[mythtv-users] Audio problems with .20 and optiocal spdif

Nathan A. Smith nasa01 at comcast.net
Mon Oct 9 21:34:06 UTC 2006


Hi,

I am running a mythtv box based on Mandriva 2007 on a AMD 3200xp (Dual
core) on an AM2 chipset.  I am attempting to get audio out to my stereo
via an optical s/pidf cable.  When I play music/video via mythtv I am
getting a lot of noise out of my right speaker, while sound from my left
speaker sounds about right.  I can play audio files via mplayer (via the
user that runs mythtv) without any issues.  Hopefully, someone can hear
my cries for help and lend me a hand :}


Nasa

Here comes the system info:

uname -a
Linux mythtv 2.6.17-5mdv #1 SMP Wed Sep 13 14:32:31 EDT 2006 i686 AMD
Athlon(tm) 64 X2 Dual Core Processor 3800+ GNU/Linux

/sbin/lsmod|grep '^snd' 
snd_seq_dummy           3620  0 
snd_seq_oss            31392  0 
snd_seq_midi_event      7072  1 snd_seq_oss
snd_seq                49488  5
snd_seq_dummy,snd_seq_oss,snd_seq_midi_event
snd_seq_device          7212  3 snd_seq_dummy,snd_seq_oss,snd_seq
snd_pcm_oss            40384  0 
snd_mixer_oss          16096  1 snd_pcm_oss
snd_hda_intel          15828  0 
snd_hda_codec         164544  1 snd_hda_intel
snd_pcm                70116  3 snd_pcm_oss,snd_hda_intel,snd_hda_codec
snd_timer              19620  2 snd_seq,snd_pcm
snd_page_alloc          8712  2 snd_hda_intel,snd_pcm
snd                    46500  9
snd_seq_oss,snd_seq,snd_seq_device,snd_pcm_oss,snd_mixer_oss,snd_hda_intel,snd_hda_codec,snd_pcm,snd_timer


 aplay -l 
**** List of PLAYBACK Hardware Devices ****
card 0: NVidia [HDA NVidia], device 0: ALC883 Analog [ALC883 Analog]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 0: NVidia [HDA NVidia], device 2: ALC883 Digital [ALC883 Digital]
  Subdevices: 1/1
  Subdevice #0: subdevice #0

**************************************************************************

# ~/.asoundrc or /etc/asound.conf
# ALSA configuration file

##### USAGE #####
# Save this file as "~/.asoundrc" (for user-specific sound
configuration) or
# "/etc/asound.conf" (for system-wide sound configuration) and specify
ALSA
# device names ad described in the next section.


##### DEVICE NAMES #####
# This configuration file defines four devices for use by the user.
Those
# devices are "analog", "mixed-analog", "digital", and "mixed-digital".
The
# user may also re-define "default" to be identical to one of the
above-named
# devices (i.e. to send all sound output to the digital output unless
otherwise
# specified).  Use the device names as described below:
#  - "analog" outputs to the analog output directly and (at least on
software
#  sound cards) blocks other audio output.  After playback completes,
"queued"
#  sounds are output in sequence.
#  - "mixed-analog" mixes audio output from multiple programs into the
analog
#  output (so you can hear beeps, alerts, and other noises while playing
back
#  an audio stream).
#  - "digital" outputs to the digital output directly.  Since most
(all?)
#  digital outputs expect 48kHz PCM audio, this may not work for some
playback
#  (i.e. CD's--which are 44.1kHz PCM audio--or 32kHz audio streams from
TV
#  recordings, etc.).
#  - "mixed-digital"

# All other devices created within this file are used only by the
configuration
# file itself and should /not/ be used directly.  In other words, do not
use
# the devices "analog-hw", "dmix-analog", "digital-hw", or
"dmix-digital".


##### IMPORTANT #####
# To make this ALSA configuration file work with your sound card, you
will need
# to define the appropriate card and device information for the
"analog-hw" and
# "digital-hw" devices below.  You can find the card and device
information
# using "aplay -l".


##### Configuration File #####
  
# Override the default output used by ALSA.  If you do not override the
# default, your default device is identical to the (unmixed) "analog"
device
# shown below.  If you prefer mixed and/or digital output, uncomment the
# appropriate four lines below (only one slave.pcm line).
#
# Note, also, that as of ALSA 1.0.9, "software" sound cards have been
modified
# such that their default "default" device is identical to the
"mixed-analog"
# device.  Whether using an ALSA version before or after 1.0.9, it does
no harm
# and has no affect on performance to redefine the device (even if the
# redefinition does not change anything).  Also, by using this ALSA
# configuration file, you once again have access to unmixed analog
output using
# the "analog" device.
pcm.!default {
  type plug
## Uncomment the following to use "mixed-analog" by default
#  slave.pcm "dmix-analog"
## Uncomment the following to use (unmixed) "digital" by default
  slave.pcm "digital-hw"
## Uncomment the following to use "mixed-digital" by default
#  slave.pcm "dmix-digital"
}
  
# Control device (mixer, etc.) for the card
# file itself and should /not/ be used directly.  In other words, do not
use
# the devices "analog-hw", "dmix-analog", "digital-hw", or
"dmix-digital".


