[FFmpeg-user] Access unit boundaries for h264 stream

Hardik Sharma hardik.sharma22 at yahoo.com
Mon Oct 24 21:42:53 CEST 2011

Hi everyone,

I am stating my problem and comments from Michael as follows-

>I want to report this bug which I reproduced more then 10 times. Putting the error file with in the link. Please look at it. In the sequence I dropped 122nd slice (p slice) and decoded this to yuv format. It dropped the whole P frame. I also observed this bug with other slices too. I know that earlier michael commented on this bug that it is not reproducible but it did many times for me. I am also trying to analyze it from the code and request that if someone can also look into this to help me. I will really appreciate it. Thanks. >>http://www.datafilehost.com/download-8e2551d5.html  >>Thanks hardik, i can reproduce it with this file.
>>The problem is that the first slice of a access unit is droped and our
>>parser (libavcodec/h264_parser.c) detects AU boundaries based on
>>the first slice in absence of other indications like SEI/AUD/PPS/... >>a patch fixing this is welcome! The H.264 spec lists how correct AU
>>boundary detection should be done, it involves parsing and comparing
>> -- Michael

This is not happening with any particular frame or slice but it is happening for each and every slice header. Also I have another doubt that I am not dropping any SEI, SPS or PPS slice then why is it happening as parser looks for access unit boundaries in slice headers in the absence of SEI/PPS/SPS slices. Does anyone faced any such situation or if u have any patch or help related to this, please let me know. I appreciate any help. Thanks. 


More information about the ffmpeg-user mailing list