JP2004312629A - System for receiving digital broadcasting - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a digital broadcasting receiver, capable of improving the efficiency of a packet receiving process and speeding up a channel selecting process by providing stream cache control means and a cache memory. <P>SOLUTION: Packets needed for a digital broadcasting signal are made to be acquired by a stream cache memory 107, in addition to packet dividing means 101 for the digital broadcasting signal, by providing a stream cache control means 102 and the stream cache memory 107 to the digital broadcasting receiver, and channel selection information can be acquired from the stream cache memory 107, without waiting for receiving the digital broadcasting signal, if the information needed in a step of channel-selecting process has already been stored in the stream cache memory 107. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a digital broadcast receiving apparatus that receives a digital broadcast signal, reduces a waiting time required for acquiring video, audio, and channel specification information, and performs high-speed channel selection.
[0002]
[Prior art]
In general channel selection processing of a conventional digital broadcast receiving apparatus, acquisition of channel selection information (PSI; Program Specific Information) such as a program association table (PAT) and a program map table (PMT), and audio / video ES (Elementary). (Stream) PID, video / audio stream playback start, video / audio stream usage information acquisition, decoding, and video / audio output start are performed in this order. Processing.
[0003]
Therefore, in order to obtain 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 separating the broadcast signal having the video PID and the audio PID obtained by receiving the channel specification information, the A / V decoder unit performs a decoding process, which is actually output as a video or audio baseband signal. Until this information is obtained, information such as the size of the video, the buffer size used, the frequency of the audio and the number of channels must be obtained. I had to.
[0005]
FIG. 5 is a diagram showing a case of acquiring a PMT according to the related art. However, after acquiring a PAT including PMT information, it is necessary to wait until the PMT included in the PAT is retransmitted. Occurs. Therefore, a processing delay occurs in the channel selection processing.
[0006]
In a digital broadcast receiving apparatus, the retransmission wait for acquiring information from a broadcast signal directly appears as a time lag due to a channel selection process from the time the user performs a channel selection operation until the user can actually view the digital signal. Then, it is considered a weak point.
[0007]
Therefore, in order to eliminate the time lag of channel selection processing of the digital broadcast receiving apparatus, attempts and proposals for speeding up channel selection have been made (for example, see Patent Document 1).
[0008]
These above proposals use a specific digital broadcasting business example to save the content of channel specification information of a service that has been selected once, and save it in advance when the same service is selected again. It is intended to reduce the waiting time until necessary information is obtained by using the obtained channel specification information and to speed up the channel selection processing.
[0009]
[Patent Document 1]
JP-A-9-233419
[Problems to be solved by the invention]
However, in the example of the proposal described above, since high speed is achieved by using empirical information such as a specific digital broadcasting business example and the history of channel specification information selected in the past, However, there is a problem in that the content which cannot be applied to this example, such as the content of reproduction of a D-VHS tape or the content of reproduction of a package medium recorded by digital broadcasting, is no different from the channel selection processing of the conventional method.
[0011]
Therefore, the present invention has been made in view of these problems, and reduces the retransmission wait for acquiring information from a broadcast signal, and furthermore, a time lag due to a channel selection process irrespective of broadcast operation contents and contents. It is an object of the present invention to provide a digital broadcast receiving apparatus capable of reducing the number of digital broadcasts.
[0012]
[Means for Solving the Problems]
A digital broadcast receiving apparatus according to the present invention is a digital broadcast receiving apparatus configured to receive a digital broadcast signal configured by multiplexing a packet including at least one or more channel specification information and a packet including a video stream and an audio stream. A broadcast receiving apparatus, comprising: extracting and registering a packet identification number of a packet including the desired channel specification information of the digital broadcast signal; and a packet including information necessary for channel selection using the packet identification number. Packet separation means for separating the packet identification number of the packet to be separated, when the packet identification number is not registered by the packet separation means, the packet identification number The packet containing the information necessary for channel selection using A stream cache memory for temporarily storing each packet identification number, and controlling writing and reading of a packet including the necessary information to and from the stream cache memory according to the identification number. Stream cache control means for transferring to a section filter and an A / V decoder as processing means; and a bit stream of desired channel specification information from a packet containing information necessary for channel selection to be transferred by the stream cache control means. And a section filter that separates the channel specification information, and an A / A that decodes the video or audio bit stream into a baseband video signal or audio signal according to the channel specification information and the information required for the channel selection. V decoder Characterized by comprising a.
