Re: [Caml-list] Is anyone using caml for music or sound synthesis?

[Ken Rose <kenarose@earthlink.net>]

Xavier Leroy wrote:
> 
> > Speaking of multimedia, would GC prevent people from writing, say,
> > an mp3 or a mpeg player in O'Caml?
> 
> For MP3, not at all.  Consider:
> - GC pauses are well below 100ms (more like 10ms, actually)
>   (provided the compactor is turned off)
> - Sound drivers can usually buffer 0.5-1s of sound.
> - MP3 decompression in real-time uses a small fraction of the CPU power.
> Ergo, the sound buffer will easily mask the GC pauses.
> 
> MPEG video is another story: buffering is much more limited, and CPU
> utilization is much higher.  But GC isn't the only source of potential
> hiccups: disk accesses are as much of a problem, if not worse.

It's actually a lot easier to skip video frames than it is to skip audio
samples.  With audio, nearly anything you miss will produce an audible
pop, but it's often possible to skip a video frame or two without it
being very noticable.  MPEG "B" frames are the best candidates, since no
other frames depend on them.  You do have to eat the bitstream, but you
don't need to do any other decode, so you get a chance to get back
ahead.

 - ken
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