[mythtv-users] Line In on Asus M3N78-EM mobo

[Michael PARKER]

Hi,

I'm running Myth 0.23rc2 on Fedora 12 x86_64. Hardware is a Asus M3N78-EM mobo with Hauppauge HVR-4000 capture card. I'm using the onboard sound of the M3N78-EM.

All is working fine except that I'm having problems recording from the Line In channel. ALSA audio in Myth is working - I can listen to sound from movies - and video is being successfully captured from the HVR-4000 card via the HVR-4000's Component input.

Audio is provided directly from a cable STB via a dual phono to stereo jack lead plugged into the Line In of the mobo. If I unmute the Line In playback channel in alsamixer, I hear the Line In input from the Line Out output. Consequently, I can watch delayed "live" TV in Myth whilst listening to real time audio straight from Line In.

I've followed the generic guidance for setting up audio (set Line In volume, mute it, set Line In as Capture source etc.) without success. Looking in the Myth backend log, I see errors regarding "Cannot create audio device ALSA:default", "ALSA:default" coming from the capture card definition in mythtv-setup. 

No matter what I try in the "Audio input" field of the capture card (ALSA:default, ALSA:analog, ALSA:default:Card=NVidia, ALSA:hw:0,0), I see the same "Cannot create audio device" error in the BE log.

Interestingly, if I look at the alsamixer Capture channels, I see that I have two Capture channels (Capture & Capture1) each with their own input source (able to select between Line In & CD, IIRC). Setting both input sources as "Line In", I've tried (without success) enabling one or both Capture channels.

My sound output is configured to just pick-up ALSA:default and that works fine. I had a brief period last night where the HVR-4000's on-card audio output grabbed card index 0 but this behaviour has (apparently) been cured by following the advice here (http://linuxtv.org/wiki/index.php/Hauppauge_WinTV-HVR-4000#Sound_driver).

Can anyone see any obvious mistakes in any of the above? 

Should the "ALSA:default" audio input normally suffice for a framegrabber card or do I need to concoct a more exotic, hardware-specific string?

I'll try and debug further by trying to pick up the Line In input using mplayer, but an initial play last night indicated the following mplayer string to have the same problem (video but no audio):

mplayer -v tv:// -tv driver=v4l2:device=/dev/video0:chanlist=europe-west:normid=4:alsa:adevice=hw.1:immediatemode=0:channel=21

NB. Following advice I found on the web re. recent Linux distros not needing a /etc/asound.conf or ~/.asoundrc file, I'm currently not running with either file. Is this likely to be problematic given my hardware? If so, has anyone got any advice on what the file contents should be?

I'm also slightly concerned that PulseAudio may be interfering with ALSA. Myth audio output only worked when I uninstalled the Pulse ALSA plugin, removing the PulseAudio card/device(?) from alsamixer and making, I assume, ALSA the default audio output (the one that appears by default when starting up alsamixer). Apart from the removal of this single plugin, PulseAudio is still installed. The actual pulseaudio package has so many dependencies within Gnome etc. that I don't believe it will be possible to remove it, although some of the other Pulse packages look removable without dire consequences.

As ever, any help/advice anyone can give would be greatly appreciated.

Mike