Does the DVD Specification Support 30p?

[Roman Melekh]

You can render 23.98p files, after add pulldwon to 29.97, and, if your DVD can do this – 29.97 will be converted to 24p signal

[Michael Spooner]

Right. I understand that 24p with 3:2 pulldown is a standard DVD format, but I much prefer the smoother motion I get from 30p.

Basically, I want to combine the picture quality of 24p with the smoothness of 60i. In other words, 30p.

I do have a question on the subject of 24p, though. In the Sony Vegas Main Concept rendering options there is an option for either 23.976 or 23.976 + 3-2 pulldown. 23.976 + 3-2 pulldown is the default setting. What would happen if you switched it to 23.976 without pulldown? I was under the impression that the DVD player added the pulldown, so I don’t understand why you would want to add it during render. Or am I missing something?

[Michael Sacci]

DVDs can handle progressive footage just fine. When played backed on a system that can handle progressive, computer or set system that has a progressive DVD hooked up correctly to a progressive TV you get pure progressive frame. If it is hooked up to an interlace TV it adds the pulldown to 24p or just sends the 30p as interlace fields. You never add the pulldown yourself the player does that for you.

But Michael you have answered your own question, in you text 30p looks the best, so go with that. It will always be smoother than 24p even when played as progressive, more frames = smoother playback. Plus it will interlace cleaner than 24p also.

[Michael Sacci]

I don’t use architect so I might be guessing here (Bitvice has the same setup) What a DVD needs is the pulldown flags added to the stream but the pulldown frames are not encoded in the file, the flags just tell the player to display this frame for 2 fields or this frame for 3 fields. It is confusing and so many people talk about it in a different manner.

[Michael Spooner]

Thanks, that’s what I thought.

My only worry is that some players might not be able to interpret a 30p DVD. It doesn’t seem to be a common standard, and it has no template in Sony Vegas. I’m not sure if I should select the 24p template and then bump it up to 30fps (well, 29.whateveritis) or, alternatively, start with the 60i template and change it to progressive.

But I would love to do 30p. (Higher than 30p doesn’t seem to be an option at all, so I’ve ruled that out, I think)

[Michael Sacci]

I can’t help with the settings but in Compressor you can set any framerates to progressive.

The difference between 24 and 30p is the player needs to do some thinking, which frames do I send as 3 parts vs 2 parts but with 30p it just sends each frame as 2 fields, no thinking needed. It is the pulldown that needs to be flagged not the interlacing.

Authoring software will not accept not compliant video streams (I’m assuming that Arch would be in this category.)

I know it is easy for me to say but I wouldn’t worry about this, go with 30p, start with a 30i setting and change the field dominance to NONE or Progressive and encode away. Make a DVD and look at it on a Computer, Progressive DVD/TV and then on a standard TV (or any DVD/TV that is connected by a S-Video or RCA cables, that is always feeding an interlaced signal.

And yes in NTSC SD there is nothing higher than 30 frames/s (which is 60 fields/s) Yes it can make your head spin.

[Enrique Orozco]

…well, I´ve made hundreds of DVDs with all my settings in progressive (shoot 30p with an EX3, which I prefer over 24p) in Sony Vegas 9pro without any problems or any complaints of any customer (played on many DVD players out there)… I also know and read about 30p being “non-standard” for DVD but when I make my final render to NTSC-mpeg2 with progressive settings, DVD architect just accept the files well without any reencoding…. in fact, the other day I have to “mix” HD-30p material with some std-VOB-DVD footage from older projects and the best results for my final NTSC-SD-DVD were with progressive settings…

good luck

Enrique Orozco R.
iDEA DigitalVideoStudio

[Eric Pautsch]

Here are the specs:

NTSC (NTSC Film)

Video:
Up to 9.8 Mbps* (9800 kbps*) MPEG2 video
Up to 1.856 Mbps (1856 kbps) MPEG1 video
720 x 480 pixels MPEG2 (Called Full-D1)
704 x 480 pixels MPEG2
352 x 480 pixels MPEG2 (Called Half-D1, same as the CVD Standard)
352 x 240 pixels MPEG2
352 x 240 pixels MPEG1 (Same as the VCD Standard)
29,97 fps*
23,976 fps with 3:2 pulldown = 29,97 playback fps (NTSC Film, this is only supported by MPEG2 video)
16:9 Anamorphic (only supported by 720×480)

Its either 29.97 or 23.98 with 3:2 PD – There are no other frame rates in DVD.

[Michael Sacci]

[eric pautsch] “Its either 29.97 or 23.98 with 3:2 PD – There are no other frame rates in DVD. “

This is a little miss leading.

First, I’m assuming when someone states 30p they truly mean 29.97p since that is what 99.99% of the cameras shoot, same as 24p is 23.98 (23.976)

with 23.98 with 3:2 PD, they actual PD frames are NOT encoded, they are only flagged. At least this is what Compressor, Bitvice and the old Sonic encodes do. The PD is added by the player itself. This is why a 6Mpbs encode of 24p footage is better then 6Mbps encode of 29.97i or p footage, there are less frames to encode in the second so more bitrate can do to each frame. Another way of putting it, 6Mbps of 24p = 6.6Mbps of 30i/p.

Then 30p and 30i carry the same amount of information since the 30i is really 60 1/2 frames (fields) the difference is if you break 30p into 60 fields there is no time difference between 1a and 1b, where as 30i has a 1/60 difference between 1a and 1b, when recorded by the camera.

So if you put together the 2 halves of a slit progressive frame you get a perfect picture. Do the same for the 2 interlace fields and not so much because the upper fields were recorded 1/60 after the lower field. But if there is no motion there is not difference, add a race car and the difference is huge. So, 2 fields does not a progressive frame make.

So not urging with Eric just adding what is hopefully some insight on why there is more to the specs that meets the eye.

[Michael Spooner]

Thanks, but that doesn’t really answer my question–which is whether DVD supports 29,97fps in progressive scan like it does for 23,976.