Get max audio channels available from alsasink

[pavel]

Hi,

> Thanks a lot for your quick response! Unfortunately, amixer does not return
> all available channels for my sound interfaces (tested with different ones).

Amixer lists controls provided by the driver and alsa-lib stack above it.

Hardware capabilities of your soundcard can be listed e.g. with

aplay --dump-hw-params -D hw:3 /usr/share/sounds/alsa/Front_Center.wav
Playing WAVE '/usr/share/./sounds/alsa/Front_Center.wav' : Signed 16 bit 
Little Endian, Rate 48000 Hz, Mono
HW Params of device "hw:3":
--------------------
ACCESS:  MMAP_INTERLEAVED RW_INTERLEAVED
FORMAT:  S32_LE
SUBFORMAT:  STD
SAMPLE_BITS: 32
FRAME_BITS: 64
CHANNELS: 2
RATE: [44100 192000]
PERIOD_TIME: (41 371520)
PERIOD_SIZE: [8 16384]
PERIOD_BYTES: [64 131072]
PERIODS: [2 1024]
BUFFER_TIME: (83 743039)
BUFFER_SIZE: [16 32768]
BUFFER_BYTES: [128 262144]
TICK_TIME: ALL


The dump is provided by snd_pcm_hw_params_dump of alsa-lib.

Best regards,

Pavel.