29.98 v. 23.97fps DVDs

[Justin Reade]

I am attempting to author a 23.98 fps DVD. I shot all my footage in 1080/24pA, reverse telecined all my clips in Cinema Tools, so that my clips and my FCP 5.1, 23.98 fps timeline were in synch. I have successfully exported as a QT .mov, which is correctly identified as 23.98fps when you GET INFO on the file in QuickTime Player. I then encoded the QT .mov in Compressor, using the settings DVD BEST QUALITY/90 min. That file, once through Compressor, also is 23.98fps when you GET INFO on it. However, when I author the DVD in DVD STUDIO PRO, I swear to Christ that the motion looks like 30fps when I'm watching it... it's just too slightly fast/smooth in parts...

Anyone confront this issue? Is there some nuance to DVD STUDIO PRO that is screwing with me here??

[imgentertainment@mac]

Well I have never seen the motion problems that your are talking about. But I know when you import the mov as an asset it say it is 29.97 this is just an error. It is really seeing the 23.98 movie. As for the motion try burnning the DVD and see what it looks like. Also check your fild order setting on the dvd and make sure it is set to none/progessive.

[Justin Reade]

Yes, I figured out a few weeks ago that DVD Studio Pro has that bizarre occurrence of still declaring that the asset is 29.97fps even though that is not the case.

However, I just feel that the DVD motion effects are a little too fast to be true 24fps. Question: do you think that if SOME, but not all, of my footage was shot in straight 1080/24p, whereas the rest of it (i.e., the bulk of it) is shot in 1080/24pA, this might account for any variance in motion effects? With respect to ALL of my clips, I reverse telecined them in Cinema Tools. Just curious what the practical effect of this "mixed" footage situation might be [24p and 24pA in the same timeline], relative to the "problem" I'm observing -- any correllation?

[jonnothin]

I'm sorry I can't help but since I'm going to be in the same situation you are in a couple days (making a 23.97 DVD using Final Cut 5.1 from 24pA footage) I was wondering...what is the "reverse telecine" process and why do we have to do that to make the DVD?

Thanks

[volcano]

do you think that if SOME, but not all, of my footage was shot in straight 1080/24p, whereas the rest of it (i.e., the bulk of it) is shot in 1080/24pA, this might account for any variance in motion effects?

Yes it would, Although I have no experience at shooting HD, and if, working with 480/24pa is similar to your workflow for the same end purpose(24p DVD output) i may have a suggestion:
Do not reverse telecine your 24pa footage in Cinema tools. Instead, just remove pulldown by using your capture settings and work on a 23.98 timeline in FCP. Do reverse telecine your 24p footage if you are gonna mix it with your 24pa workflow. Then goto 24p DVD and see the results... I am not sure, but worth trying...

[Justin Reade]

This is going to [try to] answer both posts above me.

(a) Why "reverse telecine" in Cinema Tools? Because although the literature to FCP 5.1.1 suggests that the "Advance Pulldown" feature will automatically strip the redundant frames from your 1080/24pA footage, it in reality DOES NOT. If you look carefully in your BROWSER in FCP, you will notice that -- even with the "remove advance pulldown" box checked -- your clips will import, and remain, at 29.97fps. If you scroll to the right in your FCP Browser, you will see that the fps on all of your clip properties are still at "29.97fps." This is frustrating, correct? Because you shot in 24fps and you want to edit in 24fps and you ultimately want a DVD in 24fps. Therefore, the simple answer is: the "remove advance pulldown" function does NOTHING in FCP 5.1.1.

As such,

(b) You must use the "Reverse Telecine" process in Cinema Tools [which comes with your FCP software bundle] in order to remove the frames and arrive at a true 23.98fps clip. As a testament to this, all you have to do after effectuating this "reverse telecine" process, is drag the "reversed" clip from the harddrive/source where you saved it, and place it back into your FCP BROWSER where all your clips reside and then check the properties on it. Again, scroll to the right in your Browser, and you will now see that the clip is appropriately at 23.98fps. As a result, when you drag this clip into your FCP timeline, you will NOT see a red line above it. This means, that your clip and your timeline are in synch -- i.e., both at 23.98fps, and you do not need to render it.

MY ISSUE is that I stupidly shot some footage in straight 1080/24p, while the remainder (i.e., bulk) of my footage is all in 1080/24pA. As a result, I have an end product in my timeline that consists of mixed footage. I have noticed that after compressing the QT .mov, after encoding in Compressor, and ultimately after authoring the DVD in DVD STUDIO PRO, my DVDs (at times) look a little too swift and smooth for a true 24fps movie. In an effort to diagnose where the error has occurred, there are plenty of nuances/options: (a) is it the issue of the mixed 24/p - 24/pA footage?; (b) is it how I am specifically encoding the QT .mov in Compressor?; (c) is it some adjustment to be made in DVD STUDIO PRO? As you can see, there are a myriad of possible explanations, and I am trying to isolate where the problem may exist. It is my theory that the problem is with the mixed footage, and there is an ostensible difference in the motion effect when you "reverse telecine" straight 24/p clips and then try to combine them with 24/pA. That is only a conjecture, however....

