[FFmpeg-devel] [PATCH 1/2] avformat/mov: fix timecode with high frame rate content

[Marton Balint]

On Mon, 11 Apr 2022, Anton Khirnov wrote:

> Quoting Marton Balint (2022-04-10 20:11:59)
>> 60 fps content have "Number of Frames" set to 30 in the tmcd atom, but the
>> frame duration / timescale reflects the original video frame rate.
>>
>> Therefore we multiply the frame count with the quotient of the rounded timecode
>> frame rate and the "Number of Frames" per second to get a frame count in the original
>> (higher) frame rate.
>>
>> Note that the frames part in the timecode will be in high frame rate which will
>> make the timecode different to e.g. MediaInfo which seems to show the 30 fps
>> timecode even for 120 fps content.
>>
>> Regression since 428b4aacb1a91a267650de644519882a5f700388.
>>
>> Fixes ticket #9710.
>> Fixes ticket #9492.
>
> Sounds like there should be a test for this.

The smallest file I managed to find which is affected by this is
mov/canon_6d/mvi_9114.mov, but that is still 12 MB, therefore probably not
fit for addition to fate-samples.

With our muxer, the issue is not reproducible, so remuxing is not an
option.

Regards,
Marton