| 1 | use nihav_core::codecs::*; |
| 2 | use nihav_core::io::bitreader::*; |
| 3 | use nihav_core::io::codebook::*; |
| 4 | |
| 5 | use super::SAMPLES; |
| 6 | use super::mp3data::*; |
| 7 | |
| 8 | const MP3_MAX_BANDS: usize = MP3_BANDS_SHORT * 3 + 4; |
| 9 | const IS_MODE: u8 = 1; |
| 10 | const MS_MODE: u8 = 2; |
| 11 | |
| 12 | #[derive(Clone,Copy)] |
| 13 | struct Granule { |
| 14 | part2_3_length: usize, |
| 15 | big_values: usize, |
| 16 | global_gain: u8, |
| 17 | scalefac_compress: usize, |
| 18 | blocksplit: bool, |
| 19 | block_type: u8, |
| 20 | switch_point: bool, |
| 21 | table_select: [u8; 3], |
| 22 | subblock_gain: [u8; 3], |
| 23 | region_address1: u8, |
| 24 | region_address2: u8, |
| 25 | preflag: bool, |
| 26 | scalefac_scale: bool, |
| 27 | count1table_select: bool, |
| 28 | scalefac: [u8; MP3_MAX_BANDS], |
| 29 | istereo: [u8; MP3_MAX_BANDS], |
| 30 | |
| 31 | lastcoded: usize, |
| 32 | zero_part: usize, |
| 33 | } |
| 34 | |
| 35 | impl Default for Granule { |
| 36 | fn default() -> Self { unsafe { std::mem::MaybeUninit::zeroed().assume_init() } } |
| 37 | } |
| 38 | |
| 39 | impl Granule { |
| 40 | fn get_mpeg2_params(&self, bits: &mut [u8; 4], independent: bool) -> usize { |
| 41 | if independent { |
| 42 | match self.scalefac_compress { |
| 43 | 0..=399 => { |
| 44 | bits[0] = MP3_SCF_BITS5[(self.scalefac_compress >> 4) * 2]; |
| 45 | bits[1] = MP3_SCF_BITS5[(self.scalefac_compress >> 4) * 2 + 1]; |
| 46 | bits[2] = ((self.scalefac_compress >> 2) & 3) as u8; |
| 47 | bits[3] = (self.scalefac_compress & 3) as u8; |
| 48 | 0 |
| 49 | }, |
| 50 | 400..=499 => { |
| 51 | let idx = self.scalefac_compress - 400; |
| 52 | bits[0] = MP3_SCF_BITS5[(idx >> 2) * 2]; |
| 53 | bits[1] = MP3_SCF_BITS5[(idx >> 2) * 2 + 1]; |
| 54 | bits[2] = (idx & 3) as u8; |
| 55 | bits[3] = 0; |
| 56 | 1 |
| 57 | }, |
| 58 | _ => { |
| 59 | let idx = self.scalefac_compress - 500; |
| 60 | bits[0] = MP3_SCF_BITS3[idx * 2]; |
| 61 | bits[1] = MP3_SCF_BITS3[idx * 2 + 1]; |
| 62 | bits[2] = 0; |
| 63 | bits[3] = 0; |
| 64 | 2 |
| 65 | }, |
| 66 | } |
| 67 | } else { |
| 68 | bits[3] = 0; |
| 69 | let idx = self.scalefac_compress >> 1; |
| 70 | match idx { |
| 71 | 0..=179 => { |
| 72 | bits[0] = MP3_SCF_BITS6[idx * 3]; |
| 73 | bits[1] = MP3_SCF_BITS6[idx * 3 + 1]; |
| 74 | bits[2] = MP3_SCF_BITS6[idx * 3 + 2]; |
| 75 | 3 |
| 76 | }, |
| 77 | 180..=243 => { |
| 78 | let val = (idx - 180) as u8; |
| 79 | bits[0] = val >> 4; |
| 80 | bits[1] = (val >> 2) & 3; |
| 81 | bits[2] = val & 3; |
| 82 | 4 |
| 83 | }, |
| 84 | _ => { |
| 85 | let idx = idx - 244; |
| 86 | bits[0] = MP3_SCF_BITS6[idx * 2]; |
| 87 | bits[1] = MP3_SCF_BITS6[idx * 2 + 1]; |
| 88 | bits[2] = 0; |
| 89 | 5 |
| 90 | }, |
| 91 | } |
| 92 | } |
| 93 | } |
| 94 | } |
| 95 | |
| 96 | struct MDCTContext { |
| 97 | win36: [f32; 36], |
| 98 | win36f: [f32; 36], |
| 99 | win12: [f32; 12], |
| 100 | win12f: [f32; 12], |
| 101 | tmp: [f32; 36], |
| 102 | } |
| 103 | |
| 104 | impl MDCTContext { |
| 105 | fn new() -> Self { |
| 106 | let mut win36 = [0.0; 36]; |
| 107 | let mut win36f = [0.0; 36]; |
| 108 | let mut win12 = [0.0; 12]; |
| 109 | let mut win12f = [0.0; 12]; |
| 110 | |
| 111 | for i in 0..36 { |
| 112 | win36 [i] = ((i as f32 + 0.5) * std::f32::consts::PI / 36.0).sin(); |
| 113 | win36f[i] = if (i & 1) == 0 { win36[i] } else { -win36[i] }; |
| 114 | } |
| 115 | for i in 0..12 { |
| 116 | win12 [i] = ((i as f32 + 0.5) * std::f32::consts::PI / 12.0).sin(); |
| 117 | win12f[i] = if (i & 1) == 0 { win12[i] } else { -win12[i] }; |
| 118 | } |
| 119 | |
| 120 | Self { |
| 121 | tmp: [0.0; 36], |
| 122 | win36, win36f, win12, win12f |
| 123 | } |
| 124 | } |
| 125 | fn mdct36(&mut self, src: &mut [f32], dst: &mut[f32], delay: &mut [f32], len: usize, block_type: u8) { |
| 126 | let mut flip = false; |
| 127 | for i in (0..len).step_by(18) { |
| 128 | let (win36, win12) = if flip { (&self.win36f, &self.win12f) } else { (&self.win36, &self.win12) }; |
| 129 | dct36(&mut src[i..], &mut self.tmp); |
| 130 | match block_type { |
| 131 | 0 | 2 => { |
| 132 | for j in 0..9 { |
| 133 | dst[i + j] = delay[i + j] - self.tmp[8 - j] * win36[j]; |
| 134 | delay[i + j] = self.tmp[j + 9] * win36[j + 18]; |
| 135 | } |
| 136 | for j in 9..18 { |
| 137 | dst[i + j] = delay[i + j] + self.tmp[j - 9] * win36[j]; |
