JP2008011404A - Content processing apparatus and method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To facilitate a smooth fast-forwarding reproduction by decoding an MPEG2-TS, in which a video PES (Packetized Elementary Stream) composed of a plurality of frames encoded by the H.264 system is inserted. <P>SOLUTION: This content processing apparatus 1 is provided withs a tuner 3 and a TS packet PES converting section 5. The tuner 3 receives the MPEG2-TS, in which the video PES composed of the plurality of frames is inserted. The TS packet PES converting section 5 divides the video PES in the MPEG2-TS into a first divided video PES including only an IDR (Instantaneous Decoding Refresh) picture and a second divided video PES including a non-IDR picture and inserts an adaptation field and stuffing to the first and second divided video PESs. In fast-forwarding reproduction, the TS packet including the first divided video PES is extracted by a TS extraction section 9 and then decoded. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a content processing apparatus and a content processing method for processing content such as a transport stream compressed and encoded for transmission of digital broadcasting.

  The video encoding method in digital broadcasting is defined by the ARIB standard (ARIB STD-B32). For example, a PES (Packetized Elementary Stream) of video data encoded by the MPEG2 system is composed of video data for one frame.

In the case of normal reproduction of data encoded in MPEG2, the video decoder performs decoding in units of PES, and outputs video data based on time information indicated in the PTS (Presentation Time Stamp) described at the top of the PES. To do. On the other hand, in the case of fast-forward playback, the video decoder extracts and decodes PES including a video frame called an I picture to realize fast-forward playback of video data (see, for example, Patent Document 1).
Japanese Patent Laid-Open No. 2005-192013

  By the way, in recent mobile broadcasting and one-segment broadcasting (one-segment broadcasting), H.264 is used as a video encoding method. H.264 (MPEG4-AVC) is employed. H. H.264 has higher compression performance than MPEG2, and it is allowed to insert a plurality of video frames into one video PES in order to increase the compression efficiency in the case of PES. Here, H. When fast-forward reproduction is performed based on H.264 encoded data, it is necessary to extract and display a PES including an IDR (Instantaneous Decoding Refresh) picture corresponding to the I picture described above.

  However, when a plurality of frames including an IDR picture are inserted in a single PES, other frames other than the IDR picture are also decoded together. As a result, a display image is intermittently output. Smooth fast-forward playback will not be realized.

  Therefore, in order to avoid such a situation, it is necessary to perform processing for displaying only IDR pictures from a plurality of frames in a single PES. In this case, a function for decoding only IDR pictures is provided as a video decoder. Or an additional process at the later stage of the video decoder is required to extract and display only the IDR picture from the output of the video decoder.

  The present invention has been made to solve the above-described problem, and provides a content processing apparatus and a content processing method capable of easily realizing smooth fast-forward playback of content in which video packets composed of a plurality of frames are inserted. With the goal.

  In order to achieve the above object, the content processing apparatus of the present invention inserts a video packet having a first picture obtained by intraframe coding and a second picture obtained by interframe coding. A content acquisition unit that acquires content; and a video packet in the content acquired by the content acquisition unit includes a first divided video packet having the first picture and a second picture A packet dividing unit that divides into divided video packets; and a packet adjustment unit that inserts an adaptation field and stuffing into the first and second divided video packets divided by the packet dividing unit. And

  In the present invention, a first divided video packet substantially including only the first picture can be extracted from a video packet including a plurality of frames including a first picture that is intra-frame encoded. Therefore, according to the present invention, for example, the first obtained by dividing the video packet without adding special data processing for fast-forward playback after the video decoder or expanding the function of the video decoder itself. By decoding the divided video packets, smooth fast-forward playback can be realized.

  In addition, the content processing method according to the present invention obtains content in which a video packet having a first picture obtained by intraframe coding and a second picture obtained by interframe coding is inserted. And acquiring the video packet in the content acquired in the content acquisition step into a first divided video packet having the first picture and a second divided video packet including the second picture. A packet dividing step for dividing, and a packet adjusting step for inserting an adaptation field and stuffing into the first and second divided video packets divided in the packet dividing step.

