[mythtv-users] MythTV 0.24 HDMI audio problem

[Steven Adeff]

On Sat, Nov 27, 2010 at 5:20 PM, Jean-Yves Avenard <jyavenard at gmail.com> wrote:
> 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

yes, it showed two (I've since updated the motherboard firmware and
can now disable the motherboard audio).
but that is also what mine shows.


>> 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

I'm trying compiling alsa from scratch to see if that works. I don't
know why device 7 worked fine for everthing before then now it
doesn't, but I've been swapping back and forth between self-compiled
and the ricotz ppa for alsa drivers I don't really know what worked
when/why...

Device 7 is the only device that works, the other 3 output no sound no
matter what or how I try and send audio now. it used to work for all
the devices in mplayer, now both mplayer and myth only work with
device 7, and of course, now device 7 only works with 16bit audio.

could this be because I'm using the TV's edid and not the receiver's
passed through edid? perhaps I need to capture the edid as the
reciever reports it...



-- 
Steve
http://www.mythtv.org/wiki/User:Steveadeff
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