KR20120063325A - Apparatus for synchronization of video streams in stereoscopic 3dtv broadcasting systems - Google Patents

Abstract

PURPOSE: A video stream synchronizing apparatus in a 3DTV broadcasting system is provided to supply a 3DTV broadcasting service based on double stream for utilizing an MPEG-2 encoding unit. CONSTITUTION: A second encoding unit(140) inputs a second side video signal and an audio signal. The second encoding unit encodes the second side video signal and the audio signal. The second encoding unit outputs the encoded audio signal into a second stream signal. A multiplexer inputs the first stream signal and the second stream signal.

Description

A video stream synchronization device in a binocular 3DTV broadcasting system {3DTV BROADCASTING SYSTEMS} (APPARATUS FOR SYNCHRONIZATION OF VIDEO STREAMS IN STEREOSCOPIC)

The present invention relates to a video stream synchronization device for matching frame synchronization between left and right video streams in a binocular 3DTV broadcasting system.

In the currently available binocular 3DTV broadcasting system, frame compatible (Side-by-Side or Top-and-Side) is provided to provide 3DTV broadcasting service on the basis of changing the standard or equipment as much as possible throughout the conventional HDTV broadcasting system. Bottom-based 3DTV service is being provided. Frame-compatible 3DTV broadcasting system has the advantage that the existing HDTV transmission system and the terminal can be reused as it is, but the horizontal resolution is basically achieved by frame-compatible (Side-by-Side or Top-and-Bottom). Or there is a disadvantage that the vertical resolution is reduced by half.

Recently, in order to solve such problems and to have backward compatibility with the conventional HDTV broadcasting service, research and development on a dual stream based binocular 3DTV broadcasting system has been made. In dual stream-based binocular 3DTV broadcasting system, the left video is encoded with MPEG-2 encoder and the right video is better than H.264 / AVC encoder or MPEG-2 coder for backward compatibility with conventional HDTV broadcasting service. It encodes with this excellent encoder. MPEG-2 encoders and H.264 / AVC encoders are usually configured independently and have different encoding delays, and each output TS stream constitutes a different program, so that the left and right video streams included in the output TS stream They are out of sync with each other.

SUMMARY OF THE INVENTION An object of the present invention is to provide a video stream synchronization apparatus of a dual stream based binocular 3DTV broadcasting system that synchronizes left and right video streams in order to solve the above problems.

An apparatus for synchronizing a video stream in a binocular 3DTV broadcasting system according to an embodiment of the present invention receives and encodes a left video signal and an audio signal, respectively, and responds to the synchronous clock by encoding the encoded left video signal and the encoded audio signal. A first encoder for outputting the first stream signal; A second encoder which receives the right video signal and the audio signal and encodes each, and outputs the encoded right video signal and the encoded audio signal as a second stream signal in response to the synchronization clock; And a multiplexer configured to receive the first stream signal and the second stream signal and output a stream signal in response to the synchronous clock, wherein a codec encoding the left video signal and a codec encoding the right video signal are different from each other. .

In the binocular 3DTV broadcasting system according to the present invention, the video stream synchronizer can synchronize video streams of an independently configured encoder, thereby using a dual stream utilizing the conventional MPEG-2 encoder and the H.264 / AVC encoder. Based on binocular 3DTV broadcasting service can be provided.

In addition, the apparatus for synchronizing a video stream in the binocular 3DTV broadcasting system according to the present invention can be multiplexed not only to synchronize the binocular video streams but also to the multiplex video streams of the multiview 3DTV broadcasting system. .

1 is a view showing a video stream synchronization apparatus in a dual stream based binocular 3DTV broadcasting system according to an embodiment of the present invention.
FIG. 2 is a flowchart illustrating a method for synchronizing left and right video streams in a 3DTV encoder of the video stream synchronization device shown in FIG. 1.
3 is a diagram exemplarily illustrating a timing diagram for left and right video PES streams and audio PES streams.

Hereinafter, exemplary embodiments of the present invention will be described with reference to the accompanying drawings so that those skilled in the art may easily implement the technical idea of the present invention.

1 is a diagram illustrating a video stream synchronization device 100 in a dual stream based binocular 3DTV broadcasting system according to an exemplary embodiment of the present invention. Referring to FIG. 1, the video stream synchronization apparatus 100 includes a first encoder 120, a second encoder 140, and a 3 DTV multiplexer 160.

The first encoder 120 receives a left video signal and an audio signal and outputs a first stream signal TS1. The first encoder 120 includes a first video encoder 122, a first audio encoder 124, and a first multiplexer 144.

The first video encoder 122 receives and encodes a left video signal. In an embodiment, the first video encoder 122 may use an MPEG-2 codec.

The first audio encoder 124 receives and encodes an audio signal. In an embodiment, the first audio encoder 124 may use an AC3, DTS, or AAC codec.

The first multiplexer 126 receives the output of the first video encoder 122 and the output of the first audio encoder 124 and outputs a first stream signal TS1 in response to the synchronization clock SYNC.

 The second encoder 140 receives a right video signal and an audio signal and outputs a second stream signal TS2. The second encoder 140 includes a second video encoder 142, a second audio encoder 144, and a second multiplexer 144.

The second video encoder 142 receives and encodes a right video signal. According to an embodiment, the second video encoder 142 may use other video codecs except for the MPEG-2 codec.

The second audio encoder 144 receives and encodes an audio signal. In an embodiment, the second audio encoder 144 may use an AC3, DTS, or AAC codec.

The second multiplexer 146 receives the output of the second video encoder 142 and the output of the second audio encoder 144 and outputs the second stream signal TS2 in response to the synchronization clock SYNC.

