From mboxrd@z Thu Jan 1 00:00:00 1970 From: Adam Tla/lka Subject: ALSA mixing capability Date: Thu, 11 Dec 2003 10:49:54 +0100 Sender: alsa-devel-admin@lists.sourceforge.net Message-ID: <3FD83DC2.6090502@pg.gda.pl> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-2; format=flowed Content-Transfer-Encoding: 7bit Return-path: Errors-To: alsa-devel-admin@lists.sourceforge.net List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , List-Archive: To: alsa-devel@lists.sourceforge.net List-Id: alsa-devel@alsa-project.org Welcome I'm using ALSA 1.0.0rc2 on snd_intel8x0 and .asoundrc: ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ pcm.mix { type dmix ipc_key 321456 # any unique value ipc_key_add_uid true slave { pcm "hw:0,0" periods 0 period_time 0 period_size 1024 # must be power of 2 buffer_size 4096 # ditto } bindings { 0 0 1 1 } } ctl.mix { type hw card 0 } pcm.dsp0 { type plug slave.pcm "mix" } ctl.mixer0 { type hw card 0 } ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ My problem: when using wavplay with OSS ALSA emulation playing 22050 and 11025 Hz .wav files works OK but with AOSS lib using pcm.dsp0 defined above I can't play 11025 Hz .wav file: $ aoss wavplay lburn2.wav Pathname: lburn2.wav Device: /dev/dsp Sampling Rate: 11025 Hz Mode: Mono Samples: 5999 Bits: 8 Unable to set audio sampling rate but 22050 HZ .wav is played correctly. So my question is how properly compose .asoundrc file so we could mix all sound sources which use ALSA natively through -Dmix virtual device and OSS apps routed through AOSS lib? Is this possible? Is this explained somewhere? Next case is a possibility to create a virtual mixer so ctl.mix virtually sets level of particular source before mixing it with others sources so playind applications could set volumen of only his source. Is that possible? I thing that solution should be a snd kernel module which does this jobs (mixing and correcly setting volume level independently for all apps, using hardware mixing if possible and software if not, DMA mapping etc.) which lays below OSS pcm emulation module and pcm0p device and above hardware so no configuration changes in all apps are needed. If it will working as a kernel high priority thread then some latency problems will gone too. Regards -- Adam Tla/lka mailto:atlka@pg.gda.pl ^v^ ^v^ ^v^ Computer Center, Technical University of Gdansk, Poland PGP public key: finger atlka@sunrise.pg.gda.pl ------------------------------------------------------- This SF.net email is sponsored by: SF.net Giveback Program. Does SourceForge.net help you be more productive? Does it help you create better code? SHARE THE LOVE, and help us help YOU! Click Here: http://sourceforge.net/donate/