How to fit more then 2 hours of video on a DVD

[Eric Richmond]

Hey guys,

I have what I feel is a pretty newbish question, but here it goes anyway...

On most commercial DVDs you see much more then 2 hours of footage, yet whenever I try and put more then 2 hours of DV footage on a DVD via DVD Architect, it complains that my project is too big.

Now, I know its possible to save space by reducing the bitrate of the video (using "optimize dvd" in DVDA), but obviously, this is sub-optimal cause you're losing bitrate quality.

What tips/tricks do you guys do to squeeze more video onto a DVD, or is it just not possible? I assume you could tweak/optimize the MainConcept MPEG-2 codec, but I wouldn't know where to begin to look.

I guess I'm asking a number of questions

1) Is it possible to get more then 2 hours of video on a DVD produced with Vegas/DVDA (or any NLE for that matter)

2) If so, what tricks can we do to both make this happen, and retain video quality?

Thanks guys, i know this is a long winded, open ended question, but I'm very curious :)

-Eric

[Edward Troxel]

1. yes.
2. Lower the bitrate. Generally speaking, the lower the bitrate, the lower the quality.

One reason commercial DVDs can put longer lengths of video on a DVD is because they can put more information on the DVD - the pressed DVDs hold more information. Think of the dual-layer DVDs that can hold 8.5 gig instead of 4.3 Gig.

[Richard Green]

Hi Eric,
I found this little program, which does a good job of resizing your video files to fit onto a standard DVD.
http://www.my-software-space.com/dvdshrink/

Might be of use to you.

Regards
RichardG

[Chris Barcellos]

This is one thing I like about the Pinnacle Studio 10 plus DVD burning portion of that program. You can have a 2 hour plus program, and it will automatically convert the bitrate, and do a decent job to boot.....

[Eric Richmond]

Wow, thanks for all the great responses guys.

In terms of reducing bitrate, how much reduction is "acceptable", are there any guidelines for this sort of thing?

Thanks again!

-Eric

[Chris Barcellos]

Eric, I think it really depends on your subject matter. I did a musical play that I ran for 2 hours and 10 minutes. The bitrate worked out to abou 2.9 mbs-- It was adequate because of what I was doing. But I could see that in certain situations, the video wouldn't be good enough. So you have to mess with it, and decide what your best bet is.

[Mike Kujbida]

Originally Posted by Chris Barcellos

I did a musical play that I ran for 2 hours and 10 minutes. The bitrate worked out to abou 2.9 mbs-- It was adequate because of what I was doing.

Wow. That's a very low bitrate. According to the calculator I use, a video that length works out to a CBR of 4,300 or a VBR of 2,600, 4,300, 7,600.
I've done plays that length as well and thought they looked pretty good. I could see some degradation in things like gingham dresses (moire pattern) and low light scenes getting a bit noisy but overall I was quite happy with it.
The better the image you start with (i.e. good camera & lighting), the better the overall DVD will look, especially in long form videos like 2 hr. play.

BTW, I'll second Richard's recommendation on DVD Shrink. I've used it a few times when my calculations didn't quite work out as expected and I couldn't see any difference in picture quality. This is best if you only need to shrink it 5 or 10%. I wouldn't expect a 25% reduction to still look as good.

Lastly, you can always render out an AVI from Vegas, feed that to DVD Architect and let it do the calculations for you. I've never tried it myself but I know that's the way some folks prefer to do it as they don't want to be bothered using a bitrate calculator.

[Dave Stern]

Eric - the other thing you can do is to reduce your resolution. I'm not sure what your source material is or what you are looking to do, but 720x480 is called D1 or full D1 and is 'standard' for NTSC DVD format.

Half D1 is 352x480, which cuts the vertical resolution in half. This is also legal in the DVD spec. This is particularly useful if you need to drop the bitrate to a very low number, as using half D1 will push your bits / pixel back up.