  As described above, according to the present invention, it is possible to provide a content processing apparatus and a content processing method capable of easily realizing smooth fast-forward playback of content in which video packets including a plurality of frames are inserted.

The best mode for carrying out the present invention will be described below with reference to the drawings.
(First embodiment)
FIG. 1 is a block diagram functionally showing the configuration of the content processing apparatus according to the first embodiment of the present invention.

  As shown in the figure, a content processing apparatus 1 according to the present embodiment is a digital broadcast recording / reproducing apparatus that records and reproduces content encoded for transmission of digital broadcast. That is, the content processing apparatus 1 includes an antenna 2, a tuner 3, an MPEG2-TS separation unit 8, a video PES storage unit 10, an audio PES storage unit 14, a video decoder 11, an audio decoder 15, a monitor 12, a speaker 16, and recording / reproduction control. Unit 7, TS packet PES conversion unit 5, TS recording unit 6, TS extraction unit 9, and switches 17, 18, and 19.

  The tuner 3 functions as a content acquisition unit that acquires MPEG2-TS (MPEG2-Transport Stream), which will be described in detail later. In the case of reception and reproduction, the broadcast wave received via the antenna 2 is converted into MPEG2-TS. Demodulate and output this to the MPEG2-TS separator 8. The MPEG2-TS separation unit 8 separates the MPEG2-TS into a video PES and an audio PES, which will be described later, and stores the separated PESs in the video PES storage unit 10 and the audio PES storage unit 14, respectively.

  The video decoder 11 and the audio decoder 15 perform decoding processing in units of PES. The video decoder 11 decodes the video PES and the audio PES input from the video PES storage unit 10 and the audio PES storage unit 14 side, respectively. The audio data is output to the monitor 12 and the speaker 16, respectively.

  Here, the structure of MPEG2-TS obtained by the above-described tuner 3 demodulating a broadcast wave will be described with reference to FIGS. 2 is a diagram showing the structure of the MPEG2-TS 20 as digital content, and FIG. 3 is a diagram showing the structure of the TS header 21 of the MPEG2-TS 20 in FIG. FIG. 4 is a diagram showing in detail the structure of the PESs 24 and 26 inserted into the MPEG2-TS 20 of FIG.

  As shown in FIG. 2, MPEG2-TS20 is a digital content adopted in mobile broadcasting and one-segment broadcasting (one-segment broadcasting), and is H.264 that conforms to the ARIB standard. This is a transport stream obtained by packetizing elementary streams (ES: Elementary Stream) compressed and encoded by the H.264 (MPEG4-AVC) system for transmission. MPEG2-TS 20 is composed of a packet sequence of 188 bytes per packet, and video PES (Packetized Elementary Stream) 24 and PES 26 each having PES headers 25 and 27 are divided and stored. A payload 22 and an audio payload 23, and a TS header 21 are included.

  As shown in FIG. 3, the TS header 21 includes a synchronization byte 31, a PID (Packet Identifier) 32, an adaptation field control 33, an adaptation field 34, and the like. The synchronization byte 31 is information for synchronizing the packet, functions as a seek 8-bit marker indicating the head of the TS header 21, and its value is indicated by “0x47”. That is, in MPEG2-TS 20, since one packet has a fixed length of 188 bytes, “0x47” appears every 188 bytes.

  The PID 32 is a packet identifier indicating the type of packet, and the video PES 24 and the audio PES 26 have different PID values that are uniquely determined. In other words, MPEG2-TS20 converts video PES24 and audio PES26 into TS packets and multiplexes them in the TS layer (hierarchy), but each PES can be identified by PID in the TS packet layer. PES can be demultiplexed by checking the PID. Here, the PID value “0x1FFF” means a null packet (Null Packet) that does not transmit valid data, and stuffing of the packet (a byte with no content added to keep the packet data constant) is inserted. Used when.