Justin.

[jonnothin]

wow...thanks justin for a complete answer...this really sucks and now I'm questioning if the movie we're premiering in a week is the best it can be. F**K!

[volcano]

"remove advance pulldown" function does NOTHING in FCP 5.1.1


This has been an ongoing issue among DVX users... Noah, Greame, Jimmerson all have different opinions (as you can read in Noah's sticky about how to capture 24pa footage)...
I can't comment on your problem with my limited knowledge on HD, and there are too many variables in your case as you mentioned...(Downconverting to SD, steps of QT, Compressor, DVD studio triangle)
But what i can do (and will) is to try mixing 480 24p and 24pa the way i would and the way you suggest, then do a 24p DVD to see if i encounter similar problems...
I'll report my experiment...
V for Volcano ;)

[bgundu]

What are you viewing your DVD on? Is it a progressive DVD player and monitor?





I am attempting to author a 23.98 fps DVD. I shot all my footage in 1080/24pA, reverse telecined all my clips in Cinema Tools, so that my clips and my FCP 5.1, 23.98 fps timeline were in synch. I have successfully exported as a QT .mov, which is correctly identified as 23.98fps when you GET INFO on the file in QuickTime Player. I then encoded the QT .mov in Compressor, using the settings DVD BEST QUALITY/90 min. That file, once through Compressor, also is 23.98fps when you GET INFO on it. However, when I author the DVD in DVD STUDIO PRO, I swear to Christ that the motion looks like 30fps when I'm watching it... it's just too slightly fast/smooth in parts...

Anyone confront this issue? Is there some nuance to DVD STUDIO PRO that is screwing with me here??

[Justin Reade]

What are you viewing your DVD on? Is it a progressive DVD player and monitor?

YES for both. Remarkably, I just viewed it on a different setup at a friend's place, and the motion looked like true 24fps. It baffles me how there would be an ostensible difference on different setups, but that is the nature of the beast, I guess. I'd like to see what Volcano's experiment yields however....

[zoostory]

you may also want to try and use "main concept" instead of compressor. There's a bit of a learning curve, but I find it way faster and better quality than compressor for 24p footage.

Also, instead of cinema tools, you can use After Effects pro to remove a pulldown, which I have found better as well.

Anyway, as mentioned above, I am almost sure your problems have to do with 24pA.

[Tainted]

Or switch to Vegas... LOL!

[Justin Reade]

ha. not an issue w/ final cut pro/platform. i like it when i put my p2 cards in my laptop and my OS actually understands what i'm doing! lol

[Rhydon]

I have found that its not wise to trust the simulator window in DVDSP. Always have a reference DVD player with a good TV hooked up to check your masters.


Rhydon

[smelni]

I am having a similar issue but outputting from avid - then using tmpeng to compress and encore to create the dvd - i am pretty sure it is 24p all the way through - and on the pc it looks great - but on the tv it looks like video -

anyone have any ideas about this - could it just be the dvd player/tv?

[Cynic821]

yes, im very curious about why it did that, because my theory was that the DVD player in the Mac wasnt using any pulldown to bring it back to 24p or however , whatever, whenever, tech jargon that works.

but ...well idunno.

[Edgemin]

I was wondering if volcano's experiments ever yielded any results? I too am trying to author a DVD with footage that was shoot in 480/24p and 480/24pa.

I believe I exported both footage properly using compressor. I used the 90 min High Quality encode and the files kept their appropriate frame rates (23.97 and 29.97).

However when I import the files into DVD Studio Pro the frame rate inspector indicates that they are all 29.97. Is there anyway to author a DVD that contains both 29.97 and 23.97 footage? If this question has been answered already I apologize, I thought I had control of the situation and then I read this thread and got really confused.

I was also wondering about the reverse telecine.

The footage I shoot in 480/24pa and imported into FCP with the advanced pull-down conversion indicates it is 23.97 in the browser window inspector. Justin had indicated that the Advanced Pull-Down Conversion does not work properly. When I drag the footage into a 23.97 timeline it also does not need to be rendered. It appears as if FCP recognizes it as 23.97 but how do I know if my footage is not properly being processed at 23.97? The footage was shoot on a HVX-200.

