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apedec.c
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1 /*
2  * Monkey's Audio lossless audio decoder
3  * Copyright (c) 2007 Benjamin Zores <ben@geexbox.org>
4  * based upon libdemac from Dave Chapman.
5  *
6  * This file is part of FFmpeg.
7  *
8  * FFmpeg is free software; you can redistribute it and/or
9  * modify it under the terms of the GNU Lesser General Public
10  * License as published by the Free Software Foundation; either
11  * version 2.1 of the License, or (at your option) any later version.
12  *
13  * FFmpeg is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16  * Lesser General Public License for more details.
17  *
18  * You should have received a copy of the GNU Lesser General Public
19  * License along with FFmpeg; if not, write to the Free Software
20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21  */
22 
23 #include "libavutil/avassert.h"
24 #include "libavutil/channel_layout.h"
25 #include "libavutil/opt.h"
26 #include "avcodec.h"
27 #include "dsputil.h"
28 #include "bytestream.h"
29 #include "internal.h"
30 #include "get_bits.h"
31 #include "unary.h"
32 
33 /**
34  * @file
35  * Monkey's Audio lossless audio decoder
36  */
37 
38 #define MAX_CHANNELS 2
39 #define MAX_BYTESPERSAMPLE 3
40 
41 #define APE_FRAMECODE_MONO_SILENCE 1
42 #define APE_FRAMECODE_STEREO_SILENCE 3
43 #define APE_FRAMECODE_PSEUDO_STEREO 4
44 
45 #define HISTORY_SIZE 512
46 #define PREDICTOR_ORDER 8
47 /** Total size of all predictor histories */
48 #define PREDICTOR_SIZE 50
49 
50 #define YDELAYA (18 + PREDICTOR_ORDER*4)
51 #define YDELAYB (18 + PREDICTOR_ORDER*3)
52 #define XDELAYA (18 + PREDICTOR_ORDER*2)
53 #define XDELAYB (18 + PREDICTOR_ORDER)
54 
55 #define YADAPTCOEFFSA 18
56 #define XADAPTCOEFFSA 14
57 #define YADAPTCOEFFSB 10
58 #define XADAPTCOEFFSB 5
59 
60 /**
61  * Possible compression levels
62  * @{
63  */
64 enum APECompressionLevel {
65  COMPRESSION_LEVEL_FAST = 1000,
66  COMPRESSION_LEVEL_NORMAL = 2000,
67  COMPRESSION_LEVEL_HIGH = 3000,
68  COMPRESSION_LEVEL_EXTRA_HIGH = 4000,
69  COMPRESSION_LEVEL_INSANE = 5000
70 };
71 /** @} */
72 
73 #define APE_FILTER_LEVELS 3
74 
75 /** Filter orders depending on compression level */
76 static const uint16_t ape_filter_orders[5][APE_FILTER_LEVELS] = {
77  { 0, 0, 0 },
78  { 16, 0, 0 },
79  { 64, 0, 0 },
80  { 32, 256, 0 },
81  { 16, 256, 1280 }
82 };
83 
84 /** Filter fraction bits depending on compression level */
85 static const uint8_t ape_filter_fracbits[5][APE_FILTER_LEVELS] = {
86  { 0, 0, 0 },
87  { 11, 0, 0 },
88  { 11, 0, 0 },
89  { 10, 13, 0 },
90  { 11, 13, 15 }
91 };
92 
93 
94 /** Filters applied to the decoded data */
95 typedef struct APEFilter {
96  int16_t *coeffs; ///< actual coefficients used in filtering
97  int16_t *adaptcoeffs; ///< adaptive filter coefficients used for correcting of actual filter coefficients
98  int16_t *historybuffer; ///< filter memory
99  int16_t *delay; ///< filtered values
100 
101  int avg;
102 } APEFilter;
103 
104 typedef struct APERice {
105  uint32_t k;
106  uint32_t ksum;
107 } APERice;
108 
109 typedef struct APERangecoder {
110  uint32_t low; ///< low end of interval
111  uint32_t range; ///< length of interval
112  uint32_t help; ///< bytes_to_follow resp. intermediate value
113  unsigned int buffer; ///< buffer for input/output
114 } APERangecoder;
115 
116 /** Filter histories */
117 typedef struct APEPredictor {
118  int32_t *buf;
119 
120  int32_t lastA[2];
121 
122  int32_t filterA[2];
123  int32_t filterB[2];
124 
125  int32_t coeffsA[2][4]; ///< adaption coefficients
126  int32_t coeffsB[2][5]; ///< adaption coefficients
127  int32_t historybuffer[HISTORY_SIZE + PREDICTOR_SIZE];
128 
129  unsigned int sample_pos;
130 } APEPredictor;
131 
132 /** Decoder context */
133 typedef struct APEContext {
134  AVClass *class; ///< class for AVOptions
135  AVCodecContext *avctx;
136  DSPContext dsp;
137  int channels;
138  int samples; ///< samples left to decode in current frame
139  int bps;
140 
141  int fileversion; ///< codec version, very important in decoding process
142  int compression_level; ///< compression levels
143  int fset; ///< which filter set to use (calculated from compression level)
144  int flags; ///< global decoder flags
145 
146  uint32_t CRC; ///< frame CRC
147  int frameflags; ///< frame flags
148  APEPredictor predictor; ///< predictor used for final reconstruction
149 
150  int32_t *decoded_buffer;
151  int decoded_size;
152  int32_t *decoded[MAX_CHANNELS]; ///< decoded data for each channel
153  int blocks_per_loop; ///< maximum number of samples to decode for each call
154 
155  int16_t* filterbuf[APE_FILTER_LEVELS]; ///< filter memory
156 
157  APERangecoder rc; ///< rangecoder used to decode actual values
158  APERice riceX; ///< rice code parameters for the second channel
159  APERice riceY; ///< rice code parameters for the first channel
160  APEFilter filters[APE_FILTER_LEVELS][2]; ///< filters used for reconstruction
161  GetBitContext gb;
162 
163  uint8_t *data; ///< current frame data
164  uint8_t *data_end; ///< frame data end
165  int data_size; ///< frame data allocated size
166  const uint8_t *ptr; ///< current position in frame data
167 
168  int error;
169 
170  void (*entropy_decode_mono)(struct APEContext *ctx, int blockstodecode);
171  void (*entropy_decode_stereo)(struct APEContext *ctx, int blockstodecode);
172  void (*predictor_decode_mono)(struct APEContext *ctx, int count);
173  void (*predictor_decode_stereo)(struct APEContext *ctx, int count);
174 } APEContext;
175 
176 static void ape_apply_filters(APEContext *ctx, int32_t *decoded0,
177  int32_t *decoded1, int count);
178 
179 static void entropy_decode_mono_0000(APEContext *ctx, int blockstodecode);
