JP2010141498A - Video receiver and video transmitter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a video receiver for outputting a video signal with no time lag in decoding time without mounting a delay circuit. <P>SOLUTION: The video receiver is provided with a video DTS correction part 35 for correcting a decoding start time shown by the video DTS so that a decoding time shown by the video DTS separated by a separation part 31 of a video decoder 12 coincides with a decoding time shown by a video DTSr. A video decoding part 36 starts decoding encoded data CDATA stored in a video buffer 32 at a timing where time reference STC reproduced by an STC reproduction part 33 coincides with the decoding start time shown by the video DTS corrected by the video DTS correction part 35. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to, for example, a video transmission device that divides a large screen, encodes and transmits a video signal of the divided screen, and a video reception device that decodes the video signal of the divided screen transmitted from the video transmission device. It is.

FIG. 5 is a block diagram showing a video transmission device disclosed in Patent Document 1. In FIG.
When an image signal is input from the input terminal 101, the screen dividing circuit 102 of the video transmitting apparatus divides the image into a partial image P in the first half of the field indicated by a dotted line and a partial image Q in the second half of the field in FIG. The image data of the image P is output to the encoding circuit 103, and the image data of the partial image Q is output to the encoding circuit 104.

When receiving the image data of the partial image P from the screen dividing circuit 102, the encoding circuit 103 encodes the image data in accordance with, for example, the MPEG standard.
When receiving the image data of the partial image Q from the screen dividing circuit 102, the encoding circuit 104 encodes the image data in accordance with, for example, the MPEG standard.
In general, in encoding according to the MPEG standard, it is common to insert a time stamp into an encoded stream as time information for synchronizing decoding timing.
Also in this video transmission apparatus, in order to synchronize the two encoding circuits 103 and 104, the clock circuit 105 generates time data serving as a reference for the time stamp, and the time data is transmitted to the encoding circuits 103 and 104. I am trying to supply.

Therefore, when encoding the image data of the partial images P and Q, the encoding circuits 103 and 104 generate a time stamp from the time data supplied from the clock circuit 105, and use the time stamp as the encoded data of the image data. So that an encoded stream is generated.
When generating the encoded stream, the encoding circuits 103 and 104 record the encoded stream in the recording devices 106 and 107 and output the encoded stream to the reorganization circuit 108.

Upon receiving the encoded streams from the encoding circuits 103 and 104, the reorganization circuit 108 reorganizes the two encoded streams into one and outputs one encoded stream to the transmission device 109.
Upon receiving the encoded stream from the reorganization circuit 108, the transmission apparatus 109 transmits the encoded stream to the video reception apparatus in FIG.

FIG. 6 is a block diagram showing a video receiving device disclosed in Patent Document 1. In FIG.
The playback device 111 of the video reception device plays back the encoded stream recorded by the recording device 106 of the video transmission device of FIG.
The playback device 112 plays back the encoded stream recorded by the recording device 107 of the video transmission device in FIG.
The encoded stream reproduced by the reproducing device 111 is supplied to the decoder 113. Alternatively, the encoded stream generated by the encoding circuit 103 is separated from the encoded stream transmitted by the transmission apparatus 109, and the encoded stream is supplied.
The encoded stream reproduced by the reproduction device 112 is supplied to the decoder 114. Alternatively, the encoded stream generated by the encoding circuit 104 is separated from the encoded stream transmitted by the transmission apparatus 109, and the encoded stream is supplied.

When the decoder 113 is supplied with the encoded stream, the decoder 113 performs a decoding process on the encoded stream in synchronization with the synchronization data output from the synchronization circuit 115, and outputs decoded image data (image data of the partial image P). ) Is output to the screen composition circuit 117.
When the decoder 114 receives the encoded stream, the decoder 114 performs a decoding process on the encoded stream in synchronization with the synchronization data output from the synchronization circuit 115, and the decoded image data via the delay circuit 116. (Image data of the partial image Q) is output to the screen composition circuit 117.
By outputting the image data of the partial image Q to the screen composition circuit 117 via the delay circuit 116, the time lag of the decoding time between the decoder 113 and the decoder 114 is absorbed.

  Upon receiving the image data of the partial image P and the image data of the partial image Q, the screen composition circuit 117 synthesizes one image data from the two image data and outputs the image data to the output terminal 118.

