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Hey everyone,

I've been editing an mpeg-2 movie file which I'm now wanting to burn to disc. It has Mpeg layer II audio (384kbps) and the movie is 123 minutes PAL format.

Under project properties you've got video setting and there¡¦s a couple of details I'd appreciate some advice on. Ultimately I'm wanting the best quality possible. The points of interest to me are;

-Speed Quality; I understand this is a balance between picture quality and fluid motion. Should I select 100%?
- CBR or VBR?
- Bitrate; I assume this is a maximum bitrate. In the past I've had jumpy and out of sync playback when I've selected a high bitrate, ie 8000. Using a bitrate calcuator the maximum value recommended is 7350. Is that what I should use?

Again any advice would make my day.

Ultimately I'm wanting the best quality possible.

Ultimately, with a project that long, the quality you are going to be able to get is only average. Quality in effect depends principally on the bitrate used. But the higher the bitrate = higher quality = but also the less video you can fit on a disc.

Using a single layer DVD, a bitrate of 8000 kbps will alow you around 1 hour of video, or about 70 minutes with mpeg layer 2 audio as you are using (or Dolby). That will be the best quality. You will still get good quality using a bitrate of 6000 kbps, and that will allow you 90 minutes (or 100 minutes with mpeg layer 2 audio). But to fit around 2 hours on a single layer DVD, you have to drop the bitrate to around 4000 kbps. And that at best will give you quality roughly equivalent to good VHS. But nowhere near as good as with a higher bitrate.

VBR and CBR are important also for the amount you can put on a DVD. With VBR, you can put on more since, if there is not much action, the program uses a lower bitrate for those scenes and thus use less space. More action means a higher bitrate, and less space. CBR as its name implies is fixed and in effect you can work out exactly how much will fit on a disc. I can't give you exact figures, however, but VBR might give you at most a handful of minutes extra, but not so much that it would make a great deal of difference in squeezing all your project onto a DVD.

The 100 percent slider in fact is only meant to represent a balance of the final quality and the speed it takes to render at that quality. I personally never touch the default setting which, from memory, is 70 per cent. I have played around with it in the past, and the extra time taken by setting it higher than that is not reflected by any really obvious improvement in quality. But play around with it yourself. It might just give decent results when talking about the low bitrate you are using. Note, however, that depending on your computer, some people in the past have had the program hang when they use 100. If that happens, drop it back a bit to, say, 90.

The other thing which might improve the final quality a little is to do a two pass encode. That is if you use VBR. The program scans your video in the first pass, and works out the optimum bitrates to use for different parts of it. In the second pass, it actually encodes using those bitrates. In other words, the calculations are more precise than doing it all on the fly in one pass, and the end quality again could be marginally better. Note that two pass will double the encoding time overall.

Thank you for the advice Ken but when your talking about bitrate are you referring to the maximum or the average?

The bitrate calculator I used indicated I could have a maximum bitrate of 7350 and an average of 4450.

I just a couple of days ago did a project which was 1 hour 57 minutes long. For that, I had to use a bitrate of VBR *max* 4600 kbps to fit it on a single layer DVD. That also used mpeg layer 2 audio.

I don't have a bitrate calculator handy, but I would guess that a VBR max 7350 would allow about 75 - 80 minutes of video on a single layer DVD...

Thanks for the tips