JPH1066071A - Video data transmitter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To uniformize the operation speed for data compression and the transmission speed in each transmission in the case that one pattern video data or multi-pattern video data are selected and the selected data are sent. SOLUTION: In the case of sending, e.g. 4-pattern video image, frame memories 11-14 of each video system receive data whose frames are thinned and stores them. Compression sections 15 18 provided with each frame memory conduct data compression processing while dummy frame video data (dummy frame generating section 26) whose number us equal to the thinned frame number are added to the video data of a frame group of a required frame number read from the corresponding frame memory. Through the addition of the dummy frames, the number of frames in the case of 4-pattern video transmission is equal to a frame number in the case of 1-pattern video transmission and compensation processing is conducted for the both under the same state. The video data of the frame group subject to compression processing are subject to time division for each video system and the result is sent.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a video data transmitting apparatus and, in the case of selecting and transmitting one-screen video data or multi-screen video data, equalizing the operation speed of data compression and the transmission speed in each transmission. The present invention relates to a transmission device for which

[0002]

2. Description of the Related Art FIG. 3A shows an example in which four types (systems) of input video data are transmitted for four-screen display, or one of the four types of video is transmitted for one-screen display and received. FIG. 3 is a diagram illustrating the principle configuration of a conventional system for displaying. In the figure, when transmitting four types of video data (video to) as a four-screen display signal, each of the input processing units 41 to 44 provided for each video performs frame thinning processing. When the frame configuration of one video is represented by a series of numbers as shown in the upper part of FIG. 3B, for example, frames 1, 5, 9,... And so on (x mark) are not taken in. The required number of frames captured in this manner, for example, four frames of frames 1, 5, 9, and 13,
Is a frame group, and the required compression method (H261 or MP
EG, etc.) to compress data. The four types of video data compressed by the respective compression units are sent to a multiplexer (MPX) 49, where they are arranged in a time series in a predetermined order for each frame group and each input video system. The video data arranged in time series in this manner is transmitted to the receiving side via the transmission path 50.

On the receiving side, data expansion processing is performed on the received video data by a data expansion unit 51, and a 4-screen display signal is generated by a synthesis processing unit 52 based on the expanded data. The video data from the synthesizing section 52 is converted from a digital signal to an analog signal by a D / A converter 53 and transmitted to a monitor 54. The monitor 54 displays four screens as shown. On the other hand, when transmitting an arbitrary one of the four types of input images, for example, an image, the corresponding input processing unit
41 captures frame video data without thinning out frames. The video data thus captured is subjected to compression processing in the corresponding data compression unit 45, and is transmitted to the receiving side via the multiplexer 49 and the like. In this case, the receiving monitor 54
Displays one screen of video.

[0004]

A conventional method of transmitting a plurality of types of video input as a multi-screen video or a single-screen video is as described above. If attention is paid, the compression operation is different. That is, when it is assumed that the frame thinning of the four images is performed as shown in the lower part of FIG. 3B, the compression processing of each compression unit when transmitting the four-screen image is the compression processing when transmitting the one-screen image. Must be reduced to 1/4.
In order to reduce the compression operation to １ ／, it is necessary to reduce the operation clock of each compression unit to １ ／ and to change the transmission speed of the transmission line to ４. As described above, conventionally, there has been a problem that the transmission speed is different between the case of transmitting a four-screen image and the case of transmitting one screen. The present invention has been made in view of the above problems, and has as its object to provide a video data transmitting apparatus in which transmission of a multi-screen video and transmission of a single-screen video are performed under the same conditions.

[0005]

According to the present invention, a plurality of types of video data are input and one of a plurality of types of video data is selected when displaying one screen or a plurality of types of video data when displaying multiple screens. In the transmitting device,
Provided for each of the plurality of types of video, when transmitting a plurality of types of video data, fetch and store the frame video data by thinning out each frame, and when transmitting one type of video data, decimate the frame of the corresponding video. A frame memory means for fetching and storing frame video data, and provided in correspondence with the frame memory means, when transmitting a plurality of types of video data,
Data compression means for adding the thinned-out dummy frame video data to the video data of the frame group consisting of the required number of frames read out from the frame memory means and performing compression processing; A transmitting means for transmitting the plurality of types of video data other than the dummy frame video data in a predetermined order in a time-division manner, and a control means for controlling the frame memory means, the data compression means and the transmitting means. A transmitting device is provided.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In the case where the types of input video systems are, for example, four, and these videos are transmitted as four-screen video,
In the same manner as in the related art, frames are thinned out, frame video data is taken in, and stored in a frame memory provided for each video system. In the data compression unit provided corresponding to each frame memory, the same number of dummy frame video data as the thinned frames are added to the video data of the frame group consisting of the required number of frames read from the corresponding frame memory In such a state, the data compression process is performed.

