nihav-llaudio/src/codecs/apereader.rs

   1 use nihav_core::codecs::{DecoderError, DecoderResult};
   2 use nihav_core::io::bitreader::*;
   3 use nihav_core::io::intcode::*;
   4
   5 pub struct RiceParams {
   6     k:      u8,
   7     sum:    u32
   8 }
   9
  10 impl RiceParams {
  11     pub fn new() -> Self {
  12         let k = 10;
  13         Self { k, sum: 1 << (k + 4) }
  14     }
  15     fn update(&mut self, val: u32) {
  16         let limit = if self.k > 0 { 1 << (self.k + 4) } else { 0 };
  17         self.sum -= (self.sum + 16) >> 5;
  18         self.sum += (val + 1) / 2;
  19         if self.sum < limit {
  20             self.k -= 1;
  21         } else if (self.sum >= (1 << (self.k + 5))) && (self.k < 27) {
  22             self.k += 1;
  23         }
  24     }
  25     fn update_old(&mut self, val: u32) {
  26         let limit = if self.k > 0 { 1 << (self.k + 4) } else { 0 };
  27         self.sum -= (self.sum + 8) >> 4;
  28         self.sum += val;
  29         if self.sum < limit {
  30             self.k -= 1;
  31         } else if (self.sum >= (1 << (self.k + 5))) && (self.k < 24) {
  32             self.k += 1;
  33         }
  34     }
  35 }
  36
  37 pub struct RiceCoder<'a> {
  38     br:     BitReader<'a>,
  39     rice_x: RiceParams,
  40     rice_y: RiceParams,
  41 }
  42
  43 impl<'a> RiceCoder<'a> {
  44     pub fn new(br: BitReader<'a>) -> Self {
  45         Self {
  46             br,
  47             rice_x: RiceParams::new(),
  48             rice_y: RiceParams::new(),
  49         }
  50     }
  51 }
  52
  53 struct ARangeCoder<'a> {
  54     src:    &'a [u8],
  55     pos:    usize,
  56     low:    u32,
  57     range:  u32,
  58     help:   u32,
  59     buffer: u32,
  60     error:  bool,
  61 }
  62
  63 pub struct RangeCoder<'a> {
  64     rc:     ARangeCoder<'a>,
  65     rice_x: RiceParams,
  66     rice_y: RiceParams,
  67 }
  68
  69 impl<'a> RangeCoder<'a> {
  70     pub fn new(src: &'a [u8]) -> Self {
  71         Self {
  72             rc:     ARangeCoder::new(src),
  73             rice_x: RiceParams::new(),
  74             rice_y: RiceParams::new(),
  75         }
  76     }
  77     fn had_errors(&self) -> bool { self.rc.error }
  78 }
  79
  80 const RANGE_BITS: u8 = 32;
  81 const TOP: u32       = 1 << (RANGE_BITS - 1);
  82 const BOTTOM: u32    = TOP >> 8;
  83 const START_BITS: u8 = ((RANGE_BITS - 2) & 7) + 1;
  84
  85 const MAX_MODEL_VAL: u32 = 63;
  86
  87 impl<'a> ARangeCoder<'a> {
  88     fn new(src: &'a [u8]) -> Self {
  89         let buffer = u32::from(src[0]);
  90         Self {
  91             src:    &src[1..],
  92             pos:    0,
  93             low:    buffer >> (8 - START_BITS),
  94             range:  1 << START_BITS,
  95             help:   0,
  96             buffer,
  97             error:  false,
  98         }
  99     }
 100     fn reset(&mut self) {
 101         if self.pos == 0 {
 102             self.error = true;
 103         } else {
 104             self.pos -= 1;
 105         }
 106         if self.pos < self.src.len() - 1 {
 107             self.buffer = u32::from(self.src[self.pos]);
 108             self.pos += 1;
 109         }
 110         self.low    = self.buffer >> (8 - START_BITS);
 111         self.range  = 1 << START_BITS;
 112         self.help   = 0;
 113     }
 114     fn normalise(&mut self) {
