Slow / delayed resume after skipping while paused

[johnsonx42]

I think I'm starting to see a pattern to whether I get good or bad skipping. If I watch a show with my box otherwise completely idle, the skipping is great. However if I have anything else going on, like a recording with comskip running, the skipping will be very laggy and slow. Now that sounds like merely an issue of insufficient CPU, but one comskip doesn't use more than 30% or so, and it is a dual core CPU so really there should be plenty if spare CPU power. So it may be some less-than-optimal scheduling being done by windows causing the issue. I need to have a play with the process priority on NextPVR.exe and see if I can improve things.

[BrettB]

Now that sounds like merely an issue of insufficient CPU, but one comskip doesn't use more than 30% or so, and it is a dual core CPU so really there should be plenty if spare CPU power. So it may be some less-than-optimal scheduling being done by windows causing the issue.

Is it possible that the bottleneck isn't CPU, but rather disk I/O? If you have a new recording writing to a drive, plus comskip reading from the same drive, plus a NextPVR.exe instance reading from another section on the same drive, it would be considerably more I/O and drive activity than simply playing one recording. Just a thought...

[johnsonx42]

Is it possible that the bottleneck isn't CPU, but rather disk I/O? If you have a new recording writing to a drive, plus comskip reading from the same drive, plus a NextPVR.exe instance reading from another section on the same drive, it would be considerably more I/O and drive activity than simply playing one recording. Just a thought...

yes, you may be on to something there. even with multiple recordings and comskips going on, playback is normally smooth because there's read-ahead, buffering, etc. but try to skip and now you have to wait for the disk to go seek new data instantly. still, modern SATA disks are pretty fast, and it seems like the seeking lag/delays I see are longer than it ought to take the disk to seek the data even when it's busy. I've got some spare 300GB WD VelociRaptors, maybe I should try one of those as a recording drive. all must be investigated.

[mikeh49]

FWIW, I just installed 2.2.6 on a low power machine (Sempron 2800/9600Pro/IDE disk) and now see the delayed skip, but only on .ts files recorded by NPVR. Overall playback is fine however using the MS decoder. .mpg and dvr-ms files recorded by PVRX2 skip just fine. The only thing running on the machine was NPVR in playback.

On my modern machines, the NPVR files skip pretty well, but still not as good as PVRX2 files.

[mikeh49]

@Martin

Attached is the timing info from a program recorded last night using firewire via Network Recorder. Hope this is what you're looking for.

Mike

[mvallevand]

Thanks Mike, that's a great looking timing.info and it shows that NPVR TS Writer is doing it's stuff really well. I can't imagine how GBPVR could do better skipping based on what I saw. I'd focus on decoders and improving disk access, if you are reading from a share, it's not a fair comparison.

Martin

[griffy]

Still works perfect and instantaneously in GB-PVR, sorry to be a wet blanket

I pause then skip in 2 min blocks, then press play. 1.4.7 always been perfect for me.

Still can't move to nPVR sorry
nPVR plays better if you don't pause when skipping for advert breaks

[sub]

This patch should fix the problem with skipping while paused.

[cncb]

When I "unpause" playback seems to now jump to the beginning of the recording each time.

[sub]

Ah, maybe you dont have this patch I posted earlier? http://forums.nextpvr.com/showthread.php...post419068

It also needs to be installed.