  The adaptation field control 33 is a 2-bit flag and indicates whether or not the adaptation field 34 follows the 4-byte (fixed length) TS header 21. That is, the flag “01” indicates that only a payload exists without an adaptation field, and “10” indicates that there is only an adaptation field and no payload. “11” indicates that there is a payload following the adaptation field, and “00” indicates reserve (reservation). In the present embodiment, the mode corresponding to the flag value “11” is exemplified.

  Here, a stuffing byte is mentioned as an important component of the adaptation field 34. The stuffing byte uses the value “0xFF” and is used when it is necessary to adjust the length of data following the adaptation field.

  Specifically, the adaptation field 34 is composed of an adaptation field length 33, a PCR (Program Clock Rreference) 37, a PCR flag 36, and the like. The PCR flag 36 indicates that a PCR value is included in a TS packet of MPEG2-TS20. PCR 37 is a program time reference value and indicates the current time of the clock counting at 27 MHz. That is, the MPEG2-TS 20 has a function of synchronizing the clock on the receiver side with the clock on the transmission side by using the PCR 37.

  As shown in FIG. 4, the PES (video PES / audio PES) 24 and 26 are composed of the above-described PES headers 25 and 27 and an ES main body called a PES packet data byte 43, In the case of TS packetization, packetization is performed so that the first byte of the PES becomes the first byte of the payload of the TS packet.

  The PES headers 25 and 27 are a packet start code prefix 38, a stream ID 39, a PES packet length 40, a PTS DTS flag 41, and a PTS (Presentation Time). Stamp) 42.

  The packet start code prefix 38 indicates the first 24 bits of the packet start code, and is a start code indicating the start of the PESs 24 and 26 with 32 bits combined with the stream ID 39. The stream ID 39 is an identifier of data of the PESs 24 and 26. The PES packet length 40 indicates the data length (PES packet size) from this field to the final position of the PES packet. The PTS 42 is a value of presentation time information for synchronization, and is time data indicating a start time for decoding and displaying ES and a start time for decoding and outputting ES as sound.

  The PTS DTS flag 41 is a 2-bit flag indicating the presence of fields of PTS and DTS (Decoding Time Stamp: Decoding Time Stamp). The value “10” indicates the presence of only PTS, and the value “11” indicates the PTS. And DTS are present. That is, when the value of the PTS DTS flag 41 indicates the presence of PTS as in “10” above, the PTS field is present in the PES header.

  Next, functions for realizing smooth fast-forward playback provided in the content processing apparatus 1 of the present embodiment will be described based on FIGS. 5 to 9 in addition to FIGS. 1 to 4 described above. Here, FIG. 5 is a diagram schematically showing the structure of the video PESs 45 and 48 having the PES headers 46 and 49 made up of a single frame exemplified for comparison with the video PES made up of a plurality of frames. FIG. 6 is a diagram schematically showing the structure of the video PES 51 including a plurality of frames included in the MPEG2-TS of FIG. FIG. 7 is a diagram showing the structure of the first and second divided images PES 57 and 58 obtained by dividing the image PES 51 composed of a plurality of frames in FIG. 5, and FIG. It is a figure for demonstrating the division process to the 1st and 2nd division | segmentation image | video PES57,58, and the adjustment process with respect to each divided | segmented PES. Further, FIG. 9 is a flowchart showing the dividing process and the adjusting process of FIG.

  That is, the above-described TS packet PES conversion unit 5, TS recording unit 6, TS extraction unit 9, switches 17, 18, and 19 of the content processing apparatus 1 and the recording / playback control unit 7 that controls each unit in the apparatus main body. Has the following functions. The recording / playback control unit 7 receives an input instruction from a user via a predetermined input interface (not shown), that is, a playback request for received data, a recording request, a normal playback request for recorded data, and a fast-forward playback of recorded data. When the request is received, the operation mode of the main body of the content processing apparatus 1 is switched to the reception playback mode, the recording mode, the normal playback mode, and the fast forward playback mode.

