JP4197134B2 - Digital broadcast receiver - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a digital broadcast receiving apparatus that receives a digital broadcast signal, reduces waiting time for acquiring video, audio, and channel specification information and performs channel selection at high speed.
[0002]
[Prior art]
In general channel selection processing of a conventional digital broadcast receiver, channel selection information (PSI; Program Specific Information) such as a program association table (PAT) and a program map table (PMT) is acquired, and an ES (Elementary) of Audio / Video is obtained. (Stream) PID determination, Video / Audio stream playback start, Video / Audio stream usage information acquisition, decoding, and video / audio output start are performed in this order. It is processing.
[0003]
Therefore, in order to acquire an identification number (PID; packet ID) for identifying video and audio from a digital broadcast signal, it is necessary to wait for channel specification information to be retransmitted from the digital broadcast signal.
[0004]
Further, after the broadcast signal having the video PID and the audio PID obtained by receiving the channel specification information is separated, the A / V decoder unit performs the decoding process, but the video and audio baseband signals are actually output. Until this time, information such as video size, buffer size used, audio frequency and number of channels must be acquired, so it was necessary to wait until the information was retransmitted into the video stream and audio stream of the broadcast signal. I had to.
[0005]
FIG. 5 is a diagram showing the case of acquiring a PMT according to the prior art, but after acquiring a PAT including information on the PMT, it is necessary to wait until the PMT included in the PAT is retransmitted. Arise. For this reason, a processing delay occurs in the tuning process.
[0006]
The waiting time for retransmission for acquiring information from the broadcast signal appears directly in the digital broadcast receiver as a time lag due to the channel selection process from when the user selects the channel to when it can actually be viewed. Then, it is regarded as a weak point.
[0007]
In order to eliminate the channel selection processing time lag of the digital broadcast receiving apparatus, attempts and proposals have been made to speed up the channel selection (see, for example, Patent Document 1).
[0008]
These above proposals use specific digital broadcasting business examples to save the contents of channel specification information of services that have been selected before, and save them in advance when the same service is selected again The channel specification information is used to reduce the waiting time until necessary information is acquired and to speed up the channel selection process.
[0009]
[Patent Document 1]
JP-A-9-233419 [0010]
[Problems to be solved by the invention]
However, in the example of the above proposal, the speed is achieved by using empirical information such as a specific digital broadcasting business example and a history of channel specification information selected in the past. There is a problem that content that cannot be applied to this example, such as the playback content of D-VHS tapes recorded in digital broadcasting and the playback content of package media, is not different from the conventional channel selection processing.
[0011]
Therefore, the present invention has been made in view of these problems, and reduces the waiting time for retransmission for acquiring information from a broadcast signal, and further, the time lag due to the channel selection process regardless of the contents of the broadcast operation or the contents. It is an object of the present invention to provide a digital broadcast receiving apparatus that can reduce the amount of noise.
[0012]
[Means for Solving the Problems]
A digital broadcast receiving apparatus according to the present invention receives a digital broadcast signal configured by multiplexing a packet including at least one channel specification information and a packet including a video stream or an audio stream. A packet receiving means for extracting a packet identification number of a packet including the channel specification information and separating the packet including information necessary for channel selection using the packet identification number after being registered in the broadcast receiving apparatus; a stream cache memory that stores the packet for each packet identification number temporarily containing the information necessary to switch Yan'neru selection result the packet separating means has performed a packet separating operation of the packet, the packet identification number the If it is determined that the packet is not registered in the packet separator, Only the packet including information necessary for channel selection related to the packet identification number is stored in the stream cache memory, and the packet separation unit is controlled to register the packet identification number, and the stream is again registered. While controlling to avoid storing the same packet as the packet in the cache memory, the packet stored in the stream cache memory is read according to the packet identification number of the packet output by the packet separation means Stream cache control means for controlling the packet to be transferred to a section filter and an A / V decoder, and the packet stored in advance in the stream cache memory before the processing of the section filter and the A / V decoder is performed. Is Information necessary for channel selection by performing packet analysis including type determination of whether the packet is a packet format packet of the network filter or a packet format packet of the A / V decoder, and information necessary for channel selection Packet type determining means for instructing the stream cache control means to store only packets having a type for each type in the stream cache memory, and a packet including information necessary for channel selection transferred from the stream cache control means Select a desired bitstream of the channel specification information, separate the channel specification information, and the baseband video of the video and audio bitstreams according to the channel specification information and information necessary for the channel selection. A to decode to signal or audio signal / V decoder.