180 static void entropy_decode_stereo_0000(APEContext *ctx, int blockstodecode);
181 static void entropy_decode_mono_3860(APEContext *ctx, int blockstodecode);
182 static void entropy_decode_stereo_3860(APEContext *ctx, int blockstodecode);
183 static void entropy_decode_mono_3900(APEContext *ctx, int blockstodecode);
184 static void entropy_decode_stereo_3900(APEContext *ctx, int blockstodecode);
185 static void entropy_decode_stereo_3930(APEContext *ctx, int blockstodecode);
186 static void entropy_decode_mono_3990(APEContext *ctx, int blockstodecode);
187 static void entropy_decode_stereo_3990(APEContext *ctx, int blockstodecode);
188 
189 static void predictor_decode_mono_3800(APEContext *ctx, int count);
190 static void predictor_decode_stereo_3800(APEContext *ctx, int count);
191 static void predictor_decode_mono_3930(APEContext *ctx, int count);
192 static void predictor_decode_stereo_3930(APEContext *ctx, int count);
193 static void predictor_decode_mono_3950(APEContext *ctx, int count);
194 static void predictor_decode_stereo_3950(APEContext *ctx, int count);
195 
196 // TODO: dsputilize
197 
198 static av_cold int ape_decode_close(AVCodecContext *avctx)
199 {
200  APEContext *s = avctx->priv_data;
201  int i;
202 
203  for (i = 0; i < APE_FILTER_LEVELS; i++)
204  av_freep(&s->filterbuf[i]);
205 
206  av_freep(&s->decoded_buffer);
207  av_freep(&s->data);
208  s->decoded_size = s->data_size = 0;
209 
210  return 0;
211 }
212 
213 static av_cold int ape_decode_init(AVCodecContext *avctx)
214 {
215  APEContext *s = avctx->priv_data;
216  int i;
217 
218  if (avctx->extradata_size != 6) {
219  av_log(avctx, AV_LOG_ERROR, "Incorrect extradata\n");
220  return AVERROR(EINVAL);
221  }
222  if (avctx->channels > 2) {
223  av_log(avctx, AV_LOG_ERROR, "Only mono and stereo is supported\n");
224  return AVERROR(EINVAL);
225  }
226  s->bps = avctx->bits_per_coded_sample;
227  switch (s->bps) {
228  case 8:
229  avctx->sample_fmt = AV_SAMPLE_FMT_U8P;
230  break;
231  case 16:
232  avctx->sample_fmt = AV_SAMPLE_FMT_S16P;
233  break;
234  case 24:
235  avctx->sample_fmt = AV_SAMPLE_FMT_S32P;
236  break;
237  default:
238  avpriv_request_sample(avctx,
239  "%d bits per coded sample", s->bps);
240  return AVERROR_PATCHWELCOME;
241  }
242  s->avctx = avctx;
243  s->channels = avctx->channels;
244  s->fileversion = AV_RL16(avctx->extradata);
245  s->compression_level = AV_RL16(avctx->extradata + 2);
246  s->flags = AV_RL16(avctx->extradata + 4);
247 
248  av_log(avctx, AV_LOG_DEBUG, "Compression Level: %d - Flags: %d\n",
249  s->compression_level, s->flags);
250  if (s->compression_level % 1000 || s->compression_level > COMPRESSION_LEVEL_INSANE ||
251  !s->compression_level ||
252  (s->fileversion < 3930 && s->compression_level == COMPRESSION_LEVEL_INSANE)) {
253  av_log(avctx, AV_LOG_ERROR, "Incorrect compression level %d\n",
254  s->compression_level);
255  return AVERROR_INVALIDDATA;
256  }
257  s->fset = s->compression_level / 1000 - 1;
258  for (i = 0; i < APE_FILTER_LEVELS; i++) {
259  if (!ape_filter_orders[s->fset][i])
260  break;
261  FF_ALLOC_OR_GOTO(avctx, s->filterbuf[i],
262  (ape_filter_orders[s->fset][i] * 3 + HISTORY_SIZE) * 4,
263  filter_alloc_fail);
264  }
265 
266  if (s->fileversion < 3860) {
267  s->entropy_decode_mono = entropy_decode_mono_0000;
268  s->entropy_decode_stereo = entropy_decode_stereo_0000;
269  } else if (s->fileversion < 3900) {
270  s->entropy_decode_mono = entropy_decode_mono_3860;
271  s->entropy_decode_stereo = entropy_decode_stereo_3860;
272  } else if (s->fileversion < 3930) {
273  s->entropy_decode_mono = entropy_decode_mono_3900;
274  s->entropy_decode_stereo = entropy_decode_stereo_3900;
275  } else if (s->fileversion < 3990) {
276  s->entropy_decode_mono = entropy_decode_mono_3900;
277  s->entropy_decode_stereo = entropy_decode_stereo_3930;
278  } else {
279  s->entropy_decode_mono = entropy_decode_mono_3990;
280  s->entropy_decode_stereo = entropy_decode_stereo_3990;
281  }
282 
283  if (s->fileversion < 3930) {
284  s->predictor_decode_mono = predictor_decode_mono_3800;
285  s->predictor_decode_stereo = predictor_decode_stereo_3800;
286  } else if (s->fileversion < 3950) {
287  s->predictor_decode_mono = predictor_decode_mono_3930;
288  s->predictor_decode_stereo = predictor_decode_stereo_3930;
289  } else {
290  s->predictor_decode_mono = predictor_decode_mono_3950;
291  s->predictor_decode_stereo = predictor_decode_stereo_3950;
292  }
293 
294  ff_dsputil_init(&s->dsp, avctx);
295  avctx->channel_layout = (avctx->channels==2) ? AV_CH_LAYOUT_STEREO : AV_CH_LAYOUT_MONO;
296 
297  return 0;
298 filter_alloc_fail:
299  ape_decode_close(avctx);
300  return AVERROR(ENOMEM);
301 }
302 
303 /**
304  * @name APE range decoding functions
305  * @{
306  */
307 
308 #define CODE_BITS 32
309 #define TOP_VALUE ((unsigned int)1 << (CODE_BITS-1))
310 #define SHIFT_BITS (CODE_BITS - 9)
311 #define EXTRA_BITS ((CODE_BITS-2) % 8 + 1)
312 #define BOTTOM_VALUE (TOP_VALUE >> 8)
313 
314 /** Start the decoder */
315 static inline void range_start_decoding(APEContext *ctx)
316 {
317  ctx->rc.buffer = bytestream_get_byte(&ctx->ptr);
318  ctx->rc.low = ctx->rc.buffer >> (8 - EXTRA_BITS);
319  ctx->rc.range = (uint32_t) 1 << EXTRA_BITS;
320 }
321 
322 /** Perform normalization */
323 static inline void range_dec_normalize(APEContext *ctx)
324 {
325  while (ctx->rc.range <= BOTTOM_VALUE) {
326  ctx->rc.buffer <<= 8;
327  if(ctx->ptr < ctx->data_end) {
328  ctx->rc.buffer += *ctx->ptr;
329  ctx->ptr++;
330  } else {
331  ctx->error = 1;
332  }
333  ctx->rc.low = (ctx->rc.low << 8) | ((ctx->rc.buffer >> 1) & 0xFF);
334  ctx->rc.range <<= 8;
335  }
336 }
337 
338 /**
339  * Calculate culmulative frequency for next symbol. Does NO update!
