[mythtv-users] Audio with 0.24

[Kevin Ruml]

--- On Sat, 12/4/10, Jean-Yves Avenard <jyavenard at gmail.com> wrote:

> From: Jean-Yves Avenard <jyavenard at gmail.com>
> Subject: Re: [mythtv-users] Audio with 0.24
> To: "k_ruml at yahoo.com" <k_ruml at yahoo.com>, "Discussion about MythTV" <mythtv-users at mythtv.org>
> Date: Saturday, December 4, 2010, 3:13 AM
> Hi
> 
> On Saturday, December 4, 2010, Kevin Ruml <k_ruml at yahoo.com>
> wrote:
> > Hello,
> >
> > I just upgraded to 0.24 on Debian Squeeze from the
> debian-multimedia.org packages since they released today
> after having seen fairly
> 
> Surprising that they would release 0.24 packages today, yet
> use a 0.24
> code that do not include any of the changes made in the
> past 1.5
> months
> 

Hmm..  I'm don't know how Christian decides what version/build to use, and you can't tell from the deb package version.  I kind of assumed (yeah, I know...) he would use the fixes branch and not an initial 0.24 release.  Would some of the fixes in later versions like the fixes branch perhaps have an impact on this issue?  I know from the users list that you've fixed issues as things went along with .24.  I don't recall specifically, but I thought his .23 packages were off the fixes branch for .23.  I'm lazy and like to just use the packages as they've been great for me for years, but if I'll see improvement going to building "fixes" myself I'll consider it.  I can try to check with Christian and see if he plans on using fixes soon as well.  Being lazy I'll probably just move it off of the spdif and do without surround if I can't figure it out.  Got the wife and kids to keep happy.  :)

> >good reports on the user list about the upgrade, but I
> am having a problem with audio.  I'm using straight ALSA,
> not Pulse.  I did the "scan for audio devices" setup step
> as recommended, but my audio and video are choppy -
> recordings, videos, live TV, music.  I'm running a SB Live
> with coax spdif output to my receiver.  Audio was working
> fine with 0.23 including AC3 and DTS pass-through to 5.1
> surround, and no kernel change with the upgrade to 0.24 that
> might affect ALSA.  It was pretty much only the 0.24 Myth
> packages installed from a working 0.23 setup.  I had an
> .asoundrc in place previously to handle Mythmusic outputting
> to 48KHz to the SB Live card since it doesn't do 44100.
>  I've tried without it and with it after the upgrade and no
> difference - still choppy audio/video.  I found this:
> 
> This alsa configuration isn't required with 0.23 or 0.24;
> your card
> report 48kHz as the only supported rate, mythtv will
> automatically
> resample as required.
> 
That was the one struggle I always had - getting Mythmusic to output my 44100 rips over the spdif properly.  The only thing that ever worked for me was the .asoundrc:

pcm.!default {
 type plug
 slave {
 pcm "spdif"
 rate 48000
 format S16_LE
 }
 }

and having the main audio set to "ALSA:default" and setting the spdif for pass-through for AC3/DTS.

> 
> >
> >
> > iec958:CARD=Live,DEV=0
> >     SB Live! 5.1, Multichannel Capture/PT
> Playback
> >     IEC958 (S/PDIF) Digital Audio Output
> >
> >
> >
> > 2010-12-03 23:40:25.482 VideoOutput: Created YV12
> OSD.
> > 2010-12-03 23:40:27.819 ALSA, Error: WriteAudio:
> buffer underrun
> > 2010-12-03 23:40:28.220 ALSA, Error: WriteAudio:
> buffer underrun
> > 2010-12-03 23:40:28.622 ALSA, Error: WriteAudio:
> buffer underrun
> > 2010-12-03 23:40:29.023 ALSA, Error: WriteAudio:
> buffer underrun
> > 2010-12-03 23:40:29.424 ALSA, Error: WriteAudio:
> buffer underrun
> > 2010-12-03 23:40:29.826 ALSA, Error: WriteAudio:
> buffer underrun
> > 2010-12-03 23:40:30.627 ALSA, Error: WriteAudio:
> buffer underrun
> > 2010-12-03 23:40:30.877 TV: Attempting to change from
> WatchingPreRecorded to None
> > 2010-12-03 23:40:30.892 AO: Killing AudioOutputDSP
> > 2010-12-03 23:40:30.928 AO: OutputAudioLoop: Stop
> Event
> > 2010-12-03 23:40:30.928 AO: kickoffOutputAudioLoop
> exiting
> > 2010-12-03 23:40:30.979 TV: Changing from
> WatchingPreRecorded to None
> > 2010-12-03 23:41:05.001 OpenGL: Deleting OpenGL
> Resources
> > 2010-12-03 23:41:05.011 Deleting UPnP client...
> >
> 
> 
> Actually, I'm at loss on why it would have worked in the
> past with
> 0.23 but not 0.24.
> 
> If you are using the spdif port, your system is properly
> configured.
> 

Not what I wanted to hear, though good to hear.  :)

> What about if you activate the up mixer so the pc will
> output AC3
> instead; would that help?
> 
If you mean the setting "Upconvert stereo to 5.1 surround", then no.  I tried that and still the same.

Thanks,
Kevin