Opened 12 months ago
#10368 new defect
Incorrect tbr importing h264 (default tbr?)
| Reported by: | slydiman | Owned by: | |
|---|---|---|---|
| Priority: | normal | Component: | undetermined |
| Version: | unspecified | Keywords: | |
| Cc: | Blocked By: | ||
| Blocking: | Reproduced by developer: | no | |
| Analyzed by developer: | no |
Description
Here is the h264 stream from MXF recorded by the camera Canon C300
http://slydiman.me/ffmpeg/canon_c300_mxf_h264_25fps_wrong_tbr.h264
Old ffmpeg 20200805 (libavcodec 58.101.101, libavformat 58.51.101) reports:
25 fps, 25 tbr, 1200k tbn, 50 tbc
ffmpeg -i canon_c300_mxf_h264_25fps_wrong_tbr.h264 -c copy output.mp4
produces a correct file with 25 fps.
ffmpeg 20230507 (libavcodec 60.10.100, libavformat 60.5.100) reports:
25 fps, 600k tbr, 1200l tbn
ffmpeg -i canon_c300_mxf_h264_25fps_wrong_tbr.h264 -c copy output.mp4
produces an incorrect file with 239.998 fps.
I agree that timing_info_present_flag=0 in SPS and it is hard to detect tbr in this case. But the reported fps is still 25 and it is correct. How was it detected? I see tbr=600k and it is totally wrong. Yes, it can be fixed adding -r 25. Note it is very useful when ffmpeg can detect the correct tbr itself (probably when timing_info_present_flag=1) without -r and uses 25 by default when timing_info_present_flag=0. 600k is ugly value. So the behavior of an old ffmpeg is much better. Hope it can be fixed or make the default tbr=25 back at least. Thanks.