| 138 | delay[i + j] = self.tmp[26 - j] * win36[j + 18]; |
| 139 | } |
| 140 | }, |
| 141 | 1 => { |
| 142 | for j in 0..9 { |
| 143 | dst[i + j] = delay[i + j] - self.tmp[8 - j] * win36[j]; |
| 144 | } |
| 145 | for j in 9..18 { |
| 146 | dst[i + j] = delay[i + j] + self.tmp[j - 9] * win36[j]; |
| 147 | } |
| 148 | delay[i..][..6].copy_from_slice(&self.tmp[9..][..6]); |
| 149 | if flip { |
| 150 | for j in (1..6).step_by(2) { |
| 151 | delay[i + j] = -delay[i + j]; |
| 152 | } |
| 153 | } |
| 154 | for j in 6..9 { |
| 155 | delay[i + j] = self.tmp[j + 9] * win12[j]; |
| 156 | } |
| 157 | for j in 9..12 { |
| 158 | delay[i + j] = self.tmp[26 - j] * win12[j]; |
| 159 | } |
| 160 | for j in 12..18 { |
| 161 | delay[i + j] = 0.0; |
| 162 | } |
| 163 | }, |
| 164 | _ => { |
| 165 | dst[i..][..6].copy_from_slice(&delay[i..][..6]); |
| 166 | for j in 6..9 { |
| 167 | dst[i + j] = delay[i + j] - self.tmp[8 - j] * win12[j - 6]; |
| 168 | } |
| 169 | for j in 9..12 { |
| 170 | dst[i + j] = delay[i + j] + self.tmp[j - 9] * win12[j - 6]; |
| 171 | } |
| 172 | if !flip { |
| 173 | for j in 12..18 { |
| 174 | dst[i + j] = delay[i + j] + self.tmp[j - 9]; |
| 175 | } |
| 176 | } else { |
| 177 | for j in 12..18 { |
| 178 | dst[i + j] = delay[i + j] + if (j & 1) == 0 { self.tmp[j - 9] } else { -self.tmp[j - 9] }; |
| 179 | } |
| 180 | } |
| 181 | for j in 0..9 { |
| 182 | delay[i + j] = self.tmp[j + 9] * win36[j + 18]; |
| 183 | } |
| 184 | for j in 9..18 { |
| 185 | delay[i + j] = self.tmp[26 - j] * win36[j + 18]; |
| 186 | } |
| 187 | }, |
| 188 | }; |
| 189 | |
| 190 | flip = !flip; |
| 191 | } |
| 192 | } |
| 193 | fn mdct12(&mut self, src: &[f32], dst: &mut[f32], delay: &mut [f32], len: usize) { |
| 194 | let mut flip = false; |
| 195 | for i in (0..len).step_by(18) { |
| 196 | let window = if flip { &self.win12f } else { &self.win12 }; |
| 197 | for j in 0..3 { |
| 198 | let tmp = &mut self.tmp[j * 12..]; |
| 199 | dct12(&src[i + j..], tmp); |
| 200 | for (el, &w) in tmp.iter_mut().zip(window.iter()) { |
| 201 | *el *= w; |
| 202 | } |
| 203 | } |
| 204 | |
| 205 | for j in 0..6 { |
| 206 | dst[i + j] = delay[i + j]; |
| 207 | delay[i + j] = self.tmp[j + 18] + self.tmp[j + 18 + 6]; |
| 208 | } |
| 209 | for j in 6..12 { |
| 210 | dst[i + j] = delay[i + j] + self.tmp[j - 6]; |
| 211 | delay[i + j] = self.tmp[j + 18 + 6]; |
| 212 | } |
| 213 | for j in 12..18 { |
| 214 | dst[i + j] = delay[i + j] + self.tmp[j - 6] + self.tmp[j]; |
| 215 | delay[i + j] = 0.0; |
| 216 | } |
| 217 | |
| 218 | flip = !flip; |
| 219 | } |
| 220 | } |
| 221 | } |
| 222 | |
| 223 | pub struct MP3Data { |
| 224 | cb: MP3Codebooks, |
| 225 | mdct: MDCTContext, |
| 226 | granule: [[Granule; 2]; 2], |
| 227 | scfsi: [[bool; 4]; 2], |
| 228 | pub main_data_end: usize, |
| 229 | is_mode: [i8; SAMPLES], |
| 230 | pub mpeg1: bool, |
| 231 | pub sf_idx: usize, |
| 232 | |
| 233 | delay: [[f32; SAMPLES / 2]; 2], |
| 234 | tmp: [f32; SAMPLES / 2], |
| 235 | } |
| 236 | |
| 237 | impl MP3Data { |
| 238 | pub fn new() -> Self { |
| 239 | Self { |
| 240 | cb: MP3Codebooks::new(), |
| 241 | mdct: MDCTContext::new(), |
| 242 | granule: [[Granule::default(); 2]; 2], |
| 243 | scfsi: [[false; 4]; 2], |
| 244 | main_data_end: 0, |
| 245 | is_mode: [0; SAMPLES], |
| 246 | mpeg1: false, |
| 247 | sf_idx: 0, |
| 248 | |
| 249 | delay: [[0.0; SAMPLES / 2]; 2], |
| 250 | tmp: [0.0; SAMPLES / 2], |
| 251 | } |
| 252 | } |
| 253 | pub fn reset(&mut self) { |
| 254 | for dly in self.delay.iter_mut() { |
| 255 | for el in dly.iter_mut() { |
| 256 | *el = 0.0; |
| 257 | } |
| 258 | } |
| 259 | } |
| 260 | fn calc_scale(gr: &Granule, sb: usize, ssb: usize, sblk_gain: u8) -> i8 { |
| 261 | (i32::from(gr.global_gain) - 64 - 146 |
| 262 | - 8 * i32::from(sblk_gain) |
| 263 | - if gr.scalefac_scale { 4 } else { 2 } * (i32::from(gr.scalefac[ssb]) |
| 264 | + if gr.preflag { i32::from(MP3_PREEMP_SCALES[sb]) } else { 0 }) |
| 265 | ).min(127).max(-124) as i8 |
| 266 | } |
| 267 | fn read_mp3_coeffs(&mut self, br: &mut BitReader, end: usize, gr_no: usize, ch: usize, coeffs: &mut [f32]) -> DecoderResult<()> { |
| 268 | let mut scales = [0; SAMPLES / 2]; |
| 269 | let gr = &mut self.granule[gr_no][ch]; |
| 270 | |
| 271 | // calculate scales first |
| 272 | if gr.block_type != 2 { |
| 273 | let mut off = 0; |