[0013]
The digital broadcast receiving apparatus according to the present invention is characterized in that the stream cache memory has a memory configuration divided by packet identification numbers of digital broadcast signal packets.
[0014]
In the digital broadcast receiving apparatus according to the present invention, the stream cache memory has a size capable of storing the same packet as the packet identification number, and the header information of the stored packet starts with a packet indicating the start of the stream. A plurality of packets are stored.
[0016]
Furthermore, the packet type determining unit determines a type of the stored in the stream cache memory packet, when analyzing individual information in the packet, the stream cache control means, the specification of the video or audio characterized in that so as to obtain in advance the header information of the video stream and audio stream shown.
[0017]
According to the present invention, the stream cache memory and the stream cache control means are provided, and the information necessary for all channel selections is processed in parallel, so that sequential processing is performed by the conventional channel selection method. The above-described problems are solved by providing a digital broadcast receiving apparatus that reduces the waiting time for receiving digital broadcast signals.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0019]
FIG. 1 is a block diagram showing a digital broadcast receiving apparatus according to the first embodiment of the present invention.
[0020]
The digital broadcast receiver according to the first embodiment of the present invention includes a tuner and demodulator 100, a packet separator 101, a stream cache controller 102, a stream cache memory 107, a section filter 104, an A / V A decoder 105 and one or a plurality of DMACs 103 and 106 are provided.
[0021]
The tuner and demodulator 100 demodulates an analog broadcast signal transmitted by an analog modulated wave such as QPSK (Quadrature Phase Keying) or VSB (Vestational Side Band) into a digital broadcast signal multiplexed in the form of a transport stream. To do.
[0022]
The demodulated digital signal is multiplexed and transmitted in the form of a transport stream. The transport stream is composed of transport packets of predetermined bytes, and each transport packet has a PID (Packet Identification; hereinafter referred to as PID) in the header of the packet. To do. Thereby, the attribute of the packet can be specified. PSI, SI, etc. such as PAT and PMT have a data structure called a section and are stored in the payload portion of the transport packet.
[0023]
The demodulated digital signal is sent to a packet separation means (hereinafter referred to as a PID filter) 101 which is the next stage. The PID filter 101 registers the PID indicating the transport packet including information necessary for channel selection of the digital broadcast from the transport packet included in the digital broadcast signal demodulated by the tuner and the demodulator 100, and the digital broadcast signal The transport packet corresponding to the PID is selected and extracted. The extracted transport packet group can be classified into transport packet types (video, audio, PSI, SI, etc. related to a certain program) for each PID.
[0024]
The section filter 104 analyzes transport packets including section structure data (PSI, SI, etc.) from among the transport packets extracted by the PID filter 101, and program specifications such as PAT, PMT, etc. Section information of program arrangement information such as information and EIT is extracted.
[0025]
The AV decoder 105 receives a transport packet including an elementary stream of video and audio among the transport packets selected by the stream cache control unit 102 described later, and decodes it into a baseband video signal and audio signal. A video or audio transport packet is specified by the above-mentioned program specification information, and the transport packet (or PES or ES included therein) is decoded by the AV decoder 105. Thus, it becomes possible to select one program desired by the user from the transport packet in which a plurality of programs are multiplexed, and the video or audio transport packet can be selected from the program specification information extracted by the section filter 104. PID can be determined.