Having said that, this should be used judiciously. If you had say a bunch of TV shows that you wanted to put on DVD and putting them on one disk was your first priority, then half D1 may be a good choice. Some DVD recorders for example use half D1 at some settings and it can come out ok.

If you are doing the acquisition yourself (as I think more people here on this forum do), then half D1 may not be what you want, or especially what your client wants (even if they don't know it).

But, I just throught I'd mention it since this is something that can impact how much material you put on a disk.

The other thing to mention in terms of bitrate is that if you start to drop your bitrate and your subject matter is somewhat variable in terms of motion (e.g. some scenes much more motion than others), you may benefit a little from doing your encode as Variable Bit Rate (VBR) and doing a 2 pass encode. This way, the encoder can allocate more bits to the scenes that have more motion and take from scenes that have less motion, which if you are pushing the bitrate down, can help your overall quality since your fast motion scenes will really be needing those extra bits.

One thing to note is that VBR is hard to estimate exactly, so your file size may not come out exactly as planned. If that happens, you can re-encode, or you could take that file and then (DVD)shrink it down, which is handy for an 'emergency' (and in some cases the shrink re-encode can be quicker, although as an encode of materials already encoded, it almost can't be lossless by definition, but dvdshrink can do a surprisingly decent job at it).

Oh, and also as an aside, if you want more room for your video, the other thing you can do is drop your audio bitrate down, either the bitrate or the # of bits (8 instead of 16, etc.), or mono vs. stereo.

And, if you're using Vegas, make sure you are encoding your audio in AC-3, which is very efficient in terms of bitrate, and still sounds great.

Manipulating the audio won't buy you back 50% of your space, but if your audio, say takes 500-700 meg, and you can get half of that back, that will buy you something noticible on your video bitrate side.

Also, if you have motion menus, those take some space as well, and static menus take (much) less.

These are just a few little tips, but used in the right situations, can be useful.

Hope this helps!

edit: oh also.. here's a link to a handy bitrate calculator..you can use the HTML version here or also download a java version:

http://www.videohelp.com/calc.htm

[Edward Troxel]

Originally Posted by Chris Barcellos

This is one thing I like about the Pinnacle Studio 10 plus DVD burning portion of that program. You can have a 2 hour plus program, and it will automatically convert the bitrate, and do a decent job to boot.....

DVD Architect will do the same thing. Just give it a DV-AVI file and it will automatically adjust to the proper bitrate when converting to MPEG2 and AC3.

[Eric Richmond]

Hey guys,

Thanks for all the great info.

-Eric

[Steven Davis]

Originally Posted by Edward Troxel

DVD Architect will do the same thing. Just give it a DV-AVI file and it will automatically adjust to the proper bitrate when converting to MPEG2 and AC3.

Edward, is there a limitation on this though. For example, I would not expect to have a 4 hour avi and DVDA squish it onto a 2 hour DVD. Or would it?

[Chris Barcellos]

Originally Posted by Edward Troxel

DVD Architect will do the same thing. Just give it a DV-AVI file and it will automatically adjust to the proper bitrate when converting to MPEG2 and AC3.

Yes, I suspected so, but I just haven't taken time to learn DVD Architect, since I was having such good results with this aspect in the Pinnacle Program. I rarely edit in Pinnacle, unless it is a simple edit (capture and limted transitions) but I've grown accustomed to working with the DVD burning there. I've used Architect a few times, but just haven't taken the time to sit down and learn how to make decent menus. I will have to expand my horizons...

[Bennis Hahn]

Originally Posted by Steven Davis

Edward, is there a limitation on this though. For example, I would not expect to have a 4 hour avi and DVDA squish it onto a 2 hour DVD. Or would it?

Yup it will. I did a 6.5 hour DVD over the summer (it all had to be on one single layer DVD). Using 2-pass VBR I was able to fit the whole thing on there and it actually isn't that bad considering the target audience. (Vietnam Vets who care much more about the subject then the video quality.) Granted it was talking heads so that helped a lot but still... it is possible.