| 274 | let mut sb = 0; |
| 275 | while off < SAMPLES / 2 { |
| 276 | let end = MP3_SFB_LONG_OFFS[self.sf_idx][sb + 1]; |
| 277 | let scale = Self::calc_scale(gr, sb, sb, 0); |
| 278 | for el in scales[off..end].iter_mut() { |
| 279 | *el = scale; |
| 280 | } |
| 281 | |
| 282 | if ch == 1 { |
| 283 | let scf = gr.scalefac[sb.min(MP3_BANDS - 1)]; |
| 284 | if scf != gr.istereo[sb] { |
| 285 | for el in self.is_mode[gr_no * SAMPLES/2..][off..end].iter_mut() { |
| 286 | *el = scf as i8; |
| 287 | } |
| 288 | } |
| 289 | } |
| 290 | |
| 291 | sb += 1; |
| 292 | off = end; |
| 293 | } |
| 294 | } else { |
| 295 | let end_band = if self.mpeg1 { 8 } else { 6 }; |
| 296 | |
| 297 | let mut off = 0; |
| 298 | let mut sb = 0; |
| 299 | if gr.switch_point { |
| 300 | while sb < end_band { |
| 301 | let end = MP3_SFB_LONG_OFFS[self.sf_idx][sb + 1]; |
| 302 | let scale = Self::calc_scale(gr, sb, sb, 0); |
| 303 | for el in scales[off..end].iter_mut() { |
| 304 | *el = scale; |
| 305 | } |
| 306 | |
| 307 | if ch == 1 { |
| 308 | let scf = gr.scalefac[sb.min(MP3_BANDS - 1)]; |
| 309 | if scf != gr.istereo[sb] { |
| 310 | for el in self.is_mode[gr_no * SAMPLES/2..][off..end].iter_mut() { |
| 311 | *el = scf as i8; |
| 312 | } |
| 313 | } |
| 314 | } |
| 315 | sb += 1; |
| 316 | off = end; |
| 317 | } |
| 318 | } |
| 319 | let mut ssb = if gr.switch_point { 8 } else { 0 }; |
| 320 | let mut sb = if gr.switch_point { 3 } else { 0 }; |
| 321 | while sb <= MP3_BANDS_SHORT { |
| 322 | let band_size = MP3_SFB_SHORT_SIZE[self.sf_idx][sb]; |
| 323 | for win in 0..3 { |
| 324 | let scale = Self::calc_scale(gr, sb, ssb, gr.subblock_gain[win]); |
| 325 | for el in scales[off..][..band_size].iter_mut() { |
| 326 | *el = scale; |
| 327 | } |
| 328 | |
| 329 | if ch == 1 { |
| 330 | if sb == MP3_BANDS_SHORT { |
| 331 | gr.scalefac[ssb] = gr.scalefac[ssb - 3]; |
| 332 | gr.istereo[ssb] = gr.istereo[ssb - 3]; |
| 333 | } |
| 334 | let scf = gr.scalefac[ssb]; |
| 335 | if scf != gr.istereo[ssb] { |
| 336 | for el in self.is_mode[gr_no * SAMPLES/2 + off..][..band_size].iter_mut() { |
| 337 | *el = scf as i8; |
| 338 | } |
| 339 | } |
| 340 | } |
| 341 | off += band_size; |
| 342 | ssb += 1; |
| 343 | } |
| 344 | sb += 1; |
| 345 | } |
| 346 | } |
| 347 | |
| 348 | // prepare for coefficients decoding |
| 349 | let region1_start = if gr.block_type != 2 { |
| 350 | MP3_SFB_LONG_OFFS[self.sf_idx][gr.region_address1 as usize + 1] |
| 351 | } else if gr.switch_point { |
| 352 | 36 |
| 353 | } else { |
| 354 | MP3_SFB_SHORT_OFFS[self.sf_idx][3] * 3 |
| 355 | }.min(gr.big_values); |
| 356 | let region2_start = MP3_SFB_LONG_OFFS[self.sf_idx][((gr.region_address1 + gr.region_address2 + 2) as usize).min(MP3_BANDS + 1)].min(gr.big_values); |
| 357 | |
| 358 | for el in coeffs[..SAMPLES/2].iter_mut() { |
| 359 | *el = 0.0; |
| 360 | } |
| 361 | |
| 362 | // read coefficients |
| 363 | gr.lastcoded = 0; |
| 364 | if let Some((cb, esc_bits)) = self.cb.get_cb(gr.table_select[0]) { |
| 365 | let lc = read_region(br, end, coeffs, &scales, 0, region1_start, cb, esc_bits)?; |
| 366 | gr.lastcoded = gr.lastcoded.max(lc); |
| 367 | } |
| 368 | if let Some((cb, esc_bits)) = self.cb.get_cb(gr.table_select[1]) { |
| 369 | let lc = read_region(br, end, coeffs, &scales, region1_start, region2_start, cb, esc_bits)?; |
| 370 | gr.lastcoded = gr.lastcoded.max(lc); |
| 371 | } |
| 372 | if let Some((cb, esc_bits)) = self.cb.get_cb(gr.table_select[2]) { |
| 373 | let lc = read_region(br, end, coeffs, &scales, region2_start, gr.big_values, cb, esc_bits)?; |
| 374 | gr.lastcoded = gr.lastcoded.max(lc); |
| 375 | } |
| 376 | let (lc, zp) = read_region_quad(br, end, coeffs, &scales, gr.big_values, if !gr.count1table_select { Some(&self.cb.quad_cb) } else { None })?; |
| 377 | gr.lastcoded = gr.lastcoded.max(lc); |
| 378 | gr.zero_part = if zp > 0 { zp } else { gr.lastcoded }; |
| 379 | |
| 380 | Ok(()) |
| 381 | } |
| 382 | pub fn read_mp3_side_data(&mut self, br: &mut BitReader, channels: usize) -> DecoderResult<()> { |
| 383 | if self.mpeg1 { |
| 384 | self.main_data_end = br.read(9)? as usize; |
| 385 | let _private_bits = br.read(if channels == 1 { 5 } else { 3 })?; |
| 386 | for scfsis in self.scfsi[..channels].iter_mut() { |
| 387 | for scfsi in scfsis.iter_mut() { |
| 388 | *scfsi = br.read_bool()?; |
