2010/5/20 Tyler Conant <tconant@xxxxxxxxx> > I'm trying to use dmix on an OMAP processor. I'm experiencing the first 50 > ms of the sample getting clipped. When I aplay directly to the hw:0 I don't > get the clipping. The difference I see between the alsa configuration > between dmix and hw:0 is the start_threshold, stop_threshold and > silence_size. When it's direct to hw:0 the start and stop threshold are > equal to the buffer size. For dmix the start threshold is 1 and the stop > threshold is 1445199872. Is this dmix which is setting the start and stop or > is this aplay. I'm only guessing this is the reason why the first part is > clipping. The only bug which seem similar is > http://bugs.gentoo.org/show_bug.cgi?id=218641 and it's already been closed > out. I'm using alsa lib 1.0.23 > > > with hw:0 > > Audio_Prompts # aplay -v -D hw:0 Click03.wav > Playing WAVE 'Click03.wav' : Signed 16 bit Little Endian, Rate 44100 Hz, > Mono > Hardware PCM card 0 'TWL4030' device 0 subdevice 0 > Its setup is: > stream : PLAYBACK > access : RW_INTERLEAVED > format : S16_LE > subformat : STD > channels : 1 > rate : 44100 > exact rate : 44100 (44100/1) > msbits : 16 > buffer_size : 22052 > period_size : 5513 > period_time : 125011 > tstamp_mode : NONE > period_step : 1 > avail_min : 5513 > period_event : 0 > start_threshold : 22052 > stop_threshold : 22052 > silence_threshold: 0 > silence_size : 0 > boundary : 1445199872 > appl_ptr : 0 > hw_ptr : 0 > /opt/axonapp/Audio_Prompts # > > > With dmix: > > /Audio_Prompts # aplay -v Click03.wav > Playing WAVE 'Click03.wav' : Signed 16 bit Little Endian, Rate 44100 Hz, > Mono > Plug PCM: Direct Stream Mixing PCM > Its setup is: > stream : PLAYBACK > access : RW_INTERLEAVED > format : S16_LE > subformat : STD > channels : 1 > rate : 44100 > exact rate : 44100 (44100/1) > msbits : 16 > buffer_size : 22052 > period_size : 5513 > period_time : 125011 > tstamp_mode : NONE > period_step : 1 > avail_min : 5513 > period_event : 0 > start_threshold : 22052 > stop_threshold : 22052 > silence_threshold: 0 > silence_size : 0 > boundary : 1445199872 > Hardware PCM card 0 'TWL4030' device 0 subdevice 0 > Its setup is: > stream : PLAYBACK > access : MMAP_INTERLEAVED > format : S16_LE > subformat : STD > channels : 1 > rate : 44100 > exact rate : 44100 (44100/1) > msbits : 16 > buffer_size : 22052 > period_size : 5513 > period_time : 125011 > tstamp_mode : ENABLE > period_step : 1 > avail_min : 5513 > period_event : 0 > start_threshold : 1 > stop_threshold : 1445199872 > silence_threshold: 0 > silence_size : 1445199872 > boundary : 1445199872 > appl_ptr : 0 > hw_ptr : 0 > /opt/axonapp/Audio_Prompts # > > > asound.conf: > pcm.dmixer { > type dmix > ipc_key 2048 > ipc_key_add_uid true > slave { > > channels 1 > pcm hw:0 > rate 44100 > period_time 125011 > period_size 5513 > buffer_size 22052 > } > } > > pcm.asymed { > type asym > playback.pcm "dmixer" > capture.pcm "hw:0,0" > } > > pcm.!default { > type plug > slave.pcm "asymed" > } > > > The major difference is access : MMAP_INTERLEAVED _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