[0026]
Here, the program selection information from the user and the program specification information obtained from the transport packet are combined, for example, in accordance with an instruction from a control means (not shown in FIG. 1) including a CPU, Transport packets of video and audio streams related to the program are selected and output.
[0027]
The stream cache control means 102 selects either the packet group selected by the packet separation means 101 or the transport packet group stored in the stream cache memory 107 and sends it to the A / V decoder 105 and the section filter 104. To do. Note that the stream cache control unit 102 writes the transport packet group that has passed through the packet separation unit 101 to the stream cache memory 107 in the address area divided for each identical PID (shown in FIG. 3). )Control.
[0028]
In addition, the transport packet group temporarily stored from the address area divided for each PID in the stream cache memory 107 is read by the stream cache control unit 102 according to a read operation described later. This transport packet group is sent to the A / V decoder 105 and the section filter 104, and program identification information such as PAT, audio reception information, and the like are separated.
[0029]
Each bit stream of the transport packet group divided according to the type of content of the transport packet sent out by the stream cache control means 102 is sent through one or a plurality of stream transfer means (referred to as DMAC) 103 and 106. , And transferred to the section filter 104 and the A / V decoder 105.
[0030]
Next, operations of the stream cache control unit 102 and the stream cache memory 107 will be described in detail.
[0031]
FIG. 3 is a diagram showing a memory configuration of the stream cache memory 107.
[0032]
As shown in FIG. 3, the memory configuration of the stream cache memory 107 is divided for each PID of the transport packet, and the transport packet group is stored in the divided memory area. The transport packet stored in the stream cache memory 107 is not a video / audio data itself but a packet including information that does not depend on time series such as PSI information, video format, necessary buffer size, scanning method, and audio sampling rate information. is there. Therefore, the transport packet recorded in the stream cache memory 107 is information that does not change while the transport stream is continuous, and the recording in the stream cache memory 107 is the channel selection information of the channel desired by the user. This is performed in advance to obtain from the packet.
[0033]
A control operation performed by the stream cache control unit 102 on the packet group stored in the stream cache memory 107 will be described.
[0034]
In the conventional channel selection process, the PID related to the channel selection channel is registered in the PID filter 101 in advance. Thereby, only the PID TS packets necessary for the viewing program are extracted from the transport stream by the PID filter and transferred to the section filter and the A / V decoder. In the PID filter 101, PIDs not related to the selected channel, that is, TS packets of PIDs not registered in the PID filter 101 are not acquired and discarded.
[0035]
In the present invention, transport packet groups of PIDs that are not registered in the PID filter that have been discarded in the conventional channel selection process are stored in the stream cache memory 107 through the stream cache control unit 102. Thereafter, when the PID of the transport packet group that has been transferred to the stream cache memory 107 is registered in the PID filter, the transport packet group stored in the stream cache memory 107 is read by the stream cache control means 102. Then, the gap between the transport packet signals output from the packet separation means 101 is sewn and output to the section filter 104 and the A / V decoder 105 only once. After that, since the transport packet of the PID is extracted from the PID filter as soon as it arrives in the broadcast signal, the stream cache control unit 102 sends the transport packet of the PID to the stream cache memory 107. Acts to stop the transfer.
[0036]
Next, the operation of the stream cache control unit 102 when storing a packet in the stream cache memory 107 will be described.
[0037]
The stream cache control unit 102 stores, in the stream cache memory 107, transport packets that are not selected by the PID filter 101, that is, transport packets having a PID that is not registered in the PID filter 101.
[0038]
The condition of the transport packet stored in the stream cache memory 107 is that it is a transport packet having a PID that is not registered in the PID filter 101 and that it is not a PID transport packet indicating stuffing. Furthermore, even if the above conditions are met, the unit start flag (Unit_Start_Indicator in the TS packet header) indicating the beginning of the section data or the beginning of the PES (Packetized Elementary Stream) in the packet stream having the same PID is true ( This is a packet corresponding to the size of the memory area allocated to the PID of the stream cache memory 107 after the packet “1”) arrives. The subsequent packets are not stored in the stream cache memory 107 because they are not information packets necessary for channel selection.
