--- /dev/null
+use nihav_core::codecs::{DecoderResult, DecoderError};
+use nihav_core::io::bitreader::*;
+use super::mp2data::*;
+
+#[derive(Default)]
+pub struct MP2Data {
+ pub mpeg1: bool,
+ pub sf_idx: usize,
+ pub br_idx: usize,
+ alloc: [[u8; 32]; 2],
+ scfsi: [[u8; 32]; 2],
+ scale: [[[u8; 3]; 32]; 2],
+}
+
+fn unquant(val: u8, levels: i16, scale: f32) -> f32 {
+ (((i16::from(val) << 1) + 1 - levels) as f32) * scale / (levels as f32)
+}
+
+fn read3samples(br: &mut BitReader, qbits: i8, scale: f32, band: usize, dst: &mut [[f32; 32]]) -> DecoderResult<()> {
+ if qbits > 0 {
+ let bits = qbits as u8;
+ let maxval = (1 << bits) - 1;
+ dst[0][band] = unquant(br.read(bits)? as u8, maxval, scale);
+ dst[1][band] = unquant(br.read(bits)? as u8, maxval, scale);
+ dst[2][band] = unquant(br.read(bits)? as u8, maxval, scale);
+ } else {
+ let samplecode = br.read(-qbits as u8)? as usize;
+ match qbits {
+ -5 => {
+ for i in 0..3 {
+ dst[i][band] = unquant(GROUP3[samplecode][i], 3, scale);
+ }
+ },
+ -7 => {
+ for i in 0..3 {
+ dst[i][band] = unquant(GROUP5[samplecode][i], 5, scale);
+ }
+ },
+ -10 => {
+ for i in 0..3 {
+ dst[i][band] = unquant(GROUP9[samplecode][i], 9, scale);
+ }
+ },
+ _ => unreachable!(),
+ };
+ }
+ Ok(())
+}
+
+fn read3samples_joint(br: &mut BitReader, qbits: i8, scale0: f32, scale1: f32, band: usize, gr: usize, dst: &mut [[[f32; 32]; 36]; 2]) -> DecoderResult<()> {
+ if qbits > 0 {
+ let bits = qbits as u8;
+ let maxval = (1 << bits) - 1;
+ for i in 0..3 {
+ let val = br.read(bits)? as u8;
+ dst[0][gr * 3 + i][band] = unquant(val, maxval, scale0);
+ dst[1][gr * 3 + i][band] = unquant(val, maxval, scale1);
+ }
+ } else {
+ let samplecode = br.read(-qbits as u8)? as usize;
+ match qbits {
+ -5 => {
+ for i in 0..3 {
+ dst[0][gr * 3 + i][band] = unquant(GROUP3[samplecode][i], 3, scale0);
+ dst[1][gr * 3 + i][band] = unquant(GROUP3[samplecode][i], 3, scale1);
+ }
+ },
+ -7 => {
+ for i in 0..3 {
+ dst[0][gr * 3 + i][band] = unquant(GROUP5[samplecode][i], 5, scale0);
+ dst[1][gr * 3 + i][band] = unquant(GROUP5[samplecode][i], 5, scale1);
+ }
+ },
+ -10 => {
+ for i in 0..3 {
+ dst[0][gr * 3 + i][band] = unquant(GROUP9[samplecode][i], 9, scale0);
+ dst[1][gr * 3 + i][band] = unquant(GROUP9[samplecode][i], 9, scale1);
+ }
+ },
+ _ => unreachable!(),
+ };
+ }
+ Ok(())
+}
+
+impl MP2Data {
+ pub fn new() -> Self { Self::default() }
+ pub fn read_layer2(&mut self, br: &mut BitReader, channels: usize, out: &mut [[[f32; 32]; 36]; 2], mode: u8, mode_extension: u8) -> DecoderResult<()> {
+ let (ba_bits, ba_quants) = if self.mpeg1 {
+ if channels == 1 {
+ (LAYER2_BITS[self.sf_idx][self.br_idx], LAYER2_ALLOC[self.br_idx])
+ } else {
+ let br_idx = HALF_BITRATE_IDX[self.br_idx] as usize;
+ (LAYER2_BITS[self.sf_idx][br_idx], LAYER2_ALLOC[br_idx])
+ }
+ } else {
+ (BITS_B2LFE, ALLOC_B2LFE)
+ };
+ let mut sblimit = ba_bits.len() - 1;
+ while sblimit > 0 && ba_bits[sblimit - 1] == 0 {
