The issue that I am facing with creating a snd_kcontrol is that I am not able to bind that value to a stream. Say I start the application and set the type of that control to voice and open another instance of that application and set the type to audio. There might be a clash and I might get the wrong stream type to the driver. Also, the stream ids passed cannot also be guaranteed to reach the right stream. >-----Original Message----- >From: alsa-devel-bounces@xxxxxxxxxxxxxxxx [mailto:alsa-devel-bounces@xxxxxxxxxxxxxxxx] On Behalf Of Harsha, >Priya >Sent: Thursday, April 09, 2009 1:07 PM >To: alsa-devel@xxxxxxxxxxxxxxxx >Cc: Takashi Iwai; David Dillow; Lee Revell; Clemens Ladisch >Subject: Re: question on hardware > >Hi , > >I need more help here. I tried looking at the .conf file but I have another requirement here. > >Let me put my requirements here. Please suggest me ways to get this done > >1. When I get a .prepare call in my driver, I need to know the stream type >2. When I return from that call, I need to send to the user the locally allocated stream id > >This is specific to the sound card/ DSP I am developing the driver for. The application is also proprietary. Is this >possible at all? Please suggest me ways to do the same. > >Thanks, >Harsha > >>-----Original Message----- >>From: David Dillow [mailto:dave@xxxxxxxxxxxxxx] >>Sent: Tuesday, December 09, 2008 6:14 PM >>To: Harsha, Priya >>Cc: Clemens Ladisch; alsa-devel@xxxxxxxxxxxxxxxx; Lee Revell >>Subject: Re: question on hardware mixing >> >>On Tue, 2008-12-09 at 14:25 +0530, Harsha, Priya wrote: >>> If I define mixer controls to switch between each substream, I would >>> not be able to handle multiple streams at time.... >> >>Check into the ALSA configuration file syntax -- there are number of >>things you can do there, like define a 'voice' device that uses hooks to >>set a control setting (snd_kcontrol) when you open a PCM. You can use >>that control setting to let your driver know if the PCM channel is being >>used for voice or audio traffic. >> >>Look at how the EMU10K1 handles surround sound audio >>in /etc/alsa/cards/EMU10K1.conf >> >>I started to do some similar things for sis7019 surround sound, but >>they've never made it out of my office due to lack of time/testing HW. >> >>> I had asked this in my earlier follow up email as well - can I use >>> snd_pcm_t->private_data to communicate if it's a voice or audio >>> I understand this private_data gets copied to substream->private data >>> which will reach the driver... >>> Am I right here? >> >>I can't answer this specifically, but I believe the answer is in the >>name -- 'private'. This is for the ALSA system to use, you can hang your >>own data off a substream using snd_pcm_substream_chip(). Besides, how do >>you plan on setting it in the snd_pcm_t type? >> >>I think that if you set up some controls, use the config file language, >>and have your audio apps open a 'voice' device, you can get where you >>want. >> >>Dave > >_______________________________________________ >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
