Hi David, > AFAIK, the driver should support what the hardware supports. Yes. It's my intent to add the rules between channels/rates. Well, today I did some tests for an idea to use 'plug' plugin. > 1) Edit /usr/share/pulseaudio/alsa-mixer/profile-sets/default.conf > and change "hw:%f" to "plughw:%f" in the section > "Mapping analog-stereo". If the plughw plugin can upscale, > then that should make things work. This wasn't good. Then I remembered this fact: > Hm. Actually PulseAudio tries opening "plug:hw:1" too and setting the > channel number to two fails in that case too. If the "plug" plugin can > change the number of channels, then that should have been working. Then I debug PulseAudio/libasound in a point of 'how to open ALSA PCM handle'. I have an presumption that 'plug' plugin can upscale channels correctly if PulseAudio open 'plug:hw' device as the same way as normal-aplay open. As a result, I got a conviction that 'SND_PCM_NO_AUTO_CHANNELS' flag for snd_pcm_open() disables upscaling. I can reproduce it with this program (it's too rough): http://ubuntuone.com/4T5tqqiioUZMFBe4d5I4Zn So I conclude we cannot use 'plug' plugin for this purpose. Would you please confirm this in your side? And for these two options below, I need more time to test. > To aid for applications, one can add custom per-card mapping in > alsa-lib - e g, look at /usr/share/alsa/cards/ICE1712.conf where you > can open the device "front:<card>" with two channels and it > automatically upscales to 10 or 12 channels. > 2) Alternatively, you could add channels to your mapping: > channel-map = > left,right,aux0,aux1,aux2,aux3,aux4,aux5,aux6,aux7, > aux8,aux9,aux10,aux11 Thanks for your help Takashi Sakamoto o-takashi at sakamocchi.jp
