C++ audio mixing

Question

I want to be able to combine multiple tracks of audio into one file but have no idea what to do. I need to be able to do the following:

• I need to have multiple tracks playing simultaneously, and need to be alter the volume of each track at various points,

• I need some tracks to start at different time,

• And I need to be able to write the result to file.

I'm not sure what library to use for this, if anyone has a suggestion that would be helpful.

Answer 1

Nobody has answered this question, so I'll post what I ended up doing. I tried using libffmpeg first, but it was far too confusing to get to work. So instead I used libsndfile which is available under the LGPL. It's extremely simple, but that means there's nothing messy to fool around with. The only problem is that it can't use the MP3 format, so I'll just programmatically call ffmpeg.exe and convert MP3 files to FLAC and load those. It's not perfect but it will do.