[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 a packet identification number of a digital broadcast signal packet.
[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 the packet indicating the start of the stream. , A plurality of packets are stored.
[0015]
The digital broadcast receiving apparatus according to the present invention analyzes the packet stored in the stream cache memory before performing the processing of the section filter and the A / V decoder, and acquires only the information necessary for channel selection. It is characterized by having a packet type determining means for determining the type of a packet in this way and restricting an appropriate memory capacity.
[0016]
In the digital broadcast receiving apparatus according to the present invention, after the packet type determination unit determines the type of the packet stored in the stream cache memory, the individual information in the packet is analyzed, and the audio frequency or the video and audio The information is acquired in advance.
[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 selection is processed simultaneously and in parallel, thereby performing the sequential processing by the conventional channel selection method. It is an object of the present invention to solve the above-mentioned problem by providing a digital broadcast receiving apparatus in which the waiting time for receiving a digital broadcast signal is reduced.
[0018]
BEST MODE FOR CARRYING OUT 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 receiving apparatus according to the first embodiment of the present invention includes a tuner and demodulation unit 100, a packet separation unit 101, a stream cache control unit 102, a stream cache memory 107, a section filter 104, an A / V It comprises a decoder 105 and one or more DMACs 103 and 106.
[0021]
The tuner and demodulation unit 100 demodulates an analog broadcast signal transmitted by an analog modulated wave such as QPSK (Quadrature Phase Keying) or VSB (Vestial Side Band) into a digital broadcast signal multiplexed in the form of a transport stream. I do.
[0022]
The demodulated digital signal is multiplexed and transmitted in the form of a transport stream. Further, this 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 a header portion of the packet. I do. Thereby, the attribute of the packet can be specified. Further, PSI such as PAT and PMT, SI, and the like have a data structure called a section, and are stored in a payload portion of a transport packet.
[0023]
The demodulated digital signal is sent to packet separation means (hereinafter referred to as a PID filter) 101 which is the next stage. The PID filter 101 registers, from the transport packets included in the digital broadcast signal demodulated by the tuner and the demodulation unit 100, the PID indicating a transport packet including information necessary for selecting a digital broadcast, and registers the digital broadcast signal. , A 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 a transport packet including section-structured data (PSI, SI, etc.) from among the transport packets extracted by the PID filter 101, and, for example, analyzes a program specification such as PAT or PMT from the transport packet. Information and section information of program sequence information such as EIT are extracted.
[0025]
The AV decoder 105 receives a transport packet including a video and audio elementary stream from among the transport packets selected by the stream cache control unit 102 described later, and decodes the transport packet into a baseband video signal or audio signal. The video and audio transport packets are specified by the above-described program specification information, and the transport packets (or PES or ES included therein) are decoded by the AV decoder 105. As described above, the user can select one desired program 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. The 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, by one or a plurality of instructions by a control means (not shown in FIG. 1) including a CPU. Transport packets of video and audio streams related to the program are selectively 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. I do. When writing the transport packet group that has passed through the packet separating means 101 to the stream cache memory 107, the stream cache control means 102 writes the transport packet group into the address area divided for each PID (see FIG. 3). )Control.
[0028]
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 in accordance with a read operation described later. Then, the transport packet group is sent to the A / V decoder 105 and the section filter 104 to separate program identification information such as PAT, audio reception information, and the like.
[0029]
Each bit stream of the transport packet group divided according to the type of the content of the transport packet transmitted by the stream cache control means 102 is transmitted via one or a plurality of stream transfer means (referred to as DMAC) 103 and 106. , Section filter 104 and A / V decoder 105.
