Function audio_channel_ptr 

pub unsafe fn audio_channel_ptr(
    ptr: *mut u8,
    channel: usize,
    bus: usize,
) -> *mut f32

Returns a pointer to a specific channel/bus plane.

channel is 0-based up to MAX_CHANNELS - 1. bus is 0 (main) or 1 (sidechain).

Safety

ptr must point to a valid allocation large enough to contain the audio data.