Question about AssumeFPS.

[Tryptic]

So, I'm ripping my copy of The Cowboy Bebop Movie, all happy-go-lucky like. I'm using the "Guide" for the first time... when I come across the statement that Premiere doesn't edit in 23.97 FPS. Which is what I use. Which means I'm, to quote, "SOL"

Now, I see there's a command called AssumeFPS(24), which, I assume, forces the video into 24 FPS? Will this also desync the source audio if I want to mux that on as well? (I like to cut with the audio on, but will sacrifice if need be.)
Or, should I compress the source without AssumeFPS now, put it into Premiere (treating it as if it's 24 FPS) and then use AssumeFPS(23.97) at the end?

-Sorry if this is in the wrong section. And thanks in advance!-

[Pwolf]

assumefps will change the rate at which the video plays without removing or adding frames... so that means that means that the total number of frames will stay the same but the video will play faster or slower depending on the fps change. For all my projects i use changefps. This wont speed it up or slow it down but add or remove frames to match the fps change.

[Tryptic]

Sorry, but can you put that in "For Dummies"?
I think what you're saying is I should use ChangeFPS to change it from 23.976 FPS to 24 FPS before I put the footage into Premiere? Am I correct?

[Tryptic]

*Sorry for doublepost, but:
If my previous post, I would suppose that AssumeFPS is for post-processing, to get the footage to a different speed without changing any of the actual frames? And ChangeFPS is for pre-processing?

[Pwolf]

mmmm no

i don't use assumefps at all. I convert all my footage to 24fps before editing using changefps(24) (if it's interlaced/29.976, i'll ivtc first). After i'm done, it stays at 24fps.

If you wanted to convert it back to 23.976 I would just use changefps(23.976) on the final encode.

hope that helps.

[Qyot27]

If you want to keep the audio in sync, then you'll need to use the sync_audio parameter followed by resampling it to a proper frequency, like so:

Code: Select all

AssumeFPS(24,sync_audio=true).SSRC(48000,fast=false)

It'll change the pitch of the audio, but it will remain synced. Generally I can't detect a change from 24->23.976, and would assume the same for the reverse. If the difference was much greater than 0.024 frames per second, then it might be a bigger issue.

Note: I used 48000 for the audio Hz simply because most of the time I use that trick for authoring DVDs. I don't use the source audio in my editing process, and the rescaling/resampling for the music I do using BeSweet.

[Tryptic]

Thank you both. I thought that's what you were saying PWolf, I was just trying to get it all straight in my head. I think I understand now.
And Qyot, thanks for the script line. I'll try that, but switch Assume with Change, and hope that it still works.
Finally, it's time to make me video!