In message <[EMAIL PROTECTED]>
micm <[EMAIL PROTECTED]> wrote:
> Before becoming strangely curried, Philip Blundell wrote:
>
> > > The xaudio libraries and SDK at www.xaudio.com look pretty good.
> >
> > They don't provide source, do they?
> >
> > A good starting point for this stuff might be www.mpeg.org. They have
> > links to a whole load of software.
>
> mpg123 comes in source form. No idea how well it works on ARM hardware,
> but it will certainly decode mp3 files into raw PCM audio files.
>
For realtime playback on a Risc PC, it's dreadful - for 128Kb/s streams, the
sound buffers can only be filled for about 1/5 of the time (due to heavy
reliance on floating point arithmetic). I hacked the mpg123 source to use my
own floating point library, and there was a significant improvement, but it
still wouldn't play anything better than about 32Kb/s streams contiguously. I
think most free MP3 decoder source currently available will have to be fairly
substantially rewritten (as Thomas Olsson has done) before performance is
acceptable.
(If anyone's interested in a version of my library which compiles properly
under ARM Linux, please say - I've had virtually no response about the RISC
OS version currently available, and my ego needs massaging ;-)
Jules
(Trying posting again without my usual mangled headers...)
--
.-------------------------------------------------.
| Julian Brown, Queens' College Cambridge |
| <[EMAIL PROTECTED]> http://jtb20.quns.cam.ac.uk |
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