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Does the DVD Specification Support 30p?

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Michael Spooner
Does the DVD Specification Support 30p?
on Jan 8, 2010 at 3:22:26 pm

Is it possible to author 30p video to DVD and have it be compliant with the DVD specification? From what I've read, I get the impression that 24p is the only progressive standard that DVD will accept. Sony Vegas, for example, only has templates for 24p and interlaced at 30fps (60i). That being said, I burned a test DVD in DVD Architect with 24p, 60i, and 30p versions of my video, and it didn't give me any trouble. When played back on my progressive scan TV, the 30p version is far and away the best of the three. There are NO interlacing artifacts, whereas the 60i still has some, and the motion is much smoother than 24p since there is no pulldown. When played back on a computer screen, there is absolutely no comparison between the 30p and 60i. 30p wins hands down.

My project is all still images with panning, zooming, etc done within Vegas so I can change the output frame rate and interlacing at will without concern over how the video was captured.

Disc space is not an issue, and I would like to get the best possible quality within the DVD spec. I like the progressive scan of 24p, but prefer the higher framerate of the standard 60i. Is 30p an option, or do some DVD players have trouble decoding it?


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Roman Melekh
Re: Does the DVD Specification Support 30p?
on Jan 8, 2010 at 5:48:41 pm

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



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Michael Spooner
Re: Does the DVD Specification Support 30p?
on Jan 8, 2010 at 6:04:42 pm

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?


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Michael Sacci
Re: Does the DVD Specification Support 30p?
on Jan 8, 2010 at 6:39:18 pm

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.



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Michael Sacci
Re: Does the DVD Specification Support 30p?
on Jan 8, 2010 at 6:34:04 pm

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.



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Michael Spooner
Re: Does the DVD Specification Support 30p?
on Jan 8, 2010 at 7:04:26 pm

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)


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Michael Sacci
Re: Does the DVD Specification Support 30p?
on Jan 8, 2010 at 7:47:18 pm

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.



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Enrique Orozco
Re: Does the DVD Specification Support 30p?
on Jan 13, 2010 at 5:38:40 am

...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.
http://www.dvideostudio.com >iDEA DigitalVideoStudio


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eric pautsch
Re: Does the DVD Specification Support 30p?
on Jan 13, 2010 at 5:31:56 pm

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 720x480)


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



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Michael Sacci
Re: Does the DVD Specification Support 30p?
on Jan 13, 2010 at 6:05:53 pm

[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.




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Michael Spooner
Re: Does the DVD Specification Support 30p?
on Jan 13, 2010 at 6:34:09 pm

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.


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Michael Sacci
Re: Does the DVD Specification Support 30p?
on Jan 13, 2010 at 9:27:58 pm

Dude how many time have I said yes it does.



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Michael Spooner
Re: Does the DVD Specification Support 30p?
on Jan 13, 2010 at 9:40:52 pm

Whoop, sorry. Didn't realize you were the same guy. I'm just getting mixed messages from people around the net so I think I'm going to stick with 24p.


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eric pautsch
Re: Does the DVD Specification Support 30p?
on Jan 13, 2010 at 10:36:12 pm

Never heard of 29.97 progressive on DVD. Its either 29.97 interlaced or 23.98p with pulldown flags. Not sure how you are encoding but its definitely not a 30p MPEG2 stream.

EDIT: Correction! So its still an interlaced picture, but there is no time difference between fields?


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Michael Sacci
Re: Does the DVD Specification Support 30p?
on Jan 13, 2010 at 11:19:34 pm

[eric pautsch] "Not sure how you are encoding but its definitely not a 30p MPEG2 stream. "
Both Bitvice and Compressor will handle 30p source, maybe it is adding interlace flags.

The problem when deiinterlacing true interlaced footage is the some information is thrown away, you cannot simply display two fields as a single frame. So there maybe flags in the encode similar to 24p (minus pulldown). That way the progressive player knows to use all the info of the frame and not do some type of averaging or line doubling.

All this being said 30p is not something that is normal used, but the like is smoother than a 24p but still keeps the most filmic quality of progressive.

[eric pautsch] "EDIT: Correction! So its still an interlaced picture, but there is no time difference between fields? "
Well I would say that it CAN be, just like the 24p can be, it is just a simpler process, since there no pull down.

My head is now hurting. I know what your saying, I know what the spec are saying, I know what a progressive play should do, so I put it as a your are correct but...





