JP2009218873A - Digital broadcasting receiver, and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a digital broadcasting receiver capable of switching a channel faster than before even when an encode format is different before and after switching the channel, more specifically, capable of reducing the time since instruction of selecting a station, such as switching a channel, is indicated until a program is reproduced. <P>SOLUTION: The digital broadcasting receiver stores the encode format (stream_type) of the channel which has been selected in the past, and loads a decoder based on the stored stream_type when the channel is selected. Before the stream_type is obtained by analyzing PMT, the stream_type can be obtained. Therefore, the time since the instruction of selecting the station is received until the load of the decoder is finished is reduced, and thus, speeding up switching of the channel. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a digital broadcast receiver, and more particularly to shortening the time from when a channel selection instruction such as channel switching is given until a program is reproduced.

  Conventionally, the term digital broadcasting has been widely used, but there are several forms of digital broadcasting.

  Typical digital broadcasts include terrestrial digital broadcasts, but there is also a broadcast form called IPTV that broadcasts (distributes) programs using an IP network. Further, some IPTV broadcasts a program unilaterally, and some broadcast stations distribute a desired program in response to a viewer's request (generally called VOD).

  Now, it is known that such digital broadcasting requires time for channel switching. The reason for this is that when the channel of digital broadcasting is switched, the program data of the channel after switching is buffered, or channel selection information such as PAT (Program Association Table) and PMT (Program Map Table) is broadcast from the received packet. This is because it is necessary to obtain from a stream and decode predetermined video data therefrom.

  In particular, in IPTV, MPEG-4 AVC (Advanced Video Coding) /H.264 is used in addition to the MPEG-2 (Motion Picture Coding Experts Group 2) encoding format widely used for terrestrial digital broadcasting and the like for video data. H.264 encoding format is also used, and these are mixed in channel units.

  Here, the PAT and PMT will be described. First, the PAT is a packet describing what program (program) is included in the broadcast stream, and the PID (Packet ID) of the PMT is listed. Has been. The PMT describes the PIDs of moving images, sounds, and other data included in a program (program). The PMT describes the encoding format (stream_type) of the video data of the program (program). After recognizing the encoding format (stream_type), the digital broadcast receiver decodes the data with a corresponding decoder.

  As described above, the conventional digital broadcast receiver can only decode data (that is, reproduce a program) with a decoder corresponding to the encoding format after recognizing the encoding format (stream_type) from the PMT.

  That is, the digital broadcast receiver that has received the channel switching instruction receives the data and recognizes the encoding format (stream_type) from the PMT. As a result, if it is different from the currently used decoder, the encoding format after channel switching ( The decoder corresponding to stream_type) is switched from the current decoder and loaded, and data decoding is started.

  Various techniques for shortening the time required for switching the channel of digital broadcasting have been proposed as disclosed in Patent Documents 1 to 3, for example.

JP 2000-13696 A JP 2003-169303 A JP 2002-290934 A

  Here, as described above, the conventional digital broadcast receiver decodes the data with the decoder corresponding to the encoding format (that is, reproduces the program) only after recognizing the encoding format (stream_type) from the PMT. I can't.

  Therefore, if the digital broadcast receiver is compatible only with a specific encoding format (for example, MPEG-2 used in terrestrial digital broadcasting, etc.), video data should always be decoded by a decoder corresponding to the encoding format. However, if the digital broadcast receiver is also compatible with decoding of multiple encoding formats (for example, MPEG-2 and MPEG-4 AVC / H.264) (decoder is variable), Data (program) playback, that is, channel switching is delayed by the time required for decoder switching.

  Therefore, according to the present invention, even when the encoding format is different before and after the channel switching, the channel switching can be performed at a higher speed than before, more specifically, after a channel selection instruction such as channel switching is given. An object of the present invention is to provide a digital broadcast receiver capable of shortening the time until a program is reproduced.

  The first digital broadcast receiver of the present invention loads a decoder corresponding to the stored encoding format when the encoding format of the selected channel is stored prior to channel selection.

  The second digital broadcast receiver of the present invention stores the encoding format of the channel selected in the past, and stores the encoding format of the selected channel in the stored encoding format. Load the corresponding decoder.

  The third digital broadcast receiver according to the present invention stores storage means for storing the encoding format of a channel selected in the past, and whether or not the encoding format of the selected channel is stored with reference to the storage means. Reference means for determining whether or not the storage unit stores an encoded format of the selected channel, and a decoder load unit that loads a decoder corresponding to the encoded format. And

  In the program of the present invention, whether or not the encoded format of the channel selected with reference to the storage means is stored in the digital broadcast receiver having the storage means for storing the encoded format of the channel selected in the past. A reference step for determining whether or not when the encoding format of the selected channel is stored in the storage means, a decoder loading step for loading a decoder corresponding to the encoding format is executed. And

  According to the present invention, even when the encoding format is different before and after channel switching, channel switching can be performed at a higher speed than before, more specifically, after there is a channel selection instruction such as channel switching. It is possible to provide a digital broadcast receiver that can shorten the time until a program is reproduced.