| 389 | } |
| 390 | } |
| 391 | } else { |
| 392 | self.main_data_end = br.read(8)? as usize; |
| 393 | let _private_bits = br.read(channels as u8)?; |
| 394 | } |
| 395 | let granules = if self.mpeg1 { 2 } else { 1 }; |
| 396 | for grans in self.granule[..granules].iter_mut() { |
| 397 | for gr in grans[..channels].iter_mut() { |
| 398 | gr.part2_3_length = br.read(12)? as usize; |
| 399 | gr.big_values = (br.read(9)? as usize) * 2; |
| 400 | gr.global_gain = br.read(8)? as u8; |
| 401 | gr.scalefac_compress = br.read(if self.mpeg1 { 4 } else { 9 })? as usize; |
| 402 | gr.blocksplit = br.read_bool()?; |
| 403 | if gr.blocksplit { |
| 404 | gr.block_type = br.read(2)? as u8; |
| 405 | gr.switch_point = br.read_bool()?; |
| 406 | for tsel in gr.table_select[..2].iter_mut() { |
| 407 | *tsel = br.read(5)? as u8; |
| 408 | match *tsel { |
| 409 | 4 | 14 => return Err(DecoderError::InvalidData), |
| 410 | _ => {}, |
| 411 | }; |
| 412 | } |
| 413 | for gain in gr.subblock_gain.iter_mut() { |
| 414 | *gain = br.read(3)? as u8; |
| 415 | } |
| 416 | gr.region_address1 = 7; |
| 417 | gr.region_address2 = 13; |
| 418 | } else { |
| 419 | gr.block_type = 0; |
| 420 | gr.switch_point = false; |
| 421 | for tsel in gr.table_select.iter_mut() { |
| 422 | *tsel = br.read(5)? as u8; |
| 423 | match *tsel { |
| 424 | 4 | 14 => return Err(DecoderError::InvalidData), |
| 425 | _ => {}, |
| 426 | }; |
| 427 | } |
| 428 | gr.region_address1 = br.read(4)? as u8; |
| 429 | gr.region_address2 = br.read(3)? as u8; |
| 430 | } |
| 431 | if self.mpeg1 { |
| 432 | gr.preflag = br.read_bool()?; |
| 433 | } else { |
| 434 | gr.preflag = false; |
| 435 | } |
| 436 | gr.scalefac_scale = br.read_bool()?; |
| 437 | gr.count1table_select = br.read_bool()? |
| 438 | } |
| 439 | } |
| 440 | Ok(()) |
| 441 | } |
| 442 | pub fn decode_mpeg1_layer3(&mut self, br: &mut BitReader, coeffs: &mut [[f32; SAMPLES]; 2], channels: usize) -> DecoderResult<()> { |
| 443 | let mut data_end = 0; |
| 444 | for gr_no in 0..2 { |
| 445 | for ch in 0..channels { |
| 446 | data_end += self.granule[gr_no][ch].part2_3_length; |
| 447 | |
| 448 | if self.granule[gr_no][ch].block_type != 2 { |
| 449 | if gr_no != 0 { |
| 450 | self.granule[1][ch].scalefac = self.granule[0][ch].scalefac; |
| 451 | } else { |
| 452 | for scf in self.granule[gr_no][ch].scalefac.iter_mut() { |
| 453 | *scf = 0; |
| 454 | } |
| 455 | } |
| 456 | |
| 457 | let gr = &mut self.granule[gr_no][ch]; |
| 458 | let bits1 = MP3_SCALEFAC_BITS1[gr.scalefac_compress]; |
| 459 | let bits2 = MP3_SCALEFAC_BITS2[gr.scalefac_compress]; |
| 460 | for cb in 0..11 { |
| 461 | if !self.scfsi[ch][SCFSI_FROM_BAND[cb]] || (gr_no == 0) { |
| 462 | gr.scalefac[cb] = br.read(bits1)? as u8; |
| 463 | } |
| 464 | } |
| 465 | for cb in 11..MP3_BANDS { |
| 466 | if !self.scfsi[ch][SCFSI_FROM_BAND[cb]] || (gr_no == 0) { |
| 467 | gr.scalefac[cb] = br.read(bits2)? as u8; |
| 468 | } |
| 469 | } |
| 470 | for scf in gr.scalefac[MP3_BANDS..].iter_mut() { |
| 471 | *scf = 0; |
| 472 | } |
| 473 | for is in gr.istereo.iter_mut() { |
| 474 | *is = 7; |
| 475 | } |
| 476 | } else { |
| 477 | let gr = &mut self.granule[gr_no][ch]; |
| 478 | let bits1 = MP3_SCALEFAC_BITS1[gr.scalefac_compress]; |
| 479 | let bits2 = MP3_SCALEFAC_BITS2[gr.scalefac_compress]; |
| 480 | let pivot = if gr.blocksplit && gr.switch_point { 17 } else { 18 }; |
| 481 | |
| 482 | for scf in gr.scalefac[..pivot].iter_mut() { |
| 483 | *scf = br.read(bits1)? as u8; |
| 484 | } |
| 485 | for scf in gr.scalefac[pivot..][..18].iter_mut() { |
| 486 | *scf = br.read(bits2)? as u8; |
| 487 | } |
| 488 | for scf in gr.scalefac[pivot + 18..].iter_mut() { |
| 489 | *scf = 0; |
| 490 | } |
| 491 | for is in gr.istereo.iter_mut() { |
| 492 | *is = 7; |
| 493 | } |
| 494 | } |
| 495 | self.read_mp3_coeffs(br, data_end, gr_no, ch, &mut coeffs[ch][gr_no * SAMPLES/2..])?; |
| 496 | validate!(br.tell() <= data_end); |
| 497 | br.seek(data_end as u32)?; |
| 498 | } |
| 499 | } |
| 500 | Ok(()) |
| 501 | } |
| 502 | pub fn decode_mpeg2_layer3(&mut self, br: &mut BitReader, coeffs: &mut [[f32; SAMPLES]; 2], channels: usize, mode_ext: u8) -> DecoderResult<()> { |
| 503 | let mut data_end = 0; |
| 504 | for ch in 0..channels { |
| 505 | let gr = &mut self.granule[0][ch]; |
| 506 | data_end += gr.part2_3_length; |