 115         while self.range <= BOTTOM {
 116             self.buffer <<= 8;
 117             if self.pos < self.src.len() {
 118                 self.buffer |= u32::from(self.src[self.pos]);
 119                 self.pos += 1;
 120             } else {
 121                 self.error = true;
 122             }
 123             self.low   <<= 8;
 124             self.low    |= (self.buffer >> 1) & 0xFF;
 125             self.range <<= 8;
 126         }
 127     }
 128     fn get_freq(&mut self, freq: u32) -> u32 {
 129         self.normalise();
 130         self.help = self.range / freq;
 131         self.low / self.help
 132     }
 133     fn get_bits(&mut self, bits: u8) -> u32 {
 134         self.normalise();
 135         self.help = self.range >> bits;
 136         self.low / self.help
 137     }
 138     fn update(&mut self, interval: u32, low: u32) {
 139         self.low    -= self.help * low;
 140         self.range   = self.help * interval;
 141     }
 142     fn decode_freq(&mut self, freq: u32) -> u32 {
 143         let sym = self.get_freq(freq);
 144         self.update(1, sym);
 145         sym
 146     }
 147     fn decode_bits(&mut self, bits: u8) -> u32 {
 148         let sym = self.get_bits(bits);
 149         self.update(1, sym);
 150         sym
 151     }
 152     fn decode_symbol(&mut self, freqs: &[u32; 22]) -> u32 {
 153         let bits = self.get_bits(16);
 154         if bits > 65492 {
 155             let sym = bits + MAX_MODEL_VAL - 65535;
 156             self.update(1, bits);
 157             if bits > 65536 {
 158                 self.error = true;
 159             }
 160             sym
 161         } else {
 162             let mut sym = 0usize;
 163             while freqs[sym + 1] <= bits {
 164                 sym += 1;
 165             }
 166             self.update(freqs[sym + 1] - freqs[sym], freqs[sym]);
 167             sym as u32
 168         }
 169     }
 170 }
 171
 172 pub enum Coder<'a> {
 173     Rice(RiceCoder<'a>),
 174     Range(RangeCoder<'a>),
 175 }
 176
 177 fn to_signed(val: u32) -> i32 {
 178     if (val & 1) != 0 {
 179         (val >> 1) as i32 + 1
 180     } else {
 181         -((val >> 1) as i32)
 182     }
 183 }
 184
 185 pub fn decode_mono_dummy(_c: &mut Coder, _l: &mut [i32]) -> DecoderResult<()> {
 186     unreachable!();
 187 }
 188 pub fn decode_stereo_dummy(_c: &mut Coder, _l: &mut [i32], _r: &mut [i32]) -> DecoderResult<()> {
 189     unreachable!();
 190 }
 191
 192 fn new_k(val: u32) -> u8 {
 193     (32 - (val | 1).leading_zeros()) as u8
 194 }
 195 fn rice_limit(k: u8) -> u32 { if k > 0 { 1 << (k + 4) } else { 0 } }
 196 fn decode_channel_0000(br: &mut BitReader, dst: &mut [i32]) -> DecoderResult<()> {
 197     let (part01, part2) = dst.split_at_mut(64);
 198     let (part0, part1) = part01.split_at_mut(5);
 199     let mut pos = 0;
 200     let mut last = [0u32; 64];
 201     let mut sum = 0;
 202     for el in part0.iter_mut() {
 203         let val                         = br.read_code(UintCodeType::Rice(10))?;
 204         sum += val;
 205         *el = to_signed(val);
 206         last[pos] = val;
 207         pos += 1;
 208     }
 209     if part1.is_empty() {
 210         return Ok(());
 211     }
 212     let mut k = new_k(sum / 10);
 213     let mut w = 12;
 214     for el in part1.iter_mut() {
