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Originally Posted by maphew
Hello,
Thanks for putting together this wonderful site and maintaining it for years. It is a relief to find a glade of calm concentrated information amidst this crazy, wildly variable and distributed 'net.
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Thanks!
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I've read through the guides pertaining to capturing from vhs with a target of dvd using ATI MMC and am putting it to use. I've created a custom capture set of mpeg2-dvd 352x480 ntsc following the guide for set for movies. I'm getting a low number of dropped frames, e.g. 490 dropped of 90,000 captured. Is that acceptable or is the target zero?
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Tweak the "motion compensation" preset to about 70, instead of the 95-99 shown on the
ATI All In Wonder MPEG capture guide. This can sometimes reduce the CPU use just a bit.
Tweaking the GOP size can help to shave off a few CPU% points, too. Look at using 3 or 4 P frames, instead of just 2.
While 490 our of 90,000 sounds like a relatively tiny amount of lost frames, it really depends on where those frames are! At least with an ATI All In Wonder Radeon card, you don't have to worry about audio sync loss. When the ATI drops a frame, it either repeats a frame to take its spot, or it drops the audio for that frame length, too. Many cheap/crappy cards will only drop the video, and not the audio, and it cumulatively causes sync error that cannot be fixed.
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The capture system is Windows 2000, 512mb of ram. Task manager shows MMC using 72mb with 292mb of physical memory free, while cpu usage range is 75-95%. The video card is ATI AIW 7200 and the audio SoundBlaster Live. I don't recall the cpu speed at the moment, but I believe it to be ~1GHz. The hard drive is in ultra dma mode.
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For a capture system, 1Ghz is really low. If you're only getting 490 dropped frames in a 90,000 frame capture, you're doing amazingly well. In my own tests, 1.5Ghz is really bare bones minimum, and you really don't get to problem-free capturing until you hit the 2.0Ghz range. Some of this depends on the CPU itself, too. A 2.0Ghz Celeron or an AMD, for example, would perform poorly against a 1.8 Ghz Pentium 4.
I'd say 512MB is minimum, too. RAM isn't as much of an issue. With ~300MB free, it sounds like you're okay on the memory side of things.
The audio card is fine, video card is fine.
At this late date, depending on your motherboard, you may be able to find a processor for $25 on
eBay or elsewhere. Those older ATI cards were able to compete with several professional cards, in terms of capturing quality, so it's a great idea to build a system around it.
Because the rest of the computing world has "moved on" (or so they say), new computers are all SATA, PCIe, multi core, etc etc. While you can't walk into a store and buy a new computer to work with the older ATI cards, you can get used parts for a fraction of the cost!
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Changing the preview window size from Large to Tiny dropped the cpu% a few points but no obvious change in number of dropped frames. The computer's only purpose is video capture; I'm not multi tasking on it.
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Not only should you not multitask, you need to not change the size of the preview window. Keep it maybe 66-75% of the screen size, windowed. And then be sure the mouse cursor is off of the preview window. And then don't move the mouse.
You may want to also check the BIOS configuration, and be sure the AGP aperture is set to an optimum size for this card. I'd not set it higher than 32MB. If your card is PCI, instead of AGP, that can account for slightly higher drops on the older systems. The PCI bus is slower than the AGP bus, mostly only noticeable on the older underpowered sub-1.5Ghz systems.
I did many captures on an underpowered Celeron 1.7Ghz system with 512MB RAM and only one hard drive. There were dropped frames sometimes, but it was just for "watch once" TV recordings. For archival use, I used a 2.0Ghz P4 system. Same card on both, the ATI AIW 7200.