JP 2002-125203 A (paragraph numbers [0002] to [0005], FIG. 10 and FIG. 11)

Since the conventional video transmission apparatus is configured as described above, it is necessary to mount the clock circuit 105 and supply the time data for synchronizing the decoding timing to the encoding circuits 103 and 104.
Further, in the video reception device, it is necessary to mount the delay circuit 116 in order to absorb the time lag of the decoding time between the decoder 113 and the decoder 114.
As the number of divisions increases, in the video transmission device, the number of encoding circuits to which the clock circuit 105 supplies time data increases, and in the video reception device, it becomes necessary to mount more delay circuits 116. For this reason, there is a problem that the system configuration becomes complicated and causes a cost increase.

The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a video receiving apparatus capable of outputting a video signal without a time lag of decoding time without mounting a delay circuit. To do.
Another object of the present invention is to provide a video transmission device that can be applied to the above video reception device.

  The video receiving apparatus according to the present invention provides the first decoding time stamp so that the decoding start time indicated by the first decoding time stamp separated by the separating means matches the decoding start time indicated by the second decoding time stamp. Is provided with a correcting means for correcting the decoding start time indicated by and a reproducing means for reproducing the time reference according to the time management information separated by the separating means, and the correcting means corrects the time reference reproduced by the reproducing means. The decoding of the video signal separated by the separating means is started at a timing that coincides with the decoding start time indicated by the first decoding time stamp.

  According to this invention, the decoding indicated by the first decoding time stamp so that the decoding start time indicated by the first decoding time stamp separated by the separating means matches the decoding start time indicated by the second decoding time stamp. A correction means for correcting the start time and a reproduction means for reproducing the time reference according to the time management information separated by the separation means are provided, and the time reference reproduced by the reproduction means by the reproduction means is corrected by the correction means. Since the decoding of the video signal separated by the separation means is started at a timing that coincides with the decoding start time indicated by the decoding time stamp of 1, there is no time lag of the decoding time without mounting a delay circuit. There is an effect that a video signal can be output.

Embodiment 1 FIG.
1 is a block diagram showing a video receiving apparatus according to Embodiment 1 of the present invention.
In FIG. 1, a video transmission device 1 is a device that divides a large screen represented by a video signal, encodes the video signal of each divided screen to generate an encoded stream, and transmits the encoded stream.
In the first embodiment, for simplification of description, an example in which a large screen is divided into two screens (for example, an upper half screen and a lower half screen) will be described.
In this case, the encoded stream transmitted from the video transmission device 1 includes the following data and the like. However, the following data is an example when dividing into two screens. When dividing into three or more screens, encoded data and the like for the number of divided screens are included.

In the first embodiment, the video signal of the lower half screen is decoded at the same time with reference to the video signal of the upper half screen, so the video signal of the upper half screen is required. Accordingly, it is referred to as “decoding reference video signal”, and the encoded data CDATAr of the video signal of the upper half screen is referred to as “decoding reference encoded data”.
On the other hand, the video signal of the lower half screen is referred to as “decoding target video signal” as necessary, and the encoded data CDATA of the lower half screen video signal is referred to as “decoding target encoded data”.

(1-1) Encoded data CDATAr of the video signal of the upper half screen
(1-2) Encoded data CDATA of the video signal of the lower half screen
(2-1) Decoding time stamp indicating the decoding start time of the encoded data CDATAr (second decoding time stamp: hereinafter referred to as “video DTSr”)
(2-2) Decoding time stamp indicating the decoding start time of the encoded data CDATA (first decoding time stamp: hereinafter referred to as “video DTS”)
(3-1) Time management information PCRr (Program) used for reproduction of a time reference STCr (System Time Clock) in an encoder (encoder in the video transmission apparatus 1) that encodes the video signal of the upper half screen. (Clock Reference)
(3-2) Time management information PCR used for reproduction of the time reference STC in the encoder (encoder in the video transmission apparatus 1) that encodes the video signal of the lower half screen

The transmission device 2 is a device that transmits the encoded stream transmitted from the video transmission device 1 to the video reception device 3.
The video receiving device 3 is a device that decodes the video signal of the divided screen transmitted by the transmission device 2.

