At Sun, 23 Aug 2009 09:55:18 +0000 (UTC), Halim Sahin wrote:
Hello, Is there a way to reduce latency on audiocard if the dmix plugin is in use? I am asking because there is a strange problem with asistive technologies which are outputing through alsa. E. G. speech-dispatcher takes almost a half sec to stop the speech-synthesizer. If the user navigates quickly through menus, there are simultane outputs at a time. (tested with an usb logitech headset, snd-intel8x0 based card, snd-hda-intel). The same problem can be reproduced by running mplayer with alsa output driver and pressing quickly left/right arrow. You should hear several samples at a time.
Using an sblive card which doesn't use dmix doesn't have such problems.
Using the dmix plugin should audio much faster to avoid this problem.
It's a bit hard to guess. This could be the difference of PCM drain implementation between hw and dmix, but a half second is still too long.
Could you prepare a small test case to reproduce the buggy behavior?
thanks,
Takashi