  The recording / playback control unit 7 controls the switch 17 to connect the tuner 3 and the MPEG2-TS separation unit 8 in the reception / playback mode, and controls the switch 19 to control the tuner 3 and the TS packet PES in the recording mode. The conversion unit 5 is connected. In the normal playback mode, the switches 17 and 18 are controlled to connect the TS recording unit 6 and the MPEG2-TS separation unit 8, and in the fast-forward playback mode, the switches 17 and 18 are controlled to extract the TS. The unit 9 and the MPEG2-TS separation unit 8 are connected.

  Here, as shown in FIGS. Video data encoded by the H.264 system includes IDR pictures (Instantaneous Decoding Refresh pictures) 47 and 53 and non-IDR pictures 50, 54 and 55. The IDR pictures 47 and 53 use only data obtained by intraframe encoding corresponding to an MPEG-2 I picture defined by ISO / IEC 13818-2, that is, only a video frame (original screen) to be encoded. It is the 1st picture encoded in this way. On the other hand, the nonIDR pictures 50, 54, and 55 are second pictures obtained by interframe coding using a frame before or after the target frame in addition to the video frame to be encoded. Therefore, although the IDR pictures 47 and 53 can be decoded with the information of itself, the nonIDR pictures 50, 54, and 55 can be decoded only with reference to the IDR picture in addition to the information of itself.

  H. In H.264, since it is allowed to insert a plurality of video frames into one video PES in order to increase the compression efficiency when converting ES into PES, the video PES inserted into MPEG2-TS 20 is, for example, FIG. (In the example of FIG. 6, a single PES has three frames). Therefore, when the video PES 51 including the IDR picture 53 is simply decoded for the purpose of fast-forward playback, the non-IDR pictures 54 and 55 following the IDR picture 53 are also decoded together, so that smooth fast-forward playback is performed. Becomes difficult.

  Therefore, in the recording mode, the TS packet PES converter 5 converts the video PES 51 in MPEG2-TS 20 demodulated by the tuner 3 into the first divided video PES 57 having only the IDR picture 53 in the TS packet layer. It divides | segments into the 2nd division video PES58 containing the nonIDR pictures 54 and 55, and an adaptation field and stuffing are inserted with respect to the divided | segmented 1st and 2nd division | segmentation video PES57 and 58. FIG.

  That is, as shown in FIGS. 8 and 9, first, when the tuner 3 demodulates the broadcast wave received via the antenna 2 as MPEG2-TS (S1), the TS packet PES conversion unit 5 performs the IDR picture 53 and the nonIDR. A packet that is a break between the pictures 54 and 55 (nonIDR picture 54 in the example of FIG. 3) is searched (S2). When the boundary packet is detected (S3), the TS packet PES conversion unit 5 uses the boundary packet as a reference to display the video PES 51 as the first including the tail of the IDR picture (IDR picture 53 in the example of FIG. 3). Divided video packets (first divided video PES57 consisting of a single frame having only IDR pictures) and second divided video packets (second divided video PES58) including the first nonIDR picture 54 ( S4).

  Further, the TS packet PES conversion unit 5 adds an adaptation field to the first divided video PES 57 and inserts stuffing so that the end of the packet ends at the end of the IDR picture (embeds the stuffing byte “0xFF”). ). Further, the TS packet PES conversion unit 5 positions the non-IDR pictures of the non-divided video PES 51 in the positions of the non-IDR pictures 54 and 55 after the insertion of the PES header (PES header 1) 56 for the second divided video PES 58. An adaptation field and stuffing are inserted so as to be the same as the positions on the packets 54 and 55 (S5).

  Since the IDR picture must be arranged at the head of the PES, in order to generate the first divided video PES 57 having the IDR picture as a single frame, the PES header (PES header 56) is added at the end of the IDR picture. It would be good to add. It is necessary to correctly set the PTS value shown in FIG. 7 in the PES header to be added (PES header 56). That is, in FIG. 7, the relationship between the PTS in the PES header 52 of the first divided video PES 57 and the PTS (PTS1) in the PES header 56 of the second divided video PES 58 is given by the following equation 1.