 215         let val                         = br.read_code(UintCodeType::Rice(k))?;
 216         sum += val;
 217         *el = to_signed(val);
 218         k = new_k(sum / w);
 219         w += 2;
 220         last[pos] = val;
 221         pos += 1;
 222     }
 223     if part2.is_empty() {
 224         return Ok(());
 225     }
 226     let mut top_limit = rice_limit(k + 1) * 4;
 227     let mut bot_limit = rice_limit(k)     * 4;
 228     pos = 0;
 229     for el in part2.iter_mut() {
 230         let val                         = br.read_code(UintCodeType::Rice(k))?;
 231         *el = to_signed(val);
 232
 233         sum = sum.wrapping_add(val.wrapping_sub(last[pos]));
 234         while sum < bot_limit {
 235             k -= 1;
 236             bot_limit = rice_limit(k) * 4;
 237             top_limit >>= 1;
 238         }
 239         while sum >= top_limit {
 240             k += 1;
 241             validate!(k < 24);
 242             bot_limit = rice_limit(k) * 4;
 243             top_limit <<= 1;
 244         }
 245
 246         last[pos] = val;
 247         pos = (pos + 1) & 63;
 248     }
 249
 250     Ok(())
 251 }
 252 pub fn decode_mono_0000(c: &mut Coder, l: &mut [i32]) -> DecoderResult<()> {
 253     if let Coder::Rice(ref mut rr) = c {
 254         decode_channel_0000(&mut rr.br, l)
 255     } else {
 256         Err(DecoderError::Bug)
 257     }
 258 }
 259 pub fn decode_stereo_0000(c: &mut Coder, l: &mut [i32], r: &mut [i32]) -> DecoderResult<()> {
 260     if let Coder::Rice(ref mut rr) = c {
 261         decode_channel_0000(&mut rr.br, l)?;
 262         decode_channel_0000(&mut rr.br, r)?;
 263         Ok(())
 264     } else {
 265         Err(DecoderError::Bug)
 266     }
 267 }
 268
 269 fn decode_value_3860(br: &mut BitReader, rice: &mut RiceParams) -> DecoderResult<i32> {
 270     let overflow                        = br.read_code(UintCodeType::UnaryZeroes)?;
 271
 272     let val                             = (overflow << rice.k) | br.read(rice.k)?;
 273     rice.update_old(val);
 274     Ok(to_signed(val))
 275 }
 276 fn decode_value_3890(br: &mut BitReader, rice: &mut RiceParams) -> DecoderResult<i32> {
 277     let mut overflow                    = br.read_code(UintCodeType::UnaryZeroes)?;
 278     while overflow >= 16 {
 279         overflow -= 16;
 280         rice.k += 4;
 281     }
 282
 283     let val                             = (overflow << rice.k) | br.read(rice.k)?;
 284     rice.update_old(val);
 285     Ok(to_signed(val))
 286 }
 287 pub fn decode_mono_3860(c: &mut Coder, l: &mut [i32]) -> DecoderResult<()> {
 288     if let Coder::Rice(ref mut rr) = c {
 289         for el in l.iter_mut() {
 290             *el = decode_value_3860(&mut rr.br, &mut rr.rice_y)?;
 291         }
 292         Ok(())
 293     } else {
 294         Err(DecoderError::Bug)
 295     }
 296 }
 297 pub fn decode_mono_3890(c: &mut Coder, l: &mut [i32]) -> DecoderResult<()> {
 298     if let Coder::Rice(ref mut rr) = c {
 299         for el in l.iter_mut() {
 300             *el = decode_value_3860(&mut rr.br, &mut rr.rice_y)?;
 301         }
 302         Ok(())
 303     } else {
 304         Err(DecoderError::Bug)
 305     }
 306 }
 307 pub fn decode_stereo_3860(c: &mut Coder, l: &mut [i32], r: &mut [i32]) -> DecoderResult<()> {
 308     if let Coder::Rice(ref mut rr) = c {
 309         for el in l.iter_mut() {
