[mythtv-users] Mythtv analog audio HELP!

Ray Whiteman ray.whiteman at consultant.com
Tue Dec 9 11:21:49 UTC 2008


Hello,

I have been battling with an analogue sound output problem for a couple 
days with a new myth front end I put together using old hardware. It is 
a clean install with back ports added to bring the FE up to my current 
backend FE config. My objective is to get the FE to playback DVB-T and 
PVR-150 sampled recordings via the FE to stereo speakers embedded in an 
old 4:3 CRT TV. I have tried with and without .asoundrc files, and every 
configuration of alsamixer I could think of as well as all the options 
in mythfrontend audio configuration.

My last configuration, which I thought was the closest, was the below 
configuration with the myth (Settings General > Audio) set to 
ALSA:mixed-analog

I am not categorically sure that the analog output is working hardware 
wise, I think it was, I just can't get a whimper out of it now. 
Everything looks correct to me. Sorry for the spam. ANy help would be 
seriously appreciated. I suspect this is something basic. :/

===================================================================
Hardware:
Asus P4P800-E
ALC850 sound (AC97)

===================================================================
Software:
Mythbuntu 7.10 with backports enabled (mythfrontend 0.21.20080304-1)

===================================================================
$sudo lspci -v

00:1f.5 Multimedia audio controller: Intel Corporation 82801EB/ER 
(ICH5/ICH5R) AC'97 Audio Controller (rev 02)
        Subsystem: ASUSTeK Computer Inc. Unknown device 812a
        Flags: bus master, medium devsel, latency 0, IRQ 22
        I/O ports at e800 [size=256]
        I/O ports at ee80 [size=64]
        Memory at f7fff800 (32-bit, non-prefetchable) [size=512]
        Memory at f7fff400 (32-bit, non-prefetchable) [size=256]
        Capabilities: [50] Power Management version 2

===================================================================
$ hwinfo --sound
21: PCI 1f.5: 0401 Multimedia audio controller
  [Created at pci.296]
  UDI: /org/freedesktop/Hal/devices/pci_8086_24d5
  Unique ID: W60f.GwekzbCBmC6
  SysFS ID: /devices/pci0000:00/0000:00:1f.5
  SysFS BusID: 0000:00:1f.5
  Hardware Class: sound
  Model: "ASUSTeK 82801EB/ER (ICH5/ICH5R) AC'97 Audio Controller"
  Vendor: pci 0x8086 "Intel Corporation"
  Device: pci 0x24d5 "82801EB/ER (ICH5/ICH5R) AC'97 Audio Controller"
  SubVendor: pci 0x1043 "ASUSTeK Computer Inc."
  SubDevice: pci 0x812a
  Revision: 0x02
  Driver: "Intel ICH"
  Driver Modules: "snd_intel8x0"
  I/O Ports: 0xe800-0xe8ff (rw)
  I/O Ports: 0xee80-0xeebf (rw)
  Memory Range: 0xf7fff800-0xf7fff9ff (rw,non-prefetchable)
  Memory Range: 0xf7fff400-0xf7fff4ff (rw,non-prefetchable)
  IRQ: 22 (19576 events)
  Module Alias: "pci:v00008086d000024D5sv00001043sd0000812Abc04sc01i00"
  Driver Info #0:
    Driver Status: snd_intel8x0 is active
    Driver Activation Cmd: "modprobe snd_intel8x0"
  Config Status: cfg=new, avail=yes, need=no, active=unknown

===================================================================
$ lsmod | grep snd
snd_intel8x0           34972  2
snd_ac97_codec        100644  1 snd_intel8x0
ac97_bus                3200  1 snd_ac97_codec
snd_pcm_oss            44672  0
snd_mixer_oss          17664  1 snd_pcm_oss
snd_pcm                80388  4 snd_intel8x0,snd_ac97_codec,snd_pcm_oss
snd_seq_dummy           4740  0
snd_seq_oss            33152  0
snd_seq_midi            9600  0
snd_rawmidi            25728  1 snd_seq_midi
snd_seq_midi_event      8448  2 snd_seq_oss,snd_seq_midi
snd_seq                53232  6 
snd_seq_dummy,snd_seq_oss,snd_seq_midi,snd_seq_midi_event
snd_timer              24324  2 snd_pcm,snd_seq
snd_seq_device          9228  5 
snd_seq_dummy,snd_seq_oss,snd_seq_midi,snd_rawmidi,snd_seq
snd                    54660  13 
snd_intel8x0,snd_ac97_codec,snd_pcm_oss,snd_mixer_oss,snd_pcm,snd_seq_oss,snd_rawmidi,snd_seq,snd_timer,snd_seq_device
soundcore               8800  1 snd
snd_page_alloc         11400  2 snd_intel8x0,snd_pcm

===================================================================
$dpkg -l \*alsa\* | grep ^ii
ii  alsa-base            1.0.14-1ubuntu2   ALSA driver configuration files
ii  alsa-utils           1.0.14-1ubuntu4   ALSA utilities
ii  libesd-alsa0         0.2.38-0ubuntu4.1 Enlightened Sound Daemon 
(ALSA) - Shared lib
ii  libsdl1.2debian-alsa 1.2.11-9ubuntu2   Simple DirectMedia Layer 
(with X11 and ALSA
ii  xfce4-mixer-alsa     1:4.4.1-3ubuntu1  Xfce4 Mixer ALSA backend

===================================================================
$aplay -l
**** List of PLAYBACK Hardware Devices ****
card 0: ICH5 [Intel ICH5], device 0: Intel ICH [Intel ICH5]
  Subdevices: 0/1
  Subdevice #0: subdevice #0
card 0: ICH5 [Intel ICH5], device 4: Intel ICH - IEC958 [Intel ICH5 - 
IEC958]
  Subdevices: 1/1
  Subdevice #0: subdevice #0

===================================================================
$ aplay -L
front:CARD=ICH5,DEV=0
    Intel ICH5, Intel ICH5
    Front speakers
surround40:CARD=ICH5,DEV=0
    Intel ICH5, Intel ICH5
    4.0 Surround output to Front and Rear speakers
surround41:CARD=ICH5,DEV=0
    Intel ICH5, Intel ICH5
    4.1 Surround output to Front, Rear and Subwoofer speakers
surround50:CARD=ICH5,DEV=0
    Intel ICH5, Intel ICH5
    5.0 Surround output to Front, Center and Rear speakers
surround51:CARD=ICH5,DEV=0
    Intel ICH5, Intel ICH5
    5.1 Surround output to Front, Center, Rear and Subwoofer speakers
null
    Discard all samples (playback) or generate zero samples (capture)

===================================================================
$ cat .asoundrc
# ~/.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 (unmixed) "analog" by default
#  slave.pcm "analog-hw"
## 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 4
#  - 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
}




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