340  * @param ctx decoder context
341  * @param tot_f is the total frequency or (code_value)1<<shift
342  * @return the culmulative frequency
343  */
344 static inline int range_decode_culfreq(APEContext *ctx, int tot_f)
345 {
346  range_dec_normalize(ctx);
347  ctx->rc.help = ctx->rc.range / tot_f;
348  return ctx->rc.low / ctx->rc.help;
349 }
350 
351 /**
352  * Decode value with given size in bits
353  * @param ctx decoder context
354  * @param shift number of bits to decode
355  */
356 static inline int range_decode_culshift(APEContext *ctx, int shift)
357 {
358  range_dec_normalize(ctx);
359  ctx->rc.help = ctx->rc.range >> shift;
360  return ctx->rc.low / ctx->rc.help;
361 }
362 
363 
364 /**
365  * Update decoding state
366  * @param ctx decoder context
367  * @param sy_f the interval length (frequency of the symbol)
368  * @param lt_f the lower end (frequency sum of < symbols)
369  */
370 static inline void range_decode_update(APEContext *ctx, int sy_f, int lt_f)
371 {
372  ctx->rc.low -= ctx->rc.help * lt_f;
373  ctx->rc.range = ctx->rc.help * sy_f;
374 }
375 
376 /** Decode n bits (n <= 16) without modelling */
377 static inline int range_decode_bits(APEContext *ctx, int n)
378 {
379  int sym = range_decode_culshift(ctx, n);
380  range_decode_update(ctx, 1, sym);
381  return sym;
382 }
383 
384 
385 #define MODEL_ELEMENTS 64
386 
387 /**
388  * Fixed probabilities for symbols in Monkey Audio version 3.97
389  */
390 static const uint16_t counts_3970[22] = {
391  0, 14824, 28224, 39348, 47855, 53994, 58171, 60926,
392  62682, 63786, 64463, 64878, 65126, 65276, 65365, 65419,
393  65450, 65469, 65480, 65487, 65491, 65493,
394 };
395 
396 /**
397  * Probability ranges for symbols in Monkey Audio version 3.97
398  */
399 static const uint16_t counts_diff_3970[21] = {
400  14824, 13400, 11124, 8507, 6139, 4177, 2755, 1756,
401  1104, 677, 415, 248, 150, 89, 54, 31,
402  19, 11, 7, 4, 2,
403 };
404 
405 /**
406  * Fixed probabilities for symbols in Monkey Audio version 3.98
407  */
408 static const uint16_t counts_3980[22] = {
409  0, 19578, 36160, 48417, 56323, 60899, 63265, 64435,
410  64971, 65232, 65351, 65416, 65447, 65466, 65476, 65482,
411  65485, 65488, 65490, 65491, 65492, 65493,
412 };
413 
414 /**
415  * Probability ranges for symbols in Monkey Audio version 3.98
416  */
417 static const uint16_t counts_diff_3980[21] = {
418  19578, 16582, 12257, 7906, 4576, 2366, 1170, 536,
419  261, 119, 65, 31, 19, 10, 6, 3,
420  3, 2, 1, 1, 1,
421 };
422 
423 /**
424  * Decode symbol
425  * @param ctx decoder context
426  * @param counts probability range start position
427  * @param counts_diff probability range widths
428  */
429 static inline int range_get_symbol(APEContext *ctx,
430  const uint16_t counts[],
431  const uint16_t counts_diff[])
432 {
433  int symbol, cf;
434 
435  cf = range_decode_culshift(ctx, 16);
436 
437  if(cf > 65492){
438  symbol= cf - 65535 + 63;
439  range_decode_update(ctx, 1, cf);
440  if(cf > 65535)
441  ctx->error=1;
442  return symbol;
443  }
444  /* figure out the symbol inefficiently; a binary search would be much better */
445  for (symbol = 0; counts[symbol + 1] <= cf; symbol++);
446 
447  range_decode_update(ctx, counts_diff[symbol], counts[symbol]);
448 
449  return symbol;
450 }
451 /** @} */ // group rangecoder
452 
453 static inline void update_rice(APERice *rice, unsigned int x)
454 {
455  int lim = rice->k ? (1 << (rice->k + 4)) : 0;
456  rice->ksum += ((x + 1) / 2) - ((rice->ksum + 16) >> 5);
457 
458  if (rice->ksum < lim)
459  rice->k--;
460  else if (rice->ksum >= (1 << (rice->k + 5)))
461  rice->k++;
462 }
463 
464 static inline int get_rice_ook(GetBitContext *gb, int k)
465 {
466  unsigned int x;
467 
468  x = get_unary(gb, 1, get_bits_left(gb));
469 
470  if (k)
471  x = (x << k) | get_bits(gb, k);
472 
473  return x;
474 }
475 
476 static inline int ape_decode_value_3860(APEContext *ctx, GetBitContext *gb,
477  APERice *rice)
478 {
479  unsigned int x, overflow;
480 
481  overflow = get_unary(gb, 1, get_bits_left(gb));
482 
483  if (ctx->fileversion > 3880) {
484  while (overflow >= 16) {
485  overflow -= 16;
486  rice->k += 4;
487  }
488  }
489 
490  if (!rice->k)
491  x = overflow;
492  else if(rice->k <= MIN_CACHE_BITS) {
493  x = (overflow << rice->k) + get_bits(gb, rice->k);
494  } else {
495  av_log(ctx->avctx, AV_LOG_ERROR, "Too many bits: %d\n", rice->k);