[0007] By the addition of the dummy frame video data, the number of frames at the time of four-screen video transmission is the same as the number of frames at the time of one-screen video transmission without frame thinning, and the compression processing in the compression unit is the same. Will be done below. In this manner, the video data of the frame group compressed by each compression unit is transmitted in a time-division manner for each video system. As described above, transmission of four-screen video and transmission of one-screen video are performed under the same compression operation and transmission speed.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A video data transmitting apparatus according to the present invention will be described below with reference to the drawings. FIG. 1 is a main block diagram showing an embodiment of a video data transmitting apparatus according to the present invention, in which the number of types of video input is four (video to).
2A and 2B are diagrams for explaining FIG. 1. FIG. 2A is a diagram showing a frame relationship between a one-screen image and a four-screen image, and FIG. FIG. In FIG. 1, 1 is a transmitting unit, 2 is a transmission path, 3 is a receiving unit, and 4 is a monitor. In the transmission unit 1, reference numerals 11 to 14 denote frame memory units for each input video system, which are composed of a required number of frame memories, and are used for thinning out frame video data of each system and storing a required number of frames when transmitting four-screen video. is there.

Reference numerals 15 to 18 denote data compression units provided corresponding to the frame memory units 11 to 14, respectively, for transmitting video data from the corresponding frame memory unit during one-screen video transmission and for transmitting four-screen video data. Sometimes, a required method (H261 or MP) is applied to video data obtained by adding dummy frame video data to video data from each frame memory unit.
EG). Reference numerals 19 to 22 denote buffer memories for temporarily storing valid video data (frame group video data) in the data compressed by the compression units 15 to 18.

Reference numeral 23 denotes a multiplexer (MPX) for arranging frame group video data consisting of a required number of frames read from each of the buffer memories 19 to 22 in a predetermined order in a time series for each video system. .
Reference numeral 24 denotes a transmission unit for transmitting the video data from the multiplexer 23 to the reception unit 3 via the transmission path 2. twenty five
Are the frame memory units 11 to 14, the data compression units 15 to 18,
The control unit controls the buffer memories 19 to 22 and the multiplexer 23.

Next, the operation of the present invention will be described. First, a case of transmitting one screen image will be described. Whether to transmit one-screen video or four-screen video is set by a selection signal S1 to the control unit 25. When the one-screen image is used as an image, the corresponding frame memory unit 11 (hereinafter, referred to as the frame memory unit 11)
The memory section) captures frames without thinning them out and stores them. In the upper part of FIG. 2A, video frames of one system are numbered. The first frame to be captured is referred to as “frame 1”, and is sequentially numbered. The control unit 25 controls the taking in and reading of the data into and from the memory unit 11. The video data read from the memory unit 11 is subjected to compression processing by a data compression unit 15 provided correspondingly. This data compression processing means, for example, the H261 or MPEG method similar to the conventional moving image compression.

The compressed video data is temporarily stored in a buffer memory 19 provided correspondingly. The video data read from the buffer memory 19 is sent to the multiplexer 23. The multiplexer 23 arranges the video data of each system in a time-series manner in a predetermined order when transmitting four-screen video. However, in the case of transmission of one-screen video, this array is unnecessary, and is read out from the buffer memory 19. The output video data itself is output. The video data output from the multiplexer 23 is transmitted to the reception unit 3 via the transmission unit 24 and the transmission path 2.

The receiving unit 3 includes a data decompression unit 31 for decompressing the compressed video data, and a synthesis processing unit for performing multi-screen (four in this example) processing based on the data from the data decompression unit 31.
32, a D / A converter 33 for converting the digital video data from the synthesis processor 32 into an analog video signal, and a controller 34 for controlling the data decompressor 31, the synthesis processor 32, and the like. However, in the case of transmission of the above-described one-screen image, the synthesizing process is not performed in the synthesizing processing unit 32 and is processed as a one-screen image. As a result, one screen of an image is displayed on the monitor 4. The above is the transmission of one-screen video.

Next, transmission of a four-screen image will be described.
In the case of this transmission, each of the frame memory units 11 to 14 for each video system (系統) fetches data by thinning out frames and stores the data, as shown in the lower part of FIG. 3B. FIG. 3B captures frames 1, 5, 9,...
Frames 2, 3, 4, 6, 7, 8 and the like (marked with “x”) in between mean that thinning is shown. The frame video data fetched while thinning out in this way is stored in each frame memory section.
The required number of frames are read from 11 to 14, respectively, and are made into frame groups. As shown in the lower part of FIG. 2A, when this frame group is composed of four frames 1, 5, 9, and 13, for example, at the time of frame 13, the number of frames is 9 frames as compared with the case of the above-described one-screen video transmission. Less (× in the figure
mark). Therefore, dummy frame video data is added to the 9 frames of the shortage. By adding this dummy, 4
The number of frames at the time of transmitting a screen image is the same as that at the time of transmitting one screen image.

