running time vs file size

[roger roger]

Hi all,

What I'm trying to work out here has all got to do with size. Why is it that, say, when I copy a dvd of about 100 minutes and DTS sound that I can fit it on a DVD-5 yet when I capture video from an analogue source of lesser time (say 10-20 mintues less) and with just simple stereo audio it is too big for a DVD-5 and has to be shrank to fit. I've been using WinDVD and capturing straight to mpeg with a total bitrate of 6800kbits/sec.

While it isn't so much a problem rather an annoyance, why is it so and is it just me or is there something I can do to fix it, ie lowering the bitrate (yet still keep dvd quality)?
?

[redwudz]

If your 'simple stereo audio' is a PCM .WAV file, then it takes up a lot of space compared to an AC3 audio or MPG-1 layer 2 audio. Take your video and check it with AVIcodec and you can see the sizes of the audio and video files. I use MPG-1 Layer 2 and it works well in most players. AC3 is better, but involves a little more work to produce.

[roger roger]

well, I thought that might have been the prob but I've checked and the audio capture is done in mpg-1 layer 2 so......?

[thecoalman]

Maybe your DVD software is changing it back to PCM?

AC3 is better, but involves a little more work to produce.

I'm using Ulead MediaStudio Pro and Ulead DVD Workshop, both are capable of producing AC3. No trouble at all. It's just a matter of selecting AC3 for output, but both cost quite a bit though.

[bottle-necked]

Are you using Constant Bit Rate (CBR) or Variable Bit Rate (VBR). Those times are pretty close for CBR @ 6.8Mbps. VBR should give you more time.