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

[Ulf Zibis]

Am 14.03.20 um 11:51 schrieb Carl Eugen Hoyos:
> 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?
I now have additionally changed the minor version number to "00 00 02 00". The video still plays in the camera.

>> 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.

OK, the 0x18 means, that the ftyp atom is 24 bytes long ... in contrast to 0x14 in the output from ffmpeg. So I may play around with that.

Furthermore, the original seems to have a moov atom in the header, but ffmpeg doesn't. So I forced a moov atom to the ffmpeg output with -movflags +faststart. Unfortunately this didn't make the video playable in the camera (the resulting moov atom looks very different from the one on the original). Are there other variants of moov atoms, which may could help?

-Ulf