All Adobe 24p DVD possible?

Re: All Adobe 24p DVD possible?

The frame counter on WinDVD may or may not be significant. As I said in an earlier post, I observed that WinDVD and CinePlayer both show irregular frame counting if the GOPs (groups of MPEG pictures) don't fall on even second boundaries, and that's the case with the Premiere-created MPEGs. So I'd get some seconds that were 30 frames and some that were less. Just a timekeeping anomoly, not real rate changes. Do you see these oddities in the frame counter over several seconds, or is it all 30, 30, 30?

The one thing that worries me: in another thread, you spoke of using 24p STANDARD instead of 24pADV footage. I wonder if this interlaced output is normal in that respect? All of my tests were done with 24pADV. So I'm curious which your footage is.

I still wouldn't mind taking a look at the your Premiere-saved MPEG and seeing what I see in MProbe, an MPEG analyser we have at work. I could tell you for sure whether is is 24p or 30i.
 
Re: All Adobe 24p DVD possible?

Kevin,

The 30 frames in WinDVD doesn't change unless I put in a Hollywood/Commercial DVD. And I see interlacing on my burned DVD, not on the commercial one. The 24/30 is regular -doesn't vary at all.

The footage is 24p normal. I used Adobe Media Encoder as we discussed earlier & encore accepted it without re-transcoding. Sure interesting that the set-top box at Best Buy counted in 24 frame steps. Wish it was conneted to tv to watch for interlacing. It looked fine in Premier Pro 1.5 on the 23.976 timeline.

I'll encode a 30 sec clip in Premeir, then use Encore to build the file, and get that to you. Thanks for taking a look at it. I sure would like to get this one figured out.
 
Re: All Adobe 24p DVD possible?

OK, here is a summary of my findings so far. Sorry if some of this repeats previous posts, I'm just trying to put it all together.

There's no such thing as a "pure" 24p DVD. The video must be either 29.97 Hz or 25 Hz. No other options are given. (This is directly from table 5.4.1.2-1 "Constraints on MPEG-2 Video" from page VI5-40 the DVD-Video spec, so nobody try to argue with this.    :D)

Now, to focus specifically on NTSC DVDs.

Despite 24p not being part of the spec, it is still possible to use it as long as it is NTSC legal. This means flagging the frames with pulldown flags so on output, the DVD player knows which fields to repeat to make up for the missing frames.

Some people have talked about Premiere writing 29.97 actual frames to the disc, with flags telling which frames to drop -- similar to how the DVX stores 24p video on a 60i tape. But this is NOT what happens on a DVD. In fact, it's the inverse -- there are only 24 frames, with flags that indicate what needs to be repeated. You still save the disc space, because the additional fields don't really exist.)

I tested a bunch of big-budget Hollywood discs, a disc from Vegas/DVD Architect, and a disc from Premiere/Encore, and they all handle the problem pretty much the same way -- 24 frames of video + flags.

Vegas and Premiere were very similar in their handling of 24p MPEG encoding. In fact, they both use the same Main Concept codec to encode the MPEG. (At least this is true for Vegas 4, which is all I have access to.)

Like Premiere, Vegas lets you save your MPEG as pure 24fps (without flags) if you really want to, but like Encore, DVD Architect will re-transcode that asset. To make a DVD without transcoding, you need to save with the flags. If the flags are present, neither DVD Architect or Encore will complain.

Luckily, Vegas comes with an encoding preset called "DVD Architect 24p NTSC" that makes it basically brainless to export the MPEG with the required 3-2 Pulldown flags.

Adobe, stupidly, did not provide an encoding preset for 24p MPEG, and this is what has caused a lot of our confusion. But it is possible to set it up manually, and to save it for later use.
 
Re: All Adobe 24p DVD possible?

Steve, I finally got your DVD yesterday.

The encoding is more or less correct -- 24 progressive frames with pulldown flags to enable 29.97 display. My only suggestion would be to change the GOP size ("N Frames" in the Adobe Media Encoder) from 15 frames to 12 frames.

This should also clean up time keeping problems in programs and players that only update their timecodes once per GOP. By keeping the GOP at 12 pictures (1/2 a second) the time should update predictably. If you leave it at 15 pictures, sometimes the second display will update after 30 frames, sometimes after 18 frames, and so on at weird intervals.

So the encoding is fine. The bad news: you do have interlacing artifacts actually encoded into the progressive frames. Now we need to find out why that is happening.

I see the interlacing artifacts only in the first 25 seconds of your DVD -- the first two shots of the woman walking down the beach. Everything else looks fine, with no artifacts.

The interlacing artifacts have a peculiar cadence -- 3 frames of interlacing followed by one frame of progressive. So something is definitely out of whack.

Steve -- is there anything at all different about those two clips as oppsed to the rest of the video? Any change in progressive mode or other settings that might account for the difference? Any different handling in the timeline?
 
Re: All Adobe 24p DVD possible?

Kevin,

All the footage was shot 24p normal. The DVD together when I recieved the 1.5 upgrade. While I thought it was all captured to the 24p timeline in 1.5, I may have 'imported' a shot or two that was originally captured in Premier Pro. I just can't say for sure.

I'll recapture all the footage & do it again.
 
Re: All Adobe 24p DVD possible?

The strange thing about PPro 1.5's treatment of 24p is that it doesn't seem to happen at capture time. Some footage I captured before 1.5 is imported as 24p, as is footage I captured completely oustide of Premiere in Scenalyzer.

So I'm not sure if the capture is the problem. Somehow, Premiere is bungling the pulldown removal just for those two shots.

As I've said, I wouldn't mind having a look at the raw files and Premiere project to see if I can figure out what's going on.
 
Re: All Adobe 24p DVD possible?

As always, I'm traveling now - but will send you the original files as soon as I can get it together. Also, my email server isn't sending anything now, either (which is why you haven't received a reply to the email messages.)
 
Re: All Adobe 24p DVD possible?

[quote author=Kevin_Corcoran link=board=Premier;num=1085939165;start=15#25 date=06/22/04 at 08:39:52]The strange thing about PPro 1.5's treatment of 24p is that it doesn't seem to happen at capture time. Some footage I captured before 1.5 is imported as 24p, as is footage I captured completely oustide of Premiere in Scenalyzer.

So I'm not sure if the capture is the problem. Somehow, Premiere is bungling the pulldown removal just for those two shots.

As I've said, I wouldn't mind having a look at the raw files and Premiere project to see if I can figure out what's going on.[/quote]

Actually, that is not so strange. I can't think of any program that captures the footage with the pulldown removed. You should be capturing at the normal 29.976fps. The NLE then recognizes the flags set by the dvx that tell it wich frames to skip. I use vegas, and this is how it is done with that, in fact, when you capture the footage and bring it into a vegas project, it will actually tell you on each clip if it is removing the 2:3 pulldown or the 2:3:3:2 pulldown.
 
Re: All Adobe 24p DVD possible?

That's how Vegas does it, but I don't know that other NLE's work that way. I suspect FCP strips out the pulldown on capture, doesn't it? I don't know how Adobe handles it.
 
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