Recording is made at 25fps?

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wplate
Posts: 22
Joined: Sat Nov 21, 2009 00:12

Recording is made at 25fps?

Post by wplate »

I just did a recording of some test visuals and noticed a couple of things that lead me to questions. I played two tracks in iTunes then in Avenue I played back the clips and did the recording. My clips are 29.97fps, 640x480, encoded in DXV (the Resolume-recommended codec), the recording produced by Avenue is 25fps. Since Avenue didn't record the audio from iTunes (I read the user guide, so I didn't expect it to) I brought the Avenue recording and my audio files into Final Cut Pro to edit them together. But I couldn't make it be in sync, the audio was longer than the picture.

1. Is it normal that Avenue should record at 25fps instead of the playback rate of my source clips?
2. Is it possible while recording Avenue will skip frames if it cannot keep up causing the video recording to become shorter than real time?

NEVERMIND #2, read on...
Last edited by wplate on Wed Jan 06, 2010 07:07, edited 1 time in total.

wplate
Posts: 22
Joined: Sat Nov 21, 2009 00:12

Re: Recording is made at 25fps?

Post by wplate »

Actually I don't think the movie is 25fps, though that's apparently what FCP thought it was. After Effects reports the movie as 27.027fps. Thankfully After Effects gives me enough controls that I was able to get the audio and video in sync. I tried to conform the 27fps footage as 25fps just in case the movie really was 25fps and somehow the QuickTime header was whacked or something, but that didn't get me in sync either. 27fps was too fast, 25fps too slow. Even 26fps didn't get me in sync. But I managed to leave it at 25fps then speed it up to 93% (in After Effects values less than 100% are fast, the opposite of FCP) and get things to work.

What's the deal with recording FPS?

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bart
Team Resolume
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Re: Recording is made at 25fps?

Post by bart »

Resolume will try to make the recording at 25fps but when it can't keep up, frames will be dropped and the resulting video will indeed come out shorter. Quicktime actually allows for variable framerates and this is what we're using to try and compensate this but the effect of dropped frames will always be noticable.

For a better recording you should try to record to a different (preferably fast 10.000 rpm or SSD) drive than the drive you are reading the video files from. Or lower the resolution of the composition.

wplate
Posts: 22
Joined: Sat Nov 21, 2009 00:12

Re: Recording is made at 25fps?

Post by wplate »

Good to know, thank you!

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