Rockbox mail archiveSubject: Re: FS#10199: Limiter DSP function
Re: FS#10199: Limiter DSP function
From: Jeff Goode <jeffg7_at_gmail.com>
Date: Mon, 17 Aug 2009 13:40:42 -0400
Al Le wrote:
> On 17.08.2009 16:52, Jeff Goode wrote:
>> The 7k is mostly buffers and the code itself, which is whittled down
>> pretty far already. There's not a lot of fat in there.
> Hm... I have a question: why not have a large enough buffer that would
> be used by all DSP effects? IIUC, as of now every DSP effect would
> reserve its own buffer. Why not have it once for all? Would it be
> possible at all? I.e. we'd have a buffer and then several DSP
> "processors" would sweep over it before the PCM data is sent to the
> audio chip.
> Just some thoughts generated by (but related not only to) this patch.
That was my first idea, and I did do it. But it seems there wasn't much
interest in having that kind of global buffer so I folded it back into
the procedure. It would be easy to break it back out if someone else
wanted to use it, though. Most DSP functions get along well enough
without having their input buffered anyway, so it wouldn't come up very
The only other function I can think of offhand that would really benefit
is crossfade, and that's so embedded in pcmbuf that extracting it would
be very painful. It gets its space by reserving its own aux buffer
carved out from the main PCM buffer. I'm not sure that's really "DSP"
as such, though.
Received on 2009-08-17