##### IMPORTANT #####
# To make this ALSA configuration file work with your sound card, you
will need
# to define the appropriate card and device information for the
"analog-hw" and
# "digital-hw" devices below.  You can find the card and device
information
# using "aplay -l".


##### Configuration File #####

# Override the default output used by ALSA.  If you do not override the
# default, your default device is identical to the (unmixed) "analog"
device
# shown below.  If you prefer mixed and/or digital output, uncomment the
# appropriate four lines below (only one slave.pcm line).
#
# Note, also, that as of ALSA 1.0.9, "software" sound cards have been
modified
# such that their default "default" device is identical to the
"mixed-analog"
# device.  Whether using an ALSA version before or after 1.0.9, it does
no harm
# and has no affect on performance to redefine the device (even if the
# redefinition does not change anything).  Also, by using this ALSA
# configuration file, you once again have access to unmixed analog
output using
# the "analog" device.
pcm.!default {
  type plug
## Uncomment the following to use "mixed-analog" by default
#  slave.pcm "dmix-analog"
## Uncomment the following to use (unmixed) "digital" by default
  slave.pcm "digital-hw"
## Uncomment the following to use "mixed-digital" by default
#  slave.pcm "dmix-digital"
}
  
# Control device (mixer, etc.) for the card
ctl.!default {
  type hw
  card 0
}

# Alias for (converted) analog output on the card
# - This is identical to the device named "default"--which always exists
and
# refers to hw:0,0 (unless overridden)
# - Therefore, we can specify "hw:0,0", "default", or "analog" to access
analog
# output on the card
# - Note that as of ALSA 1.0.9, "software" sound card definitions
redefine
# "default" to do mixing, meaning this device is different from
"default" and
# allows playback while blocking other sound sources (until playback
# completes).
pcm.analog {
  type plug
  slave.pcm "analog-hw"
}

# Control device (mixer, etc.) for the card
ctl.analog {
  type hw
  card 0
}

# Alias for (converted) mixed analog output on the card
# - This will accept audio input--regardless of rate--and convert to the
rate
# required for the dmix plugin (in this case 48000Hz)
# - Note that as of ALSA 1.0.9, "software" sound card definitions
redefine
# "default" to do mixing, meaning this device is identical to "default"
for
# "software" sound cards.
pcm.mixed-analog {
  type plug
  slave.pcm "dmix-analog"
}

# Control device (mixer, etc.) for the card
ctl.mixed-analog {
  type hw
  card 0
}

# Alias for (converted) digital (S/PDIF) output on the card
# - This will accept audio input--regardless of rate--and convert to the
rate
# required for the S/PDIF hardware (in this case 48000Hz)
pcm.digital {
  type plug
  slave.pcm "digital-hw"
}

# Control device (mixer, etc.) for the card
ctl.digital {
  type hw
  card 0
}

# Alias for mixed (converted) digital (S/PDIF) output on the card
#  - This will accept audio input--regardless of rate--and convert to
the rate
#  required for the S/PDIF hardware (in this case 48000Hz)
pcm.mixed-digital {
  type plug
  slave.pcm "dmix-digital"
}

# Control device (mixer, etc.) for the card
ctl.mixed-digital {
  type hw
  card 0
}

# The following devices are not useful by themselves.  They require
specific
# rates, channels, and formats.  Therefore, you probably do not want to
use
# them directly.  Instead use of of the devices defined above.

# Alias for analog output on the card
# Do not use this directly--it requires specific rate, channels, and
format
pcm.analog-hw {
  type hw
  card 0
  # The default value for device is 0, so no need to specify
#  - Uncomment one of the below or create a new "device N" line as
appropriate
#    for your sound card or 
#  device 1
#  device 4
}

# Control device (mixer, etc.) for the card
ctl.analog-hw {
  type hw
  card 0
}
# Alias for digital (S/PDIF) output on the card
# Do not use this directly--it requires specific rate, channels, and
format
pcm.digital-hw {
  type hw
  card 0
  device 1
#  - Comment out "device 1" above and uncomment one of the below or
create a
#    new "device N" line as appropriate for your sound card or 
  device 2
#  device 4
}

