[mythtv-users] RTJPEG, MPEG4 and analog TV

[Kevin Bailey]

On Mon, Apr 28, 2008 at 10:18:07AM -0400, Jesse Burt wrote:
> I have a 3400+ (1st gen Athlon64) as well with an HD5500 and HD3000 and 
> it is able to record two MPEG4 or RTJpeg simultaneously while watching 
> one of them (with MPEG4 it is definitely tight on processor time...no 
> commercial flagging :)) so as far as raw processor time (unless it's a 
> Sempron64, AthlonXP/MP...I can't vouch for those personally) you should 
> be okay, even though things may be tight.

It is a Sempron, but I haven't specifically seen any problems
with performance. I was just hoping to keep it working lightly
since it has more diskspace than spare cycles. Your experience implies
that there's not much difference between RTJPEG and MPEG4 ?

> If I understand your symptom correctly (the double-time) I have had the 
> same thing happen before. If it is the same thing I have seen, I believe 
> it is more a driver issue with the pcHDTV cards than MythTV (check the 
> output of dmesg when it happens...usually the cx88 driver says IRQ loop 
> detected, disabling interrupts). I can't remember exactly which kernel 
> version I was using when I first starting seeing the problem; it might 
> have been 2.6.22 or something even earlier. I started using 2.6.23 when 
> it came out and didn't have the problem any more. I now use a 32bit 
> installation of Myth on 2.6.24 and the problem has reappeared, though 
> not very often. You might want to experiment trying different kernel 
> versions to see if that fixes it for you.

Whatever the issue is with the drivers, its fixed by switching
recording format from RTJPEG to MPEG4 ? It just seems strange that,
if the system can pull out the correct timing, why can't it do
it while playing live TV ?

Anyways, thanks for the suggestion. I'll give it a try.