The video decoder 11 of the video receiver 3 separates the encoded data CDATAAr from the encoded stream, and performs a process of decoding the upper half screen video signal (decoding reference video signal) from the encoded data CDATAAr.
The video decoder 12 separates the encoded data CDATA from the encoded stream, and performs a process of decoding the video signal of the lower half screen from the encoded data CDATA.
The screen synthesis circuit 13 synthesizes the video signal of the upper half screen and the video signal of the lower half screen decoded at the same time by the video decoders 11 and 12 and outputs the video signal of the synthesized screen to the output terminal 14. carry out.

The separation unit 21 of the video decoder 11 performs a process of separating the decoding reference encoded data CDATAr, the video DTSr, and the time management information PCRr from the encoded stream.
The video buffer 22 is a memory that temporarily stores the decoding standard encoded data CDATAr separated by the separation unit 21.
The STC reproduction unit 23 performs a process of reproducing the time reference STCr according to the time management information PCRr separated by the separation unit 21.
The video decoding unit 24 performs the processing for the encoded data CDATAr stored in the video buffer 22 at a timing at which the time reference STCr reproduced by the STC reproduction unit 23 coincides with the decoding start time indicated by the video DTSr separated by the separation unit 21. The decoding process is started, and the video signal of the upper half screen as the decoding result is output to the screen synthesis circuit 13.

The separation unit 31 of the video decoder 12 performs a process of separating the encoded data CDATA, video DTS, video DTSr, time management information PCR, and time management information PCRr to be decoded from the encoded stream.
The separating unit 31 constitutes a separating unit.
The video buffer 32 is a memory that temporarily stores the encoded data CDATA to be decoded separated by the separation unit 31.

The STC reproduction unit 33 performs processing for reproducing the time reference STC according to the time management information PCR separated by the separation unit 31.
The STC reproduction unit 34 performs processing for reproducing the time reference STCr in accordance with the time management information PCRr separated by the separation unit 31.
Note that the STC playback units 33 and 34 constitute playback means.

The video DTS correction unit 35 performs a process of correcting the decoding start time indicated by the video DTS so that the decoding start time indicated by the video DTS separated by the separation unit 31 matches the decoding start time indicated by the video DTSr. .
That is, the video DTS correction unit 35 calculates a correction value (= DTSr−DTS) that is a time difference between the decoding start time indicated by the video DTS separated by the separation unit 31 and the decoding start time indicated by the video DTSr. A process of adding the value to the decoding start time indicated by the video DTS is performed.
The video DTS correction unit 35 constitutes correction means.

The video decoding unit 36 encodes the encoded data stored in the video buffer 32 at a timing at which the time reference STC reproduced by the STC reproduction unit 33 coincides with the decoding start time indicated by the video DTS corrected by the video DTS correction unit 35. The decoding process for CDATA is started, and the video signal of the lower half screen as the decoding result is output to the screen synthesis circuit 13.
Note that the video decoding unit 36 constitutes decoding means.
FIG. 2 is an explanatory diagram showing the decoding timing in the video decoders 11 and 12 of the video receiving apparatus according to Embodiment 1 of the present invention.

Next, the operation will be described.
When the video transmission device 1 receives a video signal representing a large screen, for example, the video transmission device 1 divides the large screen into an upper half and a lower half, encodes the video signal of the upper half screen, and converts the video signal of the lower half screen to Encode.
At this time, for example, when the MPEG (Moving Picture Experts Group) -2 standard, which is an international standard for moving picture compression, is used as a video signal encoding method, each video signal decoding / playback unit (for example, one frame) is used. A decoding time stamp is added to each), and a system time clock is defined as a time reference for the decoding time stamp.

Therefore, in the video transmission apparatus 1, an encoder that encodes the video signal of the upper half screen (decoding reference video signal) encodes the video signal of the upper half screen when using the MPEG-2 standard. When the encoded data CDATAAr is generated, a video DTSr indicating the decoding start time of the encoded data CDATAAr is generated.
Further, this encoder generates time management information PCRr used for reproduction of the time reference STCr so that the video receiving device 3 can reproduce the time reference STCr of the video DTSr, and the encoded data CDATAr. Then, an encoded stream composed of the video DTSr and the time management information PCRr is generated.

In the video transmitting apparatus 1, an encoder that encodes the video signal of the lower half screen, when using the MPEG-2 standard, encodes the video signal of the lower half screen to generate encoded data CDATA. A video DTS indicating the decoding start time of the encoded data CDATA is generated.
Further, this encoder generates time management information PCR used for reproduction of the time reference STC so that the video reference apparatus 3 can reproduce the time reference STC of the video DTS, and the encoded data CDATA. Then, an encoded stream including the video DTS and the time management information PCR is generated.

