[asterisk-users] How does format_mp3 work?

[Ishfaq Malik]

On Wed, 2012-02-22 at 14:53 +0000, Tony Mountifield wrote:
> In article <1329920656.2027.37.camel at localhost.localdomain>,
> Ishfaq Malik <ish at pack-net.co.uk> wrote:
> > Hi
> > 
> > I was using the Playback application to play an MP3 file after compiling
> > and installing asterisk 1.8.7.0 with format_mp3 and it seems to me that
> > asterisk is transcoding the file to an slin on the fly rather than
> > playing the mp3 itself. Is this what it does?
> 
> Of course. You are not going to send mp3-encoded audio over a phone line,
> are you? That would require an mp3 decoder in every phone.
> 
> In fact, any mp3 player is transcoding to linear on the fly, since that
> is part of converting it to audio for the speaker or earphones!
> 
> What did you think was the difference between "trascoding to slin" and
> "playing the mp3"?

Hmm, when you put it like that, makes me wonder what I was thinking :)

> 
> > Also, does this mean I might as well change the format of MP3s to WAV
> > seeing as I'm used to doing that anyway?
> 
> If you have the storage space available for the larger WAV files, then yes,
> this would reduce the CPU consumption of playback.
> 
> Cheers
> Tony

Thanks for the response Tony

-- 
Ishfaq Malik
Software Developer
PackNet Ltd

Office:   0161 660 3062