[mythtv-users] MythTV 0.24 HDMI audio problem

[Steven Adeff]

On Sat, Nov 27, 2010 at 4:04 PM, Jean-Yves Avenard <jyavenard at gmail.com> wrote:
> On Sunday, November 28, 2010, Steven Adeff <adeffs.mythtv at gmail.com> wrote:
>> On Wed, Nov 24, 2010 at 4:27 PM, Steven Adeff <adeffs.mythtv at gmail.com> wrote:
>>> On Wed, Nov 24, 2010 at 10:06 AM, Jean-Yves Avenard <jyavenard at gmail.com> wrote:
>>>> The fixes have been backported to 0.24-fixes.
>>>>
>>>> If you use an HDMI TV or amplifier that only supports stereo PCM but
>>>> supports 5.1 with AC3/DTS; you will have to go in the Audio Settings
>>>> and check Advance Audio Configuration and Stereo PCM only.
>>>>
>>>> Jean-Yves
>>>
>>> Great, will give it a go and let you know. Thanks for the work JYA!
>>
>> I've updated to the 27352 mythbuntu auto-build.
>>
>> What I've noticed: when I scan and use ALSA:hdmi:CARD=NVidia_1 I get
>> the following frontend output
>>
>> 2010-11-27 12:16:34.373 AFD: Opened codec 0x971a5b90, id(H264) type(Video)
>> 2010-11-27 12:16:34.374 AFD: codec AC3 has 1 channels
>> 2010-11-27 12:16:34.375 AFD: Opened codec 0x971b1d30, id(AC3) type(Audio)
>> 2010-11-27 12:16:34.588 AO: Opening audio device 'hdmi:CARD=NVidia_1'
>> ch 2(1) sr 48000 sf signed 16 bit reenc 0
>> 2010-11-27 12:16:34.617 AudioPlayer: Enabling Audio
>>
>> but no sound over HDMI
>>
>> If I go back to use the old ALSA:hw:1,7 I get sound, AC3/DTS look to
>> work properly, and my HD music plays properly. So it looks like it's
>> all good minus the general ALSA issue with device scanning, but thats
>> not your issue to deal with.
>>
>> Thanks JYA!
>>
>>
>
> Who broadcast AC3 mono these days?
>
> You said that using the "hdmi" device in mplayer got you sound?
>
> Have you tried other type of content, something not mono (should be
> automatically converted to stereo by myth but you never know)
>
> Did you make sure the device is unmuted? On my gt220, I have 4 spdif
> device showing up and I had to unmute the 2nd one to get audio

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.

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 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.

I'm going to keep playing and see if I can't get this to work properly still...

oh, the single channel AC3 is from Fox Soccer Channel, I don't know
why they do that...

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