When each encoder generates an encoded stream, the video transmission device 1 reorganizes the two encoded streams to generate one encoded stream.
When the video transmission device 1 generates one encoded stream, the transmission device 2 transmits the encoded stream to the video reception device 3.

When the video decoder 11 of the video reception device 3 receives the encoded stream from the transmission device 2, the video decoder 11 separates the encoded data CDATAr from the encoded stream, performs a decoding process on the encoded data CDATAAr, The screen video signal (decoding reference video signal) is output.
Hereinafter, the processing content of the video decoder 11 is demonstrated concretely.

The separation unit 21 of the video decoder 11 separates the decoding reference encoded data CDATAr, the video DTSr, and the time management information PCRr from the encoded stream, and stores the encoded data CDATAr in the video buffer 22.
In addition, the separation unit 21 outputs the video DTSr to the video decoding unit 24 and outputs the time management information PCRr to the STC reproduction unit 23.

When receiving the time management information PCRr from the separation unit 21, the STC reproduction unit 23 of the video decoder 11 reproduces the time reference STCr according to the time management information PCRr and outputs the time reference STCr to the video decoding unit 24.
As shown in FIG. 2, the video decoding unit 24 of the video decoder 11 performs video processing at a timing at which the time reference STCr reproduced by the STC reproduction unit 23 matches the decoding start time indicated by the video DTSr output from the separation unit 21. The decoding process for the encoded data CDATAr stored in the buffer 22 is started, and the video signal of the upper half screen as the decoding result is output to the screen synthesis circuit 13.
In the example of FIG. 2, the decoding process for the encoded data CDATAr is started at the timing when the time reference STCr becomes time 00:05.

When the video decoder 12 of the video reception device 3 receives the encoded stream from the transmission device 2, the video decoder 12 separates the encoded data CDATA from the encoded stream and performs a decoding process on the encoded data CDATA, Outputs the video signal of the screen.
Hereinafter, the processing content of the video decoder 12 will be specifically described.

The separation unit 31 of the video decoder 12 separates the encoded data CDATA, the video DTS, the video DTSr, the time management information PCR, and the time management information PCRr to be decoded from the encoded stream, and uses the encoded data CDATA as a video buffer 32. To store.
Further, the separation unit 31 outputs the video DTS and the video DTSr to the video DTS correction unit 35, outputs the time management information PCR to the STC reproduction unit 33, and outputs the time management information PCRr to the STC reproduction unit 34. .

In the example of FIG. 2, since there is a difference between the time references STC and STCr of the two encoders in the video transmission device 1, a difference occurs between the decoding start time indicated by the video DTS and the decoding start time indicated by the video DTSr. ing.
For this reason, if the decoding start time indicated by the video DTS is not corrected, there is a timing shift in which the video signal of the lower half screen is decoded and output earlier than the video signal of the upper half screen (decoding reference video signal). appear.

When receiving the time management information PCR from the separation unit 31, the STC reproduction unit 33 of the video decoder 12 reproduces the time reference STC according to the time management information PCR, and the time reference STC is converted into the video decoding unit 36 and the video DTS correction unit. 35.
When receiving the time management information PCRr from the separation unit 31, the STC reproduction unit 34 of the video decoder 12 reproduces the time reference STCr according to the time management information PCRr and outputs the time reference STCr to the video DTS correction unit 35.

When the video DTS correction unit 35 receives the video DTS and the video DTSr from the separation unit 31, the video DTS correction unit 35 decodes the video DTS indicated by the video DTS so that the decoding start time indicated by the video DTS matches the decoding start time indicated by the video DTSr. Correct the start time.
That is, the video DTS correction unit 35 calculates the delay amount from the decoding start time indicated by the video DTS and the arrival time ATS, and calculates the delay amount from the decoding start time indicated by the video DTSr and the arrival time ATSr. A correction value (= DTSr-DTS) is calculated from one delay amount and the arrival time difference (ATSr-ATS), and the correction value is added to the decoding start time indicated by the video DTS.
Correction value = DTSr−DTS
= ((ATSr-ATS) + (DTSr-DTS))-(DTS-ATS)

When the video decoding unit 36 receives the corrected video DTS from the video DTS correction unit 35, the time reference STC reproduced by the STC reproduction unit 33 coincides with the decoding start time indicated by the corrected video DTS, The decoding process for the encoded data CDATA stored in the video buffer 32 is started, and the video signal of the lower half screen as the decoding result is output to the screen synthesis circuit 13.
In the example of FIG. 2, the video decoding unit 36 starts the decoding process on the encoded data CDATA at the timing when the time reference STC becomes time 01:04, which coincides with the decoding timing of the video decoding unit 24.

