At Wed, 25 Feb 2009 12:10:24 +0100 (CET), Jaroslav Kysela wrote: > > On Wed, 25 Feb 2009, Takashi Iwai wrote: > > > At Wed, 25 Feb 2009 11:57:32 +0100 (CET), > > Jaroslav Kysela wrote: > > > > > > On Wed, 25 Feb 2009, Takashi Iwai wrote: > > > > > > > Anyway, the definitions of delay and avail in a free-wheel mode are > > > > ambiguous and rather confusing indeed... > > > > > > I don't agree. We manage appl_ptr also in no-XRUN check mode for ALSA > > > apps, so the negative values makes sense and applications can quickly > > > skip missed samples (snd_pcm_forward). > > > > Well, if we follow the definition of snd_pcm_delay(), applptr - delay > > doesn't always point to the position to write for the next. > > (Right now it works so, though). > > Sure, but negative value indicates how many samples is application behind > the output from hardware. The delay value cannot be used for buffer > filling, of course (also in standard - no-XRUN case - avail functions > should be used). The problem I foresee is that a hardware with pre-fetch style doesn't work reliably with forwarding based on the delay value. The free-wheel support on such a hardware is anyway tricky, so it's not only about avail and delay, though. Takashi _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
