Have you tried rendering it to 29.97 with resample disabled? Every 5th frame will be doubled, but there's a very good chance that no one will notice and it will look perfectly fine.

Also, check out by what method it will be viewed in 29.97 areas. If they're going to be playing it as a media file on a computer through a computer screen or projector, just give them 25fsp copies. They'll play at 25fps natively. You really only need to worry about frame rate conversion if it's going to be played on a plain old television set from a BluRay or similar playback medium.

Bob - thanks for the encouragement, I'll give it a try. As an option, I have twixtor (might be a couple of releases old) but my VP11 & VP12 don't "dig it" much and tend to crash with it.

Chienworks - No, I didn't even contemplate doing this. I assumed it would be noticeably jerky. But you may be right. I'll give it a try and report back . I'm only doing this for DVD & Blu-Ray copies. As you say, I wouldn't bother for files.

I'll also compare the 25 -> 23 -> 29 version to the straight resample disabled 25 -> 29 version and post back.

This raises a separate question in my mind: For DCP files (Digital Cinema Package), are US based cinemas (projectors and playout systems) able to handle 25fps? It's part of the DCP standard, but that doesn't mean all systems support it. I don't really expect anyone here to know, but in case you do, I'd really appreciate hearing from you.

Ent.

I'm preparing a film for some American film festivals right now and will be attempting to use Open DCP to do the conversion. From the handful of theater owners I know and the responses I got from a couple of festivals, 24f is what you need to provide for US theaters. I'm just starting to learn the digital projection workflow but from my understanding, the SMPTE DCP standard includes 25fps, but distrubuted DCPs in America only have to meet an earlier standard, "InterOP DCP," which is 24f or 48f only. Most theaters haven't either bought the equipment or learned the proper workflow to allow them to project full SMPTE DCP spec. This is what I've been told, and am still a rookie at this. It might not all be accurate.

Retiming from 25fps to 23.976 is extremely easy with Vegas, just use the "same number of frames" method. Also make certain you use the Elastique resampling option to handle the audio.

As for you other question regarding DCP I'd really stick to 24.000fps for cinema, you just never know. We supply a few local festivals with VCRs and bits a pieces and there always seems to be someone whose submitted something that there's a problem with.


I wouldn't be too hard on whoever suggested shooting 25fps. The one and only feature I've worked on was shot at 25fps. Shooting 24fps in 50Hz land can give rise to issues depending on the lights and camera. I've noticed very bad rolling bars with the SI-2K at 24fps down here with iron ballasted fluros.

Bob.

To do this "correctly," do the 25 to 23.976 conversion and then add pulldown (as you suggested). However, if you disable resample, as Chienworks suggested, and render to a 29.97i file, a modified pulldown will be added and it will play well on most devices. The caveat to this is that some devices try to detect and remove pulldown and the modified pulldown will throw them off. If you can provide more information on how you plan to deliver I might be able to help more.

Corey

You can do something like Twixtor/Speedo for free with MVTools2 in AviSynth. Here is the script I would use for 25p > 29.97p:

 #Frameserve in RGB24 format (or RGB32 if AviSynth will not accept RGB24)

AviSource("d:\fs.avi")

ConvertToYUY2(matrix="Rec601") #Rec601 is correct for encoding Ut Video Codec or Lagarith in Vdub

super = MSuper(pel=2)

backward_vec = MAnalyse(super, isb = true)

forward_vec = MAnalyse(super, isb = false)

MFlowFps(super, backward_vec, forward_vec, num=30000, den=1001, ml=100) # get 29.97 fps

There was some background to these type of scripts in this thread. Multi-threading code can be added to the above script to make it faster.

Thanks for the good information everyone - I can only work on this evenings and weekends, so my big chance is this weekend. Will post results then.

corug7 - the project is a short film, so delivery to judges will be anything and everything: DVD, Blu-Ray, MP4 files, Vimeo - and if we're good enough to be accepted into a decent festival, then DCP for most, or possibly older tape based formats for festivals still in the dark ages technically.

