VideoHelp Forum
+ Reply to Thread
Results 1 to 5 of 5
Thread
  1. Member
    Join Date
    May 2012
    Location
    Campbell, California
    Search Comp PM
    So I'm trying to change the framerate on a video from 29.97 fps to 59.94 with avidemux, I've been trying to get the audio in sync, but it has failed to do so. I know there may not be a way to do this, but if there is a way, let me know. I know this is impossible to do, but I need some help here. Once again, if there is one way let me know. I doubt there is a way.
    Quote Quote  
  2. Originally Posted by Larry4009 View Post
    So I'm trying to change the framerate on a video from 29.97 fps to 59.94 with avidemux, I've been trying to get the audio in sync, but it has failed to do so. I know there may not be a way to do this, but if there is a way, let me know. I know this is impossible to do, but I need some help here. Once again, if there is one way let me know. I doubt there is a way.

    If you double the frame rate, but keep the same number of frames, it will play 2x the speed .

    So what exactly are you trying to do and why ?

    If you add duplicate frames, or add inserted blends, or inserted interpolated frames then you can keep the audio in sync
    Quote Quote  
  3. Member
    Join Date
    May 2012
    Location
    Campbell, California
    Search Comp PM
    What I'm exactly trying to do is increase the framerate of some of my videos because I am making a movie with the fps as 59.94 fps, and trying to keep it in sync. Do you have any step by step instructions?
    Quote Quote  
  4. But WHY are you doing this ?

    You need to insert frames by one of those 3 methods. I don't think Avidemux can do this

    You can do this in editors such NLE's such as vegas, premiere , fcp , Or avisynth (but it's a bit of a learning curve).

    There are side effects to each method (you can't get more real FPS for nothing - so it won't be "real" 59.94 content, even though the FPS is 59.94.)
    Quote Quote  
  5. To illustrate: lets just use 30fps and 60fps for this example .

    You start with a 120 frame, 30fps clip . So that is 4 seconds duration because 120 frames / 30fps = 4 seconds

    Changing the FPS to 60, will make it 2 seconds because 120 frames / 60 fps = 2 seconds . This is just simple math . So audio is out of sync, or you have "chipmunk" voices as it's sped up

    If you double BOTH the FPS and the #frames , then 240 frames / 60 fps = 4 seconds and everything is in sync as the original . Thus you have to double the number of frames if you double the FPS




    BUT - where do you get those EXTRA frames from?

    1) If you just use duplicates, it will look exactly as the original in terms of motion

    2) If you use blends, it will be blurry but the motion will be the same as original

    3) If you use motion interpolation - it will be smoother than the original (it will approach the look of "real" 59.94 footage), but there can be weird edge morphing artifacts. It can work ok on some types of footage by fail miserably on others
    Quote Quote  



Similar Threads

Visit our sponsor! Try DVDFab and backup Blu-rays!