Quicktime 29.97 broken in ?

Box8068_31c338ee4bBox8068_31c338ee4b Posts: 292
edited December 1969 in Carrara Discussion

I've been rendering to Quicktime Animation codec on a Windows 7 machine at 29.97.
I know I can render to sequenced PNG. but I was just wondering if something is broken in 8.1 or is it a setting I missed.
I was successful in rendering to 29.97 in Carrara Pro 6, but I noticed my renders in 8 are coming out 30fps.
My project setting in Carrara is 30 fps. When I go to render I select 29.97 in the quicktime options, keyframe every 15 frames, animation codec, and Save the project, save the movie under a new movie name and render. If I go back and look at the qT setting it pops back to 30fps. ?


  • 3DAGE3DAGE Posts: 3,311
    edited December 1969

    HI 8068 :)

    The difference between 30 and 20.97 is negligible and impossible for the human eye to detect, so it's no surprise that two programs show a different value for what is essentially 30 FPS.

    One advantage of a "Sequenced" export, is that you can specify the playback frame rate in your Video post production software, allowing you to choose 12, 24, 30, 60 or any other frame rate,.. and change that playback rate at any time,.. depending on what you want to do.


  • wetcircuitwetcircuit Posts: 0
    edited December 1969

    3DAGE said:
    HI 8068 :)

    The difference between 30 and 20.97 is negligible and impossible for the human eye to detect, so it's no surprise that two programs show a different value for what is essentially 30 FPS.

    One advantage of a "Sequenced" export, is that you can specify the playback frame rate in your Video post production software, allowing you to choose 12, 24, 30, 60 or any other frame rate,.. and change that playback rate at any time,.. depending on what you want to do.


    The problem is with audio sync, and also unmatching framerates in an editor can be a nightmare...
  • Box8068_31c338ee4bBox8068_31c338ee4b Posts: 292
    edited December 1969

    Hey 3dage!
    Good to see you again. Without doubt a png sequence would not have this issue as I can choose frame rate on import.
    I think this is a Version 8 bug, that I didn't have in version 6. The quicktime came out properly in Carrara version 6 as 29.97.
    Maybe I should clarify here, I'm not new to Frame rates and video formats. I am still using using these 30 fps segments in my video edit.
    I just set them to pull down. If I forget they system slows down a bit as it does a resample on the fly.
    For the most part I am using PNG Seq. 1920x1080 PNG is a crazy amount of throughput off the Hard drive and does bog the system down a bit.
    I can use proxy files, or pre convert in QT but that adds more steps.
    I am working on a hour long video with about 20 minutes of animation. Lots of different files. I'll give up on it but if QT worked it is a elegant solution,
    It looks great, Streamlined file management, Editing software eats it for breakfast ( this is helpful for dissolves between scenes), no additional steps, It contains audio from the animation I can use as a guide to resync audio without guess work.
    I tend to use PNG Seq for any render taking more then 3 or 4 hours, every now and then I try QT for a short render to keep things simple.
    But I'll just go back to PNG ;(
    If daz is still working on Carrara would be nice to post a bug report though.
    Thanks for you advice, and hope you are well.

  • 3DAGE3DAGE Posts: 3,311
    edited December 1969

    HI 8068 :)

    If it's a bug in C8, it's not likely to be fixed with any updates or patches for 8.1

    Since we're on 8.5 beta, that's the only place you'll see any change,. but posting a bug would be advisable to get the developers to check it out further.

    Also, it's strange that you're seeing any notable difference between the lip-sync animation, and audio, with only 0.3 of a frame per second difference in the playback rates.

    I'd check the lip-sync animation first,.. it's possible, and probable, that the lip-sync animation needs to be corrected slightly at some points. Since it's an automated process it's very likely to be the animation that's out by a couple of frames at different points, but it's relatively easy to correct those.

    unless you're seeing a constant, and growing drift of lip-sync and audio.

    Your video editor should allow you to import animations and change the playback rate, so,.. by changing the 30fps animation, to 29.97 as a test,. would be the quickest way to see if the Lip-Sync animation was out because of the Quicktime frame rate difference,. or out because of the lip-sync animation.


