[FFmpeg-user] How to compress .MOV file compatible to Canon camera

Carl Eugen Hoyos ceffmpeg at gmail.com
Tue Mar 31 02:02:38 EEST 2020


Am Mo., 16. März 2020 um 01:43 Uhr schrieb Ulf Zibis <Ulf.Zibis at gmx.de>:
>
>
> Am 14.03.20 um 21:08 schrieb Carl Eugen Hoyos:
> > Am Sa., 14. März 2020 um 20:39 Uhr schrieb Ted Park <kumowoon1025 at gmail.com>:
> >
> >>>>>> Did you already test the following?
> >>>>>> $ ffmpeg -i MVI_1324.MOV -acodec copy -vcodec copy out.mov
> >>>>> Then the codec time base remains
> >>>> Of course.
> >>>>
> >>>> The question is if the file is still playable after remuxing.
> >>> It is no more playable on the camera.
> >>> It's about 100 kB smaller then the original with 84 MB.
> >> Maybe you should consider the possibility that it isn’t a technical limitation of the decoder capability but something else introduced by proprietary metadata or implementation detail.
> >>
> >> There’s a huge user data box in the moov, upon a quick glance it has the camera model, firmware version, etc. I have to imagine it is used somehow.
> > Same question:
> > Is the (original) file still playable if you edit this atom?
>
> I now inserted the following:
> 1. "CEAP" to ftyp (0x18 instead 0x14 bytes)
> 2. moov atom with qt-fast
> 2. udta atom from original at the start of moov atom (increases it from 0x1340E to 0x1344A)
> Result:
> Instead of a big "?" I now see a the preview picture on the camera. Unfortunately I still can't play the video because of "Not identified Picture".
> So we are a little step closer to the solution.

But the relevant test - imo - is not to change the file that does not play
but instead change the playing file and find out which change breaks
playback.

You can overwrite each atom name with "free" and the file stays a
valid (but possible unplayable) isom/mp4/mov file.

Carl Eugen


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