  The screen synthesis circuit 13 synthesizes the video signal of the upper half screen and the video signal of the lower half screen decoded at the same time by the video decoders 11 and 12 and outputs the video signal of the synthesized screen to the output terminal 14.

  As is apparent from the above, according to the first embodiment, the video DTS is set so that the decoding start time indicated by the video DTS separated by the separation unit 31 of the video decoder 12 matches the decoding start time indicated by the video DTSr. The video DTS correction unit 35 that corrects the decoding start time indicated by FIG. 4 and the STC reproduction unit 33 that reproduces the time reference STC according to the time management information PCR separated by the separation unit 31 are provided, and the video decoding unit 36 is an STC reproduction unit. The decoding of the encoded data CDATA stored in the video buffer 32 is started at a timing when the time reference STC reproduced by the video data 33 is coincident with the decoding start time indicated by the video DTS corrected by the video DTS correction unit 35. Since it is configured, the video signal of the upper half screen is not required without mounting a delay circuit as in the conventional example. Between the video signal of the lower half screen, an effect capable of outputting a video signal of a combined screen the decoding time does not shift.

  Further, according to the first embodiment, the video DTS correction unit 35 calculates the delay amount from the decoding start time indicated by the video DTS and the arrival time ATS, and also the decoding start time indicated by the video DTSr and the arrival time ATSr. The delay amount is calculated from the two delay amounts, and a correction value (= DTSr-DTS) is calculated from the difference between the two delay amounts and the arrival time (ATSr-ATS), and the correction value is added to the decoding start time indicated by the video DTS. Since it is configured, the time reference STCr in the encoder that encodes the video signal of the upper half screen (encoder in the video transmission apparatus 1) and the encoding that encodes the video signal of the lower half screen Even when there is a deviation from the time reference STC in the video encoder (encoder in the video transmission apparatus 1), the decoding start time indicated by the video DTS is accurately determined. An effect that can be matched to the decoding start time indicated by.

  In the first embodiment, the video DTS correction unit 35 corrects the decoding start time indicated by the video DTS. However, in the MPEG-2 standard, a screen is displayed in addition to the video DTS from the video transmission device. Since a presentation time stamp (hereinafter referred to as “PTS”) indicating the display time is added, the display time indicated by PTS (= video DTS + fixed decoding delay) is corrected instead of the decoding start time indicated by the video DTS. You may make it do.

  In the first embodiment, the decoding timing of the encoded data CDATA in the video decoding unit 36 of the video decoder 12 is corrected using the encoded data CDATAr decoded by the video decoding unit 24 of the video decoder 11 as a reference for starting decoding. However, when MPEG-2 video is encoded, for example, an intra picture inserted every 15 frames may be used as a reference for starting decoding, and a larger temporal shift can be dealt with.

In the first embodiment, the transmission apparatus 2 generates an encoded stream in which the encoded data CDATAr decoded by the video decoder 11 and the encoded data CDATA decoded by the video decoder 12 are multiplexed. However, the encoded data CDATAAr decoded by the video decoder 11 and the encoded data CDATA decoded by the video decoder 12 are separately transmitted, and the separating units 21 and 31 of the video decoders 11 and 12 are transmitted. You may make it give to.
In the first embodiment, a plurality of encoders that encode divided screens are shown as one video transmission apparatus 1, but encoded data output from the plurality of transmission apparatuses is converted into one stream by a reorganization circuit. Anyway.
Further, in the first embodiment, the video decoder 11 and the video decoder 12 are shown as one video receiving device 3, but screen synthesis may be performed externally as a video receiving device having a separate video decoder.

Embodiment 2. FIG.
FIG. 3 is a block diagram showing a video transmission apparatus according to Embodiment 2 of the present invention. In the figure, the same reference numerals as those in FIG.
When a video signal representing a large screen is input from the input terminal 51, the screen dividing circuit 52 divides the large screen and performs a process of outputting a plurality of video signals representing the divided screen. FIG. 3 shows an example of dividing into two screens.
The screen dividing circuit 52 constitutes a screen dividing means.

