I'm very new to audio programming, but I know this must be possible. (This is an iOS/iPhone related question).
How would I go about changing the tempo of a loaded audio file without changing the pitch, and then playing it back?
I think I need to delve into the CoreAudio framework, but I'm not sure where to begin.
If anyone could let me know what classes I need to look at, or the general process involved, that would help me get started and I'd really appreciate it!
Cheers!
On
What you are looking for is a time-pitch modification library. Core Audio on iOS currently does not contain such, but there appear to be some 3rd party libraries available (commercially). There are also time pitch tutorials on the web, such as at dspdimention, which require a large amount of DSP development to get working.
This question is highly related: it relates to pitch shifting, rather than time shifting, but I'd check out the comments and links.
Real-time Pitch Shifting on the iPhone