496  return AVERROR_INVALIDDATA;
497  }
498  rice->ksum += x - (rice->ksum + 8 >> 4);
499  if (rice->ksum < (rice->k ? 1 << (rice->k + 4) : 0))
500  rice->k--;
501  else if (rice->ksum >= (1 << (rice->k + 5)) && rice->k < 24)
502  rice->k++;
503 
504  /* Convert to signed */
505  if (x & 1)
506  return (x >> 1) + 1;
507  else
508  return -(x >> 1);
509 }
510 
511 static inline int ape_decode_value_3900(APEContext *ctx, APERice *rice)
512 {
513  unsigned int x, overflow;
514  int tmpk;
515 
516  overflow = range_get_symbol(ctx, counts_3970, counts_diff_3970);
517 
518  if (overflow == (MODEL_ELEMENTS - 1)) {
519  tmpk = range_decode_bits(ctx, 5);
520  overflow = 0;
521  } else
522  tmpk = (rice->k < 1) ? 0 : rice->k - 1;
523 
524  if (tmpk <= 16 || ctx->fileversion < 3910) {
525  if (tmpk > 23) {
526  av_log(ctx->avctx, AV_LOG_ERROR, "Too many bits: %d\n", tmpk);
527  return AVERROR_INVALIDDATA;
528  }
529  x = range_decode_bits(ctx, tmpk);
530  } else if (tmpk <= 32) {
531  x = range_decode_bits(ctx, 16);
532  x |= (range_decode_bits(ctx, tmpk - 16) << 16);
533  } else {
534  av_log(ctx->avctx, AV_LOG_ERROR, "Too many bits: %d\n", tmpk);
535  return AVERROR_INVALIDDATA;
536  }
537  x += overflow << tmpk;
538 
539  update_rice(rice, x);
540 
541  /* Convert to signed */
542  if (x & 1)
543  return (x >> 1) + 1;
544  else
545  return -(x >> 1);
546 }
547 
548 static inline int ape_decode_value_3990(APEContext *ctx, APERice *rice)
549 {
550  unsigned int x, overflow;
551  int base, pivot;
552 
553  pivot = rice->ksum >> 5;
554  if (pivot == 0)
555  pivot = 1;
556 
557  overflow = range_get_symbol(ctx, counts_3980, counts_diff_3980);
558 
559  if (overflow == (MODEL_ELEMENTS - 1)) {
560  overflow = range_decode_bits(ctx, 16) << 16;
561  overflow |= range_decode_bits(ctx, 16);
562  }
563 
564  if (pivot < 0x10000) {
565  base = range_decode_culfreq(ctx, pivot);
566  range_decode_update(ctx, 1, base);
567  } else {
568  int base_hi = pivot, base_lo;
569  int bbits = 0;
570 
571  while (base_hi & ~0xFFFF) {
572  base_hi >>= 1;
573  bbits++;
574  }
575  base_hi = range_decode_culfreq(ctx, base_hi + 1);
576  range_decode_update(ctx, 1, base_hi);
577  base_lo = range_decode_culfreq(ctx, 1 << bbits);
578  range_decode_update(ctx, 1, base_lo);
579 
580  base = (base_hi << bbits) + base_lo;
581  }
582 
583  x = base + overflow * pivot;
584 
585  update_rice(rice, x);
586 
587  /* Convert to signed */
588  if (x & 1)
589  return (x >> 1) + 1;
590  else
591  return -(x >> 1);
592 }
593 
594 static void decode_array_0000(APEContext *ctx, GetBitContext *gb,
595  int32_t *out, APERice *rice, int blockstodecode)
596 {
597  int i;
598  int ksummax, ksummin;
599 
600  rice->ksum = 0;
601  for (i = 0; i < 5; i++) {
602  out[i] = get_rice_ook(&ctx->gb, 10);
603  rice->ksum += out[i];
604  }
605  rice->k = av_log2(rice->ksum / 10) + 1;
606  for (; i < 64; i++) {
607  out[i] = get_rice_ook(&ctx->gb, rice->k);
608  rice->ksum += out[i];
609  rice->k = av_log2(rice->ksum / ((i + 1) * 2)) + 1;
610  }
611  ksummax = 1 << rice->k + 7;
612  ksummin = rice->k ? (1 << rice->k + 6) : 0;
613  for (; i < blockstodecode; i++) {
614  out[i] = get_rice_ook(&ctx->gb, rice->k);
615  rice->ksum += out[i] - out[i - 64];
616  while (rice->ksum < ksummin) {
617  rice->k--;
618  ksummin = rice->k ? ksummin >> 1 : 0;
619  ksummax >>= 1;
620  }
621  while (rice->ksum >= ksummax) {
622  rice->k++;
623  if (rice->k > 24)
624  return;
625  ksummax <<= 1;
626  ksummin = ksummin ? ksummin << 1 : 128;
627  }
628  }
629 
630  for (i = 0; i < blockstodecode; i++) {
631  if (out[i] & 1)
632  out[i] = (out[i] >> 1) + 1;
633  else
634  out[i] = -(out[i] >> 1);
635  }
636 }
637 
638 static void entropy_decode_mono_0000(APEContext *ctx, int blockstodecode)
639 {
640  decode_array_0000(ctx, &ctx->gb, ctx->decoded[0], &ctx->riceY,
641  blockstodecode);
642 }
643 
644 static void entropy_decode_stereo_0000(APEContext *ctx, int blockstodecode)
645 {
646  decode_array_0000(ctx, &ctx->gb, ctx->decoded[0], &ctx->riceY,
647  blockstodecode);
648  decode_array_0000(ctx, &ctx->gb, ctx->decoded[1], &ctx->riceX,
649  blockstodecode);
650 }
651 
652 static void entropy_decode_mono_3860(APEContext *ctx, int blockstodecode)
653 {
654  int32_t *decoded0 = ctx->decoded[0];
655 
656  while (blockstodecode--)
657  *decoded0++ = ape_decode_value_3860(ctx, &ctx->gb, &ctx->riceY);
658 }
659 