| 507 | |
| 508 | let mut bits = [0; 4]; |
| 509 | let idx = gr.get_mpeg2_params(&mut bits, (ch == 0) || ((mode_ext & IS_MODE) == 0)); |
| 510 | let idx2 = if gr.block_type != 2 { 0 } else if !gr.switch_point { 1 } else { 2 }; |
| 511 | |
| 512 | gr.preflag = idx == 2; |
| 513 | let ends = &MP3_SCF_ENDS[idx][idx2]; |
| 514 | |
| 515 | for (scf, is) in gr.scalefac[0..ends[0]].iter_mut().zip(gr.istereo[0..ends[0]].iter_mut()) { |
| 516 | *scf = br.read(bits[0])? as u8; |
| 517 | *is = (1 << bits[0]) - 1; |
| 518 | } |
| 519 | for (scf, is) in gr.scalefac[ends[0]..ends[1]].iter_mut().zip(gr.istereo[ends[0]..ends[1]].iter_mut()) { |
| 520 | *scf = br.read(bits[1])? as u8; |
| 521 | *is = (1 << bits[1]) - 1; |
| 522 | } |
| 523 | for (scf, is) in gr.scalefac[ends[1]..ends[2]].iter_mut().zip(gr.istereo[ends[1]..ends[2]].iter_mut()) { |
| 524 | *scf = br.read(bits[2])? as u8; |
| 525 | *is = (1 << bits[2]) - 1; |
| 526 | } |
| 527 | for (scf, is) in gr.scalefac[ends[2]..ends[3]].iter_mut().zip(gr.istereo[ends[2]..ends[3]].iter_mut()) { |
| 528 | *scf = br.read(bits[3])? as u8; |
| 529 | *is = (1 << bits[3]) - 1; |
| 530 | } |
| 531 | self.read_mp3_coeffs(br, data_end, 0, ch, &mut coeffs[ch])?; |
| 532 | validate!(br.tell() <= data_end); |
| 533 | br.seek(data_end as u32)?; |
| 534 | } |
| 535 | Ok(()) |
| 536 | } |
| 537 | pub fn synth(&mut self, coeffs: &mut [[f32; SAMPLES]; 2], output: &mut [[[f32; 32]; 36]; 2], mode: u8, mode_ext: u8) { |
| 538 | let channels = if mode == 3 { 1 } else { 2 }; |
| 539 | let granules = if self.mpeg1 { 2 } else { 1 }; |
| 540 | |
| 541 | let mut end_freq = [[0; 2]; 2]; |
| 542 | for gr_no in 0..granules { |
| 543 | for ch in 0..channels { |
| 544 | end_freq[gr_no][ch] = self.granule[gr_no][ch].lastcoded; |
| 545 | } |
| 546 | } |
| 547 | |
| 548 | let mut band_flags = [[0; MP3_MAX_BANDS + 3]; 2]; |
| 549 | let mut band_start = [[0; MP3_MAX_BANDS + 3]; 2]; |
| 550 | let mut band_end = [[0; MP3_MAX_BANDS + 3]; 2]; |
| 551 | |
| 552 | if mode == 1 { // joint stereo |
| 553 | let mut bound_band = [0; 2]; |
| 554 | let mut num_bands = [MP3_BANDS + 1; 2]; |
| 555 | |
| 556 | for (gr_no, grans) in self.granule[..granules].iter_mut().enumerate() { |
| 557 | if grans[1].block_type != 2 { |
| 558 | for band in 0..=MP3_BANDS { |
| 559 | band_flags[gr_no][band] = mode_ext; |
| 560 | band_start[gr_no][band] = MP3_SFB_LONG_OFFS[self.sf_idx][band]; |
| 561 | band_end [gr_no][band] = MP3_SFB_LONG_OFFS[self.sf_idx][band + 1]; |
| 562 | if (end_freq[gr_no][1] >= band_end[gr_no][band]) || (grans[1].scalefac[band.min(MP3_BANDS - 1)] == grans[1].istereo[band.min(MP3_BANDS - 1)]) { |
| 563 | band_flags[gr_no][band] &= !IS_MODE; |
| 564 | } |
| 565 | if band_start[gr_no][band] < end_freq[gr_no][1] { |
| 566 | bound_band[gr_no] = band; |
| 567 | } |
| 568 | if (band_flags[gr_no][band] & IS_MODE) == 0 { |
| 569 | for el in self.is_mode[gr_no * SAMPLES/2..][band_start[gr_no][band]..band_end[gr_no][band]].iter_mut() { |
| 570 | *el = -1; |
| 571 | } |
| 572 | } |
| 573 | } |
| 574 | } else { |
| 575 | let switch_off = if grans[1].switch_point { 3 } else { 0 }; |
| 576 | let mut start = 0; |
| 577 | let mut band = 0; |
| 578 | if grans[1].switch_point { |
| 579 | let long_bands = if self.mpeg1 { 8 } else { 6 }; |
| 580 | for _ in 0..long_bands { |
| 581 | band_flags[gr_no][band] = mode_ext; |
| 582 | band_start[gr_no][band] = MP3_SFB_LONG_OFFS[self.sf_idx][band]; |
| 583 | band_end [gr_no][band] = MP3_SFB_LONG_OFFS[self.sf_idx][band + 1]; |
| 584 | if end_freq[gr_no][1] >= band_end[gr_no][band] { |
| 585 | band_flags[gr_no][band] &= !IS_MODE; |
| 586 | } |
| 587 | start = band_end[gr_no][band]; |
| 588 | band += 1; |
| 589 | } |
| 590 | } |
| 591 | for sb in switch_off..=MP3_BANDS_SHORT { |
| 592 | let band_size = MP3_SFB_SHORT_SIZE[self.sf_idx][sb]; |
| 593 | for _win in 0..3 { |
| 594 | band_flags[gr_no][band] = mode_ext; |
| 595 | band_start[gr_no][band] = start; |
| 596 | band_end [gr_no][band] = start + band_size; |
| 597 | if end_freq[gr_no][1] >= band_end[gr_no][band] { |
| 598 | band_flags[gr_no][band] &= !IS_MODE; |
| 599 | } |
| 600 | start += band_size; |
| 601 | band += 1; |
| 602 | } |
| 603 | } |
| 604 | num_bands[gr_no] = band; |
| 605 | } |
| 606 | } |
| 607 | if (mode_ext & IS_MODE) != 0 { |
