Counting back from the end?

[doublefox]

Is it possible to trim by counting back from the end, instead of forward from the beginning? I've used A=, B= etc to trim this one clip 8 times, and my final result is 4700 frames. I want to select the last 4 seconds and overlay an image onto it, but by saying "100 frames before the end". Is that possible?

[guns1inger]

Why not just find out how many frames in the file, and go

Trim(number of frames - 100, number of frames)

where you fill in the correct numbers ?

[doublefox]

Well I'm trying that, but it doesn't seem to work. It would be 5340,0 (going by the frames in the source) or 4600,0 (going by the frames in my work-in-progress video so far), but neither of those values do anything.

I think it's because I'm a little confused about where I'm counting from -- when I trim B, is frame 1 the first frame of the source video, or the first frame of the source video after it's processed A?

I'll work out how to do it properly, but it'd be easiest to do it from the end this time, because this is the very last piece.

[poisondeathray]

One way to do it is to use reverse() , then whatever function, the reverse() it back

[guns1inger]

I believe the numbers are always relative to the original video unless you specify a specific clip

[AlanHK]

I'm a little confused about where I'm counting from -- when I trim B, is frame 1 the first frame of the source video, or the first frame of the source video after it's processed A?

The frame numbers will change depending on cuts you made previously.
(Where "previously" means in lines above.)

If using VirtualDub, or AvsP, you can see the current frame number displayed below the image.

When I need to adjust a Trim and there has already been a lot of chopping, I put in a temporary line before any cuts to display the frame number, relative to the original, uncut clip:

ShowFrameNumber(x=100,y=100)
Trim(0,7850)++Trim(8070,18364) ++Trim(18537,28347) ++Trim(28498,30965) ++Trim(31848,0)

If I put that, it will show me the frame numbers I need to adjust the Trims in the next line.
Then comment it out after making the adjustment.