packet switch. 88. The method of claim 81, 86, or 87, wherein the transmitting comprises transmitting the video signal of the compatible format through a packet switch. 88. The method of claim 81, 86, or 87, wherein the transmitting comprises transmitting the video signal of the compatible format through two or more packet switches. 88. The method of claim 81, 86 or 87, wherein the native format is different from the displayable format. 88. The method of claim 81 or 87, wherein the transformation comprises dropping one or more frames of the video signal to result in a frame rate of the video signal in the compatible format that is less than the frame rate of the video signal in the raw format. How to. 88. The method of claim 81 or 87, wherein the transformation comprises downscaling a frame of the video signal to result in a frame size of the video signal in the compatible format that is less than the frame size of the video signal in the raw format. Way. 88. The method of claim 81, 86 or 87, wherein the transformation comprises changing a color space (color space) representation of a pixel of the image signal. 88. The method of claim 81 or 87, wherein the transformation comprises interlacing a frame of the video signal. 88. The method of claim 81 or 87, wherein the transformation comprises de-interlacing a frame of the video signal. 88. The method of claim 86 or 87, further comprising selecting the compatible format according to the image processing capability of the capture node. 88. The method of claim 81, 86 or 87, wherein the compatible format is a digital format. 88. The method of claim 86 or 87, wherein the converting further comprises adding one or more frames of the video signal to result in a frame rate of the video signal in the displayable format that is greater than the frame rate of the video signal in the compatible format. How to include. 88. The method of claim 86 or 87, wherein the transformation comprises upscaling a frame of the video signal to result in a frame size of the video signal in the displayable format that is greater than the frame size of the video signal in the compatible format. How to. 88. The method of claim 86 or 87, wherein the transformation comprises changing a color space (color space) representation of a pixel of the image signal. 88. The method of claim 86 or 87, wherein the transformation comprises interlacing a frame of the video signal. 88. The method of claim 86 or 87, wherein the transformation comprises de-interlacing a frame of the video signal. 88. The method of claim 81, 86 or 87, Receiving data describing one or more predetermined compatible formats executed by the display node; Determining that one or more supported ones of the predetermined compatible format are to be executed locally; Selecting one of the supported predetermined compatible formats as the compatible format. 109. The method of claim 108, wherein the supported predetermined compatible format selectively represents a range of supported values of a characteristic of the video signal. 88. The method of claim 81 or 87, wherein the selection is Taking into account one of the supported predetermined compatible formats, a loss in fidelity of at least one predetermined supported compatible format relative to the native format; Considering excess signal amount of at least one predetermined supported compatible format for the displayable format; Selecting the compatible format by considering an amount of signal bandwidth for a remote display node. 88. The method of claim 81 or 87, further comprising selecting the compatible format according to the amount of bandwidth available for the display node. 117. The method of claim 111, wherein the selection comprises the steps of: determining the required bandwidth for the video signal of the compatible format; Comparing the required bandwidth with the amount of available bandwidth. 118. The method of claim 112, further comprising determining that the required bandwidth exceeds an amount of available bandwidth. 117. The method of claim 113, further comprising adopting a compatible format to reduce the bandwidth required by the signal in the compatible format. 117. The method of claim 114, wherein the adopting comprises configuring the compatible format such that the transformation comprises one or more frames of the video signal including a frame rate less than the frame rate of the raw format. 116. The method of claim 114, wherein the adopting comprises configuring the compatible format such that the transformation comprises reducing the color depth of the video signal to include a color depth less than the color depth of the raw format. How to. 117. The method of claim 114, wherein the adopting comprises configuring a compatible format to include a color space that is different from the color space of the native format. 116. The method of claim 114, wherein the adopting comprises configuring the compatible format such that the transformation comprises downsizing a frame of the video signal including a frame size less than the frame size of the raw format. 116. The method of claim 114, wherein the transform comprises applying lossless compression techniques to the video signal. 118. The method of claim 114, wherein the transformation comprises applying lossy compression techniques to the video signal. 88. The method of claim 81 or 87, wherein transmitting comprises: determining a maximum amount of data; Determining a minimum time interval, Transmitting at least a maximum amount of data of a video signal during a time interval not shorter than the minimum time interval. 124. The method of claim 121, wherein the maximum amount of data is determined according to a buffer of a minimum size at which an image signal moves to the display node. 124. The method of claim 121, wherein the maximum amount of data is determined in accordance with another traffic moving through at least one buffer in which a video signal moves to the display node. 126. The method of claim 121, wherein the maximum amount of data and the minimum time interval are determined according to the amount of bandwidth available to the display node. 88. The method of claim 81 or 87, further comprising transmitting the video signal in the compatible format to a second remote display node, such that the second display node receives the video signal from the compatible format into a second displayable format. Method of displaying the video signal by converting. 