 310             *el = decode_value_3860(&mut rr.br, &mut rr.rice_y)?;
 311         }
 312         for el in r.iter_mut() {
 313             *el = decode_value_3860(&mut rr.br, &mut rr.rice_x)?;
 314         }
 315         Ok(())
 316     } else {
 317         Err(DecoderError::Bug)
 318     }
 319 }
 320 pub fn decode_stereo_3890(c: &mut Coder, l: &mut [i32], r: &mut [i32]) -> DecoderResult<()> {
 321     if let Coder::Rice(ref mut rr) = c {
 322         for el in l.iter_mut() {
 323             *el = decode_value_3890(&mut rr.br, &mut rr.rice_y)?;
 324         }
 325         for el in r.iter_mut() {
 326             *el = decode_value_3890(&mut rr.br, &mut rr.rice_x)?;
 327         }
 328         Ok(())
 329     } else {
 330         Err(DecoderError::Bug)
 331     }
 332 }
 333
 334 const COUNTS_3900: &[u32; 22] = &[
 335         0, 14824, 28224, 39348, 47855, 53994, 58171, 60926,
 336     62682, 63786, 64463, 64878, 65126, 65276, 65365, 65419,
 337     65450, 65469, 65480, 65487, 65491, 65493
 338 ];
 339 fn decode_value_3900(rc: &mut ARangeCoder, rice: &mut RiceParams) -> i32 {
 340     let mut overflow = rc.decode_symbol(COUNTS_3900);
 341     let k = if overflow == MAX_MODEL_VAL {
 342             overflow = 0;
 343             rc.decode_bits(5) as u8
 344         } else {
 345             rice.k.saturating_sub(1)
 346         };
 347     let base = rc.decode_bits(k);
 348     let val = base + (overflow << k);
 349     rice.update(val);
 350     to_signed(val)
 351 }
 352 fn decode_value_3910(rc: &mut ARangeCoder, rice: &mut RiceParams) -> i32 {
 353     let mut overflow = rc.decode_symbol(COUNTS_3900);
 354     let k = if overflow == MAX_MODEL_VAL {
 355             overflow = 0;
 356             rc.decode_bits(5) as u8
 357         } else {
 358             rice.k.saturating_sub(1)
 359         };
 360     let base = if k <= 16 {
 361             rc.decode_bits(k)
 362         } else if k <= 32 {
 363             let low = rc.decode_bits(k);
 364             let high = rc.decode_bits(k - 16);
 365             (high << (k - 16)) | low
 366         } else {
 367             rc.error = true;
 368             return 0;
 369         };
 370     let val = base + (overflow << k);
 371     rice.update(val);
 372     to_signed(val)
 373 }
 374 pub fn decode_mono_3900(c: &mut Coder, l: &mut [i32]) -> DecoderResult<()> {
 375     if let Coder::Range(ref mut rc) = c {
 376         for el in l.iter_mut() {
 377             *el = decode_value_3900(&mut rc.rc, &mut rc.rice_y);
 378         }
 379         validate!(!rc.had_errors());
 380         Ok(())
 381     } else {
 382         Err(DecoderError::Bug)
 383     }
 384 }
 385 pub fn decode_mono_3910(c: &mut Coder, l: &mut [i32]) -> DecoderResult<()> {
 386     if let Coder::Range(ref mut rc) = c {
 387         for el in l.iter_mut() {
 388             *el = decode_value_3910(&mut rc.rc, &mut rc.rice_y);
 389         }
 390         validate!(!rc.had_errors());
 391         Ok(())
 392     } else {
 393         Err(DecoderError::Bug)
 394     }
 395 }
 396 pub fn decode_stereo_3900(c: &mut Coder, l: &mut [i32], r: &mut [i32]) -> DecoderResult<()> {
 397     if let Coder::Range(ref mut rc) = c {
 398         for el in l.iter_mut() {
 399             *el = decode_value_3900(&mut rc.rc, &mut rc.rice_y);
 400         }
 401         rc.rc.normalise();