As the dummy frame video data, a dummy frame video data generation unit 26 is provided under the control unit 25, and the generated dummy frame is added. Or
The data stored in each frame memory may be used as a dummy frame. Each data compression unit
15 to 18 perform data compression processing with the dummy frame added. As a result, the compression operation for one-screen video and the compression operation for four-screen video are performed under the same conditions, and the data compression operation speeds are the same. The video data compressed by the compression units 15 to 18 is temporarily stored in the corresponding buffer memories 19 to 22.In this case, valid video data excluding dummy frames, that is, each frame memory unit Frame group video data captured in 11 to 14 is stored. Since the number of frames in the frame group is predetermined, and these video data are continuous, it is known which range of the output of each compression unit is valid data (or dummy frame data).

In the case of FIG. 2A (lower), frames 1, 5, 9, and 13 are valid video data, and the buffer memories 19 to 22 store the video data of the frame numbers, respectively. The video data stored in each of the buffer memories 19 to 22 is read out and input to the multiplexer 23. The multiplexer 23 arranges the input video data of the four systems in a time series in a predetermined order. FIG. 2B shows an example of this arrangement. This figure shows an example in which a frame group is made up of four frames and video to video are arranged in order. The video data arranged as described above is transmitted from the transmission unit 24 to the transmission path 2.
Is transmitted to the receiving unit 3 via the.

The receiving section 3 performs expansion processing on the time-divided compressed video data in the data expansion section 31, and performs processing for forming a four-screen video in the synthesis processing section 32 based on the processed data. The four-screen video data from the synthesizing unit 32 is converted from digital video data into an analog video signal by the D / A conversion unit 33 and sent to the monitor 4. Thereby, for example, a four-screen image as shown in the figure is projected on the monitor 4.

[0018]

As described above, according to the present invention, for example, when selecting and transmitting either one-screen video or four-screen video data based on four types of input video,
The compression operation for one-screen video and the compression operation for four-screen video are performed under the same conditions. That is, when transmitting four-screen video, dummy frame video data is added to frame video data captured by thinning out frames,
The number of frames is the same as the number of frames at the time of one-screen video transmission without frame thinning. By performing this compression operation under the same conditions, no difference occurs in the transmission speed of the transmission path.

On the other hand, in the related art, the number of frames of each video system is smaller than the number of frames at the time of transmitting one screen image due to the frame thinning process at the time of transmitting four screen images, and the frame configurations do not match. Therefore, when transmitting a 4-screen image, the compression operation is reduced by 1 /
4, which results in the disadvantage that the transmission speed of the transmission line is also reduced to 1/4, but these are solved by the present invention. As described above, the present invention can contribute to improving the performance of an apparatus that selects and transmits one-screen video data or multi-screen video data.

[Brief description of the drawings]

FIG. 1 is a main block diagram showing an embodiment of a video data transmitting apparatus according to the present invention.

FIG. 2 is a diagram for explaining FIG. 1;
FIG. 4B is a diagram showing a frame relationship between a screen and four screens, and FIG.

FIG. 3 is a principle configuration diagram for explaining conventional video data transmission / reception.

[Explanation of symbols]

 1 Transmission unit 2 Transmission path 3 Receiver 4 Monitor 11, 12, 13, 14 Frame memory unit 15, 16, 17, 18 Data compression unit 19, 20, 21, 22 Buffer memory 23 Multiplexer 24 Transmission unit 25 Control unit 26 Dummy Frame video data generation unit 31 Data decompression unit 32 Synthesis processing unit 33 D / A conversion unit 34 Control unit 41, 42, 43, 44 Input processing unit 45, 46, 47, 48 Compression unit 49 Multiplexer 50 Transmission line 51 Decompression unit 52 Synthesizing unit 53 D / A conversion unit 54 Monitor

Claims (4)

[Claims] 1. An apparatus for inputting a plurality of types of video data and selecting and transmitting one type of video data when displaying one screen or a plurality of types of video data when displaying multiple screens. Provided for each type of video, when transmitting multiple types of video data, each frame is thinned out to capture and store frame video data, and when transmitting one type of video data, the frame of the corresponding video is not thinned out Frame memory means for receiving and storing video data; and, when transmitting a plurality of types of video data, video data of a frame group consisting of a required number of frames read from the frame memory means, provided in correspondence with the frame memory means. And add the thinned dummy frame video data to the Data compression means for processing, transmission means for time-divisionally transmitting the plurality of types of video data other than the dummy frame video data from the data compressed by the data compression means in a predetermined order, and the frame memory means, A video data transmitting device comprising a data compressing unit and a control unit for controlling a transmitting unit. 2. The video data transmitting apparatus according to claim 1, wherein said dummy frame video data is used by duplicating data stored in said frame memory means. 3. The video data transmitting apparatus according to claim 1, wherein said dummy frame video data uses data from a dummy frame video data generating means provided based on said control means. . 4. A buffer memory corresponding to said data compression means, said buffer means storing video data other than said dummy frame video data from data from said compression means, and A video characterized by comprising a video data array unit for arranging the plurality of types of read frame group video data in a predetermined order in a time-division manner, and a transmission unit for transmitting video data from the video data array unit. Data transmission device.