On Sun, 18.01.09 10:22, Jon Smirl (jonsmirl at gmail.com) wrote: > I definitely have two playback devices: > > jonsmirl at terra:/etc$ hal-device | grep playback > 28: udi = '/org/freedesktop/Hal/devices/pci_8086_284b_alsa_playback_1' > info.udi = '/org/freedesktop/Hal/devices/pci_8086_284b_alsa_playback_1' > (string) > alsa.type = 'playback' (string) > 29: udi = '/org/freedesktop/Hal/devices/pci_8086_284b_alsa_playback_0' > info.udi = '/org/freedesktop/Hal/devices/pci_8086_284b_alsa_playback_0' > (string) > alsa.type = 'playback' (string) > jonsmirl at terra:/etc$ > > playback_0 is analog out > playback_1 is SPDIF out > > module module-hal-detect does not load the second one. Things are not always as easy as they might seem. Currently ALSA exports no way to find out what ways to access the audio devices are exclusive and what ways are not. Also it is generally not defined what an ALSA "subdevice" actually refers to. In your case #0 and #1 are each independant PCMs as it appears. However for other cards #1 might be the front speakers of a suround setup, #1 the rear speakers and so on. The actual logic mapping of these subdevices is done by the device strings "front:", "iec958:", "surround51:" and so on in ALSA userspace. Also, on some devices you can either do 7.1 playback and no recording, or you can do stereo duplex -- but you cannot do 7.1 playback and stereo recording. Similar limitations can apply with the combination of SPDIF and other ways to access the audio device for playback/capturing. There is just no way right now to automatically discover the subdevices we can use independantly and which ones we cannot. In current git there are the beginnings of a logic that autoprobes the available "profiles" and their possible combinations and then allows to switch between them dynamically during runtime. This is still very much incomplete however. (Load module-alsa-card into your server instead of module-alsa-source/-sink and it will show you the possible configs of your card when you do an "ls-cards" in pacmd). Doing this autoprobing is ugly and slow, but the easiest way for now to overcome this limitation in the underlying ALSA layers for now. In summary: supporting multiple subdevices and SPDIF like this is much more difficult then it might appear, but I am working on it. Also see #139. Lennart -- Lennart Poettering Red Hat, Inc. lennart [at] poettering [dot] net ICQ# 11060553 http://0pointer.net/lennart/ GnuPG 0x1A015CC4