[0039]
As described above, when a packet that matches the above condition to be stored in the stream cache memory 107 arrives, the stream cache control unit 102 calculates the head arrangement position in the area allocated for each PID of the stream cache memory 107, and determines the packet. Transfer and save to the stream cache memory 107.
[0040]
For the section information handled by the section filter 104, a stream cache memory 107 having a capacity that can accommodate at least the program association table (PAT) and the program map table (PMT) is required.
[0041]
Here, the PAT specifies the PID of the transport packet that transmits the PMT. The PMT selected from the PID of the PMT, which is the registered content of the PAT, describes the PID of the transport packet that transmits each encoded signal constituting the program, for example, the PID of the video signal and the PID of the audio signal. . Therefore, by acquiring PAT and PMT, it is possible to acquire information on PID necessary for channel selection.
[0042]
As described above, when a packet is extracted from a digital broadcast signal, the packet information necessary for channel selection can be acquired from the stream cache memory 107 in advance, so that the channel selection time can be shortened. .
[0043]
Next, a second embodiment of the present invention that takes advantage of the features of the stream cache memory 107 will be described with reference to FIG. In addition, the same code | symbol is attached | subjected to the structure same as the structure shown in the said 1st Embodiment, and description is abbreviate | omitted.
[0044]
FIG. 2 is a block diagram showing a digital broadcast receiving apparatus according to the second embodiment of the present invention. In the second embodiment according to the present invention, a stream type analysis determination unit 208 is newly added to the first embodiment according to the present invention.
[0045]
As described in the first embodiment, the target packet for storing the input stream in the stream cache memory 207 is a transport packet having a valid PID. There is no need to be subject to preservation.
[0046]
Therefore, after analyzing the contents of the packet stored in the stream cache memory 107, a stream type analysis determining unit 208 is provided for determining whether the transport packet is section format data or Video / Audio PES data. It is a thing. As a result, the storage capacity of the stream cache memory 107 is reduced, the channel selection time process is made more efficient, and the channel selection time is further shortened.
[0047]
Hereinafter, a specific operation of the stream type analysis determination unit 208 will be described.
[0048]
FIG. 4 is a diagram illustrating an example of acquiring packet information necessary for channel selection in the present invention.
[0049]
The stream type analysis determination unit 208 analyzes a bit arrangement pattern in a packet stored in the stream cache memory 107, and is, for example, PMT of section data, other SI information, or PES format of a video stream. Or data in the PES format of the audio stream . If the transport packet input to the stream cache memory 207 is a section data PMT, a PES format of a video stream, or a PES format of an audio stream, the stream type analysis determination means 208, as shown in FIG. In the stream cache memory 207, the type of the identified stream and the packet are stored as the PID attribute of the packet.
[0050]
If the packet has a format other than the above, it is not stored in the stream cache memory 107. Thereby, the mounted storage capacity of the stream cache memory 107 can be reduced by limiting the packet group to be stored in the stream cache memory 107.
[0051]
Next, an example in which the PMT of section data is acquired and the channel selection processing time can be shortened will be described with reference to FIG.
[0052]
The stream type analysis determination unit 208 determines the above-described stream type based on the contents of the packet stored in the stream cache memory 107. For example, when the section data is a PMT, all of the PMTs are configured. When the transport packet is stored in the stream cache memory 107, the analysis can be performed prior to the analysis of the section filter 104, so that the PID of the Audio / Video stream can also be acquired in advance. That is, as shown in FIG. 4, when the PAT is acquired, since the PMT is already stored in the stream cache memory 107, the PMT can be immediately transferred to the section filter 104. On the other hand, since the PID of the Audio / Video stream can also be acquired in advance, the stream type analysis determination unit 208 can start analyzing the bit arrangement pattern in the packet stored in the stream cache memory 107. it can. Therefore, the tuning process delay time can be further reduced in the tuning process.
