Really strange bug by Anterag at 5:08 PM EDT on July 28, 2018
Hi. I'm currently trying to remove the ambience out of a music from a video game, because there is also the ambience only. The main issue is that I need to synchronize the ambience only with the ambience + music since the ambience mixed with the music doesn't start at the same time. I managed to do it, but since a part of the ambience only was deleted (everything before the start of ambience mixed), the track doesn't cover all the ambience mixed music so I need to loop the track till the end of ambience mixed music. Phase inversion works at the first segment, but then at first loop and others it is restarted and I get the ambience again... (but the weird thing is that the peaks are still PERFECTLY aligned!!) I actually tested this on Sony Vegas Pro and Audacity. The exact same thing happens.
It is not a file issue, as I tested this with other games.
Sorry for not being clear: the ambience that is mixed with the music is not synchronized with the "ambience only" track (same ambience without the music). For example, the ambience with the music is what can be heard at approx. 46 seconds in the "ambience only", so to sync them, I'll remove what is before the 46 seconds and make it begins like the start of the ambience + music track. The main issue is that since I cutted a part of the ambience only track, this track will ends before the ambience + music so I have to loop the "ambience only" track, and when I loop, phase inversion starts doesn't working from the first loop. Everything before the first loop: no ambience (phase inversion works perfectly).
Are you sure the ambience and the music track are the same? Cancelling out has to have high precision. Are you sure that your encoding didn't add artifacts which harm the phase inversion cancellation?
I'm sure. The ambience is exactly the same as the "ambience only".
Here is music + ambience & ambience only. At approx. 8 seconds for the ambience only, you have the beginning of the ambience in ambience + music. Any way to help me? You'll see it will work for the first segment, then after loop, no more.
I TRIED TO: loop the original "ambience only" so that even if I cut a part, it will cover the whole ambience + only. Doesn't work. I also tried to resync each loop: it works sometimes when I click play, but sometimes no. I don't change anything, just "PLay" but it's always different. If I start playing the first segment, that is always good, then when the loop begins, it doesn't work. Tried to save the file and it also doesn't work.
From what I can tell, the loop of the ambience found in the music track is shorter than the start to end loop of the standalone ambience file. The first 27 samples of the ambience file just contain dead silence. Anyway, here's what I came up with: phase inversion.wav
I'll add that the inversion was not nearly precise enough for me to cancel the ambience entirely, but I took out what I could.
Thank you. I obtained the exact same sound before the loop, but then the ambience was back. How did this work after the loop? Could you explain your method? Thx.
All I did was clip off the pure silence at the beginning of the waveform and did a start to end loop from there. Additionally, the very end of the ambience waveform lines up perfectly with the end of the music, which should make it a little bit easier to line up in general; just remember to cut off the silence at the start of the waveform and you should be fine.