  • JoeMamma2000JoeMamma2000 Posts: 2,615
    edited February 2013

    If you’re even semi-serious about doing any editing, I really suggest that you read up on stuff like video formats and frame rates. It will save you a lot of head scratching, and it really is kind of interesting. At least to me…

    I’ll try to give me simplistic explanation of what the OP is referring to.

    What you’re talking about is apples and oranges. Why? Well, some of the old timers might remember black and white TV. When they designed B&W TV they decided to make the frame rate (how many frames of video pass every second) to be half of the frequency of the electrical system. Y’know, the electricity you get when you plug your hair dryer into the wall. In the US that is 60Hz. So they picked 30Hz for a frame rate of video. In other countries it’s a 50Hz electrical system, so they chose 25Hz frame rate. It made things easy for the engineers.

    Anyway, when color TV came along they couldn’t use a frame rate of 30Hz. So they decided on something close, which was 29.97 FPS. Don’t ask why, it’s complicated engineering stuff which I don't understand. But once they decided that, it became difficult to label each frame of video with a simple label, otherwise known as “timecode”. The thing that video editors use to identify each frame of video they’re working on. And to give them an idea of how much time has passed.

    Without going thru a lengthy explanation which I’ll probably get wrong, the bottom line is that ALL NTSC color video nowadays has a FRAME RATE of 29.97 FPS. There ain’t no 30 FPS frame rate. You can call 29.97 FPS as 30 FPS, and that’s fine, but the 30 FPS designation is actually referring NOT to a frame rate, but to a TIMECODE designation.

    Kind of confusing, but since it’s difficult to assign a simple timecode to each frame of video when it’s running at 29.97 FPS, while at the same time giving editors what they need, they use a 30 FPS timecode for the 29.97 FPS video. And you may have heard of “drop frame” timecode. In order to line up the 30 FPS timecode designation with the actual 29.97 FPS video rate, they drop some frames of timecode at regular intervals to make sure the time code designation matches the actual frame rate. So if you notice while you’re watching the 00:00:00 timecode progressing in your editor, you’ll see frames missing at regular intervals. And if you don't care about the timecode designation matching the actual time passed, then you can choose "non drop frame", and when you're working on a two hour long production the time code will be very different from the actual time passed.

    Anyway, bottom line is that 29.97 FPS and 30 FPS are the exact same thing. Only COMPLETELY different.

    Post edited by JoeMamma2000 on
  • Box8068_31c338ee4bBox8068_31c338ee4b Posts: 292
    edited December 1969

    Guys ;) !
    I have a 30 years experience in audio. Much of that has been mixing for Film, and T.V.
    Including multiple showtime and HBO specials. I am fully fluent on frame rates, video and film.
    I understand B&W at 30 frm 60hz, and color at 29.97 @ 59.94, and the clocks at home used to be kept ontime
    by varying the generator freq, but was a stable clock ref for film until replaced by crystals.
    The first film transfer machines I worked with resolved off the power line.
    I worked on HBO concerts that were shot on film using 30frame code on the slates, even though the cameras were running at 24 frm
    so when it was transferred to video it was pulled down to 29.97 lined up and every thing stayed in sync.
    I understand that NTSC 29.97 time code runs slow so drop frame is used to made 29.97 run in time of day.
    I am chief engineer at one of NY's largest recording studios and deal with major motion picture scores on a regular basis.
    With frame rates of 23.976, 24, 30 and 29.97, and I'm responsible that it all works properly.
    The first NLE project I edited on was a lucas film Editdroid ( not a sounddroid) I've owned final cut, and sony vegas pro.

    My project has no sync issues.

    I was just wondering that Carrara was constantly spitting out 30 fps video when I had set the render at 29.97.
    Was there another setting I was missing because this never happened in Carrara Pro 6. When I rendered in 6 I got 29.97.
    Unlike Final cut, Sony Vegas pro Will play all formats native. When it see a 30 frame video in a 29.97 session it will play it
    at the proper speed but it will interpolate which eats processing. So I go in and tell it to pull all the carrara clips down which fixes
    the problem. Short answer, I understand Timecode, editing and frame rates. I was just wondering if carrara has a bug or was there a hidden setting.

  • JoeMamma2000JoeMamma2000 Posts: 2,615
    edited December 1969

    Oh, okay... so you understand all that stuff...