 402         validate!(!rc.had_errors() && rc.rc.pos < rc.rc.src.len());
 403         rc.rc.reset();
 404         for el in r.iter_mut() {
 405             *el = decode_value_3900(&mut rc.rc, &mut rc.rice_x);
 406         }
 407         validate!(!rc.had_errors());
 408         Ok(())
 409     } else {
 410         Err(DecoderError::Bug)
 411     }
 412 }
 413 pub fn decode_stereo_3910(c: &mut Coder, l: &mut [i32], r: &mut [i32]) -> DecoderResult<()> {
 414     if let Coder::Range(ref mut rc) = c {
 415         for el in l.iter_mut() {
 416             *el = decode_value_3910(&mut rc.rc, &mut rc.rice_y);
 417         }
 418         rc.rc.normalise();
 419         validate!(!rc.had_errors() && rc.rc.pos < rc.rc.src.len());
 420         rc.rc.reset();
 421         for el in r.iter_mut() {
 422             *el = decode_value_3910(&mut rc.rc, &mut rc.rice_x);
 423         }
 424         validate!(!rc.had_errors());
 425         Ok(())
 426     } else {
 427         Err(DecoderError::Bug)
 428     }
 429 }
 430 pub fn decode_stereo_3930(c: &mut Coder, l: &mut [i32], r: &mut [i32]) -> DecoderResult<()> {
 431     if let Coder::Range(ref mut rc) = c {
 432         for (l, r) in l.iter_mut().zip(r.iter_mut()) {
 433             *l = decode_value_3910(&mut rc.rc, &mut rc.rice_y);
 434             *r = decode_value_3910(&mut rc.rc, &mut rc.rice_x);
 435         }
 436         validate!(!rc.had_errors());
 437         Ok(())
 438     } else {
 439         Err(DecoderError::Bug)
 440     }
 441 }
 442
 443 const COUNTS_3990: &[u32; 22] = &[
 444         0, 19578, 36160, 48417, 56323, 60899, 63265, 64435,
 445     64971, 65232, 65351, 65416, 65447, 65466, 65476, 65482,
 446     65485, 65488, 65490, 65491, 65492, 65493
 447 ];
 448 fn decode_value_3990(rc: &mut ARangeCoder, rice: &mut RiceParams) -> i32 {
 449     let pivot = (rice.sum >> 5).max(1);
 450     let mut overflow = rc.decode_symbol(COUNTS_3990);
 451     if overflow == MAX_MODEL_VAL {
 452         overflow  = rc.decode_bits(16) << 16;
 453         overflow |= rc.decode_bits(16);
 454     }
 455     let base = if pivot < (1 << 16) {
 456             rc.decode_freq(pivot)
 457         } else {
 458             let shift = (16 - pivot.trailing_zeros()) as u8;
 459             let hi = rc.decode_freq((pivot >> shift) + 1);
 460             let lo = rc.decode_bits(shift);
 461             (hi << shift) | lo
 462         };
 463     let val = base + overflow * pivot;
 464     rice.update(val);
 465     to_signed(val)
 466 }
 467 pub fn decode_mono_3990(c: &mut Coder, l: &mut [i32]) -> DecoderResult<()> {
 468     if let Coder::Range(ref mut rc) = c {
 469         for el in l.iter_mut() {
 470             *el = decode_value_3990(&mut rc.rc, &mut rc.rice_y);
 471         }
 472         validate!(!rc.had_errors());
 473         Ok(())
 474     } else {
 475         Err(DecoderError::Bug)
 476     }
 477 }
 478 pub fn decode_stereo_3990(c: &mut Coder, l: &mut [i32], r: &mut [i32]) -> DecoderResult<()> {
 479     if let Coder::Range(ref mut rc) = c {
 480         for (l, r) in l.iter_mut().zip(r.iter_mut()) {
 481             *l = decode_value_3990(&mut rc.rc, &mut rc.rice_y);
 482             *r = decode_value_3990(&mut rc.rc, &mut rc.rice_x);
 483         }
 484         validate!(!rc.had_errors());
 485         Ok(())
 486     } else {
 487         Err(DecoderError::Bug)
 488     }
 489 }