[mythtv-users] IOBOUND - blocking write / free AUDIO buffers

[Nathan Cournia]

Hi Guys,

I just started playing around with MythTV.  It seems great.  However,
when I try to record live TV, I get the following errors after a
couple of minutes:

IOBOUND = blocking in ThreadedFileWriter::Write()

followed by many:

NVR: Ran out of free AUDIO buffers :-(

The system then becomes unresponsive (can't kill mythfrontend or
mythbackend, mouse still works).

I'm using March 30, 2005's CVS.  I searched the mailinglists, and
found individuals with similar problems, but unfortunately could not
find a solution.  I've tried:

- Increasing the buffer size in RingBuffer.cpp - Almost works. 
Setting the buffer size to 4*1024*1024 causes LiveTV to randomly
rewind at the beginning of recording.  The audio also randomly
hiccups.  Setting the buffer size to anything larger causes audio
underrun errors.
- Enabling/Disabling aggressive sound buffering.
- Enabling/Disabling frontend volume control.
- Setting the binary as SUID.
- Setting frontend sound device to both "ALSA:default" and /dev/dsp.

My system is:

Athlon XP 2800
Linux 2.6.11
Plextor ConvertX PX-TV402U-NA
Latest ConvertX SDK
ALSA 1.0.8

DMA is enabled on the harddrive.  I considered trying to set the audio
device of the ConvertX device (in mythtv-setup) from /dev/dsp1 to
ALSA:?, but I'm not sure what the "?" should be.  I tried: "ALSA:1,0"
and "ALSA:hw:1,0", but mythtv-setup would not store those values.

Any help would be greatly appreciated.  If you need any other
information, I'll get it to you ASAP.

Thanks.

nathan