[alsa-devel] Rawmidi vs. /dev/snd/*
Paul D. DeRocco
pderocco at ix.netcom.com
Mon Apr 2 19:02:15 CEST 2012
> From: Gabriel M. Beddingfield [mailto:gabrbedd at gmail.com]
> It would be a good idea for you to check out the alsa-lib sources and
> snoop around in the src/rawmidi/ folder.
> In reality, only one file descriptor is returned by
> snd_rawmidi_poll_descriptors(). However, the API returns an array so
> that it can expand in the future without having to recompile programs
> linked to the library.
> Yes, the ALSA documentation sucks. But I assure you that if
> you try to
> use the raw kernel interface... the documentation is worse. :-)
Since ALSA is big an complicated, and since my embedded system will probably
be based on SALSA, I downloaded that source, which is comparatively simple
(hence the S, I guess). It makes it clear what's going on: the RawMidi
handle already contains a pollfd for its internal use, and
snd_rawmidi_poll_descriptors makes that available to the app.
Thanks for your time.
Ciao, Paul D. DeRocco
Paul mailto:pderocco at ix.netcom.com
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