| 608 | for (gr_no, grans) in self.granule[..granules].iter_mut().enumerate() { |
| 609 | let (coef0, coef1) = coeffs.split_at_mut(1); |
| 610 | let coef0 = &mut coef0[0][gr_no * SAMPLES/2..]; |
| 611 | let coef1 = &mut coef1[0][gr_no * SAMPLES/2..]; |
| 612 | let is_mode = &self.is_mode[gr_no * SAMPLES/2..]; |
| 613 | let start = band_end[gr_no][bound_band[gr_no]]; |
| 614 | let end = grans[0].zero_part; |
| 615 | |
| 616 | if self.mpeg1 { |
| 617 | let coef0 = &mut coef0[start..end]; |
| 618 | let coef1 = &mut coef1[start..end]; |
| 619 | let is_mode = &self.is_mode[gr_no * SAMPLES/2..][start..end]; |
| 620 | for ((l, r), &is) in coef0.iter_mut().zip(coef1.iter_mut()).zip(is_mode.iter()) { |
| 621 | if is >= 0 && is < 7 { |
| 622 | let t = *l * MP3_ISTEREO_COEFFS[is as usize]; |
| 623 | *l -= t; |
| 624 | *r = t; |
| 625 | } |
| 626 | } |
| 627 | } else { |
| 628 | let iscale = (grans[1].scalefac_compress & 1) as u8; |
| 629 | for band in 0..num_bands[gr_no] { |
| 630 | if (band_flags[gr_no][band] & IS_MODE) != 0 { |
| 631 | apply_istereo(&mut coef0[start..end], &mut coef1[start..end], is_mode[start], iscale, (band_flags[gr_no][band] & MS_MODE) != 0); |
| 632 | } |
| 633 | } |
| 634 | } |
| 635 | end_freq[gr_no][1] = end_freq[gr_no][1].min(end); |
| 636 | } |
| 637 | } |
| 638 | if (mode_ext & MS_MODE) != 0 { |
| 639 | for (gr_no, grans) in self.granule[..granules].iter_mut().enumerate() { |
| 640 | let end = grans[0].zero_part.max(grans[1].zero_part); |
| 641 | let (coef0, coef1) = coeffs.split_at_mut(1); |
| 642 | let coef0 = &mut coef0[0][gr_no * SAMPLES/2..]; |
| 643 | let coef1 = &mut coef1[0][gr_no * SAMPLES/2..]; |
| 644 | for band in 0..num_bands[gr_no] { |
| 645 | if band_start[gr_no][band] >= end { |
| 646 | break; |
| 647 | } |
| 648 | if (band_flags[gr_no][band] & MS_MODE) != 0 { |
| 649 | let start = band_start[gr_no][band]; |
| 650 | let end = band_end[gr_no][band]; |
| 651 | super::apply_ms(&mut coef0[start..end], &mut coef1[start..end]); |
| 652 | } |
| 653 | } |
| 654 | end_freq[gr_no][0] = end; |
| 655 | end_freq[gr_no][1] = end; |
| 656 | } |
| 657 | } |
| 658 | } |
| 659 | for (gr_no, grans) in self.granule[..granules].iter_mut().enumerate() { |
| 660 | for (ch, gr) in grans[..channels].iter_mut().enumerate() { |
| 661 | let src = &mut coeffs[ch][gr_no * SAMPLES/2..][..SAMPLES/2]; |
| 662 | if gr.block_type != 2 { |
| 663 | dealias(src, SAMPLES/2); |
| 664 | self.mdct.mdct36(src, &mut self.tmp, &mut self.delay[ch], end_freq[gr_no][ch], gr.block_type); |
| 665 | } else { |
| 666 | let switch_off = if gr.switch_point { MP3_SFB_LONG_OFFS[self.sf_idx][if self.mpeg1 { 8 } else { 6 }] } else { 0 }; |
| 667 | let mut band_buf = [0.0; 66 * 3]; |
| 668 | let mut sb = if gr.switch_point { 3 } else { 0 }; |
| 669 | let mut off = switch_off; |
| 670 | |
| 671 | while sb <= MP3_BANDS_SHORT { |
| 672 | let band_size = MP3_SFB_SHORT_SIZE[self.sf_idx][sb]; |
| 673 | for win in 0..3 { |
| 674 | for i in 0..band_size { |
| 675 | band_buf[win + i * 3] = src[off + win * band_size + i]; |
| 676 | } |
| 677 | } |
| 678 | src[off..][..band_size * 3].copy_from_slice(&band_buf[..band_size * 3]); |
| 679 | off += band_size * 3; |
| 680 | sb += 1; |
| 681 | } |
| 682 | if gr.switch_point { |
| 683 | dealias(src, switch_off); |
| 684 | self.mdct.mdct36(src, &mut self.tmp, &mut self.delay[ch], switch_off, gr.block_type); |
| 685 | } |
| 686 | self.mdct.mdct12(&src[switch_off..], &mut self.tmp[switch_off..], &mut self.delay[ch][switch_off..], end_freq[gr_no][ch] - switch_off); |
| 687 | } |
| 688 | |
| 689 | let dst = &mut output[ch][gr_no * 18..]; |
| 690 | let end = (end_freq[gr_no][ch] + 17) / 18; |
| 691 | for i in 0..end { |
| 692 | for j in 0..18 { |
| 693 | dst[j][i] = self.tmp[i * 18 + j]; |
| 694 | } |
| 695 | } |
| 696 | for i in end..32 { |
| 697 | for j in 0..18 { |
| 698 | dst[j][i] = self.delay[ch][i * 18 + j]; |
| 699 | } |
| 700 | for el in self.delay[ch][i * 18..][..18].iter_mut() { |
| 701 | *el = 0.0; |
| 702 | } |
| 703 | } |
| 704 | } |
| 705 | } |
| 706 | } |
| 707 | } |
| 708 | |
| 709 | fn mp3_unquant(val: u32, scale: i8) -> f32 { |
| 710 | (val as f32) * (val as f32).cbrt() * 2.0f32.powf((scale as f32) * 0.25) |
| 711 | } |
| 712 | |
| 713 | #[allow(clippy::too_many_arguments)] |
