AVI Synth - Smooth Audio Transitions

[lomaidala]

I have a DVD I'm editing using AVI Synth. The video edits are done, but the final stage is to smooth out audio transitions so that when the video skips over a section of video and audio I removed, the audio transition is gradual instead of abrupt. Is there a recommended way to do this using AVI Synth?

Here are the problems I've had with the methods I've tried:
At first I was using AudioTrim, but the problem I'm having here is that the more edits there are, the more the audio goes out of sync with the video.

So then I decided to use Dissolve with AudioDub to create smooth audio transitions based on the exact frames of the video edits, then export an audio file with smooth transitions created by the dissolves, with the intention of later importing the edited audio file and combining it with the edited video without the dissolves (since the dissolves were only created to gradate audio transitions, and not video transitions). But the problem I'm having here is that every time I use Dissolve, the total frame count shrinks. If this is a viable method for what I'm doing, is there a way to use Dissolve so that it doesn't change the total frame count?

[jagabo]

The problem is that Dissolve overlaps the two segments by the specified amount in order to crossfade between them. So you end up with overlap fewer frames. I don't know how complex your AviSynth editing is but you can probably write functions for each type of edit. For example, here's a function that will remove a segment of video with a simple cut transition for the video, but a dissolve for the audio:

function CutWithAudioDissolve(clip v, int start, int end, int overlap)
{
    # simple cut transition for the video
    v1 = Trim(v, 0, start-1)
    v2 = Trim(v, end+1, 0)
    v12 = v1++v2

    # cut with dissolve for the audio
    half = overlap/2
    otherhalf = overlap-half
    a1 = Trim(v, 0, start-1+half)
    a2 = Trim(v, end+1-otherhalf, 0)
    a12 = Dissolve(a1, a2, overlap)

    # join the cut video with the dissolve audio
    AudioDub(v12, a12)
}

Calling it like:

CutWithAudioDissolve(50, 150, 30)

will remove frames 50 to 150 (inclusive) with a 30 frame audio dissolve.