I’m a DirectSound programmer new to iOS. I want to implement the ability to play streaming multichannel audio, sometimes looping back to a specified point when the stream is finished playing (think of a song that has a little intro diddy that is played once, then the song loops indefinitely, skipping that intro).
With DirectSound and libvorbis, at least, I’d feed a chunk of the OGG data into the libvorbis decoder, it’d spit out some PCM, and I’d fill the buffer and queue it up to play right after the current sound buffer is finished, swapping between two buffers.
Probably looking at using some kind of hardware-supported format on iOS, like AAC. What programming APIs should I be using that will allow me to do multichannel and loop points? Any input is appreciated, thanks!
The iOS AVAssetReader class can be used to read compressed audio file data into a PCM buffer. Either the Audio Queue API (simpler) or the RemoteIO Audio Unit (lower latency) can be used to play buffers of PCM data.