| 714 | fn read_region(br: &mut BitReader, br_end: usize, coeffs: &mut [f32], scales: &[i8; SAMPLES/2], start: usize, end: usize, cb: &Codebook<u8>, esc_bits: u8) -> DecoderResult<usize> { |
| 715 | let mut lastcoded = 0; |
| 716 | for (i, (cpair, scpair)) in coeffs[start..end].chunks_exact_mut(2).zip(scales[start..end].chunks_exact(2)).enumerate() { |
| 717 | if br.tell() >= br_end { break; } |
| 718 | let val = br.read_cb(cb)?; |
| 719 | if val == 0 { |
| 720 | continue; |
| 721 | } |
| 722 | let a = if (val >> 4) != 0xF || esc_bits == 0 { |
| 723 | u32::from(val >> 4) |
| 724 | } else { |
| 725 | br.read(esc_bits)? + 15 |
| 726 | }; |
| 727 | if a != 0 { |
| 728 | let a = mp3_unquant(a, scpair[0]); |
| 729 | cpair[0] = if br.read_bool()? { -a } else { a }; |
| 730 | } |
| 731 | let b = if (val & 0xF) != 0xF || esc_bits == 0 { |
| 732 | u32::from(val & 0xF) |
| 733 | } else { |
| 734 | br.read(esc_bits)? + 15 |
| 735 | }; |
| 736 | if b != 0 { |
| 737 | let b = mp3_unquant(b, scpair[1]); |
| 738 | cpair[1] = if br.read_bool()? { -b } else { b }; |
| 739 | } |
| 740 | lastcoded = start + (i + 1) * 2; |
| 741 | } |
| 742 | Ok(lastcoded) |
| 743 | } |
| 744 | |
| 745 | fn read_region_quad(br: &mut BitReader, br_end: usize, coeffs: &mut [f32], scales: &[i8; SAMPLES/2], start: usize, cb: Option<&Codebook<u8>>) -> DecoderResult<(usize, usize)> { |
| 746 | let mut lastcoded = 0; |
| 747 | let mut zero_part = 0; |
| 748 | if br.tell() >= br_end { |
| 749 | return Ok((0, 0)); |
| 750 | } |
| 751 | for (i, (cquad, scquad)) in coeffs[start..SAMPLES/2].chunks_exact_mut(4).zip(scales[start..].chunks_exact(4)).enumerate() { |
| 752 | zero_part = start + i * 4 + 4; |
| 753 | if br.tell() >= br_end { |
| 754 | break; |
| 755 | } |
| 756 | let val = if let Some(cbook) = cb { br.read_cb(cbook)? } else { (br.read(4)? as u8) ^ 0xF }; |
| 757 | if val == 0 { |
| 758 | continue; |
| 759 | } |
| 760 | for j in 0..4 { |
| 761 | if ((val >> (3 - j)) & 1) != 0 { |
| 762 | cquad[j] = mp3_unquant(1, scquad[j]); |
| 763 | if br.read_bool()? { |
| 764 | cquad[j] = -cquad[j]; |
| 765 | } |
| 766 | lastcoded = start + i * 4 + j + 1; |
| 767 | } |
| 768 | } |
| 769 | } |
| 770 | Ok((lastcoded, zero_part)) |
| 771 | } |
| 772 | |
| 773 | const DCT12_0: f32 = -0.92387953251128675613; |
| 774 | const DCT12_1: f32 = -0.38268343236508977174; |
| 775 | |
| 776 | const DCT12_2: f32 = -0.1305261922200516; |
| 777 | const DCT12_3: f32 = -0.6087614290087205; |
| 778 | const DCT12_4: f32 = 0.7933533402912348; |
| 779 | const DCT12_5: f32 = 0.9914448613738103; |
| 780 | |
| 781 | fn dct12(src: &[f32], dst: &mut [f32]) { |
| 782 | let t0 = src[0] - src[9] - src[12]; |
| 783 | let t1 = src[3] - src[6] - src[15]; |
| 784 | |
| 785 | dst[ 4] = t0 * DCT12_1 - t1 * DCT12_0; |
| 786 | dst[ 7] = t0 * DCT12_0 + t1 * DCT12_1; |
| 787 | dst[ 1] = -dst[4]; |
| 788 | dst[10] = dst[7]; |
| 789 | |
| 790 | let t0 = src[3] * DCT12_1 - src[12] * DCT12_0; |
| 791 | let t1 = src[3] * DCT12_0 + src[12] * DCT12_1; |
| 792 | |
| 793 | dst[ 3] = src[0] * DCT12_2 + src[6] * DCT12_3 + src[9] * DCT12_4 + src[15] * DCT12_5 - t0; |
| 794 | dst[ 5] = src[0] * DCT12_3 - src[6] * DCT12_2 - src[9] * DCT12_5 + src[15] * DCT12_4 - t1; |
| 795 | dst[ 6] = -src[0] * DCT12_4 + src[6] * DCT12_5 - src[9] * DCT12_2 + src[15] * DCT12_3 - t0; |
| 796 | dst[ 8] = -src[0] * DCT12_5 - src[6] * DCT12_4 + src[9] * DCT12_3 + src[15] * DCT12_2 + t1; |
| 797 | dst[ 2] = -dst[3]; |
| 798 | dst[ 0] = -dst[5]; |
| 799 | dst[11] = dst[6]; |
| 800 | dst[ 9] = dst[8]; |
| 801 | } |
| 802 | |
| 803 | const DCT36_PRESCALE: [f32; 18] = [ |
| 804 | 0.99904822158185776240, 0.99144486137381041114, 0.97629600711993336597, |
| 805 | 0.95371695074822692114, 0.92387953251128675613, 0.88701083317822170105, |
| 806 | 0.84339144581288570127, 0.79335334029123516458, 0.73727733681012404139, |
| 807 | 0.67559020761566024435, 0.60876142900872063942, 0.53729960834682383185, |
| 808 | 0.46174861323503393057, 0.38268343236508977174, 0.30070579950427312163, |
| 809 | 0.21643961393810287977, 0.13052619222005159156, 0.04361938736533599979 |
| 810 | ]; |
| 811 | const DCT36_TWIDDLE: [f32; 9] = [ |
| 812 | 0.99619469809174553229, 0.96592582628906828675, 0.90630778703664996324, |
| 813 | 0.81915204428899178969, 0.70710678118654752440, 0.57357643635104609611, |
| 814 | 0.42261826174069943619, 0.25881904510252076236, 0.08715574274765817357 |