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Enrique Orozco
Re: Does the DVD Specification Support 30p?
on Jan 13, 2010 at 11:19:36 pm

...again.... I've made many DVDs encoding my progressive HD source files as progressive mpeg2 and DVDarchitect doesn't reencode the files.... the DVDs are 100% fully compatible with any player, looks great and if you "check" the VOB file-properties appears as 720 x 480 29.97 progressive files !!!!


good luck

Enrique Orozco R.
http://www.dvideostudio.com >iDEA DigitalVideoStudio


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eric pautsch
Re: Does the DVD Specification Support 30p?
on Jan 13, 2010 at 11:39:10 pm

The only problem Enrique is that the spec only supports 29.97 interlaced and 23.98 with PD flags - the spec is very clear on this. So there's a missing piece of the puzzle here.

My guess is that the "30p" is actually interlaced just that each frame has NO temporal differences. A "faux" 30p if you will. I'll have to post this on the Tully List to see what the rest of the DVD world thinks.

I've never worked with 30p material before myself - find all this very confusing :)


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Michael Spooner
Re: Does the DVD Specification Support 30p?
on Jan 14, 2010 at 12:08:31 am

I'm under the impression that 24p on DVD is also "faux" progressive, but for all intents and purposes it looks and behaves exactly like a progressive image should. The same is true when I tried encoding 30p on dvd. The image is most definitely progressive (no interlace lines or artifacts), and it's running at 30fps. The motion of 60i with the picture quality of 24p.

I think I noticed a bit of flicker when I played it back on an interlaced TV. I think I read elsewhere that trying to interlace is where 30p has problems on some players/TVs.


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eric pautsch
Re: Does the DVD Specification Support 30p?
on Jan 14, 2010 at 1:47:23 am

Here's good thread to read:

http://forums.creativecow.net/thread/8/1040702#1040702

The thing to remember is DVD is 20 yr old technology. Progressive video was not a thought in the late eighties. A DVD compliant NTSC MPEG-2 video file must be stamped with a frame rate of 29.97 fps. There is only place for one frame rate code in the MPEG-2 headers, so you cannot stamp it with two different rates. This is regardless whether the original movie comes from film or not. There is no doubt about that. It is just a matter of fact.

RELATED POSTS
http://discussions.apple.com/message.jspa?messageID=3943775

http://forums.creativecow.net/thread/155/870715#870746


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Michael Sacci
Re: Does the DVD Specification Support 30p?
on Jan 14, 2010 at 7:12:13 am

how about this for an answer, from http://www.dvddemystified.com/dvdfaq.html#1.40

There's enormous confusion about whether DVD video is progressive or interlaced. Here's the one true answer: Progressive-source video (such as from film) is usually encoded on DVD as interlaced field pairs that can be reinterleaved by a progressive player to recreate the original progressive video.

This is different from being interlaced footage being de-interlaced.



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eric pautsch
Re: Does the DVD Specification Support 30p?
on Jan 14, 2010 at 9:20:58 am

Bingo! There's the answer.

So to make it clear:

1. DVD is an interlaced format only
2. All MPEG 2 streams are stamped 29.97; 23.98 with PD flags=29.97
3. Progressive-source video (such as from film) is usually encoded on DVD as interlaced field pairs that can be reinterleaved by a progressive player to recreate the original progressive video.

This is different from being interlaced footage being de-interlaced.

So the 30p is actually encoded 29.97 interlaced field matching pairs

Do we agree on this? :) I would love to put this away for good. lol



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Michael Spooner
Re: Does the DVD Specification Support 30p?
on Jan 14, 2010 at 3:57:20 pm

That's what I thought.

So 30p SHOULD work just fine.


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eric pautsch
Re: Does the DVD Specification Support 30p?
on Jan 14, 2010 at 7:24:49 pm

Sure...but the original question was "does the spec support 30P"? No it doesn't but the outcome is the same. Best thread in months!! :)



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Michael Spooner
Re: Does the DVD Specification Support 30p?
on Jan 14, 2010 at 11:41:43 pm

Happy to know a noob like me could be responsible for it ;D


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enrique orozco
Re: Does the DVD Specification Support 30p?
on Jan 14, 2010 at 10:05:26 pm

...maybe that's why DVD architect doesn´t reencode my 30p mpeg2 files and the DVDs are fully compatible.....


great forum !!!!

Enrique Orozco R.
http://www.dvideostudio.com >iDEA DigitalVideoStudio


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Joel Hufford
Re: Does the DVD Specification Support 30p?
on Mar 26, 2010 at 6:18:08 pm

I know this thread is a few month old, but I've just been reading up on DVD authoring and came across it. I love that this resource is here for people to explore, I continue to learn so much just by scrolling down the forum lists!

After reading this thread, would it be correct to say that the way a Progressive video is encoded on to a DVD is Progressive segmented Frames (PsF)?

It seems to me that the encoder is taking a 30p, (or really, 29.97p) splitting it up into two fields that exist at the same point in time. So even though it is being drawn as an interlaced signal, there is no temporal shift on the display, thus no interlaced artifacts.

Is it correct to think about this process this way?

Thanks!

joel


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