I have discovered something else. Choppy audio occurs when snd_pcm_playback_silence, in pcm_lib.c, will silence the same period than the capture pointer is pointing at. I am printing this variables "ofs" in snd_pcm_playback_silence and what is returned from snd_card_loopback_pointer when the substream is capture. How snd_pcm_playback_silence is supposed to work? Must it silence the next period from the playback pointer? How is ensured that this situation (ofs == capture pointer) does not happen with sound cards? Thanks ANY help... any... Gustavo da Silva Serra escreveu: > I forgot a very important detail, when I can choose the output plugin > (alsa or oss in Kaffeine, for example), only alsa has choppy audio. oss > plugin works perfectly, only using kernel module emulation. > > Gustavo da Silva Serra escreveu: > >> I have tried to implement the solution you proposed. However I still >> get choppy audio, just like before, otherwise the sound is clear. >> >> Basically I moved the timer to the cable struct, and updated the timer >> function to update both playback and capture. >> I am sending the code attached so you can see if I implemented what >> you suggested. The code is not very clean, nor completely functional, >> as I never programmed to kernel before, and might cause kernel panic >> when closing a stream. >> >> Any other suggestions? >> Thanks for the help and the attention. >> >> Takashi Iwai escreveu: >> >>> At Wed, 25 Jun 2008 08:24:33 -0300, >>> Gustavo da Silva Serra wrote: >>> >>> >>>> If I keep the difference between the playback and capture pointers >>>> at one period, no choppy audio occurs. If the difference is 0, 2 or >>>> 5 periods for example, choppy audio will always occur. Any ideas why? >>>> >>>> >>> Through a quick look at the code, it's likely the problem of the >>> timing of timer handlers for playback/capture streams. In the current >>> code, the timer handlers are invoked individually. >>> >>> One possible fix would be to force to synchronize the updates of both >>> directions instead of individual timers. That is, share the same >>> timer for the connected streams so that the update order is >>> guaranteed. >>> >>> >>> Just my $0.02. >>> >>> Takashi >>> _______________________________________________ >>> Alsa-devel mailing list >>> Alsa-devel@xxxxxxxxxxxxxxxx >>> http://mailman.alsa-project.org/mailman/listinfo/alsa-devel >>> > _______________________________________________ > Alsa-devel mailing list > Alsa-devel@xxxxxxxxxxxxxxxx > http://mailman.alsa-project.org/mailman/listinfo/alsa-devel > > __________ NOD32 3241 (20080704) Information __________ > > This message was checked by NOD32 antivirus system. > http://www.eset.com > > > > _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