| 815 | ]; |
| 816 | const SDCT2_TWIDDLE: [f32; 7] = [ |
| 817 | -2.0 * 0.98480775301220805936, -2.0 * 0.86602540378443864676, |
| 818 | -2.0 * 0.76604444311897803520, -2.0 * 0.64278760968653932633, |
| 819 | -2.0 * 0.34202014332566873305, -2.0 * 0.17364817766693034887, |
| 820 | 2.0 * 0.93969262078590838404 |
| 821 | ]; |
| 822 | |
| 823 | fn sdct_ii(buf: &mut [f32]) { |
| 824 | let t0 = buf[ 6] + buf[10]; |
| 825 | let t1 = buf[ 6] - buf[10]; |
| 826 | let t2 = buf[12] + buf[ 4]; |
| 827 | let t3 = buf[12] - buf[ 4]; |
| 828 | let t4 = buf[16] + buf[ 0]; |
| 829 | let t5 = buf[16] - buf[ 0]; |
| 830 | |
| 831 | let t6 = t0 + t2; |
| 832 | let t7 = (t0 - t2) * SDCT2_TWIDDLE[2]; |
| 833 | let t8 = (t1 + t3) * SDCT2_TWIDDLE[3]; |
| 834 | let t9 = t1 - t3; |
| 835 | let t0 = (t0 - t4) * SDCT2_TWIDDLE[5]; |
| 836 | let t1 = (t1 - t5) * SDCT2_TWIDDLE[0]; |
| 837 | let t2 = (t2 - t4) * SDCT2_TWIDDLE[6]; |
| 838 | let t3 = (t3 + t5) * SDCT2_TWIDDLE[4]; |
| 839 | |
| 840 | let ta = t6 + t4; |
| 841 | let tb = (t9 + t5) * SDCT2_TWIDDLE[1]; |
| 842 | |
| 843 | let tc = buf[2] + buf[14]; |
| 844 | let td = (buf[2] - buf[14]) * SDCT2_TWIDDLE[1]; |
| 845 | |
| 846 | let t6 = buf[8] + tc; |
| 847 | let t9 = buf[8] * 2.0 - tc; |
| 848 | let te = t9 + t2; |
| 849 | let tf = t9 - t2; |
| 850 | let t9 = t9 + t0; |
| 851 | |
| 852 | buf[ 0] = ta + t6; |
| 853 | buf[ 2] = t8 - td - t1; |
| 854 | buf[ 4] = t7 - te; |
| 855 | buf[ 6] = tb; |
| 856 | buf[ 8] = tf - t0; |
| 857 | buf[10] = td - t3 - t1; |
| 858 | buf[12] = ta - t6 * 2.0; |
| 859 | buf[14] = t8 + t3 + td; |
| 860 | buf[16] = t9 + t7; |
| 861 | } |
| 862 | |
| 863 | fn dct36(src: &mut [f32], dst: &mut [f32]) { |
| 864 | for (el, &w) in src.iter_mut().zip(DCT36_PRESCALE.iter()) { |
| 865 | *el *= w; |
| 866 | } |
| 867 | |
| 868 | let mut tmp = [0.0; 18]; |
| 869 | for i in 0..9 { |
| 870 | tmp[i * 2] = src[i] + src[17 - i]; |
| 871 | tmp[i * 2 + 1] = (src[i] - src[17 - i]) * DCT36_TWIDDLE[i] * 2.0; |
| 872 | } |
| 873 | sdct_ii(&mut tmp); |
| 874 | sdct_ii(&mut tmp[1..]); |
| 875 | |
| 876 | for i in (3..18).step_by(2) { |
| 877 | tmp[i] -= tmp[i - 2]; |
| 878 | } |
| 879 | tmp[0] *= 0.5; |
| 880 | for i in 1..18 { |
| 881 | tmp[i] = tmp[i] * 0.5 - tmp[i - 1]; |
| 882 | } |
| 883 | for i in 0..18 { |
| 884 | dst[i] = -tmp[17 - i] * 2.0; |
| 885 | } |
| 886 | } |
| 887 | |
| 888 | const ALIAS_COEFFS_S: [f32; 8] = [ |
| 889 | 0.85749292571254418689, 0.88174199731770518178, |
| 890 | 0.94962864910273289205, 0.98331459249179014599, |
| 891 | 0.99551781606758576429, 0.99916055817814750453, |
| 892 | 0.99989919524444704627, 0.99999315507028023572 |
| 893 | ]; |
| 894 | const ALIAS_COEFFS_A: [f32; 8] = [ |
| 895 | -0.51449575542752651213, -0.47173196856497227225, |
| 896 | -0.31337745420390185437, -0.18191319961098117700, |
| 897 | -0.09457419252642064760, -0.04096558288530404768, |
| 898 | -0.01419856857247114805, -0.00369997467376003687 |
| 899 | ]; |
| 900 | fn dealias(buf: &mut [f32], len: usize) { |
| 901 | for i in (18..len).step_by(18) { |
| 902 | for (j, (&cs, &ca)) in ALIAS_COEFFS_S.iter().zip(ALIAS_COEFFS_A.iter()).enumerate() { |
| 903 | let a = buf[i - j - 1]; |
| 904 | let b = buf[i + j]; |
| 905 | let c0 = a * cs - b * ca; |
| 906 | let c1 = a * ca + b * cs; |
| 907 | buf[i - j - 1] = c0; |
| 908 | buf[i + j] = c1; |
| 909 | } |
| 910 | } |
| 911 | } |
| 912 | |
| 913 | fn apply_istereo(ch0: &mut [f32], ch1: &mut [f32], is_mode: i8, iscale: u8, ms_mode: bool) { |
| 914 | match (is_mode, ms_mode) { |
| 915 | (-1, true) => { |
| 916 | for (c0, c1) in ch0.iter_mut().zip(ch1.iter_mut()) { |
| 917 | let a = (*c0 + *c1) * std::f32::consts::FRAC_1_SQRT_2; |
| 918 | let b = (*c0 - *c1) * std::f32::consts::FRAC_1_SQRT_2; |
| 919 | *c0 = a; |
| 920 | *c1 = b; |
| 921 | } |
| 922 | }, |
| 923 | (-1, false) => {}, |
| 924 | (0, _) => { |
| 925 | ch1.copy_from_slice(ch0); |
| 926 | }, |
| 927 | _ => { |
| 928 | let scale = mp3_unquant(1, -((is_mode + 1) >> 1) << iscale); |
| 929 | if (is_mode & 1) == 0 { |
| 930 | for (&c0, c1) in ch0.iter().zip(ch1.iter_mut()) { |
| 931 | *c1 = c0 * scale; |
| 932 | } |
| 933 | } else { |
| 934 | for (c0, c1) in ch0.iter_mut().zip(ch1.iter_mut()) { |
| 935 | *c1 = *c0; |
| 936 | *c0 *= scale; |
| 937 | } |
| 938 | } |
| 939 | }, |
| 940 | }; |
| 941 | } |