[mythtv-users] Buffer underrun/audio stuttering

[Michael Sciscenti]

I've tried to avoid emailing the list until I was absolutely sure I couldn't
get any further without help.

I'm trying to get a Mythtv frontend/backend server up and running on a P4
2.8 GHz box with 1 GB RAM and Nvidia Geforce 6800. HDTV over firewire is
what I'm having trouble with. I can now reliably connect to the cable box
and get HDTV streams using test-mpeg2 and in Mythtv itself, however I've
been completely unsuccessful at solving my audio stuttering problem. I've
tried every combination of settings and every little suggestion I could find
on the internet and this list yet I still get the following errors:

2005-11-24 04:33:52.663 audio waiting for buffer to fill: have 2048 want
4096

or

2005-11-24 04:33:54.567 WriteAudio: Preparing 4096 bytes (1024 frames)
2005-11-24 04:33:54.568 WriteAudio: buffer underrun

Things I've tried but none have gotten rid of the stuttering:
ALSA, OSS emulation through ALSA, an asoundrc is present, Xvmc on/off,
deinterlacing (bob) on/off, extra sound card buffering on/off (the TV
settings option), agressive buffering on/off (in General settings), priority
process on/off, etc, you name, I've tried it.

The problem exists in both the current release of mythtv and svn from two
days ago. I'm running Gentoo. Does anyone have any suggestions?

My configure setting:
./configure --disable-distcc --prefix=/usr --mandir=/usr/share/man
--disable-altivec --disable-xvmc-vld --disable-directfb --disable-audio-oss
--disable-directx --enable-firewire --disable-audio-jack
--disable-joystick-menu --enable-lirc --enable-xvmc --enable-opengl-vsync
--enable-xv --enable-x11 --enable-proc-opt --disable-dbox2 --disable-ivtv

Also of note, I'm using a PCI firewire card that has a VIA chipset. Some
have said there are issues with these, but I dont think its the source of my
problems since I'm able to grab streams fine using test-mpeg2 and they
playback perfectly in mplayer using xvmc. My motherboard is a SiS chipset.

Any help would be awesome, I'm about at my wits end and starting to look at
other platforms, but really would like to stick with myth if possible.
Thanks.
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