660 static void entropy_decode_stereo_3860(APEContext *ctx, int blockstodecode)
661 {
662  int32_t *decoded0 = ctx->decoded[0];
663  int32_t *decoded1 = ctx->decoded[1];
664  int blocks = blockstodecode;
665 
666  while (blockstodecode--)
667  *decoded0++ = ape_decode_value_3860(ctx, &ctx->gb, &ctx->riceY);
668  while (blocks--)
669  *decoded1++ = ape_decode_value_3860(ctx, &ctx->gb, &ctx->riceX);
670 }
671 
672 static void entropy_decode_mono_3900(APEContext *ctx, int blockstodecode)
673 {
674  int32_t *decoded0 = ctx->decoded[0];
675 
676  while (blockstodecode--)
677  *decoded0++ = ape_decode_value_3900(ctx, &ctx->riceY);
678 }
679 
680 static void entropy_decode_stereo_3900(APEContext *ctx, int blockstodecode)
681 {
682  int32_t *decoded0 = ctx->decoded[0];
683  int32_t *decoded1 = ctx->decoded[1];
684  int blocks = blockstodecode;
685 
686  while (blockstodecode--)
687  *decoded0++ = ape_decode_value_3900(ctx, &ctx->riceY);
688  range_dec_normalize(ctx);
689  // because of some implementation peculiarities we need to backpedal here
690  ctx->ptr -= 1;
691  range_start_decoding(ctx);
692  while (blocks--)
693  *decoded1++ = ape_decode_value_3900(ctx, &ctx->riceX);
694 }
695 
696 static void entropy_decode_stereo_3930(APEContext *ctx, int blockstodecode)
697 {
698  int32_t *decoded0 = ctx->decoded[0];
699  int32_t *decoded1 = ctx->decoded[1];
700 
701  while (blockstodecode--) {
702  *decoded0++ = ape_decode_value_3900(ctx, &ctx->riceY);
703  *decoded1++ = ape_decode_value_3900(ctx, &ctx->riceX);
704  }
705 }
706 
707 static void entropy_decode_mono_3990(APEContext *ctx, int blockstodecode)
708 {
709  int32_t *decoded0 = ctx->decoded[0];
710 
711  while (blockstodecode--)
712  *decoded0++ = ape_decode_value_3990(ctx, &ctx->riceY);
713 }
714 
715 static void entropy_decode_stereo_3990(APEContext *ctx, int blockstodecode)
716 {
717  int32_t *decoded0 = ctx->decoded[0];
718  int32_t *decoded1 = ctx->decoded[1];
719 
720  while (blockstodecode--) {
721  *decoded0++ = ape_decode_value_3990(ctx, &ctx->riceY);
722  *decoded1++ = ape_decode_value_3990(ctx, &ctx->riceX);
723  }
724 }
725 
726 static int init_entropy_decoder(APEContext *ctx)
727 {
728  /* Read the CRC */
729  if (ctx->fileversion >= 3900) {
730  if (ctx->data_end - ctx->ptr < 6)
731  return AVERROR_INVALIDDATA;
732  ctx->CRC = bytestream_get_be32(&ctx->ptr);
733  } else {
734  ctx->CRC = get_bits_long(&ctx->gb, 32);
735  }
736 
737  /* Read the frame flags if they exist */
738  ctx->frameflags = 0;
739  if ((ctx->fileversion > 3820) && (ctx->CRC & 0x80000000)) {
740  ctx->CRC &= ~0x80000000;
741 
742  if (ctx->data_end - ctx->ptr < 6)
743  return AVERROR_INVALIDDATA;
744  ctx->frameflags = bytestream_get_be32(&ctx->ptr);
745  }
746 
747  /* Initialize the rice structs */
748  ctx->riceX.k = 10;
749  ctx->riceX.ksum = (1 << ctx->riceX.k) * 16;
750  ctx->riceY.k = 10;
751  ctx->riceY.ksum = (1 << ctx->riceY.k) * 16;
752 
753  if (ctx->fileversion >= 3900) {
754  /* The first 8 bits of input are ignored. */
755  ctx->ptr++;
756 
757  range_start_decoding(ctx);
758  }
759 
760  return 0;
761 }
762 
763 static const int32_t initial_coeffs_fast_3320[1] = {
764  375,
765 };
766 
767 static const int32_t initial_coeffs_a_3800[3] = {
768  64, 115, 64,
769 };
770 
771 static const int32_t initial_coeffs_b_3800[2] = {
772  740, 0
773 };
774 
775 static const int32_t initial_coeffs_3930[4] = {
776  360, 317, -109, 98
777 };
778 
779 static void init_predictor_decoder(APEContext *ctx)
780 {
781  APEPredictor *p = &ctx->predictor;
782 
783  /* Zero the history buffers */
784  memset(p->historybuffer, 0, PREDICTOR_SIZE * sizeof(*p->historybuffer));
785  p->buf = p->historybuffer;
786 
787  /* Initialize and zero the coefficients */
788  if (ctx->fileversion < 3930) {
789  if (ctx->compression_level == COMPRESSION_LEVEL_FAST) {
790  memcpy(p->coeffsA[0], initial_coeffs_fast_3320,
791  sizeof(initial_coeffs_fast_3320));
792  memcpy(p->coeffsA[1], initial_coeffs_fast_3320,
793  sizeof(initial_coeffs_fast_3320));
794  } else {
795  memcpy(p->coeffsA[0], initial_coeffs_a_3800,
796  sizeof(initial_coeffs_a_3800));
797  memcpy(p->coeffsA[1], initial_coeffs_a_3800,
798  sizeof(initial_coeffs_a_3800));
799  }
800  } else {
801  memcpy(p->coeffsA[0], initial_coeffs_3930, sizeof(initial_coeffs_3930));
802  memcpy(p->coeffsA[1], initial_coeffs_3930, sizeof(initial_coeffs_3930));
803  }