+ sblimit -= 1;
+ }
+ if sblimit == 0 {
+ return Err(DecoderError::Bug);
+ }
+
+ *out = [[[0.0; 32]; 36]; 2];
+ if channels == 1 {
+ for (bits, &b) in self.alloc[0][..sblimit].iter_mut().zip(ba_bits.iter()) {
+ *bits = br.read(b)? as u8;
+ }
+ for (scf, &alloc) in self.scfsi[0][..sblimit].iter_mut().zip(self.alloc[0].iter()) {
+ if alloc != 0 {
+ *scf = br.read(2)? as u8;
+ }
+ }
+ for (band, scales) in self.scale[0].iter_mut().take(sblimit).enumerate() {
+ if self.alloc[0][band] == 0 {
+ continue;
+ }
+ scales[0] = br.read(6)? as u8;
+ match self.scfsi[0][band] {
+ 0 => {
+ scales[1] = br.read(6)? as u8;
+ scales[2] = br.read(6)? as u8;
+ },
+ 1 => {
+ scales[1] = scales[0];
+ scales[2] = br.read(6)? as u8;
+ },
+ 2 => {
+ scales[1] = scales[0];
+ scales[2] = scales[0];
+ },
+ _ => {
+ scales[1] = br.read(6)? as u8;
+ scales[2] = scales[1];
+ },
+ };
+ }
+
+ for gr in 0..12 {
+ for band in 0..sblimit {
+ if self.alloc[0][band] == 0 {
+ continue;
+ }
+ let scale = QUANTS[self.scale[0][band][gr / 4] as usize];
+ let qbits = ba_quants[band][self.alloc[0][band] as usize];
+ read3samples(br, qbits, scale, band, &mut out[0][gr * 3..])?;
+ }
+ }
+ } else {
+ let mut bound = if mode == 1 {
+ (mode_extension as usize + 1) * 4
+ } else {
+ sblimit
+ };
+ while bound > 0 && ba_bits[bound - 1] == 0 {
+ bound -= 1;
+ }
+
+ for band in 0..sblimit {
+ self.alloc[0][band] = br.read(ba_bits[band])? as u8;
+ if band < bound {
+ self.alloc[1][band] = br.read(ba_bits[band])? as u8;
+ } else {
+ self.alloc[1][band] = self.alloc[0][band];
+ }
+ }
+ for band in 0..sblimit {
+ for ch in 0..2 {
+ if self.alloc[ch][band] != 0 {
+ self.scfsi[ch][band] = br.read(2)? as u8;
+ }
+ }
+ }
+ for band in 0..sblimit {
+ for ch in 0..2 {
+ if self.alloc[ch][band] == 0 {
+ continue;
+ }
+ let scales = &mut self.scale[ch][band];
+ scales[0] = br.read(6)? as u8;
+ match self.scfsi[ch][band] {
+ 0 => {
+ scales[1] = br.read(6)? as u8;
+ scales[2] = br.read(6)? as u8;
+ },
+ 1 => {
+ scales[1] = scales[0];
+ scales[2] = br.read(6)? as u8;
+ },
+ 2 => {
+ scales[1] = scales[0];
+ scales[2] = scales[0];
+ },
+ _ => {
+ scales[1] = br.read(6)? as u8;
+ scales[2] = scales[1];
+ },
+ };
+ }
+ }
+ for gr in 0..12 {
+ for band in 0..bound {
+ for ch in 0..2 {
+ if self.alloc[ch][band] == 0 {
+ continue;
+ }
+ let scale = QUANTS[self.scale[ch][band][gr / 4] as usize];
+ let qbits = ba_quants[band][self.alloc[ch][band] as usize];
+ read3samples(br, qbits, scale, band, &mut out[ch][gr * 3..])?;
+ }
+ }
+ for band in bound..sblimit {
+ if self.alloc[0][band] == 0 {
+ continue;
+ }
+ let scale0 = QUANTS[self.scale[0][band][gr / 4] as usize];
+ let scale1 = QUANTS[self.scale[1][band][gr / 4] as usize];
+ let qbits = ba_quants[band][self.alloc[0][band] as usize];
+ read3samples_joint(br, qbits, scale0, scale1, band, gr, out)?;
+ }
+ }
+ }
+
+ Ok(())
+ }
+ pub fn reset(&mut self) {
+ }
+}
projects / nihav.git / blobdiff