[0053]
Also, since the TS packet of the Audio / Video stream can be acquired in advance, the video format information and audio frequency information can be extracted from the stream cache memory 207 and the back-end system setting process can be performed in advance. This makes it possible to further shorten the channel selection processing time.
[0054]
【The invention's effect】
As described above, according to the present invention, when extracting a packet from a digital broadcast signal, the packet information can be acquired in advance, so that the channel selection time can be shortened.
[0055]
In addition, if the present invention is used, since it does not depend on past experience information at the time of channel selection or a broadcast specification paradigm, it can be used for various digital broadcasts.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a digital broadcast receiving apparatus according to a first embodiment of the present invention.
FIG. 2 is a block diagram showing a digital broadcast receiving apparatus according to a second embodiment of the present invention.
FIG. 3 is a diagram illustrating a memory configuration of the stream cache memory 107;
FIG. 4 is a diagram illustrating an example of acquiring packet information necessary for channel selection in the present invention.
FIG. 5 is a diagram illustrating an example of acquiring packet information necessary for channel selection in the related art.
[Explanation of symbols]
100 Tuner and Demodulator 101 Packet Separation Unit 102 Stream Cache Control Unit 103, 106 DMAC
104 Section filter 105 AV decoder 107 Stream cache memory 208 Stream type analysis determination means

Claims (4)

A digital broadcast receiving apparatus that receives a digital broadcast signal configured by multiplexing a packet including at least one channel specification information and a packet including a video stream and an audio stream,
A packet separating means for extracting a packet identification number of a packet including the channel specification information and registering the packet including information necessary for channel selection using the packet identification number;
A stream cache memory that stores the packet temporarily each packet identification number containing the information required to switch Yan'neru selection,
If the packet separation unit determines that the packet identification number is not registered in the packet separation unit as a result of performing the packet separation operation of the packet, the packet separation unit includes information necessary for channel selection related to the packet identification number. Only the packet is stored in the stream cache memory, and the packet separation unit is controlled to register the packet identification number, and the same packet as the packet is stored in the stream cache memory again. The packet stored in the stream cache memory is read out and transferred to the section filter and the A / V decoder according to the packet identification number of the packet output by the packet separation means. Stream carrier to control Zhu control means,
Before performing the processing of the section filter or the A / V decoder, the packet stored in the stream cache memory in advance is a packet in the packet format of the section filter or in the packet format of the A / V decoder. The packet cache analysis including the type determination of whether it is a packet, the information necessary for channel selection is determined, and the stream cache control is performed so that only packets having information necessary for channel selection are stored for each type in the stream cache memory A packet type determination means for instructing the means;
A section filter that selects a desired bitstream of the channel specification information from a packet including information necessary for channel selection transferred from the stream cache control means, and separates the channel specification information;
A digital broadcast reception comprising: an A / V decoder that decodes the video or audio bitstream into a baseband video signal or audio signal according to the channel specification information and information necessary for channel selection apparatus.   2. The digital broadcast receiving apparatus according to claim 1, wherein the stream cache memory has a memory configuration that is divided according to packet identification numbers of digital broadcast signal packets.   The stream cache memory has a size capable of storing at least the packet indicated by the packet identification number, and a plurality of packets are stored starting with a packet indicating that the header information of the stored packet indicates the start. The digital broadcast receiver according to claim 1 or 2. Further, the packet type determining means determines the type of the packet stored in the stream cache memory, and analyzes video or audio specifications to the stream cache control means when analyzing individual information in the packet. the digital broadcast receiving apparatus according to any one of claims 1 to 3, characterized in that it has to acquire in advance the header information of the video stream and audio stream shown.

Images