88. The method of claim 81 or 87, further comprising: converting the video signal in the raw format into a second compatible format; And transmitting the video signal of the second compatible format to a second remote display node, wherein the second display node converts the video signal from the second compatible format to a second displayable format to display the video signal. How to. 88. The method of claim 81 or 87, wherein the converting comprises converting the video signal from a native format to two or more compatible formats, In addition, the transmission transmits a video signal of the compatible format to the one or more display nodes for each of the two or more compatible formats so that each of the one or more display nodes can respectively display the video signal from the compatible format. Converting to a format to display the video signal. 88. The method of claim 81, 86, or 87, wherein the compatible format includes a timestamp. 87. The method of claim 81, 86, or 87, wherein the compatible format includes a timestamp associated with the video signal. 129. The method of claim 129, further comprising inserting a time stamp into a speech signal associated with the video signal, wherein the time stamp of the speech signal is associated with a time stamp of the video signal. 88. The method of claim 81 or 87, wherein the transmitting comprises transmitting the video signal of the compatible format to the display node via at least two separate communication channels. 87. The method of claim 86 or 87, Receiving a second video signal in a second compatible format converted from a second raw format by a second remote capture node;  Converting the second video signal from the second compatible format into a displayable format; And displaying the second image signal. 134. The method of claim 132, further comprising providing a user interface for selecting one or more available video signals and a second video signal. 134. The method of claim 133, wherein displaying the video signal and displaying the second video signal comprises synthesizing the video signal and the second video signal into a combined video display. 134. The method of claim 134, wherein the composite image display combines the image signal and the second image in a picture in picture configuration. 143. The method of claim 134, wherein the composite image display combines the image signal and the second image in a picture beside picture configuration. 143. The method of claim 134, wherein the composite image display combines the image signal and the second image in a picture over picture configuration. 88. The apparatus of claim 86 or 87, wherein the compatible format includes a timestamp associated with the video signal; In addition, the method further includes inserting a time stamp into the audio signal associated with the video signal, wherein the time stamp of the audio signal is related to the time stamp of the video signal; The display further comprises synchronizing the reproduction of the video signal and the audio signal according to the timestamps of both the video and audio signals. 88. The method of claim 86 or 87, further comprising providing a user interface for selecting an image from one or more available image signals. 88. The method of claim 86 or 87, wherein the receiving comprises receiving a video signal from an intermediate signal processing node; The intermediate signal processing node receives a video signal from a remote capture node in a first compatible format; Converting a video signal from the first compatible format into the compatible format. 87. The method of claim 86, wherein receiving comprises receiving a video signal of the compatible format through a packet switch. 87. The method of claim 86, wherein receiving comprises receiving the video signal of the compatible format through two or more packet switches. 87. The method of claim 86, wherein the receiving, converting and displaying are executed simultaneously in succession. 145. The method of claim 143, wherein the receiving, converting and displaying are executed in real time. 87. The method of claim 86, further comprising: receiving data indicative of one or more predetermined compatible formats executed by the display node; Determining that one or more supported ones of the predetermined compatible format are to be executed locally; Selecting one of the supported predetermined compatible formats as the compatible format; The selection includes taking into account the amount of loss of Fidelity of at least one predetermined supported compatible format for the native format. Taking into account the excess signal amount of at least one predetermined supported compatible format for the displayable format; Taking into account the amount of signal bandwidth for the remote display node. 87. The method of claim 86, wherein the transmitting comprises transmitting the compatible format video signal to the display node via at least two separate communication channels. 88. The method of claim 87, wherein the receiving, converting and transmitting the video signal from the native format to the compatible format, and converting and displaying the video signal from the compatible format to the displayable format are performed in succession with each other simultaneously. 147. The method of claim 147, wherein the receiving, converting, transmitting a video signal from the native format to the compatible format, and converting and displaying the video signal from the compatible format to the displayable format in real time. A method for displaying a video signal, Receiving an image signal in a raw format into a capture node; Converting the video signal from the original format into a first compatible format; Transmitting the video signal of the first compatible format from the capture node to an intermediate signal processing node; Converting the video signal from the first compatible format to a second format; Transmitting the video signal of the second compatible format from the intermediate signal processing node to a display node; Converting the video signal from the second compatible format to a displayable format; Transmitting the video signal in the displayable format to a display device, the display device displaying the video signal.

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