[Ffmpeg-devel] Incorrect frame rate detected for DivX clip

Harikrishnan Varma hvarma
Tue Mar 7 23:54:01 CET 2006


ffmpeg detects frame rate of PAL clips generated by Samsung Miniket
camcorders as 30 fps. Debugging the problem lead me to:


h263.c: decode_vol_header()

For these clips, vop_time_increment_resolution seems to be set to 30
(post DivX 5 clips have this set to 30,000)

Also, fixed_vop_rate is 0, which means that the frame rate should be
derived from vop_time_increment instead of fixed_vop_time_increment


utils.c: av_find_stream_info()

AVStream.r_frame_rate is finally set to 30/1


Not sure where the fix is to be done, but a few questions first:

1. For AVI containers, shouldn't the values in the VOL header be
disregarded and the strh rate & scale values be used directly?

2. For cases where fixed_vop_rate is 0, shouldn't time_base be updated
based on vop_time_increment





P.S. The problem clip can be found here:

Server: ftp.divxnetworks.com

Username: niedrand

Password: tionspul

File: clip.avi




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