[Libav-user] unsynchronous for H.264+AAC:

Kalileo kalileo at universalx.net
Mon Mar 26 14:26:25 CEST 2012

On Mar 26, 2012, at 18:58 , Li Zhang wrote:
> Yes, I agree with what you said. But I do not know how to compute the dts exactly.  I just let the muxer add that for me. But I do not know if muxer did that.
> I tried just now that starting the audio transcoding when the first video transcoding was succeeded. Then the audio was earlier than video. So, obviously, the failed video transcoding (50 frames)

keep in mind that when encoding h264 i is normal that you have to encode man frames before you get the first frames back.

> I have another question about the frame rate. I configured video encoder's AVCodecContext->time_base->den= 25. I think the final video frame rate should be 25frames per second. But when I check that using VLC, it was 50. I do not know why.

probably you have "ticks per frame"=2 , then 50 / 2 = 25, nothing to worry about.

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