[Libav-user] mov demuxer: avformat_seek_file with AVSEEK_FLAG_BYTE

Beni Weine onlineweinies at bluewin.ch
Tue Jul 10 16:22:05 CEST 2012

Hi all,

We need to improve the seeking 
capabilities (performance) in our video player. 
The video player concurrently 
manages 5 
different video files (MP4), 

and plays them in a time synchronized manner. 
Each video file has a time 
index file (proprietary) 
which includes among other things a time stamp and 
the corresponding byte position of the H.
264 data (I frame). 

Pure time-based seeking is not an option 
due to performance reasons. 

The same player can 
handle MPEG-2 file. 
They come with a video time index file as well. 
We have amazing results with bytes-wise seeking 
avformat_seek_file with AVSEEK_FLAG_BYTE). 
It seems that the mpegtsraw demuxer (libavformat/mpegts.c) is 
doing that 
pretty good. 

Different story with the mov demuxer: 
To me it looks that the current implementation of 

libavformat/mov.c does not support 
byte-wise seeking. 

Having a look into the mov.c confirms my impression. 

there a possibility that this feature 
will be added to the mov demuxer any time soon? 

Thanks and best regards,

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