Best capture format ?

[Nightcrawler]

most capture programs seem to capture in avi format, but the files seem huge. Is it not better to capture as a divx ? I want to transfer old vhs tapes to vcd and would like to know the best format to capture to.

[widemouth]

Trying to capture to anything other that AVI puts too much load on even the fastest PC's out there. Capturing Analog video must happen in real time, ie. 25-30 frames per second. Unless you have a capture card with a hardware compressor onboard, to compress that amount of data on the fly to MPEG in next to impossible using Software compression. You might get better results with Divx but If you have the hard disk space, better to capture to AVI then convert it to VCD compiant MPG afterwards where timing isn't an issue.

[Nelson37]

I agree, running any kind of compression increases the chance of dropping frames, and AVI is probably best, although huge.

Huffy and Mjpeg are two options, Huffly lossless but slight compression, Mjpeg lossy but better compression.

One solution which works well with ATI cards is to capture MPEG 1 or 2, I-frame only, with a high bitrate (8000 - 12000). This puts minimal strain on the CPU while still giving a good quality image, and reasonable file size.
Re-Encoding is a pain in the ass, however.

I have been told by ATI that using MMC, their cards provide a minimal amount of hardware assistance for MPEG compression via some kind of memory buffer used in the conversion. I have also read here that when resizing the capture, ATI uses some kind of resizing algorithm rather than simply throwing away lines as most do, this last part I have not verified.

I will note that as I have upgraded processor speed, REAL-TIME SVCD captures have gradually increased in quality (2.3 Bitrate, default GOP, 480x480, VBR) to the point where I consider them acceptable, but not as good as the above capture with a re-encode. If I could get the on-the-fly IVTC to work, and if the compression was just a little bit better, and if I could find a way to edit ATI's non-standard MPEG files, and if MMC 7.7 would work on my box, and ...........

But that's half the fun.

[Nightcrawler]

thanx for the help, its really appreciated

[jugernaut]

I think the same, but it looks like at least divx 3.11 is not so heavy. I have a Duron 800 with Windows 2000 Adv. Server and W98SE. I have been able to capture directly from avi at 320*240 or 352*240, using divx 3.11 at 750-800 Kbits /s and audio PCM at 44100 16 bit (then using direct stream copy for video and compressing the audio to mp3, i get what i want, without a huge free space on the disc)