[mythtv-users] Not getting Dolby Prologic out of s/pdif

[Steven Adeff]

On 3/15/06, Matt <skd5aner at gmail.com> wrote:
> On 3/15/06, Steven Adeff <adeffs.mythtv at gmail.com> wrote:
> > On 3/15/06, Matt <skd5aner at gmail.com> wrote:
> > > On 3/15/06, Steve Skarda <steveskarda at gmail.com> wrote:
> > > > Make sure you have use video as timebase turned off in the playback
> > > > settings.   Having it checked will allow digital signals to work but AC3
> > > > passthrough won't.   Not sure if that is related to your problem or not.
> > >
> > > It is turned off.
> > >
> > > Let me just try to quickly sum up my issue:
> > >
> > > 1) I receive HDTV OTA ATSC signal via HD5000
> > > 2) The first audio track says it's AC3 5.1
> > > 3) Receiver set to "AFD" - Auto Format Decode
> > > 4) When it receives the signal, the LCD on the receiver doesn't do
> > > anything (doesn't say what kind of signal it is receiving" and I can
> > > hear noice out of my left and right channels, but never the full
> > > signal (missing voices, etc).
> > > 5) If I switch the receiver to "Normal Surround" I'll get the
> > > channels, but the receiver NEVER says it's decoding AC3.
> > > 6) If I play a Standard Def recording from my PVR250/500, the receiver
> > > will get the signal and say it's playing a PCM signal.
> > >
> > > I think I'm going to submit a ticket, but before I do that, what else
> > > should I do/try/troubleshoot?
> > >
> > > Thanks!
> > > Matt
> >
> > sounds like you don't have ALSA set up to pass AC3 signals, thus they
> > are being sent as stereo pcm. search the list/wiki and you should find
> > information on how to enable AC3 using .asoundrc
> >
>
> Correct me if I'm wrong, but I believe I do.  Here's my .asoundrc:
>
> Here's my .asoundrc 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).
> 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"
> }

Here's my asoundrc file, as well I have "ALSA:digital" for my audio
output device in MythTV...

# 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).
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"
# slave.pcm "digital-hw"
## Uncomment the following to use mixed digital by default
# slave.pcm "dmix-digital"
}

# Alias for analog output on the nForce2 (hw:0,0)
# - 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 nForce2
pcm.analog {
 type plug
 slave.pcm "analog-hw"
}

# Control device (mixer, etc.) for the nForce2 card
ctl.analog {
 type hw
 card 0
}

# Alias for (rate-converted) mixed analog output on the
# nForce2 (hw:0,0)
# - This will accept audio input--regardless of rate--and
# convert to the rate required for the dmix plugin
# (in this case 48000Hz)
pcm.mixed-analog {
 type plug
 slave.pcm "dmix-analog"
}

# Control device (mixer, etc.) for the nForce2 card
ctl.mixed-analog {
 type hw
 card 0
}

# Alias for (rate-converted) digital (S/PDIF) output on the
# nForce2 (hw:0,2)
# - 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 nForce2 card
ctl.digital {
 type hw
 card 0
}

# Alias for mixed (rate-converted) digital (S/PDIF) output on the
# nForce2 (hw:0,2)
# - 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 nForce2 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 nForce2 (hw:0,0)
# 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
}

# Control device (mixer, etc.) for the nForce2 card
ctl.analog-hw {
 type hw
 card 0
}

# Alias for digital (S/PDIF) output on the nForce2 (hw:0,2)
# Do not use this directly--it requires specific rate,
# channels, and format
pcm.digital-hw {
 type hw
 card 0
 device 2
}

# Control device (mixer, etc.) for the nForce2 card
ctl.digital-hw {
 type hw
 card 0
}

# Direct software mixing plugin for analog output on
# the nForce2 (hw:0,0)
# 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 nForce2 card
ctl.dmix-analog {
 type hw
 card 0
}

# Direct software mixing plugin for digital (S/PDIF) output
# on the nForce2 (hw:0,2)
# 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 nForce2 card
ctl.dmix-digital {
 type hw
 card 0
}

--
Steve