On Mo, Aug 31 2009, Takashi Iwai wrote: > 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? Yes that's easy: The following should be tested with active dmix. 1. login to a textconsole 2. mplayer -ao alsa your_favourite_file 3. Press space during playback. Result: it takes about an half sec to stop the playback. The second test would be: 1. login to a console 2. mplayer -ao alsa:device=hw=0,0 your_file 3. press space during playback Result: The playback stops without delay Hope you can help. Thanks for your response Kind regards Halim > > thanks, > > Takashi -- Halim Sahin E-Mail: halim.sahin (at) t-online.de _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
