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

Carl Eugen Hoyos ceffmpeg at gmail.com
Sat Mar 14 12:51:32 EET 2020


Am Do., 12. März 2020 um 01:11 Uhr schrieb Ulf Zibis <Ulf.Zibis at gmx.de>:
>
>
> Am 12.03.20 um 00:07 schrieb Carl Eugen Hoyos:
> > Am Mi., 11. März 2020 um 23:56 Uhr schrieb Ulf Zibis <Ulf.Zibis at gmx.de>:
> >
> >>      compatible_brands: qt  CAEP
> > What happens if you remove CAEP with a binary editor?
>
> When I replace CAEP in the original video with 4 0x00 it is still playable.

Ok.
What happens if you change the minor version number?

> Here are the first 32 bytes of the original:
> 00 00 00 18 66 74 79 70 71 74 20 20 20 07 09 00 71 74 20 20 43 41 45 50
> 00 01 7F E8 6D 6F 6F 76   ....ftypqt   ...qt  CAEP...èmoov
>
> Here replaced with 4 0x00:
> 00 00 00 18 66 74 79 70 71 74 20 20 20 07 09 00 71 74 20 20 00 00 00 00
> 00 01 7F E8 6D 6F 6F 76   ....ftypqt   ...qt  .......èmoov
>
> Here are the first 32 bytes from ffmpeg:
> 00 00 00 14 66 74 79 70 71 74 20 20 00 00 02 00 71 74 20 20 00 00 00 08
> 77 69 64 65 01 67 16 A6   ....ftypqt  ....qt  ....wide.g.¦
>
> As you can see:

> - the magic number (the first 4 bytes) is different, why?

There is no "magic number" in the (general) context of multimedia
files.
Longer brand strings make the ftyp atom longer.

Did you already test the following?
$ ffmpeg -i MVI_1324.MOV -acodec copy -vcodec copy out.mov

Carl Eugen


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