The clock circuit 53 is a clock that supplies time data serving as a time stamp reference to the encoding circuits 54 and 55.
In accordance with the MPEG-2 standard, for example, the encoding circuit 54 encodes the video signal of the upper half screen output from the screen division circuit 52 and outputs an encoded stream including the encoded data CDATAr. carry out.
In accordance with the MPEG-2 standard, for example, the encoding circuit 55 encodes the video signal of the lower half of the screen output from the screen division circuit 52 and outputs an encoded stream including the encoded data CDATA. carry out.
Note that the encoding circuits 54 and 55 constitute an encoder.

The reorganization circuit 56 performs a process of reorganizing the two encoded streams output from the encoding circuits 54 and 55 into one and outputting one encoded stream to the transmission apparatus 2.
The reorganization circuit 56 and the transmission device 2 constitute transmission means.

The video encoding unit 61 of the encoding circuit 54 encodes the video signal of the upper half screen output from the screen dividing circuit 52 and performs processing for generating the encoded data CDATAr.
Note that the video encoding unit 61 constitutes encoding means.
The STC generation unit 62 generates a time reference STCr according to the time data supplied from the clock circuit 53 and performs processing for generating time management information PCRr used for reproduction of the time reference STCr.
The STC generator 62 constitutes a time reference generator.

The time stamp generator 63 refers to the time base STCr generated by the STC generator 62 and refers to the video DTSr (or video signal display time) indicating the decoding start time of the video signal encoded by the video encoder 61. To generate a PTSr). Here, the video DTSr or the PTSr is generated, but both the video DTSr and the PTSr may be generated.
The time stamp generation unit 63 constitutes a time stamp generation unit.

The offset setting unit 64 includes, for example, a man-machine interface such as a keyboard and a switch, and performs processing for receiving a predetermined offset setting.
Here, a configuration is shown in which the offset setting unit 64 outputs the offset set by the user to the adding unit 65, but the offset stored in the internal memory in advance may be output to the adding unit 65. Good.
The adding unit 65 performs processing for adding the offset output from the offset setting unit 64 to the decoding start time indicated by the video DTSr generated by the time stamp generating unit 63 (or the display time of the video signal indicated by PTSr). carry out.
The offset setting unit 64 and the adding unit 65 constitute correction value adding means.

The multiplexing unit 66 multiplexes and encodes the encoded data CDATAr generated by the video encoding unit 61, the video DTSr with an offset output from the adding unit 65, and the time management information PCRr generated by the STC generation unit 62. A process of generating a stream and outputting the encoded stream to the reorganization circuit 56 is performed.
The multiplexing unit 66 constitutes a multiplexing unit.

The video encoding unit 71 of the encoding circuit 55 encodes the video signal of the lower half screen output from the screen dividing circuit 52, and performs processing for generating the encoded data CDATA.
Note that the video encoding unit 71 constitutes encoding means.
The STC generation unit 72 generates a time reference STC according to the time data supplied from the clock circuit 53, and performs processing for generating time management information PCR used for reproduction of the time reference STC.
Note that the STC generator 72 constitutes a time reference generator.

The time stamp generation unit 73 refers to the time reference STC generated by the STC generation unit 72 and refers to the video DTS indicating the decoding start time of the video signal encoded by the video encoding unit 71 (or the display time of the video signal). To generate a PTS). Here, the video DTS or PTS is generated, but both the video DTS and PTS may be generated.
The time stamp generator 73 constitutes a time stamp generator.

The offset setting unit 74 includes, for example, a man-machine interface such as a keyboard and a switch, and performs processing for receiving a predetermined offset setting.
Here, a configuration is shown in which the offset setting unit 74 outputs the offset set by the user to the adding unit 75. However, the offset stored in advance in the internal memory may be output to the adding unit 75. Good.
The adding unit 75 adds the offset output from the offset setting unit 74 to the decoding start time indicated by the video DTS generated by the time stamp generating unit 73 (or the display time of the video signal indicated by the PTS). carry out.
The offset setting unit 74 and the adding unit 75 constitute correction value adding means.

