Problem with video lag when using analog capture source.

[russr1123]

I have an ATI HD TV Wonder 650 PCI card. In addition to a ATSC tuner and a QAM tuner, it also has an analog capture port with composite and s-video connectors. I set up the analog capture sources last night using the methods here:http://www.nextpvr.com/nwiki/pmwiki.php?...ugeSoftPVR and here: http://www.nextpvr.com/nwiki/pmwiki.php?...alogDevice.

I got NPVR to detect the ATI AVStream Analog Capture no problem and when I configured the input sources, i was able to see video. I hooked up my video camera to the analog inputs as a test and while I saw the video, it was lagged by several seconds (maybe 5). So if I repositioned the camera to look at something else, I would see the change I made in NPVR 5 seconds later. I don't know if this is because of the live buffer or not, but I would like to be able not have this lag at all. If I hook up a vcr to this, it is very annoying. I have tested this with other software (ATI Catalyst media center) and there is no lag there. The problem is that particular software from ATI is very old and only works on XP.

Any ideas on this? Please let me know if I need to provide my AnalogDevices.xml file.

Thanks

[sub]

You're never going get no delay between the live signal and what you see on the screen. NPVR is pretty much designed for TV, and everything is MPEG2 encoded before the app gets it which adds some delay. For TV usage this delay is no major concern. The only users we've ever had caring about the delay in the past, have been user's trying to plugin in their game consoles and play with zero delay - these users choose the wrong type of app for their intended usage.

That said, you can see a slightly longer delay on the first channel on any source, and changing to another channel on the same device can remove the delay. ie, after changing to your composite/svideo input, change to it again. This would hopefully reduce the delay to about 1.5 seconds, which is about the least you'll ever get.

[russr1123]

Okay, I will try switching from svideo to composite and then back as these are the only two channels on the analog capture port. You're right though that this setup wouldn't work well for hooking up a game console, but even for watching on a vcr the delay can cause issues.

[sub]

Okay, I will try switching from svideo to composite and then back as these are the only two channels on the analog capture port.

No - I'm pretty sure you'd need to switch from svideo to svideo, or from composite to composte.

You're right though that this setup wouldn't work well for hooking up a game console, but even for watching on a vcr the delay can cause issues.

If you're dubbing off videos or something like that, you should probably just using the simple video capture app that came with your capture card. I have no idea why you'd want to do this in NPVR.

[russr1123]

So just click on the composite channel in the channels list again and that will cause it to switch to the channel again? I thought I had to switch to another channel and then back to it.

I would use the capture app that came with the card, but for some reason that capture app (ATI Catalyst Media Center) is an XP only app...they didn't make one for Vista or Windows 7. Maybe there's a freeware app out there that I can use. If you know of one, please let me kno.

[sub]

So just click on the composite channel in the channels list again and that will cause it to switch to the channel again?

Yes, it should let you. If not, then you can setup an extra channel on the same source.

[Lao Pan]

Why not use virtualdub (freeware) or such for Composite or Svideo capture - I've used it in the past - or for firewire WinDV, its old (2003) but never drops frames.

[Reddwarf]

So just click on the composite channel in the channels list again and that will cause it to switch to the channel again? I thought I had to switch to another channel and then back to it.

I would use the capture app that came with the card, but for some reason that capture app (ATI Catalyst Media Center) is an XP only app...they didn't make one for Vista or Windows 7. Maybe there's a freeware app out there that I can use. If you know of one, please let me kno.

You could run XP in a virtual machine under W7, but I guess that require more horsepower from the cpu.