[LAU] audio collage?

Renato rennabh at gmail.com
Sat Jan 9 07:45:14 EST 2010


On Sat, 09 Jan 2010 13:14:28 +0100
Atte André Jensen <atte.jensen at gmail.com> wrote:

> Renato wrote:
> 
> > ha, I guess the sox you have doesn't handle mp3. does 'play
> > file.mp3' work? It was the first time I ever used sox so I'm no
> > expert... probably compile time options?
> 
> No:
> 
> atte at vestbjerg:~/tmp/collage/licks$ play do_you_like_it.mp3
> play FAIL formats: no handler for file extension `mp3'
> 
> Indeed a compile time option. Another reason to be extra careful with
> sox.
> 
> >> 3) Although I did this myself, sox is not really nice to wrap in
> >> the first place, since it sometimes changes the names of the
> >> arguments and stuff like that. So your script might not work after
> >> the next upgrade of sox :-(
> > 
> > uh, this is bad news indeed
> 
> Exactly, add to that the no-mp3-support-problem, and you get
> headaches pretty soon.
> 
> >> 4) I'm not sure mp3 files are the most obvious file format to work
> >> with, any specific reason you're not working with simple .wav's?
> > 
> > well, most of my music collection is in mp3... I guess I could
> > prompt the user for which filetype to look for
> 
> Or how about this: define using mplayer to convert all found
> audiofiles (at least m4a, wma, ogg, wav, aif, flv, au, aiff, mp3 and
> mov should work) into wav, for instance by wrapping the following
> oneliner in os.system():
> 
> mplayer -vo null -vc dummy -ao pcm:waveheader FILE_TO_CONVERT
> 
> Note that that'll give you the result in audiodump.wav, so remember
> to rename that after each pass. Then to make it easier on the user,
> check if mplayer is installed at the top of the script, if not,
> abort, else proceed. Deliver the result in wav, and let the user
> decide of he wants to degrade the quality and encode to mp3.
> 
> All this means that sox should only worry about the splicing, no en-
> or decoding, which should make things a little simpler and more
> robust.
> 

yeah, but all files would be converted entirely to wav, taking up
potentially much hard disk space... I was concerned about this. Instead
with 
sox in.mp3 out.wav trim 1:35 5  
you'll end up with a wav of 5 seconds... Since anyway for the purpose
of the script I'd have to trim them, I prefer it.
Does mplayer have a way to trim? i.e. outputting only a portion of the
file, not the whole from beggining to end

renato



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