'Twas brillig, and Mark Brown at 18/01/11 11:57 did gyre and gimble: > On Tue, Jan 18, 2011 at 11:15:16AM +0000, Colin Guthrie wrote: > >> People have requested h/w mixing before tho', but I'm not sure if that's >> simply because their h/w supports it and they want to offload to it, or >> whether they had real, practical benefits. The only practical benefit of >> h/w mixing I can think of is to allow for separate sample rates to be >> pushed to the card simultaneously and let it mix them (with SRC in h/w) >> as appropriate. That way we don't do any SRC in software but support > > It also supports routing to different sets of outputs - the ringtone > plus music playback example I mentioned in reply to Pierre-Louis is one > of the more obvious examples. This is probably more important in the > embedded case than in the desktop case. Wouldn't that be better handled by different Sinks and/or Ports tho'? Otherwise the paradigm of having a Sink as a deterministic path to output is totally broken... unless I'm misunderstanding your point - perhaps the hardware will automatically do some internal routing based on sample rate because it knows ringtones are just 8kHz or whatever? If so we need to make sure the hardware doesn't outsmart us, and I guess that's where the UCM stuff would come in? Col -- Colin Guthrie gmane(at)colin.guthr.ie http://colin.guthr.ie/ Day Job: Tribalogic Limited [http://www.tribalogic.net/] Open Source: Mageia Contributor [http://www.mageia.org/] PulseAudio Hacker [http://www.pulseaudio.org/] Trac Hacker [http://trac.edgewall.org/]