[FFmpeg-user] mov [ProRes/pcm_s24le] -> mp4 same quality

Rhodri James rhodri at kynesim.co.uk
Thu Nov 17 14:14:50 CET 2011

On Wed, 16 Nov 2011 23:58:41 -0000, HallMarc Websites  
<marc at hallmarcwebsites.com> wrote:

[Carl said:]
>> mp4 does not support pcm audio (mov does).
> Um I beg to differ. I have an mp4 container with pcm-s24be and it plays
> beautifully. However, it was done with a piece of software for Windows.
> While it uses ffmpeg and almost all of the codecs; I have no way of
> seeing what and how it is going about this.
> So, I know it can be done. The question is how.

Both of you are right, and the answer is "by lying."  There are no
official MP4 ids identifying PCM audio, so you have to make one up.
Probably the MOV ids work.  Probably.  The disadvantage of using
unofficial ids is that you have *NO* guarantee that anything else
will read your file.

> Stop asking me for the file. I cannot give it to you. It is a commercial  
> and is copyright protected. Not a fan of getting sued. It is the only
> one I have where ProRes was used in the post.

Without a clip that provokes the problem you are seeing, there's pretty
much nothing anyone else can do other than take wild guesses.  Unless
you are prepared to go through and debug the source yourself -- not
an experience for the faint of heart! -- there simply isn't enough
information to work on.

Rhodri James
Kynesim Ltd

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