[mythtv-users] Issues with audio over HDMI

Andrew Close aclose at gmail.com
Sun Jan 18 17:31:23 UTC 2009


On Sun, Jan 18, 2009 at 8:48 AM, Phil Wild <philwild at gmail.com> wrote:
>
>
> 2009/1/18 Phil Wild <philwild at gmail.com>
>>
>> Hello all,
>>
>> I am chasing some expert advice...
>>
>> I am building my first MythTV frontend. I have an Asus m3n78-em
>> motherboard with onboard HDMI. I have install mythbuntu amd64. I have
>> upgraded alsa to 1.0.18.
>>
>> I can send audio to the TV through hdmi using aplay
>>
>> e.g. aplay /usr/share/sounds/card_shuffle.wav
>>
>> aplay -l lists
>>
>> root at juliette:~# aplay -l
>> **** List of PLAYBACK Hardware Devices ****
>> card 0: NVidia [HDA NVidia], device 0: ALC1200 Analog [ALC1200 Analog]
>>   Subdevices: 1/1
>>   Subdevice #0: subdevice #0
>> card 0: NVidia [HDA NVidia], device 1: ALC1200 Digital [ALC1200 Digital]
>>   Subdevices: 1/1
>>   Subdevice #0: subdevice #0
>> card 0: NVidia [HDA NVidia], device 3: NVIDIA HDMI [NVIDIA HDMI]
>>   Subdevices: 1/1
>>   Subdevice #0: subdevice #0
>> root at juliette:~#
>>
>>
>> and I have setup a default entry in /etc/asound.conf as
>>
>> pcm.!default {
>>         type hw
>>         card 0
>>         device 3
>> }
>>
>> From within mythtv, I can send sound and video to the screen from an apple
>> movie trailer, but with liveTV or a recording from my backend with a Nova-T
>> 500, I get no sound. I am trying to figure out if the sound issue is a
>> backend problem or a frontend problem.
>>
>> Where should I be looking?
>
> I have gotten a little further and now know my issue is somehow related to
> mythtv. I have exported my backend recordings directory and have mounted it
> on my frontend via nfs. This allowed my to open one of the .mpg files with
> mplayer and it played on the TV with audio through the hdmi cable.
>
> MythTV however, does not give me audio from live TV or recordings..
>
> Cheers
>
> Phil

hi Phil, looks like we're in a similar boat on this one.  and you
nicely replied to my 'YAAT' :)  i believe that audio via HDMI using
the Realtek chips and Intel snd_hda_intel drivers is hit or miss at
the moment.  cool that you can get it working with mplayer.
one thing to try, in MythTv frontend, Utilites/Setup -> setup ->
General (pg3) you'll see audio settings for Myth.  try the following
settings:

Audio output device: ALSA:spdif
Passthrough output device: ALSA:iec958:{AES0 0x02}
Max Audio Channels: Stereo
Upmix: Passive
Enable AC3 to SPDIF passthrough (checked)
Enable DTS to SPDIF passthrough (checked)
Aggressive Sound card Buffering (UNchecked)
User internal volume controls (UNchecked)

now for the caveat.  you may need to play around with these settings,
and since you aren't using SPDIF, see if you can change that first
dropdown to ALSA:device=hw=0,3 or something similar to use your HDMI,
instead of SPDIF.
keep us updated :)


-- 
Andrew Close


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