[FFmpeg-devel] [PATCH] lavf: inspect more frames when the time base is unreliable

Anssi Hannula anssi.hannula
Sat Jan 29 13:41:11 CET 2011

On 29.01.2011 06:45, M?ns Rullg?rd wrote:
> Anssi Hannula <anssi.hannula at iki.fi> writes:
>> 23.976 fps H.264 Matroska files are usually detected as 24 fps
>> (r_frame_rate) by av_find_stream_info(). Fix that by inspecting the
>> timestamps of 30 frames instead of just 20 for video codecs with
>> unreliable time base.
> In my experience most matroska files have correct timing information
> in the headers.  It sounds me more like the "clever" estimation code
> is hallucinating inaccuracies where none exist.

Yes, the timing information is correct in the headers.

The timing estimation code is triggered simply because codec_id ==
CODEC_ID_H264, and the timings simply can't be estimated correctly in
just 20 frames by the current algorithm with only millisecond-precision

Anssi Hannula

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