804  memset(p->coeffsB, 0, sizeof(p->coeffsB));
805  if (ctx->fileversion < 3930) {
806  memcpy(p->coeffsB[0], initial_coeffs_b_3800,
807  sizeof(initial_coeffs_b_3800));
808  memcpy(p->coeffsB[1], initial_coeffs_b_3800,
809  sizeof(initial_coeffs_b_3800));
810  }
811 
812  p->filterA[0] = p->filterA[1] = 0;
813  p->filterB[0] = p->filterB[1] = 0;
814  p->lastA[0] = p->lastA[1] = 0;
815 
816  p->sample_pos = 0;
817 }
818 
819 /** Get inverse sign of integer (-1 for positive, 1 for negative and 0 for zero) */
820 static inline int APESIGN(int32_t x) {
821  return (x < 0) - (x > 0);
822 }
823 
824 static av_always_inline int filter_fast_3320(APEPredictor *p,
825  const int decoded, const int filter,
826  const int delayA)
827 {
828  int32_t predictionA;
829 
830  p->buf[delayA] = p->lastA[filter];
831  if (p->sample_pos < 3) {
832  p->lastA[filter] = decoded;
833  p->filterA[filter] = decoded;
834  return decoded;
835  }
836 
837  predictionA = p->buf[delayA] * 2 - p->buf[delayA - 1];
838  p->lastA[filter] = decoded + (predictionA * p->coeffsA[filter][0] >> 9);
839 
840  if ((decoded ^ predictionA) > 0)
841  p->coeffsA[filter][0]++;
842  else
843  p->coeffsA[filter][0]--;
844 
845  p->filterA[filter] += p->lastA[filter];
846 
847  return p->filterA[filter];
848 }
849 
850 static av_always_inline int filter_3800(APEPredictor *p,
851  const int decoded, const int filter,
852  const int delayA, const int delayB,
853  const int start, const int shift)
854 {
855  int32_t predictionA, predictionB, sign;
856  int32_t d0, d1, d2, d3, d4;
857 
858  p->buf[delayA] = p->lastA[filter];
859  p->buf[delayB] = p->filterB[filter];
860  if (p->sample_pos < start) {
861  predictionA = decoded + p->filterA[filter];
862  p->lastA[filter] = decoded;
863  p->filterB[filter] = decoded;
864  p->filterA[filter] = predictionA;
865  return predictionA;
866  }
867  d2 = p->buf[delayA];
868  d1 = (p->buf[delayA] - p->buf[delayA - 1]) << 1;
869  d0 = p->buf[delayA] + ((p->buf[delayA - 2] - p->buf[delayA - 1]) << 3);
870  d3 = p->buf[delayB] * 2 - p->buf[delayB - 1];
871  d4 = p->buf[delayB];
872 
873  predictionA = d0 * p->coeffsA[filter][0] +
874  d1 * p->coeffsA[filter][1] +
875  d2 * p->coeffsA[filter][2];
876 
877  sign = APESIGN(decoded);
878  p->coeffsA[filter][0] += (((d0 >> 30) & 2) - 1) * sign;
879  p->coeffsA[filter][1] += (((d1 >> 28) & 8) - 4) * sign;
880  p->coeffsA[filter][2] += (((d2 >> 28) & 8) - 4) * sign;
881 
882  predictionB = d3 * p->coeffsB[filter][0] -
883  d4 * p->coeffsB[filter][1];
884  p->lastA[filter] = decoded + (predictionA >> 11);
885  sign = APESIGN(p->lastA[filter]);
886  p->coeffsB[filter][0] += (((d3 >> 29) & 4) - 2) * sign;
887  p->coeffsB[filter][1] -= (((d4 >> 30) & 2) - 1) * sign;
888 
889  p->filterB[filter] = p->lastA[filter] + (predictionB >> shift);
890  p->filterA[filter] = p->filterB[filter] + ((p->filterA[filter] * 31) >> 5);
891 
892  return p->filterA[filter];
893 }
894 
895 static void long_filter_high_3800(int32_t *buffer, int order, int shift,
896  int32_t *coeffs, int32_t *delay, int length)
897 {
898  int i, j;
899  int32_t dotprod, sign;
900 
901  memset(coeffs, 0, order * sizeof(*coeffs));
902  for (i = 0; i < order; i++)
903  delay[i] = buffer[i];
904  for (i = order; i < length; i++) {
905  dotprod = 0;
906  sign = APESIGN(buffer[i]);
907  for (j = 0; j < order; j++) {
908  dotprod += delay[j] * coeffs[j];
909  coeffs[j] -= (((delay[j] >> 30) & 2) - 1) * sign;
910  }
911  buffer[i] -= dotprod >> shift;
912  for (j = 0; j < order - 1; j++)
913  delay[j] = delay[j + 1];
914  delay[order - 1] = buffer[i];
915  }
916 }
917 
918 static void long_filter_ehigh_3830(int32_t *buffer, int length)
919 {
920  int i, j;
921  int32_t dotprod, sign;
922  int32_t coeffs[8], delay[8];
923 
924  memset(coeffs, 0, sizeof(coeffs));
925  memset(delay, 0, sizeof(delay));
926  for (i = 0; i < length; i++) {
927  dotprod = 0;
928  sign = APESIGN(buffer[i]);
929  for (j = 7; j >= 0; j--) {
930  dotprod += delay[j] * coeffs[j];
931  coeffs[j] -= (((delay[j] >> 30) & 2) - 1) * sign;
932  }
933  for (j = 7; j > 0; j--)
934  delay[j] = delay[j - 1];
935  delay[0] = buffer[i];
936  buffer[i] -= dotprod >> 9;
937  }
938 }
939 
940 static void predictor_decode_stereo_3800(APEContext *ctx, int count)
941 {
942  APEPredictor *p = &ctx->predictor;
943  int32_t *decoded0 = ctx->decoded[0];
944  int32_t *decoded1 = ctx->decoded[1];
