[mythtv-users] Bob deinterlacing drops frames, but not high CPU

[Matt Doran]

Hi,

I've been using myth for a while, and I've been using the kernel 
deinterlacer.  It works pretty well, but some people seem to suggest 
that you get smoother results with Bob.

System specs/details:

    CPU: AMD X2 3600
    Video: nvidia 6160
    Tuners: Hauppauge Nova-T 500 and Avermedia A777
    MB: Asus M2NPV-VM

    Kernel: 2.6.20
    Nvidia driver: 1.0-9631

I'm just using standard video output, not XvMC.

When I switch to bob deinterlacing, I get a huge number of dropped 
frames, and messages like this in the logs:

    2007-05-16 20:54:57.830 NVP: Video is 5.53125 frames behind audio
    (too slow), dropping frame to catch up.
    2007-05-16 20:54:57.835 NVP: Video is 9.36092 frames behind audio
    (too slow), dropping frame to catch up.
    2007-05-16 20:54:57.839 NVP: Video is 12.0144 frames behind audio
    (too slow), dropping frame to catch up.


But while this is happening I'm not seeing any significant CPU usage.  
It's sitting at around 20-30%, and the processor not even running at 
full speed (1GHz, not the full 2GHz).

Why would this be happening?  What should I look out for to avoid this?

I've had nothing problems when trying to enable bob.  There must be 
something simple I'm missing ... but what? :)

Thanks,
Matt