ffmpeg - possible usage scenarios!

[shupantha]

Hi,

I read your posts and they helped me out a lot!

I had 2 scenarios in mind and am wondering if those are possible using FFMPEG:

1) How I can output only part of a video using FFMPEG, example: the output video will start form 10 minutes into the source video and end 15 minutes before the end of the source video.

2) Whether it is possible to output 1 video from 2 source videos in the following manner: output video starts 10 minutes into the first source video and end 15 minutes before the second source video.

I hope you understand what I'm looking for.

I would appreciate any help, or suggestions.

[guns1inger]

Avisynth.

You can use the trim statement to set start and end frames for segments, then join them together


a=AviSource("movie1.avi).Trim(23000,0)
b=AviSource("movie2.avi).Trim(0,48000)
a+b

This is a very simple script that loads the first movie from frame 23000 to the end, loads the second movie from the start to frame 48000, then outputs the two a joined movie. Your encode will see a single video that starts from from 23000 of the first movie and ends at frame 48000 of the second.

[shupantha]

Thanks for the help, but I think it might not work in my system. I forgot to mention in my post, I'm using FFMPEG on a Windows XP machine. How can I make that script work there?

I really appreciate the you have responded to my post.

[guns1inger]

You start by installing Avisynth, which is a script based frameserver. Very powerful application.

You open notepad, and you type in the script I gave you (above), changing movie1.avi and movie2.avi for the full path and file name of your movies, and the numbers in the trim statements for the actual frame numbers of your start and end points. Save this file with the extension .avs (e.g. myscript.avs)

Load this script into virtualdub to test it. If it si wrong, you will see an error message. If it is right, you should see the video as it will be encoded. Once you are happy with the trim points, exit virtualdub,

Encode with ffmpeg, but use the avs file instead of the original avi file.

Avisynth can seem daunting at first, as it doesn't seem to make sense working with text in what is essentially a visual medium. However once you start to get your head around the basics, you will (hopefully) start to understand just how much can be done with it, and how fast it is.

[shupantha]

Thanks a lot, I really appreciate your help.