  PTS1 = time of PTS + one frame of video (IDR picture 53)

  Therefore, the TS packet PES conversion unit 5 sets the value of PTS (PTS1) in the PES header 56 of the second divided video PES 58 so as to satisfy the above formula 1.

  The TS recording unit 6 has a rewritable storage medium such as a hard disk or a DVD, for example, and the first and second divided images PES 57 and 58 into which the adaptation field and the stuffing are inserted as described above are inserted. Stored TS packets. Further, the TS extraction unit 9 extracts only TS packets including the first divided video PES 57 from the TS recording unit 6 in which such TS packets are stored.

  Therefore, in the fast-forward playback mode, the recording / playback control unit 7 extracts only the TS packet including the first divided video PES57 consisting of a single frame through the TS extraction unit 9, and extracts the extracted data from the MPEG2-TS separation unit. 8 and the video PES storage unit 10 are decoded by a video decoder (decoder that performs decoding processing in units of PES) 11, and a fast-forward image is displayed and output on the monitor 12. On the other hand, in the normal playback mode, the recording / playback control unit 7 extracts both the first and second divided video PESs 57 and 58, and outputs the video decoder 11 via the MPEG2-TS separation unit 8 and the video PES storage unit 10. And the normal reproduction image is displayed and output on the monitor 12.

  Here, when the video PES 51 is divided, as shown in FIG. 8, the end of the first divided video PES 57 ends with the IDR picture 53 and the non-IDR pictures 54 and 55 on the packet (PES) before and after the division. Since the adjustment process of the packet in which the adaptation field and the stuffing are inserted is performed so that the positions of the first and second video PESs 57 are not provided with a special function. , 58 can be reproduced normally.

  As described above, according to the content processing apparatus 1 according to the present embodiment, the first divided video PES57 having only the IDR picture is obtained from the video PES51 including a plurality of frames including the IDR picture encoded in the frame. The included TS packet can be extracted. Therefore, according to the content processing apparatus 1, for example, the video PES 51 is obtained by dividing the video PES 51 without adding special data processing for fast-forward playback after the video decoder or expanding the function of the video decoder itself. By decoding the first divided video PES 57, smooth fast-forward playback can be realized.

(Second Embodiment)
Next, a second embodiment of the present invention will be described with reference to FIG. Here, FIG. 10 is a block diagram functionally showing the configuration of the content processing apparatus 70 according to this embodiment. In FIG. 10, the same constituent elements as those provided in the content processing apparatus 1 of the first embodiment shown in FIG.

  As shown in FIG. 10, the content processing device 70 of this embodiment includes a recording / playback control unit 73 instead of the recording / playback control unit 7 provided in the content processing device 1 of the first embodiment. A switch 76 is added. Further, in the content processing device 70, the arrangement relationship of the preceding stage and the succeeding stage of the TS packet PES conversion unit 5 and the TS recording unit 6 is arranged in reverse with respect to the content processing apparatus 1.

  That is, in the content processing apparatus 70 of this embodiment, in the recording mode, the recording / playback control unit 73 controls the switch 76 so that the TS recording unit 6 and the TS packet PES conversion unit 5 are not connected, and FIG. The MPEG2-TS in which the undivided video PES 51 including the plurality of frames shown is inserted is recorded in the TS recording unit 6 as it is. On the other hand, in the fast-forward playback mode, the recording / playback control unit 73 controls the switch 76 so that the TS recording unit 6 and the TS packet PES conversion unit 5 are connected, and the video PES 51 is illustrated in FIGS. 7 and 8. As described above, the TS packet PES conversion unit 5 divides the first video PES 57 and the second video PES 58 and extracts the TS packet including the divided first video PES 57 through the TS extraction unit 9.

  Therefore, the content processing apparatus 70 according to this embodiment is configured to divide the video PES 51 composed of a plurality of frames only when a fast-forward playback request is received. Efficiency can be improved. Also in the content processing device 70 of this embodiment, smooth fast-forward playback can be easily realized without expanding the function of the video decoder.

