[mythtv-users] MythTV 0.24 HDMI audio problem

[Jean-Yves Avenard]

Hi

On 28 November 2010 08:51, Steven Adeff <adeffs.mythtv at gmail.com> wrote:
> I've never wanted to throw something out the window more than I do right now.
>
> I don't know what I did, but now things seem to be working.
>
> Actually, I can tell you what I did. I was having another "issue" I
> decided to fix since I didn't know what more to do until you had a
> chance to respond. What I have is my Myth frontend running via HDMI to
> my pre-amp which then connects to the TV. Because of this chain and
> how my pre-amp works if the receiver and tv were off when turning on
> Myth, X would get no video edid information and then start up at
> 800x600. So I decided to capture the TV edid directly (reconnect the
> HDMI cables temporarily) to a file and have the nvidia driver load
> that custom edid. So I got that working (easy) after a reboot.

I was about to suggest that when I hit the reply button.


>
> So I figured I'd keep playing around. This time when I scanned I got
> these devices as options:
> ALSA:hw:CARD=NVidia_1,DEV=
> with devices 3,7,8,9!

so aplay -L shows more than one hdmi device?

On my machine, aplay -L only shows one hdmi
aplay -l on the other hand, shows 4:
**** List of PLAYBACK Hardware Devices ****
card 0: NVidia [HDA NVidia], device 3: NVIDIA HDMI [NVIDIA HDMI]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 0: NVidia [HDA NVidia], device 7: NVIDIA HDMI [NVIDIA HDMI]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 0: NVidia [HDA NVidia], device 8: NVIDIA HDMI [NVIDIA HDMI]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 0: NVidia [HDA NVidia], device 9: NVIDIA HDMI [NVIDIA HDMI]
  Subdevices: 1/1
  Subdevice #0: subdevice #0


>
> so I tried 7 and lo and behold, it works! well, it works with DEV=7
> for AC3/DTS and 48KHz stereo,  but now my HD audio (24/96) gets down
> converted. in the audio setup myth says device 3, 8 and 9 all support
> AC3/DTS/LPCM but that device 7 only supports AC3/LPCM.
> But this seems to be an ALSA issue because if I try to play the HD
> audio via mplayer it also downconverts.

probably related to what alsa reports for your device. Probably only
16 bits audio.

What you can do then is use one of the device for passthrough and
another for LPCM , HD-AUDIO

Use DEV=7 in the advance passthrough section, and try another DEV= for
the main audio device