I have a situation in AE CS3 with a 3 minute composition of 3D motion graphics where there is about 20 layers, a lot of camera movement and a lot of keyframes for some of the object layers. This is accompanied by a voice over that I have in AE for reference, but I don't formally mate with the video until Premier Pro.
I need to add about 10 second to the middle consisting of additional audio and video. I hope there is an easier way, here is how I have started to do it, but all of this could be wrong:
1. Edit the composition setting to make the composition 10 seconds longer.
2. Replace the audio file with the new longer one and add to the composition.
3. On the timeline, I drag the right end of each layer to the right 10 seconds so that it fills the composition.
4. Now, from the middle of the video forward the video is, as you would expect, 10 seconds ahead of where it should be with respect to the audio.
The idea of manually dragging each keyframe to right (even with mutlipe selection) and having it match the action in other layers seems to hard.
Nest the composition into a second one, split it into two layers and move the end part to the new position. Add the audio to the newly created comp as well as any other stuff. Give the comp a fancy name like "Comp A insert". Should give youi all you need without tons of pushing keyframes. Enable "collapse transformations" to retain the 3D-ishness if needed.