  The present invention has been specifically described above with reference to the embodiments. However, the present invention is not limited to these embodiments, and various modifications can be made without departing from the scope of the invention. In the content processing apparatuses according to the first and second embodiments described above, the specific type as the electric device is not illustrated, but the present invention is a mobile phone capable of receiving, for example, one-segment broadcasting or mobile broadcasting. This is useful when applied to mobile terminals such as mobile phones and in-vehicle receivers. In the above-described embodiment, the recording / reproducing apparatus having both the function of storing the received content and the function of reproducing the stored content has been exemplified. However, instead of this, for example, the content can be stored. The present invention may be applied to a read-only device that supports reading of a portable storage medium and does not have an external storage device (and / or tuner) such as an HDD.

The block diagram which shows functionally the structure of the content processing apparatus which concerns on the 2nd Embodiment of this invention. The figure which shows the structure of MPEG2-TS which the content processing apparatus of FIG. 1 receives. The figure which shows the structure of TS header of MPEG2-TS of FIG. The figure which shows the structure of PES inserted in MPEG2-TS of FIG. 2 in detail. The figure which shows typically the structure of the image | video PES which consists of a single frame illustrated for the comparison with the image | video PES which consists of a some flame | frame. The figure which shows typically the structure of the video PES which consists of a some flame | frame contained in MPEG2-TS of FIG. The figure which shows the structure of the 1st and 2nd division | segmentation image | video PES obtained by dividing | segmenting the image | video PES which consists of a some flame | frame of FIG. The figure for demonstrating the division process to the 1st and 2nd division | segmentation image | video PES shown in FIG. 7, and the adjustment process with respect to each divided | segmented PES. The flowchart which shows the division | segmentation process and adjustment process of FIG. The block diagram which shows functionally the structure of the content processing apparatus which concerns on the 2nd Embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1,70 ... Content processing apparatus, 2 ... Antenna, 3 ... Tuner, 5 ... TS packet PES conversion part, 6 ... TS recording part, 7, 73 ... Recording / reproduction control part, 9 ... TS extraction part, 11 ... Video decoder, 12 ... Monitor, 20 ... MPEG2-TS, 24, 45, 48, 51 ... Video PES, 34 ... Adaptation field, 47, 53 ... IDR picture, 50, 54, 55 ... NonIDR picture, 52, 56 ... PES header, 57 ... first divided video PES, 58 ... second divided video PES.

Claims (5)

A content acquisition unit that acquires content in which a video packet having a first picture obtained by intraframe coding and a second picture obtained by interframe coding is inserted;
Packet division for dividing the video packet in the content acquired by the content acquisition unit into a first divided video packet having the first picture and a second divided video packet including the second picture And
A content processing apparatus comprising: a packet adjustment unit that inserts an adaptation field and stuffing into the first and second divided video packets divided by the packet dividing unit. A packet extraction unit for extracting the first divided video packet in which the adaptation field and the stuffing are inserted by the packet adjustment unit;
The content processing apparatus according to claim 1, further comprising a video decoding unit that decodes the first divided video packet extracted by the packet extraction unit.   The packet adjustment unit includes the adaptation field and the adaptation field and the second picture so that the end of the first divided video packet ends with the first picture and the position of the second picture is the same on the packets before and after the division. The content processing apparatus according to claim 1, wherein the stuffing is inserted.   The content is H.264. 4. The content processing apparatus according to claim 1, wherein the content processing apparatus is a transport stream obtained by packetizing an elementary stream compressed and encoded by the H.264 system for transmission. 5. A content acquisition step of acquiring content in which a video packet having a first picture obtained by intraframe coding and a second picture obtained by interframe coding is inserted;
Packet division for dividing the video packet in the content acquired in the content acquisition step into a first divided video packet having the first picture and a second divided video packet including the second picture Steps,
A content processing method comprising: a packet adjustment step of inserting an adaptation field and stuffing into the first and second divided video packets divided in the packet division step.

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