Change speed/velocity of the video

[roglopes]

Dear friends,

I want to accelerate a video, what the soft that I've to use?
VirtualDub? How?
Thanks!!!

[thor300]

Load the avi in virtualdub, click menu Video - Framerate, select change to and enter the new number of framerates.
If you want the audio to follow you have to mess around in the audio filters menu as well, in that case its much easier to use AviSynth:
Avisource("yourvid.avi")
AssumeFPS(100, sync_audio=true)

[roglopes]

OK, I've an audio file that has 1 minute and the video has 5 minutes.
I want to accelerate the video to combine with the audio (1 minute).
I don't want cut the video, I want to acceletare it.
In VirtualDub I change the frame rate to 300 but the VirtualDub didn't allow this value.
What I've to do?

[thor300]

Ok, i see! Lets say you will later convert it into Avi or Mpeg, then you would want to have a normal framerate that can be played back in a decent way. First find the framerate of your sourcefile, lets say it is 29.97 for now. Then create an AviSynth script, and add these 3 lines:
AviSource("Yourvideo.avi")
SelectEvery(5,0)
AssumeFPS(29.97)

That will make a videoclip play 5 times faster and keep the source framerate, replace "29.97" with the framerate of your original videofile. This script can be loaded into for example Virtualdub where you can multiplex it with your audio file (Audio -> Wav Audio...).

[thor300]

Sorry im no good at using virtualdub, but i had a look anyway. There is a Decimate-thing in the framerate settings, you could try to play around with that one if you have very much against AviSynth I tried to load a 23.976fps video, then set the framerate to 120 and then put 5 in the decimate by thing. Looks like that works well too.

[daamon]

Hi roglopes,

Check out the following. They are freeware video editors that might be better suited to what you want to do (in no particular order):

Avid Free DV
AviTricks
Zwei-stein

I've not used any of them, but they are described as Non-Linear Editors (NLEs) with basic to average editing capabilities - I'd expect that one of them will do what you want.

I use Premiere Pro, also an NLE. In that, it's a case of drop the clip onto the timeline, select the clip and adjust the speed by changing a percentage:

200% = Twice as fast
50% = Half speed
-100% = Normal speed, but reverse because of the minus sign

Each of the apps I mention have timelines, so at least they're similar in that respect to Premiere Pro. It just remains to be seen whether you can adjust the speed of the clip, and how it's done.

Good luck...

[roglopes]

How I run/execute the script in AviSynth?

[thor300]

Open it in virtualdub.