[Libav-user] muxing h264/aac stream

Nisar Ahmed nisar.med at gmail.com
Fri Aug 16 16:00:35 CEST 2013

I am muxing h264/aac stream to mp4 coming from an encoder and having issues
syncing audio and video streams.

I suspect that the problem is with PTS and DTS but I am not sure what
values should i set to properly sync both streams.

I have set the time_base of video stream's AVCodecContext to 1001/30000 and
each AVPacket gets a duration of 1001

I am recieving time stamps from the encoder with each NAL packet which is
set as PTS of the AVPacket. the sequence of PTS/DTS I set is (2002/0,
0/1001, 1001/2002, 5005/3003, 3003/4004...)

Audio stream AVCodecContext sample rate is 48000 and PTS/DTS are simply
multiples of 1024 starting from 0 and AVPacket duration is 1024.

The output movie 's frame rate is 20fps when it should be 29.97fps as it is

Please tell me how to debug this problem and what are the guidelines of
creating pts/dts for both video and audio in my case
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