The multiplexing unit 76 multiplexes the encoded data CDATA generated by the video encoding unit 71, the video DTS with an offset output from the addition unit 75, and the time management information PCR generated by the STC generation unit 72, and encodes them. A process of generating a stream and outputting the encoded stream to the reorganization circuit 56 is performed.
The multiplexing unit 76 constitutes multiplexing means.
FIG. 4 is an explanatory diagram showing the decoding timing in the video decoders 11 and 12 of the video receiving apparatus according to the second embodiment of the present invention.

Next, the operation will be described.
In the video receiving device 3, the decoding timing of the encoded data CDATA in the video decoding unit 36 of the video decoder 12 is corrected using the encoded data CDATAr decoded by the video decoding unit 24 of the video decoder 11 as a reference for starting decoding. Yes.
Therefore, when the encoded data CDATA decoded by the video decoding unit 36 of the video decoder 12 arrives later than the encoded data CDATA decoded by the video decoding unit 24 of the video decoder 11 due to the influence of transmission delay or the like, the video DTS correction unit The correction processing by 35 becomes impossible, and it becomes impossible to match the decoding timing.

  In the example of FIG. 4, if the video transmission device does not perform decoding reference correction value addition processing described later, the display time based on the video DTS corrected by the video DTS correction unit 35, that is, decoding fixed to the video DTS is performed. The time to which the delay is added (or the PTS corrected by the video DTS correction unit 35) is a display time based on the video DTSr output from the separation unit 21 to the video decoding unit 24, that is, decoding fixed to the video DTSr. It becomes later than the time to which the delay is added (or the PTS output from the separation unit 21 to the video decoding unit 24), and the display time is reversed and the display cannot be performed accurately.

Therefore, in the second embodiment, the encoded data CDATA decoded by the video decoding unit 36 of the video decoder 12 is slower than the encoded data CDATAr decoded by the video decoding unit 24 of the video decoder 11 due to the influence of transmission delay or the like. The structure of the video transmission device has been devised so that it can be displayed properly even if it arrives at.
Hereinafter, the processing content of the video transmission apparatus will be specifically described.

For example, when the offset value output from the offset setting unit 64 of the encoding circuit 54 and the offset value output from the offset setting unit 74 of the encoding circuit 55 are the same value, there is no influence on transmission delay, etc. The encoded data CDATAr decoded by the video decoding unit 24 of the video decoder 11 and the encoded data CDATA decoded by the video decoding unit 36 of the video decoder 12 arrive at the same time.
However, the encoded data CDATA decoded by the video decoding unit 36 of the video decoder 12 is, for example, transmitted in one frame more than the encoded data CDATAr decoded by the video decoding unit 24 of the video decoder 11 due to the influence of delay or the like. When the arrival is delayed by a corresponding time, the offset value output from the offset setting unit 64 of the encoding circuit 54 is transmitted to one frame from the offset value output from the offset setting unit 74 of the encoding circuit 55. Set a value larger than the corresponding time.
For example, the offset value output from the offset setting unit 64 of the encoding circuit 54 is set to a time corresponding to transmission of two frames, and the offset value output from the offset setting unit 74 of the encoding circuit 55 is set to “0”. Set.

As described above, when the offsets of the offset setting units 64 and 74 are set, the video DTSr and DTS generated by the time stamp generating units 63 and 73 are the offsets set by the adding units 65 and 75 by the offset setting units 64 and 74, respectively. The decoding start time indicated by the video DTSr is later than the decoding start time indicated by the video DTS by the difference between the two offsets (decoding reference correction value).
In the example of FIG. 4, the decoding start time indicated by the video DTSr is delayed by the difference between the two offsets (decoding reference correction value).
As a result, even if the encoded data CDATAAr to be decoded by the video decoding unit 24 of the video decoder 11 has arrived first, the decoding timing of the encoded data CDATAAr and the decoding timing of the encoded data CDATA are optimized. It is possible to plan.
That is, correction processing by the video DTS correction unit 35 can be performed, and finally the decoding timing can be matched.

  As is apparent from the above, according to the second embodiment, the encoding circuits 54 and 55 set the offset with respect to the decoding start time indicated by the video DTSr and DTS generated by the time stamp generators 63 and 73. Since the addition units 65 and 75 for adding the offsets output from the units 64 and 74 are mounted, the encoded data CDATA decoded by the video decoding unit 36 of the video decoder 12 is affected by transmission delay and the like. Even if it arrives later than the encoded data CDATAr decoded by the video decoding unit 24 of the video decoder 11, it is possible to display appropriately.

