We start with this mono file:
audacity it looks like this:
Then we convert it to stereo with this command:
ffmpeg -i test.wav -ac 2 out.wav
Now it looks like this:
Notice that the amplitude changed!
Finally, we convert the stereo back to mono:
ffmpeg -i out.wav -ac 1 back.wav
We should get the same file from which we started. But in
audacity we get the following picture:
The questions are:
1) Why did the amplitude change when converting to stereo?
2) Why did the amplitude not change back when converting to mono?
3) how can I make the amplitude change back when converting to mono?