[mythtv-users] Unable to get video playback in MythTV

Yan-Fa Li yanfali at best.com
Wed Oct 13 03:41:10 UTC 2004

Hi Brian,

I'm not familiar with the saa7133/34 video capture.  I'm assuming it 
works via V4L is framegrabbed and then transcoded to NUV.  Not used the 
SiS chipset much, but I hear it's pretty solid.  One thing I noticed in 
your dmesg log is the kernel is not compiled to use the IO-APIC.  If you 
can recompile the kernel and turn on in .config:


This should take you off XT-PIC and onto IO-APIC which can use IRQs 
numbers higher than 15 and also introduces Level IRQ triggers which have 
much higher performance.  It also makes the IRQ sharing code saner.

I assume you've followed the mythtv instructions and set up the device 
permissions for the V4L device.  Are you running MythTV as root ?  You 
should set MythTV to run as SUID root as this allows it to use more 
aggressive kernel scheduling.  Have you asked on the V4L list to see if 
anyone has tried to use MythTV with that particular capture card.

The log seems to indicate it can't get any data from the capture side. 
I would double check your settings for mythtv-setup.  Have you run 
mythfilldatabase to populate the TV channel info ?  I'm not sure live TV 
will work if it has no channel info.  Looking at it, it seems to be 
standard V4L parameters.  Are all the required files there and do they 
work ?

Hope that helps,


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