Function shine_inner_loop 

pub fn shine_inner_loop(
    ix: &mut [i32],
    max_bits: i32,
    gr: i32,
    ch: i32,
    config: &mut ShineGlobalConfig,
) -> i32

Inner loop: find optimal quantization step size for given scalefactors Corresponds to shine_inner_loop() in l3loop.c

The code selects the best quantizerStepSize for a particular set of scalefacs.