localhost ~ # aplay -D hw:0,7 /dev/zero --dump-hw-params
Playing raw data '/dev/zero' : Unsigned 8 bit, Rate 8000 Hz, Mono
HW Params of device "hw:0,7":
--------------------
ACCESS:  MMAP_INTERLEAVED RW_INTERLEAVED
FORMAT:  S16_LE S32_LE
SUBFORMAT:  STD
SAMPLE_BITS: [16 32]
FRAME_BITS: [32 192]
CHANNELS: [2 6]
RATE: [32000 48000]
PERIOD_TIME: [125 8192000]
PERIOD_SIZE: [6 262144]
PERIOD_BYTES: [128 6291456]
PERIODS: [2 32]
BUFFER_TIME: [250 16384000]
BUFFER_SIZE: [12 524288]
BUFFER_BYTES: [128 2097152]
TICK_TIME: ALL
--------------------
aplay: set_params:1341: Sample format non available
Available formats:
- S16_LE
- S32_LE