What devices remove the pulldown? Are you referring to consumer devices (DVD players, some TVs?) or are you talking about professional time based correctors/sync correctors?

Ent.

Hi Bob & others

I tried a straight slowdown from 25 to 24, but after I viewed the results on scrolling text, I could see there was a minor jump every 24 frames. Something was not quite right.

I'm guessing it's done a simple frame drop every 24 frames. I obviously am not doing it right. This is confirmed because the resulting video is the same length as the original.

I was going to the media properties, selecting "disable resample" and setting the undersample rate to 0.959 (23.975 fps) and changing the project speed to 23.976 (and same for the resulting render).

Disclosure, just in case it makes a difference: I'm loading my entire veg project into a new veg file, allowing me to perform media properties on the veg asset as a whole like it was a normal media file.

I searched here and google for more info - but didn't find what I needed.

Can some kind sole link me to a tutorial, etc? More information on the proposed elastique sound solution would be helpful too!

Thanks,
Ent.

Trying to do this to a project would be messy so:

1) Render project to the least lossy codec at source frame rate. Avid DNxHD would be good. You now have a 25fps Master.
2) Take 25fps Master into a new 25p Project.
3) Change T/L Ruler to absolute frames. Note exactly how many frames long your movie is.
4) Change Project and Ruler to 23.976 fps. Whilst holding down Ctl use the mouse to drag the end of your movie's event until it is the same number of frames long as noted previously.
5) Render out. You now have a 23.976 master of your project.

Regarding Elastique.
R Click the audio track and select Elastique as the resampling method. Then you'll get a number of choices, don't remember the exact names but one is reasonably obvious as being the best choice.

Bob.

What Bob said, although you should leave your ruler at absolute frames so you know how far to stretch the clip in step 4.

As far as the devices you asked about, some consumer televisions, DVD players, projectors, etc. will fail at the pulldown removal when going from 25p to 29.97i. Bottom line, if it needs to be correct, do it the correct way, and Bob spelled it out for you!

Corey

If you've matched the slower speed exactly, undersample shouldn't be used as it's unnecessary. If you haven't matched the slower speed exactly then undersample can cause more dropped/duplicated frames. At best i see undersample being unhelpful, and possibly cause more problems.

To convert from 25 to 23.976, simply multiple the length of the project by 25/23.976 (1.042703976). However, it's even easier to let Vegas do the math. While the project properties are still 25fps, set the timecode to absolute frames and mark where the end of the project comes, and write that frame number down. Now change the project frame rate from 25 to 23.976 (or 24, if you're going that route). Find the same ending frame number that you've written down and move the cursor there. Hold down the Ctrl-key and drag the end of the clip from where it is now to the cursor position; it will snap there to get an exact fit. Disable resample.

Your project is now the same number of frames it was before, with one source frame exactly matching one output frame. Guaranteed no frame drops or duplicates, no cadence errors or jumpiness at all.

Of course, you'll have to decide whether you want to adjust the pitch of the audio to maintain it, or let it slow down to match the new playback speed.

Another way to do this is export the video as an image sequence at 25fps, start a project at 23.98 and import the images where each image is one frame long. You will still have to resync audio as above, and the end result should be the same.

Dave T2

From my own experience of sending NTSC DVD's and Blu-rays back to my parents in the UK, everyone single one has played in whatever player my dad and brothers have had at the time. I was very surprised at this as I had assumed they would only play on a computer.

I think there is more flexibility built into the players in Europe than vice versa. He has sent PAL DVD's to me and they have never played in my Sony DVD and Blu-ray players but have played in a Phillips and Denon.

I know this doesn't help you much as you need to know your DVD's will play in every player.

Always a lot of mention of Twixtor which I see and hear is very good but but if you have After Effects, timewarp has given me much better results than slow motion and changing frame rates in Vegas.