[Edgemin]

do you think that if SOME, but not all, of my footage was shot in straight 1080/24p, whereas the rest of it (i.e., the bulk of it) is shot in 1080/24pA, this might account for any variance in motion effects?
Yes it would, Although I have no experience at shooting HD, and if, working with 480/24pa is similar to your workflow for the same end purpose(24p DVD output) i may have a suggestion:
Do not reverse telecine your 24pa footage in Cinema tools. Instead, just remove pulldown by using your capture settings and work on a 23.98 timeline in FCP. Do reverse telecine your 24p footage if you are gonna mix it with your 24pa workflow. Then goto 24p DVD and see the results... I am not sure, but worth trying...
I converted the 480/24p footage with reverse telecine, but it produced 24fps rather than 23.97 Are you suggesting that if one mixes 29.97 and 23.97 it is better to mix 24 and 23.97 instead? Or should have the reverse telesine produced 23.97 footage?

[Justin Reade]

I still don't have a true answer for this - but here is what time has told me...

Since my initial post, FCP has updated their software to 5.1.2, which takes away the need for reverse telecine'ing clips in Cinema Tools, although there is supposedly still a timecode issue (according to another thread in here somewhere). Nonetheless, in FCP 5.1.2, if you drop your 1080/24pA footage in your 24p timeline, you won't have to render, etc., and it looks just fine.

The question still remains what motion effects, if any, result from mixing footage shot in 24p with footage shot in 24pA in the same timeline and then authoring a DVD. The motion effects that I believe I was seeing was a result of specifications that you can adjust in the INSPECTOR window of DVD Studio Pro, and that is by virtue of selecting "Motion Estimate: Best. " I believe -- maybe am wrong -- but believe that by selecting BEST, you are getting smoothed out motion effects in particular sequences. This is why I believe I'm seeing almost 30 fps like motion effects in certain fast movements on screen, despite the fact that they are 24p.

This is TOTAL hypothesis, and I welcome anyone who has more specific/definitive information.

Justin

[Edgemin]

Justin thank you for the information, it was very useful. If you don't mind I have one last question regarding the creation of a 24p DVD.

I've read on a few treads that this is a useless attempt due to the fact that TV's display the picture at 60i. However I am still curious as to how this works. My encoded footage from compressor has been exported at 23.97 fps and when I import it into DVD studio pro it is identifying it as 29.97. My question is this, does 23.97, 24, etc even matter when exporting to DVD? I'm watching the video in the stimulator and their appears to be no difference so I am wondering if this whole 24p DVD thing is worth the hassle.

[DavidBeier]

If you shot 24p you certainly won't get motion that looks like 60i; it's just not going to happen. However, if you're mixing your pulldown then it wouldn't surprise me if you're getting some motion artifacts. If you're shooting 24pA the pulldown is 2:3:3:2. The NLE will just delete every third split frame to get a true 24p. In regular 24p however, you're only doing 2:3. The third frame is spread across two split frames and has to be extracted and rebuilt. If you're trying to mix that into a 24pA timeline, thenit means that you're just dumping the one of the split frames and then seeing only half of the origional 3rd frame. This could make parts of the motion look speed up as you describe.

In other words:

24pA:

A Frame (two fields), B Frame (two fields), Split frame half B half C, C Frame (two fields, D Frame (two fields)

The third frame is then dropped to be pure A, B, C, D, E, F

24p

A frame (two fields), B frame (two fields), Split frame half B half C, Split frame half C (other half) half D, D frame two fields.

Extracting using the 24pA pulldown however would give you:

A, B, Split frame half C half D, D, split frame half E half F, F

The result is that every other frame is being chopped in half. This will certainly look odd.

[Justin Reade]

David, YES YES -- that is most likely the reason why there are motion issues. Thank you very much for the clarity in your response. That makes a lot of sense. I knew there had to be some motion issues when you fuse straight 24p and 24pA footage together in one timeline.

Edgemin, do not worry whatsoever about the anomaly that you are finding in DVD STUDIO PRO. It is a known problem with the software that it wrongly/incorrectly identifies your movie file as being "29.98" when it really is, in fact, "23.97."

A television is not going to brute force you into 60i. If you purchase a DVD, i.e., a commercial one like any major motion picture, you are seeing 24 frames per second because that's is the speed frame rate of actual FILM in which it was originally shot -- you can't ADD frames to that. So, assuming you shot your movie, etc., with the HVX and edited it in a 23.97 timeline in Final Cut Pro, or what have you, you will be yielding a 24p product.

Check your Quick Time movie file. You will note in its "Properties" that it's 23.97. Don't worry about what DVD STUDIO PRO says, as I noted above. The bizarre issue discussed previously in this thread, and I believed answered very competently by David, is that I stupidly dropped straight 24p footage into a timeline along with 24pA footage and noticed motion effects in the final DVD product. In an effort to diagnose why this was happening, I was conjecturing a lot, and felt (I guess rightly) that my 24p and 24pA blend was a potential cause/factor. Makes sense why, based upon the pulldown.

Anyway, author away. Your 23.97 project will burn as a 24p DVD and you're good to go! As a test, why not shoot something on the HVX in true 60i and then author a DVD of that footage? I haven't tried it, but my guess is, you will see the appreciable difference in frame speeds.