945  int32_t coeffs[256], delay[256];
946  int start = 4, shift = 10;
947 
948  if (ctx->compression_level == COMPRESSION_LEVEL_HIGH) {
949  start = 16;
950  long_filter_high_3800(decoded0, 16, 9, coeffs, delay, count);
951  long_filter_high_3800(decoded1, 16, 9, coeffs, delay, count);
952  } else if (ctx->compression_level == COMPRESSION_LEVEL_EXTRA_HIGH) {
953  int order = 128, shift2 = 11;
954 
955  if (ctx->fileversion >= 3830) {
956  order <<= 1;
957  shift++;
958  shift2++;
959  long_filter_ehigh_3830(decoded0 + order, count - order);
960  long_filter_ehigh_3830(decoded1 + order, count - order);
961  }
962  start = order;
963  long_filter_high_3800(decoded0, order, shift2, coeffs, delay, count);
964  long_filter_high_3800(decoded1, order, shift2, coeffs, delay, count);
965  }
966 
967  while (count--) {
968  int X = *decoded0, Y = *decoded1;
969  if (ctx->compression_level == COMPRESSION_LEVEL_FAST) {
970  *decoded0 = filter_fast_3320(p, Y, 0, YDELAYA);
971  decoded0++;
972  *decoded1 = filter_fast_3320(p, X, 1, XDELAYA);
973  decoded1++;
974  } else {
975  *decoded0 = filter_3800(p, Y, 0, YDELAYA, YDELAYB,
976  start, shift);
977  decoded0++;
978  *decoded1 = filter_3800(p, X, 1, XDELAYA, XDELAYB,
979  start, shift);
980  decoded1++;
981  }
982 
983  /* Combined */
984  p->buf++;
985  p->sample_pos++;
986 
987  /* Have we filled the history buffer? */
988  if (p->buf == p->historybuffer + HISTORY_SIZE) {
989  memmove(p->historybuffer, p->buf,
990  PREDICTOR_SIZE * sizeof(*p->historybuffer));
991  p->buf = p->historybuffer;
992  }
993  }
994 }
995 
996 static void predictor_decode_mono_3800(APEContext *ctx, int count)
997 {
998  APEPredictor *p = &ctx->predictor;
999  int32_t *decoded0 = ctx->decoded[0];
1000  int32_t coeffs[256], delay[256];
1001  int start = 4, shift = 10;
1002 
1003  if (ctx->compression_level == COMPRESSION_LEVEL_HIGH) {
1004  start = 16;
1005  long_filter_high_3800(decoded0, 16, 9, coeffs, delay, count);
1006  } else if (ctx->compression_level == COMPRESSION_LEVEL_EXTRA_HIGH) {
1007  int order = 128, shift2 = 11;
1008 
1009  if (ctx->fileversion >= 3830) {
1010  order <<= 1;
1011  shift++;
1012  shift2++;
1013  long_filter_ehigh_3830(decoded0 + order, count - order);
1014  }
1015  start = order;
1016  long_filter_high_3800(decoded0, order, shift2, coeffs, delay, count);
1017  }
1018 
1019  while (count--) {
1020  if (ctx->compression_level == COMPRESSION_LEVEL_FAST) {
1021  *decoded0 = filter_fast_3320(p, *decoded0, 0, YDELAYA);
1022  decoded0++;
1023  } else {
1024  *decoded0 = filter_3800(p, *decoded0, 0, YDELAYA, YDELAYB,
1025  start, shift);
1026  decoded0++;
1027  }
1028 
1029  /* Combined */
1030  p->buf++;
1031  p->sample_pos++;
1032 
1033  /* Have we filled the history buffer? */
1034  if (p->buf == p->historybuffer + HISTORY_SIZE) {
1035  memmove(p->historybuffer, p->buf,
1036  PREDICTOR_SIZE * sizeof(*p->historybuffer));
1037  p->buf = p->historybuffer;
1038  }
1039  }
1040 }
1041 
1042 static av_always_inline int predictor_update_3930(APEPredictor *p,
1043  const int decoded, const int filter,
1044  const int delayA)
1045 {
1046  int32_t predictionA, sign;
1047  int32_t d0, d1, d2, d3;
1048 
1049  p->buf[delayA] = p->lastA[filter];
1050  d0 = p->buf[delayA ];
1051  d1 = p->buf[delayA ] - p->buf[delayA - 1];
1052  d2 = p->buf[delayA - 1] - p->buf[delayA - 2];
1053  d3 = p->buf[delayA - 2] - p->buf[delayA - 3];
1054 
1055  predictionA = d0 * p->coeffsA[filter][0] +
1056  d1 * p->coeffsA[filter][1] +
1057  d2 * p->coeffsA[filter][2] +
1058  d3 * p->coeffsA[filter][3];
1059 
1060  p->lastA[filter] = decoded + (predictionA >> 9);
1061  p->filterA[filter] = p->lastA[filter] + ((p->filterA[filter] * 31) >> 5);
1062 
1063  sign = APESIGN(decoded);
1064  p->coeffsA[filter][0] += ((d0 < 0) * 2 - 1) * sign;
1065  p->coeffsA[filter][1] += ((d1 < 0) * 2 - 1) * sign;
1066  p->coeffsA[filter][2] += ((d2 < 0) * 2 - 1) * sign;
1067  p->coeffsA[filter][3] += ((d3 < 0) * 2 - 1) * sign;
1068 
1069  return p->filterA[filter];
1070 }
1071 
1072 static void predictor_decode_stereo_3930(APEContext *ctx, int count)
1073 {
1074  APEPredictor *p = &ctx->predictor;
1075  int32_t *decoded0 = ctx->decoded[0];
1076  int32_t *decoded1 = ctx->decoded[1];
1077 
1078  ape_apply_filters(ctx, ctx->decoded[0], ctx->decoded[1], count);
1079 
1080  while (count--) {
1081  /* Predictor Y */
1082  int Y = *decoded1, X = *decoded0;
