Stuttering on DVB-T channels. Record service cures issue....for a while.

[shaunpatrick77]

Further testing is showing that recordings via the Colossus also cause the problem, its not just live tv. So probably not due to the graph.

Its just related to starting and stopping the card.

[shaunpatrick77]

Just wondering if I would be better off starting a new thread in the hardware section?

[sub]

Try this patch:

http://forums.nextpvr.com/showthread.php...post487766

[shaunpatrick77]

Sorry Sub. No difference. Still a gradual increase in CPU use the more times the card is cycled.

[shaunpatrick77]

I'm totally stuck. The CPU use that builds up on card cycles is being consumed by 'deferred procedure calls and Interrupt service routines'.
I've got a HD PVR2 I picked up on eBay coming in the desperate hope that it might get along better with NextPVR.
In the meanwhile I have to reset Nrecord every 4 cycles of the Colossus. That gets old real quick

[sub]

I'm still waiting for you to supply one of these recordings that has the problem.

[sub]

The CPU use that builds up on card cycles is being consumed by 'deferred procedure calls and Interrupt service routines'.

I can see some people have used LatencyMon to find which driver is causing high DPC. It might be worth trying it.

[shaunpatrick77]

Hi Sub
I've used LatencyMon, and it I've found something with hcwD1xcd.sys, which is the Colossus Xcode driver.

Here's what I can see happening.
Starting with a fresh reset on nrecord, hcwD1xcd.sys is pulling around 1 ISR per second, which I would imagine would just be normal housekeeping.

When nrecord starts the card, the hcwD1xcd.sys IRS count jumps to 100's/sec, which seems normal I guess for frame processing, and the system is happy.
Here's the interesting bit, when I stop the recording or live tv, the hcwD1xcd.sys ISR count is still continuing to run at 100's/sec. If you then restart a recording or live tv, the hcwD1xcd.sys ISRs jumps even higher, approximately double actually.

After a few card starts/stops you end up with many 1000's of hcwD1xcd.sys ISR's/sec flooding the system, and the card should be stopped. It should be back to 1/ sec I would think.
This is of course when the system latency goes totally south and it becomes slow to respond to everything (remote, keyboard etc) and of course tv/recording from the DVB-T card is cactus.

Resetting nrecord instantly drops the ISRs back to one a second. It looks to me that nrecord is not releasing the card/driver somehow, but I'm obviously WAY out of my depth here and have no idea how the interaction is managed (micros for embbeded control are my thing, and they've bitten me with out of control ISRs before...hmmmm)

So does any of this make any sense or help at all?


PS. Testing with the Hauppauge Capture program (dev by you apparently!) I get 1/sec ISRs ramping to 100's/sec on capture and back to 1/sec when I shut it down.

PPS I can upload a bad DVB-t clip if you still want, but give how the system latency is horrible at that point its obvious now what's causing that symptom. That was just the first thing I noticed at the time.