[mythtv-users] Alsa SPDIF SP13000 (via8237)

Robin Gilks g8ecj at gilks.org
Mon Aug 14 09:47:50 UTC 2006


> Hi,
>
> For my machine :
>
> stella ~ # aplay -l
> **** List of PLAYBACK Hardware Devices ****
> card 0: V8237 [VIA 8237], device 0: VIA 8237 [VIA 8237]
>   Subdevices: 4/4
>   Subdevice #0: subdevice #0
>   Subdevice #1: subdevice #1
>   Subdevice #2: subdevice #2
>   Subdevice #3: subdevice #3
> card 0: V8237 [VIA 8237], device 1: VIA 8237 [VIA 8237]
>   Subdevices: 1/1
>   Subdevice #0: subdevice #0
> stella ~ # cat /proc/asound/pcm
> 00-01: VIA 8237 : VIA 8237 : playback 1 : capture 1
> 00-00: VIA 8237 : VIA 8237 : playback 4 : capture 1
>
> Looks pretty similar to what you have.  I use hw:0,1, and get nice rate
> converted sound output from mythmusic using the (pretty std) .asoundrc
> that's
> floating around the web.  I had what seemed to be the same problem as you
> after updating my alsa.  Check this out and see if it helps...
>
> http://forums.gentoo.org/viewtopic-t-485631-highlight-.html
>
>

OK, had a play with all that but set the amp to coax input and spdif works
but nowt else does. I've narrowed it down to hw:0,0,3 from the following
snippet of using Mike's asound.conf file against using the sdpif output
direct. I'm using a sample with a 48KHz rate to remove as many variables
as possible.

# aplay -v -D mixed-digital /usr/share/sounds/alsa/Rear_Center.wav
Playing WAVE '/usr/share/sounds/alsa/Rear_Center.wav' : Signed 16 bit
Little Endian, Rate 48000 Hz, Mono
Plug PCM: Route conversion PCM (sformat=S16_LE)
  Transformation table:
    0 <- 0
    1 <- 0
Its setup is:
  stream       : PLAYBACK
  access       : RW_INTERLEAVED
  format       : S16_LE
  subformat    : STD
  channels     : 1
  rate         : 48000
  exact rate   : 48000 (48000/1)
  msbits       : 16
  buffer_size  : 4096
  period_size  : 1024
  period_time  : 21333
  tick_time    : 0
  tstamp_mode  : NONE
  period_step  : 1
  sleep_min    : 0
  avail_min    : 1024
  xfer_align   : 1024
  start_threshold  : 4096
  stop_threshold   : 4096
  silence_threshold: 0
  silence_size : 0
  boundary     : 1073741824
Slave: Direct Stream Mixing PCM
Its setup is:
  stream       : PLAYBACK
  access       : MMAP_INTERLEAVED
  format       : S16_LE
  subformat    : STD
  channels     : 2
  rate         : 48000
  exact rate   : 48000 (48000/1)
  msbits       : 16
  buffer_size  : 4096
  period_size  : 1024
  period_time  : 21333
  tick_time    : 0
  tstamp_mode  : NONE
  period_step  : 1
  sleep_min    : 0
  avail_min    : 1024
  xfer_align   : 1024
  start_threshold  : 4096
  stop_threshold   : 4096
  silence_threshold: 0
  silence_size : 0
  boundary     : 1073741824
Hardware PCM card 0 'VIA 8237' device 0 subdevice 3
Its setup is:
  stream       : PLAYBACK
  access       : MMAP_INTERLEAVED
  format       : S16_LE
  subformat    : STD
  channels     : 2
  rate         : 48000
  exact rate   : 48000 (48000/1)
  msbits       : 16
  buffer_size  : 4096
  period_size  : 1024
  period_time  : 21333
  tick_time    : 1000
  tstamp_mode  : NONE
  period_step  : 1
  sleep_min    : 0
  avail_min    : 1024
  xfer_align   : 1024
  start_threshold  : 1
  stop_threshold   : 1073741824
  silence_threshold: 0
  silence_size : 1073741824
  boundary     : 1073741824



# aplay -v -D spdif /usr/share/sounds/alsa/Rear_Center.wav
Playing WAVE '/usr/share/sounds/alsa/Rear_Center.wav' : Signed 16 bit
Little Endian, Rate 48000 Hz, Mono
Hooks PCM
Its setup is:
  stream       : PLAYBACK
  access       : RW_INTERLEAVED
  format       : S16_LE
  subformat    : STD
  channels     : 1
  rate         : 48000
  exact rate   : 48000 (48000/1)
  msbits       : 16
  buffer_size  : 24000
  period_size  : 6000
  period_time  : 125000
  tick_time    : 1000
  tstamp_mode  : NONE
  period_step  : 1
  sleep_min    : 0
  avail_min    : 6000
  xfer_align   : 6000
  start_threshold  : 24000
  stop_threshold   : 24000
  silence_threshold: 0
  silence_size : 0
  boundary     : 1572864000
Slave: Hardware PCM card 0 'VIA 8237' device 0 subdevice 3
Its setup is:
  stream       : PLAYBACK
  access       : RW_INTERLEAVED
  format       : S16_LE
  subformat    : STD
  channels     : 1
  rate         : 48000
  exact rate   : 48000 (48000/1)
  msbits       : 16
  buffer_size  : 24000
  period_size  : 6000
  period_time  : 125000
  tick_time    : 1000
  tstamp_mode  : NONE
  period_step  : 1
  sleep_min    : 0
  avail_min    : 6000
  xfer_align   : 6000
  start_threshold  : 24000
  stop_threshold   : 24000
  silence_threshold: 0
  silence_size : 0
  boundary     : 1572864000


Still confounded...

-- 
Robin Gilks




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