Using avisynth to fade to black screen?

[killerteengohan]

I have a video and I would like to make the first 23 frames slowly fade in from a complete black screen and make the last 23 frames at the end slowly fade out to a complete black screen.

How would I do this with avisynth?

[davexnet]

http://www.avisynth.nl/index.php/Fade

[killerteengohan]

http://www.avisynth.nl/index.php/Fade

Thanks, that works great.


What would I use if I want to fade together 2 scenes?

for instance lets say I trim the video like this.

__film = last
__t0 = __film.trim(47806, 49911)
__t1 = __film.trim(51900,51969)
__t2 = __film.trim(52169,53019)
__t0 ++ __t1 ++ __t2


What would I use if I wanted to fade in 15 frames between the 51969 end trim and 52169 start trim?

I'm not wanting a black fade in, I want the scene frames to fade/blend together by about 15-23 frames in length so it looks like a transition between scenes.

I only see how to fade in and out color frames, I didn't notice anything about what I just asked on that fade wiki page.

[poisondeathray]

What would I use if I wanted to fade in 15 frames between the 51969 end trim and 52169 start trim?

I'm not wanting a black fade in, I want the scene frames to fade/blend together by about 15-23 frames in length so it looks like a transition between scenes.

I only see how to fade in and out color frames, I didn't notice anything about what I just asked on that fade wiki page.

http://avisynth.nl/index.php/Dissolve

[killerteengohan]

What would I use if I wanted to fade in 15 frames between the 51969 end trim and 52169 start trim?

I'm not wanting a black fade in, I want the scene frames to fade/blend together by about 15-23 frames in length so it looks like a transition between scenes.

I only see how to fade in and out color frames, I didn't notice anything about what I just asked on that fade wiki page.

http://avisynth.nl/index.php/Dissolve

I'm sorry, maybe I don't quite understand how to add it in with the trimming.

I tried this, but it completely removes the first half the video
Dissolve(__t1, __t2, 23)

[killerteengohan]

This seems to work fine, but I want different frame counts between fades. Inserting a different number right after t1 gives an error so that's obviously not how to do it.
Dissolve(__t0, __t1, __t2, 10)

That uses 10 for all the fades though.

I want 6 for the first one (t0 - t1) and 10 for the second (t1 - t2).

[killerteengohan]

This works, but now there's a problem.

Piece1 = Dissolve(__t0, __t1, 6)
Dissolve(Piece1, __t2, 10)

The number that I dissolve by gets removed from the frame count and its throwing the sync off because the video is not the same amount of frames anymore.

Am I even using this correctly? Can I not keep the same frame count when doing this?

[davexnet]

You can assign the whole video to another variable then use that for the second dissolve, ensuring the original frame numbers

[poisondeathray]

This works, but now there's a problem.

Piece1 = Dissolve(__t0, __t1, 6)
Dissolve(Piece1, __t2, 10)

The number that I dissolve by gets removed from the frame count and its throwing the sync off because the video is not the same amount of frames anymore.

Am I even using this correctly? Can I not keep the same frame count when doing this?

No you always lose frames, unless you do something to add frames (e.g. duplicates or something else like interpolated frames to extend the clips) before hand

When you blend or crossfade 2 clips, there is overlap for the transition frames. So the duration is shorter

In this schematic - This is 6 frames long, because 2 frames were overlapped

AAAA
__BBBB

vs

If there is no crossfade, the clips end to end are 8 frames

AAAABBBB

[killerteengohan]

This works, but now there's a problem.

Piece1 = Dissolve(__t0, __t1, 6)
Dissolve(Piece1, __t2, 10)

The number that I dissolve by gets removed from the frame count and its throwing the sync off because the video is not the same amount of frames anymore.

Am I even using this correctly? Can I not keep the same frame count when doing this?

No you always lose frames, unless you do something to add frames (e.g. duplicates or something else like interpolated frames to extend the clips) before hand

When you blend or crossfade 2 clips, there is overlap for the transition frames. So the duration is shorter

In this schematic - This is 6 frames long, because 2 frames were overlapped

AAAA
__BBBB

vs

If there is no crossfade, the clips end to end are 8 frames

AAAABBBB

I'll just make it so whatever I set for dissolve, I will trim that many less frames before the dissolve happens. That should even it out.

Thanks!!