[0030]
Next, operations of the stream cache control means 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 a transport packet, and a 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 containing information that is not influenced by time series such as PSI information, a video format, a required buffer size, a scanning method, and an 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 stores the channel selection information desired by the user. This is performed in advance to obtain from the packet.
[0033]
A control operation performed by the stream cache control means 102 on a group of packets stored in the stream cache memory 107 will now be described.
[0034]
In the conventional tuning process, the PID related to the tuning channel is registered in the PID filter 101 in advance. As a result, 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, a PID that is not related to the selected channel, that is, a TS packet of a PID that is not registered in the PID filter 101 is discarded without being obtained.
[0035]
In the present invention, the transport packet group of the PID which is not registered in the PID filter and discarded in the conventional channel selection processing is 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 continuously 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 unit 102. Then, the signal is output to the section filter 104 and the A / V decoder 105 only once by sewing the gap of the signal of the transport packet output from the packet separating means 101. Thereafter, the PID filter is extracted from the PID filter as soon as the transport packet of the PID arrives in the broadcast signal. Therefore, the stream cache control unit 102 stores the transport packet of the PID in 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 the transport packets not selected by the PID filter 101, that is, transport packets having a PID not registered in the PID filter 101, in the stream cache memory 107.
[0038]
The condition of the transport packet stored in the stream cache memory 107 is that the transport packet has a PID that is not registered in the PID filter 101 and that the transport packet is not a PID transport packet indicating stuffing. Further, even if the above conditions are met, a flag (Unit_Start_Indicator in the TS packet header) indicating the start of a unit indicating the head of section data or the head of a PES (Packetized Elementary Stream) in the packet stream having the same PID is true ( This is a packet of the size of the memory area allocated to the PID of the stream cache memory 107 after the arrival of the packet “1”). Note that subsequent packets are not information packets necessary for tuning, and are not stored in the stream cache memory 107.
[0039]
As described above, when a packet that satisfies 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 to each PID of the stream cache memory 107, and The data is transferred to the stream cache memory 107 and stored.
[0040]
For the section information handled by the section filter 104, at least a stream cache memory 107 having a capacity to accommodate a program association table (PAT) and a program map table (PMT) is required.
[0041]
Here, the PAT specifies a PID of a transport packet transmitting the PMT. In the PMT selected from the PIDs of the PMTs registered in the PAT, the PID of a transport packet transmitting each encoded signal constituting the program, for example, the PID of a video signal and the PID of an audio signal are described. . Therefore, by acquiring PAT and PMT, it is possible to acquire PID information necessary for tuning.
[0042]
As described above, when a packet is extracted from a digital broadcast signal, packet information necessary for channel selection can be obtained from the stream cache memory 107 in advance, so that the channel selection time can be reduced. .
[0043]
Next, a second embodiment of the present invention utilizing the features of the stream cache memory 107 will be described with reference to FIG. The same components as those of the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.
[0044]
FIG. 2 is a block diagram showing a digital broadcast receiving device according to a second embodiment of the present invention. The second embodiment according to the present invention is obtained by adding a stream type analysis determining unit 208 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 preserved.
[0046]
Therefore, after analyzing the contents of the packet stored in the stream cache memory 107, there is provided a stream type analysis determining means 208 for determining whether the transport packet is section 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 efficiency of the tuning time process is improved, and the tuning time is further reduced.
[0047]
Hereinafter, a specific operation of the stream type analysis determination unit 208 will be described.
[0048]
FIG. 4 is a diagram showing an example of a case where packet information necessary for tuning in the present invention is obtained.
[0049]
The stream type analysis determination unit 208 analyzes the bit arrangement pattern in the packet stored in the stream cache memory 107, and determines whether it is a PMT of section data, other SI information, a PES format of a video stream, for example. The transport packet input to the stream cache memory 207, which is a part for determining whether the data is the data of the audio stream or the data of the PES format of the audio stream, is the PMT of the section data or the PES format of the video stream, the audio stream. In the case of the PES format, the stream type analysis determination means 208 stores the identified stream type and the storage of the packet in the stream cache memory 207 as the PID attribute of the packet, as shown in FIG. Cormorant.
