[FFmpeg-user] Trying to create matching multi-audio-track mp4s from ProRes sources

Harvey Pikelberger communque at gmail.com
Wed Feb 13 22:01:44 EET 2019

> On Feb 13, 2019, at 10:04 AM, Ted Park <kumowoon1025 at gmail.com> wrote:
> I wonder if adding -f mov to the output options, or just using mov extension makes it handle the timecode track?

Thanks Ted.

I'm not familiar with the -f option and didn't immediately find it in the FFmpeg documentation
How does that work?

Tried simply switching to the .mov extension instead of .mp4
The tracks mapped properly, the quality is good, and -- though it didn't occur to me until your suggestion -- .mov is preferable to .mp4 for our workflow.
So thanks for the suggestion.  An "obvious" idea that only became obvious after you suggested it.

BUT for some reason the time code changed.  So a clip that had started at TC start/end of 12:31:20:13 / 12:31:42:16 converted to 12:30:35:12 / 12:30:57:15.
Duration matches, frame rate matches, but the start/end TCs are earlier by 45:01.

> On Feb 13, 2019, at 10:57 AM, Gyan <ffmpeg at gyani.pro> wrote:
> unmap the data streams,
>     -i '/Path/To/ProRes/Source.mov' -map 0 -map -0:d -g 48 -c:v libx264 -profile:v baseline -crf 16 -c:a aac -b:a 256k -vf scale=1280:720 -pix_fmt yuv420p '/Path/To/Mp4/Dest.mp4'

-map -0:d fixed the problem entirely.
Audio Tracks are good / TC is good both for .mov and .mp4

Any idea why failing to un-map the data streams causes the time code to change?

Thanks to both of you.  Very helpful!!

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