[mythtv-users] MythTV 0.24 HDMI audio problem

[Steven Adeff]

On Thu, Nov 18, 2010 at 5:32 PM, Jean-Yves Avenard <jyavenard at gmail.com> wrote:
> Hi
>
> On Friday, November 19, 2010, Steven Adeff <adeffs.mythtv at gmail.com> wrote:
>> On Wed, Nov 17, 2010 at 6:11 PM, Jean-Yves Avenard <jyavenard at gmail.com> wrote:
>>> On 18 November 2010 06:28, Mr. Duncan McDonald
>>> <duncan.john.mcdonald at gmail.com> wrote:
>>>> Hi folks,
>>>>
>>>> Upgraded to 0.24 from 0.23 and it was nearly seamless! :-)
>>>>
>>>> I'm using Mythbuntu 10.4 with Alsa 1.0.23 (not Pulse Audio because for some reason I could never get this to work with 10.4) - the connection is over a Nvidia GT220 card using HDMI to a surround sound receiver.
>>>>
>>>> The problem is that when I first boot the machine I don't get audio out of MythTV until I run something like Mplayer (which does output audio straight away) - once I've run a video using Mplayer and  go back into MythTV audio works within it again! My audio device in MythTV has correctly been discovered as 'ALSA:hdmi:CARD=NVidia' and outputs Dolby Digital no problem.
>>>>
>>>> Has anyone come across this before or have any suggestions for how to fix this? (audio worked perfectly using this setup in 0.23 but I realise there's been a lot of great audio changes from 0.23 to 0.24). I'm using revision 27251. I understand getting PulseAudio to work is the correct solution but unfortunately I've had no luck with 10.4 (especially since I have a slightly different setup and am using Alsa 1.0.23) - maybe upgrading to 10.10 would help?
>>>
>>> The ALSA drivers for the newer hdmi nvidia card is far from perfect yet.
>>> It detects several hdmi audio device, and only one works.
>>> It's a bit of a try&test to find out which one work.
>>>
>>> XBMC has a good wiki on the matter:
>>> http://wiki.xbmc.org/?title=HOW-TO_set_up_HDMI_audio_on_nVidia_GeForce_G210%2C_GT220%2C_or_GT240
>>>
>>> It has a list of cards, what is known to work for both which device to
>>> use and the speaker configuration.
>>>
>>> Myth relies on ALSA to provide the correct information to test devices
>>> capabilities ; so until the values returned by alsa are correct, you
>>> will have to manually set it.
>>
>> JYA, the issue I have with manually setting it is that the features
>> like AC3/DTS passthrough, and multichannel LPCM don't appear. I think
>> this may be why when I try and play 24bit/96KHz FLAC files from
>> HDTracks that all I hear is static. Last night I figured I'd try and
>> play the same through my bedroom system which doesn't have HDMI, only
>> S/PDIF and it played fine.
>>
>
> If you manually enter ALSA:hw:1,7 etc, and you do not press the scan
> button, you are in manual mode, and you can enter any settings you
> want.
>
> The only way to have some fields greyed out is if you press the scan button.

Well, I just got home, turned the machine on, put in ALSA:hw:1,7 try
and watch a recording, and no sound.

ssh in, use mplayer with "-ao alsa:device=hw=1.3", I can replace 3
with 7, 8 or 9 and all will playback stereo from mp3, AC3 and DTS from
movies, and my 96KHz 24bit FLAC from HDTracks.

here's what it shows in the frontend log,
2010-11-18 22:32:38.650 AO: Opening audio device 'hw:1,7' ch 2(6) sr
48000 sf signed 16 bit reenc 0
2010-11-18 22:32:38.650 Opening ALSA audio device
'hw:AES0=0x6,AES1=0x82,AES2=0x0,AES3=0x2,1,7'.
ALSA lib conf.c:4484:(parse_args) Unknown parameter AES0
ALSA lib conf.c:4617:(snd_config_expand) Parse arguments error: No
such file or directory
ALSA lib pcm.c:2211:(snd_pcm_open_noupdate) Unknown PCM
hw:AES0=0x6,AES1=0x82,AES2=0x0,AES3=0x2,1,7
2010-11-18 22:32:38.650 ALSA, Error:
snd_pcm_open(hw:AES0=0x6,AES1=0x82,AES2=0x0,AES3=0x2,1,7): No such
file or directory
2010-11-18 22:32:38.650 AudioOutput Error: Aborting reconfigure
2010-11-18 22:32:38.651 AudioPlayer: Disabling Audio, reason is:
Aborting reconfigure

now, if I try and play music in myth and I use ALSA:hw:1,7 it works
fine. plays mp3, 24/96 FLAC, etc. if I use ALSA:hw:1,3 mp3 works but
24/96 produces static. now, remember, in mplayer I can play all that
with 1,7 or 1,3 or 1,8 or 1,9.

2010-11-18 22:42:53.314 AO: Opening audio device 'hw:1,7' ch 2(2) sr
44100 sf signed 16 bit reenc 0
2010-11-18 22:42:53.314 Opening ALSA audio device 'hw:1,7'.
2010-11-18 22:42:53.545 AO: Opening audio device 'hw:1,7' ch 2(2) sr
96000 sf signed 32 bit reenc 0
2010-11-18 22:42:53.545 Opening ALSA audio device 'hw:1,7'.

Now, I think, maybe it's just passthrough for AC3/DTS? so I try
watching a video I have that is just stereo and not AC3 or DTS, and it
works,
2010-11-18 22:48:49.779 AFD: Opened codec 0xadeb93d0, id(MPEG4) type(Video)
2010-11-18 22:48:49.779 AFD: codec MP3 has 2 channels
2010-11-18 22:48:49.779 AFD: Opened codec 0xaf1b4990, id(MP3) type(Audio)
2010-11-18 22:48:49.941 AO: Opening audio device 'hw:1,7' ch 2(2) sr
48000 sf signed 16 bit reenc 0
2010-11-18 22:48:49.941 Opening ALSA audio device 'hw:1,7'.
2010-11-18 22:48:50.067 AudioPlayer: Enabling Audio

So, it looks to be with how Myth is trying to open the device and pass
AC3/DTS through. I also don't quite understand why in mplayer I can
use 3,7,8, or 9 but Myth seems to only work with 7?

So I tried using 1,3 for mp3 music, and it plays, but the quality
sounds as though its been downmixed to some horrible quality level.
24/96 produces static. same with 8 and 9.

anymore info I can provide?

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