[mythtv-users] IR blaster fails sometimes?

[Mark J. Small]

Hi everybody,

I've got a recurring issue that is starting to really annoy me.  On many 
weeknights I record two consecutive programs on the same channel.  The first 
recording stops at at 00:35, and the second record starts at the same time.  

Quite often, the second recording gets tuned to the wrong channel.  Last 
night, I got half an hour of Leno instead of Ghost in the Shell.  My ir 
blaster tuned my DCT2000 to channel 6 instead of channel 26.  The 2 got lost 
somewhere along the way.  

When I look in my syslog, I can see the lirc events for each digit.

The 2 gets sent at 00:35:05 
The 6 gets sent at 00:35:08
The OK gets sent at 00:35:09 (tell dct2000 to really change the channel -- 
auto tune is off)
The EXIT gets sent at 00:35:10 (kill dct2000 osd)

I think that the 3 second lag between the 2 and the 6 is causing my problem.  
By the time the 6 comes along, the 2 has been ignored.

On successful channel changes, the digits get sent every second.  (I pause 0.7 
seconds between sends.)

I'm guessing that at the time of the failed channel change, the machine is 
heavily loaded.  But why would it happen for at 00:35 every night, thus 
killing the channel change for some of my favourite shows?

I checked, and there are no cron jobs running at 00:35 to slow things down.  
My cron.hourly is at 17 minutes past, my cron.daily is at 12:25 (noonish), 
and my cron.weekly and cron.monthly are between 4:00 and 6:00.

I looked through lots of logs, and I noticed that at 00:35:03, in 
mythtvbackend.log, there is a "reschedule requested for id 0"  This finishes 
at 00:35:08.  Is this what is slowing my machine down so much?

What can I do about it?

Faster CPU? More RAM? nice the channel change script?

My backend is a Duron 800 with 256MB RAM and 3 PVR 250s.

Mark