The 3DTV multiplexer 160 receives the first stream signal TS1 and the second stream signal TS2 and outputs a transport stream TS in response to the synchronous clock SYNC.

The apparatus 100 for synchronizing video streams satisfies the following conditions in order to synchronize the binocular video stream.

First multiplexer 126 of first encoder 120. The second multiplexer 146 and the 3DTV multiplexer 160 of the second encoder 140 share an external synchronization clock SYNC in order to synchronize a program clock reference (PCR).

The same audio signal is simultaneously input to the first encoder 120 and the second encoder 140, and is encoded in the same encoding scheme and the same mode, and multiplexed so that a Decoding Time Stamp (DTS) and a Presentation Time Stamp (PTS) are generated at the same period. .

Audio signals that are not muted are input.

The left video signal is encoded by MPEG-2 (left video ES stream) in the first encoder 120 and the audio signal is encoded by AC3, DTS, or AAC (audio ES stream) and then input to the first multiplexer 126. do. The left video Elementary Stream (ES) stream and the audio ES stream input to the first multiplexer 126 are multiplexed so as to have a lip sync, and then the first stream signal TS1 is output.

Similarly, the right video signal is encoded in the second encoder 140 in a different manner than MPEG-2 (right video ES stream) and the same audio signal input to the first encoder 120 is the same as that set in the first encoder 120. Scheme and the same mode (audio ES stream) are input to the second multiplexer 146. The right video elementary stream (ES) stream and the audio ES stream input to the second multiplexer 146 are multiplexed so as to have a lip sync and then a second stream signal TS2 is output.

The first stream signal TS1 and the second stream signal TS2 constituting different programs are input to the 3DTV multiplexer 160 and output as one TS stream in synchronization with the left and right video streams.

2 is a flowchart illustrating a method for synchronizing between left and right video streams in the 3DTV multiplexer 160 of the video stream synchronization device 100 shown in FIG. 1.

The 3DTV multiplexer 160 extracts a TS stream corresponding to the audio stream from the first stream signal TS1 (S110), extracts an audio PES stream therefrom (S120), and stores it in a buffer (S130).

The 3DTV multiplexer 160 extracts a TS stream corresponding to an audio stream and a right video stream from the first stream signal TS2 (S115), and extracts an audio PES stream and a right video packetized elementary stream (PES) stream therefrom. (S125) and store it in a buffer (S135).

Thereafter, the 3DTV multiplexer 160 extracts the audio ES streams from the audio PES streams stored in the respective buffers (S140 and 145), compares the extracted audio ES streams with each other (S150), and searches for the same audio ES packet. (S160).

The audio PES stream and the right video PES stream in the audio / right video PES stream buffer of the second stream signal TS2 based on the DTS and PTS of the audio PES packet of the first stream signal TS1 including the same audio ES packet. The DTS and PTS are corrected as follows (S170).

In general, when the bit rate of the left video encoder MPEG-2 is set high and the bit rate of the right video encoder is set low, the encoding delay of the first encoder 120 increases more than the encoding delay of the second encoder 140. The DTS and PTS of the audio PES stream and the right video PES stream of the second stream signal TS2 are corrected based on the DTS and PTS of the audio PES stream of the first stream signal TS1.

3 is a diagram exemplarily illustrating a timing diagram for left and right video PES streams and audio PES streams.

The following is the audio DTS, PTS correction formula.

The DTS and PTS of the audio PES packet of the second stream signal TS2 at the time of synchronization are the same as the DTS and PTS of the audio PES packet of the first stream signal TS1. The audio of the second stream signal TS2 is excluded from the multiplexed output since the same signal as that of the audio of the first stream signal TS1 is input to synchronize the left and right video streams. Therefore, it is not necessary to correct the DTS and PTS of the audio PES stream of the second stream signal TS2 except at the moment of synchronization.

Below is the video DTS, PTS correction formula.

For the DTS and PTS of the right video PES stream in the right video PES stream buffer of the second stream signal TS2, the corrected DTS and PTS of the corrected audio PES packet of TS2 are regarded as absolute reference clocks, from which the right uncorrected The time difference between the DTS and PTS of the video PES stream and the DTS and PTS of the audio PES packet of the uncorrected second stream signal TS2 is reflected and corrected.

After correcting the DTS and PTS of the right video PES stream so as to synchronize the left and right video streams, the 3DTV multiplexer 160 performs the right and left video TS streams and the audio TS streams on the basis of the PCR of the first stream signal TS1. The output PCR of the 3DTV multiplexer 160 is corrected (S180).

While the invention has been shown and described with reference to certain preferred embodiments thereof, it will be understood by those skilled in the art that various changes and modifications may be made therein without departing from the spirit and scope of the invention. Therefore, the scope of the present invention should not be limited to the above-described embodiments, but should be determined by the equivalents of the claims of the present invention as well as the claims of the following.

100: video stream synchronizer
120: first encoder
140: second encoder
122: first video encoder
124: first audio encoder
126: first multiplexer
142: second video encoder
144: second audio encoder
146: second multiplexer
160: 3DTV multiplexer
SYNC: Synchronous Clock

Claims (1)

A first encoder receiving a first side video signal and an audio signal and encoding the first side video signal and an audio signal, respectively, and outputting the encoded left video signal and the encoded audio signal as a first stream signal in response to a synchronous clock;
A second encoder that receives a second side video signal and the audio signal and encodes the second side video signal and the audio signal, and outputs the encoded right video signal and the encoded audio signal as a second stream signal in response to the synchronization clock; And
A multiplexer which receives the first stream signal and the second stream signal and outputs a stream signal in response to the synchronization clock;
And a codec for encoding the first side video signal and a codec for encoding the second side video signal are different from each other.

Images