It is a block diagram which shows the video receiver by Embodiment 1 of this invention. It is explanatory drawing which shows the decoding timing in the video decoders 11 and 12 of the video receiver by Embodiment 1 of this invention. It is a block diagram which shows the video transmission apparatus by Embodiment 2 of this invention. It is explanatory drawing which shows the decoding timing in the video decoders 11 and 12 of the video receiver by Embodiment 2 of this invention. 1 is a configuration diagram illustrating a video transmission device disclosed in Patent Document 1. FIG. 1 is a configuration diagram illustrating a video reception device disclosed in Patent Document 1. FIG.

Explanation of symbols

  1 video transmission device, 2 transmission device (transmission means), 3 video reception device, 11 video decoder, 12 video decoder, 13 screen composition circuit, 14 output terminal, 21 separation unit, 22 video buffer, 23 STC playback unit, 24 video Decoding unit, 31 Separating unit (separating unit), 32 Video buffer, 33, 34 STC reproducing unit (reproducing unit), 35 Video DTS correcting unit (correcting unit), 36 Video decoding unit (decoding unit), 51 Input terminal, 52 Screen division circuit (screen division means), 53 clock circuit, 54, 55 encoding circuit (encoder), 56 reorganization circuit (transmission means), 61, 71 video encoding unit (encoding means), 62, 72 STC generator (time reference generator), 63, 73 Time stamp generator (time stamp generator), 64, 74 Offset setting (Correction value adding means), 65, 75 adding section (correction value adding means), 66, 76 multiplexing section (multiplexing means), 101 input terminal, 102 screen dividing circuit, 103, 104 encoding circuit, 105 clock circuit 106, 107 Recording device, 108 Reorganization circuit, 109 Transmission device, 111, 112 Playback device, 113, 114 Decoder, 115 Synchronization circuit, 116 Delay circuit, 117 Screen composition circuit, 118 Output terminal.

Claims (3)

  A decoding target video signal encoded from the encoded stream, a first decoding time stamp indicating a decoding start time of the video signal, and a time used for reproduction of a time reference in an encoder encoding the video signal Separation means for separating the management information and a second decoding time stamp indicating a decoding start time of the video signal that is a reference for starting decoding of the video signal, and a decoding indicated by the first decoding time stamp separated by the separation means The correction means for correcting the decoding start time indicated by the first decoding time stamp and the time management information separated by the separating means so that the start time matches the decoding start time indicated by the second decoding time stamp. Therefore, the reproduction means for reproducing the time reference, and the first reference in which the time reference reproduced by the reproduction means is corrected by the correction means. At a timing that matches the decoding start time of the decoding time stamp indicates, the video receiver including a decoding unit to start decoding the separated video signal by said separating means.   In addition to the time management information used for the reproduction of the time reference in the encoder in which the separation means encodes the video signal, the time reference in the encoder that encodes the video signal that is the reference for starting decoding from the encoded stream The time management information used for the reproduction is separated, the reproduction means reproduces the time reference according to both time management information, and the correction means obtains the decoding start time and the second decoding time stamp indicated by the first decoding time stamp. A correction value is calculated from the time difference between the decoding start times indicated and the time difference between the two time references, and the correction value is added to the decoding start time indicated by the first decoding time stamp. Item 14. The video receiving device according to Item 1.   A screen dividing unit that divides the screen represented by the video signal and outputs a plurality of video signals representing the divided screen, a plurality of encoders that encode the video signal output from the screen dividing unit, and A video transmission apparatus comprising: a transmission means for generating an encoded stream including a video signal encoded by a plurality of encoders and transmitting the encoded stream; wherein the plurality of encoders include the screen division Generated by the encoding means for encoding the video signal output from the means, the time reference generating means for generating time management information used for reproducing the time reference, and the time reference generating means. A time stamp generating means for generating a decoding time stamp indicating a decoding start time of the video signal encoded by the encoding means with reference to the time reference, Correction value adding means for adding a predetermined decoding reference correction value to the decoding start time indicated by the decoding time stamp generated by the time stamp generating means, the video signal encoded by the encoding means, and the correction value adding means A video transmission apparatus comprising: a multiplexing unit that multiplexes the decoding time stamp output from the time management information generated by the time reference generation unit.

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