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use std::f32::consts;
pub const MAX_BANDS: usize = 25;
const CRITICAL_FREQS: [usize; MAX_BANDS] = [
100, 200, 300, 400, 510, 630, 770, 920,
1080, 1270, 1480, 1720, 2000, 2320, 2700, 3150,
3700, 4400, 5300, 6400, 7700, 9500, 12000, 15500,
24500
];
pub const RUN_TAB: [usize; 16] = [ 2, 3, 4, 5, 6, 8, 9, 10, 11, 12, 13, 14, 15, 16, 32, 64 ];
pub fn init_bands(srate: usize, len: usize, num_bands: &mut usize, bands: &mut [usize; MAX_BANDS + 1]) {
*num_bands = 1;
while *num_bands < CRITICAL_FREQS.len() && CRITICAL_FREQS[*num_bands - 1] < srate {
*num_bands += 1;
}
bands[0] = 2;
for i in 1..*num_bands {
bands[i] = (CRITICAL_FREQS[i - 1] * len / srate) & !1;
}
bands[*num_bands] = len;
}
pub fn get_quants_table() -> [f32; 96] {
let mut quants: [f32; 96] = [0.0; 96];
for i in 0..quants.len() {
quants[i] = ((i as f32) * 0.0664 / consts::LOG10_E).exp();
}
quants
}
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