  The best mode for carrying out the present invention will be described below with reference to the drawings. First, briefly explaining the outline of the present embodiment, the digital broadcast receiver of the present embodiment stores the encoding format (stream_type) of the channel selected in the past (before the current channel selection), When the channel is selected, the decoder is loaded based on the stored encoding format (stream_type). This will be described in detail below.

  FIG. 1 is a block diagram of a main part of the digital broadcast receiver according to the present embodiment. Referring to FIG. 1, the digital broadcast receiver includes a control unit 10 and a storage unit 20. The control unit 10 includes a channel selection reception unit 11, a stream_type acquisition unit 12, a stream_type reference unit 13, and a decoder load unit 14.

  Next, the operation of the digital broadcast receiver according to this embodiment will be described. FIG. 2 is a flowchart for explaining the operation of the digital broadcast receiver according to the present embodiment.

  Referring to FIG. 2, when a channel switching instruction is given from the inside or the outside (in this case, switching to channel A), the channel selection receiving means 11 receives the channel selection instruction (step S1), see stream_type. The means 13 determines whether or not the stream_type corresponding to the channel A is stored in the storage unit 20 (step S2).

  If the stream_type corresponding to channel A is stored in the storage unit 20 in the process of step S2, the decode load means 14 loads the decoder corresponding to the stream_type (step S3), and the program of channel A is Played. That is, as described above, it is not necessary to obtain the stream_type from the PMT and load the decoder. Of course, when the decoder loaded in this way is different from the decoder corresponding to the actual stream_type, that is, the stream_type acquired from the PMT, it is necessary to reload the decoder corresponding to the actual stream_type. In this case, the process of step S6 described later is performed. That is, the newly acquired actual stream_type is registered in the storage unit 20.

  On the other hand, if the stream_type corresponding to channel A is not stored in the storage unit 20 in the process of step S2, the stream_type acquisition unit 12 acquires the stream_type from the PMT (step S4), and the decoder load unit 14 The corresponding decoder is loaded (step S5). The operation from step S4 to step S5 is the same as the conventional one.

  Here, at a predetermined timing, the stream_type acquisition unit 12 stores the stream_type of the channel A acquired in step S4 in the storage unit 20 in association with the channel A (step S6). The process of step S6 may always overwrite the stream_type of channel A registered in the storage unit 20, or may determine whether or not there is a change and update it only when there is a change. .

  In the above-described embodiment, if the stream_type corresponding to channel A is not stored in the storage unit 20 in step S2, the stream_type of the same carrier as channel A is stored in the storage unit 20. A decoder corresponding to this stream_type may be loaded.

  As described above, according to the present embodiment, the stream_type can be acquired before analyzing the PMT and acquiring the stream_type. The time until is finished is shortened. That is, channel switching speed can be increased.

1 is a block diagram of a digital broadcast receiver according to an embodiment of the present invention. It is a flowchart for demonstrating operation | movement of this Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Control part 11 Channel selection reception means 12 Stream_type acquisition means 13 Stream_type reference means 14 Decoder load means 20 Memory | storage part

Claims (7)

  A digital broadcast receiver that loads a decoder corresponding to a stored encoding format when the encoding format of the selected channel is stored prior to channel selection.   A digital broadcast receiver that stores an encoding format of a channel selected in the past and loads a decoder corresponding to the stored encoding format when the encoding format of the selected channel is stored. Storage means for storing the encoding format of the channel selected in the past;
Referring to the storage means, to determine whether or not the encoded format of the selected channel is stored;
A digital broadcast receiver comprising: a decoder loading unit that loads a decoder corresponding to the encoding format when the encoding format of the selected channel is stored in the storage unit.   4. The digital broadcast receiver according to claim 3, further comprising acquisition means for acquiring an encoding format from the stream of the selected channel.   5. The digital broadcast receiver according to claim 4, further comprising registration means for registering the encoding method acquired by the acquisition means in the storage means in association with a channel.   6. The digital broadcast receiver according to claim 4, wherein the encoding format is stream_type described in a PMT (Program Map Table) included in the stream. In a digital broadcast receiver having storage means for storing the encoding format of a channel selected in the past,
A step of referring to the storage means to determine whether or not the encoded format of the selected channel is stored;
A program that, when the encoding format of the selected channel is stored in the storage means, executes a decoder loading step of loading a decoder corresponding to the encoding format.

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