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

HallMarc Websites marc at hallmarcwebsites.com
Thu Nov 17 14:43:58 CET 2011


> [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.
> 
> --
I understand about the need of the file. Sorry, I can't provide it. I'm not
looking for absolute answers; if I were, I would have one of you sign a NDA
and hire you to write the correct command line(s). What I hope for is a
general idea as to how something might be done or why it might have failed.
i.e. I have read many references to the supposed necessity to compile ffmpeg
with certain flags enabled in order to use the ProRes codec. I have also
read where this isn't necessary anymore. Seems awfully fast for a codec I
could swear ffmpeg only recently started including in the stable
releases(?). So when I posted the output and the sample command lines I used
I expected someone to spot a glaring mistake. Didn't happen. 
[>] 
Such is life. As far as not being playable here or there. Not my concern
here as the ONLY place this file will be played is from a web page and that
through an older version of Floatbox. It plays it happily. I know, I know,
"You have a way of making the file you want why don't you just use that and
be done with it?" Because, it is done from my PC with a 3rd party piece of
software called SUPER (c) which is in the same genre as Handbrake, etc. and
I need my server side ffmpeg to do this. 

Not faint of heart here, I started myself in web development 10 years ago. I
am completely self-taught and because of the nature of this beast, still
learning. If I need to get down to the source code and figure it out, I
will. 

Can you provide a sample command line that would do what you are thinking
concerning the mov IDs?

Next, what is the best way to view the errors? Is the error I see in the
output, is that it?

I asked this before, please recommend some reading material/books that I can
use to learn about ffmpeg. 




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