# Control device (mixer, etc.) for the card
ctl.digital-hw {
  type hw
  card 0
}

# Direct software mixing plugin for analog output on the card
# Do not use this directly--it requires specific rate, channels, and
format
pcm.dmix-analog {
  type dmix
  ipc_key 1234
  slave {
    pcm "analog-hw"
    period_time 0
    period_size 1024
    buffer_size 4096
    rate 48000
  }
}

# Control device (mixer, etc.) for the card
ctl.dmix-analog {
  type hw
  card 0
}

# Direct software mixing plugin for digital (S/PDIF) output on the card
# Do not use this directly--it requires specific rate, channels, and
format
pcm.dmix-digital {
  type dmix
  ipc_key 1235
  slave {
    pcm "digital-hw"
    period_time 0
    period_size 1024
    buffer_size 4096
    rate 48000
  }
}

# Control device (mixer, etc.) for the card
ctl.dmix-digital {
  type hw
  card 0
}

*********************************************************************************
scanpci:
...
pci bus 0x0000 cardnum 0x06 function 0x01: vendor 0x10de device 0x0371
 nVidia Corporation MCP55 High Definition Audio
....

 amixer
Simple mixer control 'Headphone',0
  Capabilities: pswitch
  Playback channels: Front Left - Front Right
  Mono:
  Front Left: Playback [on]
  Front Right: Playback [on]
Simple mixer control 'Front',0
  Capabilities: pvolume pswitch
  Playback channels: Front Left - Front Right
  Limits: Playback 0 - 31
  Mono:
  Front Left: Playback 25 [81%] [-9.00dB] [on]
  Front Right: Playback 25 [81%] [-9.00dB] [on]
Simple mixer control 'Front Mic',0
  Capabilities: pvolume pswitch
  Playback channels: Front Left - Front Right
  Limits: Playback 0 - 31
  Mono:
  Front Left: Playback 25 [81%] [3.00dB] [on]
  Front Right: Playback 25 [81%] [3.00dB] [on]
Simple mixer control 'Surround',0
  Capabilities: pvolume pswitch
  Playback channels: Front Left - Front Right
  Limits: Playback 0 - 31
  Mono:
  Front Left: Playback 25 [81%] [-9.00dB] [on]
  Front Right: Playback 25 [81%] [-9.00dB] [on]
Simple mixer control 'Center',0
  Capabilities: pvolume pvolume-joined pswitch pswitch-joined
  Playback channels: Mono
  Limits: Playback 0 - 31
  Mono: Playback 25 [81%] [-9.00dB] [on]
Simple mixer control 'LFE',0
  Capabilities: pvolume pvolume-joined pswitch pswitch-joined
  Playback channels: Mono
  Limits: Playback 0 - 31
  Mono: Playback 25 [81%] [-9.00dB] [on]
Simple mixer control 'Line',0
  Capabilities: pvolume pswitch
  Playback channels: Front Left - Front Right
  Limits: Playback 0 - 31
  Mono:
  Front Left: Playback 25 [81%] [3.00dB] [on]
  Front Right: Playback 25 [81%] [3.00dB] [on]
Simple mixer control 'CD',0
  Capabilities: pvolume pswitch
  Playback channels: Front Left - Front Right
  Limits: Playback 0 - 31
  Mono:
  Front Left: Playback 25 [81%] [3.00dB] [on]
  Front Right: Playback 25 [81%] [3.00dB] 
Simple mixer control 'Mic',0
  Capabilities: pvolume pswitch
  Playback channels: Front Left - Front Right
  Limits: Playback 0 - 31
  Mono:
  Front Left: Playback 0 [0%] [-34.50dB] [off]
  Front Right: Playback 0 [0%] [-34.50dB] [off]
Simple mixer control 'IEC958',0
  Capabilities: pswitch pswitch-joined
  Playback channels: Mono
  Mono: Playback [on]
Simple mixer control 'Capture',0
  Capabilities: cvolume cswitch
  Capture channels: Front Left - Front Right
  Limits: Capture 0 - 31
  Front Left: Capture 0 [0%] [-12.00dB] [on]
  Front Right: Capture 0 [0%] [-12.00dB] [on]
Simple mixer control 'Capture',1
  Capabilities: cvolume cswitch
  Capture channels: Front Left - Front Right
  Limits: Capture 0 - 31
  Front Left: Capture 0 [0%] [-12.00dB] [on]
  Front Right: Capture 0 [0%] [-12.00dB] [on]
Simple mixer control 'Input Source',0
  Capabilities: enum
  Items: 'Mic' 'Front Mic' 'Line' 'CD'
  Item0: 'Line'
Simple mixer control 'Input Source',1
  Capabilities: enum
  Items: 'Mic' 'Front Mic' 'Line' 'CD'
  Item0: 'Line'






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