0
$\begingroup$

Is there a way to handle 2 different frame rates in the VSE? 99% of my footage is 24p, 1% is in 25p. My editing is in 24p, audio from the 25p footage is out of sync. If the VSE can't handle it, do you know of another open source software who could do this? Many thanks.

$\endgroup$
  • $\begingroup$ in ffmpeg there are tools such as decimate that will allow you to kill frames "ffmpeg -i input.mp4 -vf mpdecimate,setpts=N/FRAME_RATE/TB output.mp4" // This automatically tries to detect repeat frames and drops them. Commands like these are suggested when trying to drop framerates. I am unsure how to finetune them to fit your situation exactly though. You could followup on the video editing stack exchange with ffmpeg to see. The generic command as written, fill in ur own inputs and outputs though. will give you an idea of how it works though. $\endgroup$ – kite Jan 8 at 6:44
  • $\begingroup$ So you could potentially use the above with the speed control mentioned below in blender to automate for a myriad of situations. The option that gives you the most control is manually going frame by frame and dropping/increasing them yourself with cuts. Not sure how long your footage is to make that viable or not. Maybe consider using all 3. Another trick is to add a multiplier to your workspace fps. 2x to 48fps for example. Then you half the 24fps with a 0.5 speed control multiplier. This allows wiggle room when assigning the maximum 3 decimal place multiplier for the 25fps, if its needed. $\endgroup$ – kite Jan 8 at 6:49
1
$\begingroup$

If you can, just separate both into two separated scenes rendered at different frame rates. This will be the case if your final footage doesn't change too often (ideally, one time).

If the amount of footage is manageable, use the speed control effect strip to make both the same speed.

Otherwise, put all your raw 25fps into one large edit and render it at 24fps. Now you can import it into your actual project and edit it like the rest of the video.

$\endgroup$
  • $\begingroup$ Thanks for answering. If you render 25fps footage at 24fps, your audio is not synchronized. $\endgroup$ – Maxime Jan 4 '17 at 10:38
  • $\begingroup$ I haven't successfully rendered audio in Blender yet, so I can't tell you. You'll probably have to correct the audio speed manually in Audacity $\endgroup$ – piegames Jan 4 '17 at 10:50
0
$\begingroup$

I assume that your render is set at 24 fps. If this is the case, and your 25 fps strip has audio included, you should see a small difference in length between that 25 video strip and its corresponding audio. If not, you should set your render at 24 fps.

I had a similar problem, having to mix 50 fps strips with 30 fps strips.

According to samblers answer to this question, you could insert a speed effects strip over your 25 fps strip to downspeed it and make frames match with your projects render (and with strips corresponding audio). I think you should set speed modifier to 1.04 (25*100/24=96 - 100-96=4). That should make your 25 fps strip equivalent to the 24 ones. But that math didn't work for me. I had neither time nor necessity to have an awesome quality video rendered, so I just tried different speeds until it looked just well.

Surely someone else can improve this answer, I hope it helps you getting forward with your job.

$\endgroup$
  • $\begingroup$ From what I've seen this is the only route to go in blender. Apply the speed control to the video strip, deselect the generic fit to strip and input the value of the multiplier. So long as the speed control multiplier calculated is within the range of 3 decimal places, this should work fine. You need to be careful when adjusting the length of the strip once speed control is on it though, they sometimes offset the sync when moved around. If this is an issue, try metastripping the two or just retain the length of the speed control as is and build ontop on the next channel. $\endgroup$ – kite Jan 8 at 6:39

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.