At Sun, 8 Apr 2007 20:35:32 -0400, Lee Revell wrote: > > On 4/7/07, Simon Lewis <simon.lewis@xxxxxxxxxxxxxx> wrote: > > Dear Alsa developers > > > > Audacity seems to work perfectly with AOSS and Jack but not directly > > with ALSA on some linux PCs. Trying to use ALSA directly leads to severe > > distortion due to lack of sync with Alsa. (I hope that is the correct > > terminology.) > > > > I received this reply from the Audacity developers, what tools are > > available from ALSA to investigate this problem? How can I determine > > what the real "Alsa configuration" is that portaudio has used setting up > > communication with Alsa. > > Please try to narrow it down some. What hardware/kernel/distro > versions work OK and which don't? Especially important is the > motherboard chipset, ALSA version and exact make/model of soundcard. > > My guess is that different soundcards default to different > period/buffer config values, and that Audacity wrongly assumes the > buffer/period size it gets from ALSA by default is sane on all > hardware. Yes, and note that one of the most complicated things is the use of dmix/dsnoop plugin. Many devices are set up to use dmix/dsnoop as default with ALSA, so when you open the PCM via "default" name, the dmix/dsnoop will be invoked automatically. When dmix plugin is used, many parameters are restricted via the plugin setting rather than the hardware constraints. I believe the recent dmix/dsnoop code is stable enough, but it's worth to try once "hw" PCM instead of "default" PCM to reduce the possible problems around plugins. Takashi _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
