On Tue, 2011-01-18 at 16:53 -0600, pl bossart wrote: > >> In my normal usage, there is a potential (solvable) problem with this > >> approach, though. I use Rhythmbox and most of my songs are at 44100 Hz, > >> but there are some at 48000 Hz. If I start playing one of the 48000 Hz > >> songs, all subsequent streams will be upsampled to 48000 Hz till I pause > >> for >5 seconds. > >> > >> As you suggest, this will become less of a problem if we decrease the > >> idle time required before suspend, and IMO this enough to make this a > >> non-blocker. > > > > I wonder what happens if we set the timeout to zero for ALSA devices? > > Arun, I just tried with load-module module-suspend-on-idle timeout=0, > and it seems to work fine on the HDAudio output. I was able to switch > back and forth between 44.1 and 48kHz tracks without audible issues. I > am not sure what happens with Rhythmbox if you enabled the cross-fade > between tracks, most likely you would remain at the rate defined by > the first song. The xfade backend always resamples the stream to 44100 Hz (since it does the mixing in GStreamer). Not much we can do there, but I am trying to see if we can push the mixing to PulseAudio (we also need this to maintain reasonable response time when setting a large tlength in pulsesink to save power). Even if this is done, though, we're stuck with the rate defined by the first song till a pause, but this is still not so bad. FWIW, the zero-length wait seems to work fine for me as well (also HDAudio). A couple of things to consider if we do decide to go ahead with this are are that: * This will cause a pause on every seek in GStreamer as well (should be fine in general since a seek causes a flush as well, but just something to keep in mind while testing) * We probably need to be more intelligent about resetting the alsa-sink smoother since it tends to swing wildly for a while after resume (right now it gets reset on every suspend/resume - probably makes more sense to only reset if some minimum amount of time has passed) Cheers, Arun
