[MPlayer-users] AO_ALSA: Using SND_PCM_ACCESS_MMAP_INTERLEAVED.

[Michaël Cadilhac]

  Hi there, people!

  In February 2006 [1], mmap support has been disabled in AO_ALSA.  The
reason was, IIUC, that the implementation was basically a generic
implementation of non-mmap access using mmap.

  I currently own a Tacsam US144, a usb sound card, which has very
specific drivers from alsa-plugins (called usb_stream).  The problem is,
the device only allows SND_PCM_ACCESS_MMAP_INTERLEAVED access type,
which causes mplayer to refuse playing on the device (well, it causes it
to fail setting access type indeed... ao_alsa.c:529).

  I have one simple question : who's to blame? :-) Mplayer could be the
culprit for being narrow minded about which access type it can deal
with, although it could emulate it for other access types.  On the other
hand, maybe the usb_stream plugin should provide RW_INTERLEAVED access
(possibly by simply wrapping the mmap access).

  Any answer very much appreciated!

  Have a great day.

Footnotes: 
[1]  http://lists.mplayerhq.hu/pipermail/mplayer-dev-eng/2006-February/040295.html

-- 
Michaël `Micha' Cadilhac (LITQ, U. de Montréal) -- http://michael.cadilhac.name
	|| La culture c'est comme la confiture,
	||     c'est meilleur avec du pain.
	||          -- MOI59