Audio broken (loud "machine-gun" noise) when attempting to play DVD images
#1
When I attempt to play a DVD image (ie: ripped and then put into an image using mkisofs --dvd-video) the video works fine but the audio is just a continual fast clicking/machine-gun kind of noise.

When playing other video sources (eg: HD MP4s) and navigating the UI, the sound is fine.

The same DVD images play fine with proper sound on a Mac running XBMC 9.04.1.

The system I'm having this problem with is a recent svn build on an Acer Revo running Ubuntu Jaunty. XBMC is running standalone.

The svn version currently running is r21746.

It's built with --disable-debug in an attempt to speed things up and thus eliminate dropped frames on HD playback, so I don't expect I have any debug output. :-) So at this stage I'm just hoping someone recognises the problem from the description and knows an easy fix before starting to rebuild with debug and so forth... :-)
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#2
You're using a .asoundrc or /etc/asound.conf? Sounds like a house-made ALSA issue.
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#3
vdrfan Wrote:You're using a .asoundrc or /etc/asound.conf? Sounds like a house-made ALSA issue.


I am using a ~/.asoundrc pasted in from another place that appeared to be necessary to get sound coming through the HDMI on the Acer Revo at all.

(And as noted, it works fine for other content, just doesn't seem to like DVD audio.)

Contents of this file:

Code:
# ~/.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 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
# hdmi out:
  device 3
}

# 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
}

Bet it's that pcm.dmix-digital section, but I have no idea what to do about it. Smile

TBH I'm starting to think I've done so much messing about with this system config to get this to work I should probably work up the energy to do a complete fresh reinstall. :-}
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#4
Solved the problem. :-) In my case I had to disable the options saying the receiver can support Dolby Digital (AC3) and DTS. It's just a TV and I guess it can't. :-) Disabling those forced XBMC to use the downmixing options it has.

In the process I upgraded ALSA to 1.0.20, but I don't think that was relevant. I also set default output to "plug:hdmi" rather than just "hdmi" but I'm not sure that was either (before disabling dolby-digital and DTS, and despite the alsa upgrade, it made no difference).

Oh, but I have lost the GUI sounds. But playback sound is fine. Ho-hum... I'm not using the ~/.asoundrc file quoted earlier; I suspect that may be required for the gui sounds now, but got caught up watching one of the stored DVDs so I'll test such stuff later...
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#5
Glad to hear it's working now.
Always read the online manual (wiki), FAQ (wiki) and search the forum before posting.
Do not PM or e-mail Team-Kodi members directly asking for support. Read/follow the forum rules (wiki).
Please read the pages on troubleshooting (wiki) and bug reporting (wiki) before reporting issues.
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Audio broken (loud "machine-gun" noise) when attempting to play DVD images0