How do I get a 25fps AVI?

[JimmyWimmy]

I'm going to be using SharpCap to take a video of lunar craters. I want to edit it and create a 25fps video as the result. It makes sense to start off with a 25fps video so I thought I would try to capture one with SharpCap.

So, I set the exposure to 40 milliseconds for my Altair camera and captured some test video. Sharpcap reported capturing at between 24.9 and 25.1 frames per second, so that seemed to be working just fine.

However, I see that the AVI created is marked as 30fps. When I play it back in Adobe Premiere Pro it happily plays back at 30 fps. If I view it slowly, frame by frame, I see that each frame is different. So I have useable video but it plays back a little faster than the recorded speed.

I can adjust the framerate or duration of the video in Premiere Pro but that will involve some compromise in quality, so I thought it would be better if I could persuade SharpCap to output a video marked as 25fps in the first place...How is this done?

Thanks, Jim

[admin]

Hi,

currently this is not possible in SharpCap, but the framerate is just an entry in the AVI file headers, so there may be software that will allow you to update this after the AVI file has been written ( I found this by a quick web search - http://www.am-soft.ru/avifrate.html - but have not tried it. I would virus scan any downloads!).

Alternatively you could write an SER file which stores an exact timestamp for each frame, then perhaps convert it to AVI (maybe PIPP can do this?)

Hope this helps, Robin

[JimmyWimmy]

Thanks Robin.

I have been poking around in Premiere Pro and discovered that if I load the AVI file as a clip, right-click on it and do...
Modify>Interpret Footage and set "Assume This Framerate" to 25fps it does just what I want. The clip length increases from ~22 seconds to ~27 and it plays back at 25fps without any frame skipping or merging etc.

Perfect!

[admin]

Hi,

Good to hear that you have a solution.

Cheers, Robin