I went through this in some detail a while ago, put a number sequence 1-25 on 25 consecutive PAL frames, converted to different rates, slowed frame rate, etc and saw what happened just to confirm there's no magic. 25 into 24 or 30 or any fraction of it won't go. Resampling is actually sensible in theory - rebuild images from bit stream - but in practice is useless. It creates a mess of blended frames. Its not a question of whether disable sampling should be the default - Sony should just drop it. Resampling disabled, 25 to 24 dropped every 25th frame. 25 to 30 doubles every fifth frame. It's a reasonable approach. Clever software can drop/double the frames where there's less motion, but where everything moves uniformly like scrolling credits, Vegas approach is as good as anything. The good news is when you play back ordinary footage only you will notice, and if there's nothing much happening on screen you won't either. For video you either have to compromise on quality or shoot at the framerate you want to distribute.

Hi guys,

Reporting back on my findings. Mostly good, but something weird is up with the final 24->29.97 conversion.

1. Straight 25 fps to 29.97 fps conversion with no Smart Resampled frames, and held frames inserted by Vegas where it deems: mostly looks OK, but is stuttery to the trained eye on constant motion (eg, credit scrolls, passing cars). Looks better than blended frames that Vegas Smart Resample automatically applies, but I am wary of the warnings from others about playback on some gear.

2. Straight 25 fps to 23.976 fps conversion with no Smart Resampled frames, and a repitched soundtrack via elastique as described above by Bob (farass). This works beautifully, with no audio artifacts from the pitch shift. Every frame a crisp copy.

3. 25fps to 29.97 fps conversion via conversion to 23.976 first (point 2 above), then straight conversion to 29.97 via 3:2 pulldown, no Smart Resample. Something went wrong in the 3:2 pull down step - I don't have clean frames for the "2" part of the "3:2". They are both blended frames. None the less, it plays nicely a looks reasonably sharp thanks to 3 of the frames being sharp! It has the added benefit of being undoubtedly smoother looking than a normal 3:2 pulldown. I'm pretty happy with that result actually.

Now - what went wrong (why are the 2 frames blended)? I'm ruling out any issues with the 23.976 source, as I checked each frame over 48 frames and they are perfect.

I loaded the 23.976 source into a 29.97 project, and disabled smart resample. I checked 60 frames by hand on the Vegas timeline and the frames were converting correctly (frames 1-4 normal, frame 5 a dupe of frame 4). I then rendered out at 29.97, but upon checking the render, frames 4 & 5 are separate blends as described, not held frames as expected.

I tried changing my timeline to 23.976 but it made the same output. I double checked smart resample was disabled.

Any ideas? I'm keen to do it right and compare it, even through I suspect I'll end up going with this hybrid that looks sharp and has smooth movement.

Thanks again guys
Ent.

All I can add is method 2. works because, well it is the way the industry has been doing it for over 50 years albiet the other way around.
Film is traditionally shot at 24.000 fps so how to put a movie to air in PAL land?
Simple, run it at 25fps.
What about the sounds track? Simple too, even if it was optical or mag. It too just ran a bit faster and in the early days indeed the pitch was shifted. The viewing public coped, some with perfect pitch did notice
Advances were made and pitch correction was added to telecines. Like the old resampling algoithm in Vegas it mostly worked but some music (solo bugle playing Taps) was problematic. No doubt today the hardware solutions are better.

We also have to deal with incoming video feeds that are from Region60 countries and the conversion needs to be done in real time.
Original solution was a monitor with long persistance phosphor running as NTSC with a PAL camera pointed at it. Go figure but it worked well enough. Then along came DICE that took up a couple of 19" racks. Today a couple of rack units of electronics handle the task. That said even Vegas can do a quite decent job of 50i <-> 60i. No complaints from any of the people I've done it for, in fact up against expensive hardware boxes it doesn't look shabby.
However: 50i or 60i has double the temporal resolution of 25p or 30p and blended frames don't looks so bad. Even duplicated or dropped frames can be tolerated. 24p and 25p are already right on the limit, it's hard to shoot and I guess I'd say it's fragile.
Trying to convert 25p to 30p without motion estimation software is impossible.

ps: The thought did occur to me that if you wanted to avoid making a 25p DI and retiming that to 23.976p you could probably just nest your 25p project into a 23.976 project but with the child event stretched to the same number of frames.

Bob.