I put together my own cover of a musical composition from How to Train Your Dragon, which I intend to put on YouTube. I want to sync it up with the scene from the movie where it plays, but I thought it would interesting if instead of just replacing the audio, I could put the dialogue from that scene on top of my music.
Of course to do that, I would have to isolate the dialogue audio from the rest of the movie soundtrack, but how hard could that be, right?
I've included links to two audio clips which I've cut directly from the movie. They haven't been re-recorded or anything, so they should be the exact waveforms from the film, cut from exactly the same time. One of them has English dialogue, the other has Spanish.
My theory was that the two clips should be exactly the same except for where the dialogue occurs. I thought I should be able to:
1) Take the left audio tracks from both stereo clips.
2) Pan one hard left and one hard right.
3) Use mid-side processing to separate out what's the same between the two tracks (the music and sound effects, which would be the mid channel), from what's different (the overlapping Spanish/English dialogue, which would be the side channel).
4) Subtract the mid channel from the original English clip and be left with only the English dialogue. 5) Repeat for the right stereo tracks and then put them back together.
This approached failed at step 3. Looking at the two waveforms (from the two languages) side by side, you can see that they are actually different, even in the parts where there is no dialogue, despite the fact that those parts sound exactly the same (at least from what I can hear).
This is where I'm hoping you can help. Can you tell what's actually different between these two files? Or even provide an educated guess? If I can figure that out I might be able to account for it.
Otherwise if you have another suggestion on how I can isolate the dialogue, I'll take it. But before you suggest it, I already tried going through the 5.1 surround-sound channels and none of them have the dialogue by itself.