On Thu, 10 Jul 2008, Takashi Iwai wrote: > At Thu, 10 Jul 2008 12:19:05 +0200 (CEST), > Jaroslav Kysela wrote: > > > > On Thu, 10 Jul 2008, Clemens Ladisch wrote: > > > > > Norbert van Bolhuis wrote: > > > > as far as I know: > > > > sample format S24_LE is 24bit sample in 4 bytes > > > > sample format S24_3LE is 24bit sample in 3 bytes > > > > (why else have separate definitions), right ? > > > > > > Yes. > > > > > > > In the ALSA-LIb example /test/pcm.c however > > > > (http://www.alsa-project.org/alsa-doc/alsa-lib/_2test_2pcm_8c-example.html) > > > > there is no diff between the 2 sample formats. > > > > > > That example program uses snd_pcm_format_width() although it should > > > have used snd_pcm_format_physical_width() when calculating memory > > > buffer sizes. > > > > I think that the problem is in wrong area->step calculation in alsa-lib, > > but I'm still investigating where the real culprit is. The > > snd_pcm_format_width() is used only for sample filling (which is OK). > > I think Clemens is right. The program uses snd_pcm_format_width() > wrongly. Also, it won't work properly with strict aliasing... Yes, the patch looks good. I overlooked that the area initialization is directly in pcm.c code (I looked only to generate_sine(). I tested it and it produces good samples. I'm getting some underruns on my notebook with 24-bit formats (but it's probably different problem). Jaroslav ----- Jaroslav Kysela <perex@xxxxxxxx> Linux Kernel Sound Maintainer ALSA Project, Red Hat, Inc. _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
