Alsa can't play 88.2/24 files via DAC

aliensub · 09-24-2015, 04:44 PM

Hello,

I have a weird issue with Alsa. For some reason it decline to play 88.2/24 files via my Nuforce Icon HDP DAC on my desktop computer

96/24 files works fine, so does 88.2/16 files.

On my laptop it works perfectly fine (both run Ubuntu 14.04).

When running mpd -v --no-daemon --stdout, I get the following info:

Code:

decoder: audio_format=88200:24:2, seekable=true
client: [0] process command "currentsong"
client: [0] command returned 0
client: [0] process command "idle"
client: [0] command returned 1
output: closed plugin=alsa name="My ALSA Device"
alsa_output: opened hw:2,0 type=HW
alsa_output: format=S24_3LE (Signed 24 bit Little Endian in 3bytes)
alsa_output: buffer: size=178..174762 time=2018..1981429
alsa_output: period: size=89..87381 time=1009..990715
alsa_output: default period_time = buffer_time/4 = 500000/4 = 125000
alsa_output: Failed to open "My ALSA Device" [alsa]: Error opening ALSA device "hw:2,0" (snd_pcm_hw_params): Invalid argument
output: Failed to open audio output
player: problems opening audio device while playing "Seal/Best 1991 2004/1-Crazy.flac"

Trying via aplay, returns the following:

Code:

aplay -f S24_3LE -D hw:2,0 -c2 -r88200 1-Crazy.flac
Playing raw data '1-Crazy.flac' : Signed 24 bit Little Endian in 3bytes, Rate 88200 Hz, Stereo
aplay: set_params:1297: Unable to install hw params:
ACCESS:  RW_INTERLEAVED
FORMAT:  S24_3LE
SUBFORMAT:  STD
SAMPLE_BITS: 24
FRAME_BITS: 48
CHANNELS: 2
RATE: 88200
PERIOD_TIME: 125000
PERIOD_SIZE: 11025
PERIOD_BYTES: 66150
PERIODS: 4
BUFFER_TIME: 500000
BUFFER_SIZE: 44100
BUFFER_BYTES: 264600
TICK_TIME: 0

Any ideas what could cause this?

aliensub · 09-25-2015, 04:16 PM

Just tried to cat /proc/asoun/DAC/stream0, and here it's reporting that it doesn't support 24 bit at 88.2. It's really odd.....

Code:

Nuforce, Inc. Nuforce Icon HDP DAC at usb-0000:00:1d.0-1.7.1, full speed : USB Audio

Playback:
  Status: Stop
  Interface 3
    Altset 1
    Format: S16_LE
    Channels: 2
    Endpoint: 3 OUT (ADAPTIVE)
    Rates: 8000, 16000, 32000, 44100, 48000, 88200, 96000
  Interface 3
    Altset 2
    Format: S24_3LE
    Channels: 2
    Endpoint: 3 OUT (ADAPTIVE)
    Rates: 44100, 48000, 96000

jimmy.kl · 10-13-2015, 01:13 AM

Hi,

I don't think it's an ALSA/Linux issue, rather the HDP itself.

According to this post (and other specs search for '88.2') the HDP doesn't support 88.2 via USB. Only through coax or optical SPDIF.

I can confirm on my Mac Mini I can't set the output to 88.2 in OS X's Audio MIDI setup when it's connected via USB but I can with optical.

Of course that doesn't explain how you'd be getting output from 88.2/16 files!