    But since the vast majority of folks here probably don't, there's nothing wrong with going over the basics, right?

    In any case, I guess if you understand all of that then I don't really understand your question. But since I basically never render from Carrara direct to video, I probably can't be of much help anyway.

  • evilproducerevilproducer Posts: 9,040
    edited December 1969

    8068, I've read you posts in this thread, and I'm also at a bit of a loss as to what you're describing. As I recall, going all the way back to RayDream Studio (on which, Carrara is partially derived from) the render settings always rounded to 30 FPS. I would use the Options dialogue that brings up the compression settings to set it at 29.97 FPS. I could be wrong, but I had assumed that Carrara rendered the file, then used the compressor settings to output the final movie. I'm kind of tired at the moment, so I may not be explaining myself clearly.

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  • JoeMamma2000JoeMamma2000 Posts: 2,615
    edited February 2013

    I dunno, this sure seems like nothing more than a case of mistaken identity... :)

    As Evil shows, it looks like Carrara just calls the video "30fps" when I'm guessing it's actually NTSC 29.97. Maybe just to minimize confusion to its hobbyist users who probably don't want to (or need to) know the difference.

    While there's no law against generating a non-NTSC standard "true" 30fps video, and I'm sure there's some equipment out there that does that (maybe some fancy HD equipment somewhere...), I'm guessing it's pretty rare. Or maybe extremely rare.

    So yeah, you can probably set up your conversion software to convert to 30FPS, because to the converter it's just another number, and they like to be universal. But I'm guessing that the vast majority of folks really want 29.97 NTSC compatible.

    So maybe the problem isn't really a problem, just a confusion about terminology?

    Post edited by JoeMamma2000 on
  • Box8068_31c338ee4bBox8068_31c338ee4b Posts: 292
    edited December 1969

    Without doubt this thread offers some good information for people attempting to render video.
    Though I agree with most people's point that rendering to PNG Sequence is probably the safest way to go.
    The issue I'm having in 8 that I didn't have in Carrara 6 is this. Carrara is overriding the setting I enter in the Quicktime
    window. I enter 29.97 but carrara renders 30. If I go back immediately and reopen the Quicktime setting window
    after setting it to 29.97 it has reset to 30. This didn't happen in 6.
    The issue was noticed after doing a large batch render and entering the clips in my video editing program.
    My system was bogged down. High CPU overhead. It was then that I noticed that the movies had rendered at 30 not 29.97

    The editing software can deal with differing frame rates but it tries to resample on the fly rather then play the clip a little slower.
    If I tell the editing program to play the 30frame movies .01% slower ( pulldown to 29.97) everything goesback to smooth running
    and it's all good. But yes since the world has moved to computer editing,HD video and flat screen monitors that can pretty much handle any thing you throw at it the frame rate world has gotten a little sloppy. Go back a few years when video had to go out to a CRT monitor and to had to have it correct. All interesting stuff, and I appreciate everybody's input.
    My only problem was Carrara overiding my Frame rate setting, not a big deal as I have a easy workaround.
    I don't know if this exists in 8.5, 8.1 is perfect for my needs, but if it does would be nice if they fixed it.

  • 3DAGE3DAGE Posts: 3,311
    edited December 1969

    HI 8068 ;)

    I did a quick test in C6. C7, C8 and the 8.5 beta.,. and although it may be different on the mac,.. (maybe someone can check that)
    when I set the frame rate to 29.97 in the quicktime options panel,. then check it again,. it's always set to 30 fps.

    Whether that's an issue with quicktime, or carrara, I don't know. but I think it's something worth checking with the Carrara developers.

    In After Effects or Premiere, it's an easy option to "Interpret footage" from 30fps to 29.97, or 24, or whatever is needed.
    it's a single step process and as far as I can see,. it doesn't take any additional resources to work with.


  • Box8068_31c338ee4bBox8068_31c338ee4b Posts: 292
    edited December 1969

    I can fix it in Vegas Pro As well. The only annoying thing in Vegas is I can't do it to the imported file, it seems I have to select each edit segment in the timeline, which is a little annoying. I think Joemama 2000 is correct in that it's basically the same file the quicktime container is just labeled at the less desired frame rate.
    PNG here I come. :)

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