[0050]
If the packet has a format other than the above, it is not stored in the stream cache memory 107. Thus, the 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 the section data is acquired and the channel selection processing time can be reduced will be described with reference to FIG.
[0052]
The stream type analysis determining unit 208 determines the contents of the packet stored in the stream cache memory 107 based on the type of the stream described above, so that, for example, when the section data is a PMT, 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 obtained in advance. That is, as shown in FIG. 4, when the PAT is acquired, the PMT is already stored in the stream cache memory 107, so that the PMT can be immediately transferred to the section filter 104. On the other hand, since the PID of the Audio / Video stream can be obtained in advance, the stream type analysis determination unit 208 may start analyzing the bit arrangement pattern in the packet stored in the stream cache memory 107. it can. Therefore, in the channel selection processing, it is possible to further reduce the channel selection processing delay time.
[0053]
In addition, since the TS packet of the Audio / Video stream can be obtained in advance, the format information of the video and the frequency information of the audio can be extracted from the stream cache memory 207, and the setting process of the back-end system can be performed in advance. This makes it possible to further reduce the tuning 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 obtained in advance, so that the channel selection time can be reduced.
[0055]
Further, according to the present invention, since it does not depend on the experience information at the time of the past channel selection or the example of the broadcast specification, it can be used for various digital broadcasts.
[Brief description of the drawings]
FIG. 1 is a block diagram illustrating a digital broadcast receiving device according to a first embodiment of the present invention.
FIG. 2 is a block diagram illustrating a digital broadcast receiving device according to a second embodiment of the present invention.
FIG. 3 is a diagram illustrating a memory configuration of a stream cache memory 107;
FIG. 4 is a diagram showing an example of a case where packet information necessary for tuning in the present invention is obtained.
FIG. 5 is a diagram showing an example of a case where packet information necessary for channel selection in the related art is obtained.
[Explanation of symbols]
Reference Signs List 100 Tuner and demodulation unit 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 (5)

A digital broadcast receiving apparatus for receiving a digital broadcast signal configured by multiplexing a packet including at least one or more channel specification information and a packet including a video stream and an audio stream,
Extracting a packet identification number of a packet including the channel specification information, registering the packet, and separating the packet including information necessary for channel selection using the packet identification number;
As a result of performing the packet separation operation of the packet by the packet separation unit, if the packet identification number is not registered in the packet separation unit, the packet including information necessary for channel selection is temporarily stored for each packet identification number. A stream cache memory for temporarily storing
According to the packet identification number, writing and reading of a packet including information necessary for the channel selection is controlled in the stream cache memory, and the read packet is transmitted to a section filter and an A / V decoder as post-processing means. Stream cache control means for transferring;
A section filter that selects a desired bit stream of the channel specification information from a packet including information necessary for the channel selection transferred from the stream cache control unit, and separates the channel specification information;
An A / V decoder that decodes the video or audio bit stream into a baseband video signal or audio signal according to the channel specification information and information necessary for the channel selection;
A digital broadcast receiving device comprising: 2. The digital broadcast receiving device according to claim 1, wherein the stream cache memory has a memory configuration divided by a packet identification number of the digital broadcast signal packet. The stream cache memory has a size enough to store at least the packet indicated by the packet identification number, and a plurality of packets are stored, with a header indicating the start of the header information of the stored packet at the beginning. The digital broadcast receiving apparatus according to claim 1 or 2, wherein Before the packet stored in the stream cache memory is processed by the section filter or the A / V decoder, the contents of the packet are analyzed to determine information necessary for channel selection, and information necessary for channel selection is determined. 4. The digital broadcast receiving apparatus according to claim 1, further comprising a packet type determination unit configured to store only the packet having the digital broadcast. Further, the packet type determination means determines the type of the packet stored in the stream cache memory, analyzes individual information in the packet, and determines header information of a video stream or an audio stream indicating video or audio specifications. 5. The digital broadcast receiving apparatus according to claim 4, wherein the digital broadcast is acquired in advance.

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