Frames per second... how do I change from 8 to 15??

[27am_dot_com]

Oh my god... I've posted several threads this morning trying to resolve a resampling issue. Virtual Dub told me that I couldn't append an AVI because it was a different sampling (or something) and told me it was 15.0000 vs 8.0000.

I assumed this meant audio. ANd because of that, the replies I received so far were regarding resampling the audio.

But all of my audio is 16-bit. Somehow it's the FRAMES PER SECOND which switched to 8.000 in 2 of my 20 or so AVI files.

WIth that said, how do I change the frames per second in these AVIs in order to append them to the rest of the AVIs and get this project wrapped up?

[dipstick]

Click on Video > Framerate.

[27am_dot_com]

Thanks. But now I get a mismatch saying that one is 15.00000 and the other is 14.999993.

I've tried entering 15 as well as 15.0 and of course several other decimal place options as well (beyond 6 decimal points even). Yet nothing.

Here's what the origianl specs looked like:

[27am_dot_com]

Doesn't look like my screen capture showed up. Anyways, the point is that the new file states 15 frames per second even though Virtual Dub says it's 14.99993.

Any ideas?

[junkmalle]

Try using AVIFrate.

But the real question is why are you capturing at 15 fps? PAL video is 25 fps and NTSC is 29.97. You're losing half your frames.

[27am_dot_com]

>> But the real question is why are you capturing at 15 fps?
What the? Thanks for the heads up junkmalle. Came to my aide again.

I don't have an answer for you except to say that I think I just went through a crash course in DVD production at a pace that was set by time restrictions not by my preference.

All of the "filming" is of Powerpoint and other computer based tutorial activity via Camtasia. I didn't even know that I could change the frame rate nor would I have known what to change it to and what it all meant.

This may well explain why when there's motion, we are having jerky transitions. Hmmm...

I will say this to everyone on the board... you guys are a phenomenal resource. I give credit to me for being resourceful enough in finding this forum but I give a LOT of credit to everyone who helped... your answers (jukmalle very much included) has allowed to bring this project in for a landing (only some basic audio work and this frame rate issue to work out).

Thanks.

I may be back with a few more requests in the next 24 hours and for similar future projects, this is the first place I'll come to for guidance.

- Rob Toth

[junkmalle]

27am_dot_com, Did you capture with VirtualDub? I think it defaults to 15 frames per second. It also doesn't work well with some cards.

[27am_dot_com]

The AVIs were recorded (captured) with Camtasia. I just downloaded Virtual Dub yesterday.

Oh and I went to grab a copy of AVIFrate and it said it couldn't open it. The program would load but would not allow me to browse/open any files to work with.

Any other frame rate software suggestions?

[junkmalle]

When I've played with screen capture type programs before they would get slow and choppy if the running program was consuming most of the CPU (a game for instance). I wonder if the 8 fps
videos were captured while the main program was using lots of CPU time?

My guess is Camtasia records at 15 fps by default because that's fast enough to give fairly fluid motion and slow enough that it doesn't swamp the system while capturing.

I don't know why AVIFrate isn't working for you. There are several programs with that same name. Maybe the one linked to here isn't the right one. I use this one:

http://www.inmatrix.com/files/avifrate_download.shtml

Note that this program only changes the frame rate value in the header of the AVI file. So if you change the frame rate from 8 to 15 it will play almost twice as fast and audio will de-sync.

[27am_dot_com]

So if you change the frame rate from 8 to 15 it will play almost twice as fast and audio will de-sync.

You're absolutely right. How do I re-sync it? I have Audacity... I'll dig around in there. Can I re-sync directly in VDub??

[junkmalle]

Use VirtualDub as you originally did to change the frame rate from 8 to 15. Use the middle box, "frame rate convesion", of the frame rate dialog. Tick the "Convert to fps:" button and enter 15.0. If that gives you a final frame rate of 14.999993 use AVIFrate to set the frame rate to exactly 15.

The result will be a little jerky because VirtualDub will duplicate 7 of the 8 frames to create 15 frames out of 8.

1 2 3 4 5 6 7 8 --> 1 1 2 2 3 3 4 4 5 5 6 6 7 7 8

[BJ_M]

please do not double post