1083  *decoded0 = predictor_update_3930(p, Y, 0, YDELAYA);
1084  decoded0++;
1085  *decoded1 = predictor_update_3930(p, X, 1, XDELAYA);
1086  decoded1++;
1087 
1088  /* Combined */
1089  p->buf++;
1090 
1091  /* Have we filled the history buffer? */
1092  if (p->buf == p->historybuffer + HISTORY_SIZE) {
1093  memmove(p->historybuffer, p->buf,
1094  PREDICTOR_SIZE * sizeof(*p->historybuffer));
1095  p->buf = p->historybuffer;
1096  }
1097  }
1098 }
1099 
1100 static void predictor_decode_mono_3930(APEContext *ctx, int count)
1101 {
1102  APEPredictor *p = &ctx->predictor;
1103  int32_t *decoded0 = ctx->decoded[0];
1104 
1105  ape_apply_filters(ctx, ctx->decoded[0], NULL, count);
1106 
1107  while (count--) {
1108  *decoded0 = predictor_update_3930(p, *decoded0, 0, YDELAYA);
1109  decoded0++;
1110 
1111  p->buf++;
1112 
1113  /* Have we filled the history buffer? */
1114  if (p->buf == p->historybuffer + HISTORY_SIZE) {
1115  memmove(p->historybuffer, p->buf,
1116  PREDICTOR_SIZE * sizeof(*p->historybuffer));
1117  p->buf = p->historybuffer;
1118  }
1119  }
1120 }
1121 
1122 static av_always_inline int predictor_update_filter(APEPredictor *p,
1123  const int decoded, const int filter,
1124  const int delayA, const int delayB,
1125  const int adaptA, const int adaptB)
1126 {
1127  int32_t predictionA, predictionB, sign;
1128 
1129  p->buf[delayA] = p->lastA[filter];
1130  p->buf[adaptA] = APESIGN(p->buf[delayA]);
1131  p->buf[delayA - 1] = p->buf[delayA] - p->buf[delayA - 1];
1132  p->buf[adaptA - 1] = APESIGN(p->buf[delayA - 1]);
1133 
1134  predictionA = p->buf[delayA ] * p->coeffsA[filter][0] +
1135  p->buf[delayA - 1] * p->coeffsA[filter][1] +
1136  p->buf[delayA - 2] * p->coeffsA[filter][2] +
1137  p->buf[delayA - 3] * p->coeffsA[filter][3];
1138 
1139  /* Apply a scaled first-order filter compression */
1140  p->buf[delayB] = p->filterA[filter ^ 1] - ((p->filterB[filter] * 31) >> 5);
1141  p->buf[adaptB] = APESIGN(p->buf[delayB]);
1142  p->buf[delayB - 1] = p->buf[delayB] - p->buf[delayB - 1];
1143  p->buf[adaptB - 1] = APESIGN(p->buf[delayB - 1]);
1144  p->filterB[filter] = p->filterA[filter ^ 1];
1145 
1146  predictionB = p->buf[delayB ] * p->coeffsB[filter][0] +
1147  p->buf[delayB - 1] * p->coeffsB[filter][1] +
1148  p->buf[delayB - 2] * p->coeffsB[filter][2] +
1149  p->buf[delayB - 3] * p->coeffsB[filter][3] +
1150  p->buf[delayB - 4] * p->coeffsB[filter][4];
1151 
1152  p->lastA[filter] = decoded + ((predictionA + (predictionB >> 1)) >> 10);
1153  p->filterA[filter] = p->lastA[filter] + ((p->filterA[filter] * 31) >> 5);
1154 
1155  sign = APESIGN(decoded);
1156  p->coeffsA[filter][0] += p->buf[adaptA ] * sign;
1157  p->coeffsA[filter][1] += p->buf[adaptA - 1] * sign;
1158  p->coeffsA[filter][2] += p->buf[adaptA - 2] * sign;
1159  p->coeffsA[filter][3] += p->buf[adaptA - 3] * sign;
1160  p->coeffsB[filter][0] += p->buf[adaptB ] * sign;
1161  p->coeffsB[filter][1] += p->buf[adaptB - 1] * sign;
1162  p->coeffsB[filter][2] += p->buf[adaptB - 2] * sign;
1163  p->coeffsB[filter][3] += p->buf[adaptB - 3] * sign;
1164  p->coeffsB[filter][4] += p->buf[adaptB - 4] * sign;
1165 
1166  return p->filterA[filter];
1167 }
1168 
1169 static void predictor_decode_stereo_3950(APEContext *ctx, int count)
1170 {
1171  APEPredictor *p = &ctx->predictor;
1172  int32_t *decoded0 = ctx->decoded[0];
1173  int32_t *decoded1 = ctx->decoded[1];
1174 
1175  ape_apply_filters(ctx, ctx->decoded[0], ctx->decoded[1], count);
1176 
1177  while (count--) {
1178  /* Predictor Y */
1179  *decoded0 = predictor_update_filter(p, *decoded0, 0, YDELAYA, YDELAYB,
1180  YADAPTCOEFFSA, YADAPTCOEFFSB);
1181  decoded0++;
1182  *decoded1 = predictor_update_filter(p, *decoded1, 1, XDELAYA, XDELAYB,
1183  XADAPTCOEFFSA, XADAPTCOEFFSB);
1184  decoded1++;
1185 
1186  /* Combined */
1187  p->buf++;
1188 
1189  /* Have we filled the history buffer? */
1190  if (p->buf == p->historybuffer + HISTORY_SIZE) {
1191  memmove(p->historybuffer, p->buf,
1192  PREDICTOR_SIZE * sizeof(*p->historybuffer));
1193  p->buf = p->historybuffer;
1194  }
1195  }
1196 }
1197 
1198 static void predictor_decode_mono_3950(APEContext *ctx, int count)
1199 {
1200  APEPredictor *p = &ctx->predictor;
1201  int32_t *decoded0 = ctx->decoded[0];
1202  int32_t predictionA, currentA, A, sign;
1203 
1204  ape_apply_filters(ctx, ctx->decoded[0], NULL, count);
1205 
1206  currentA = p->lastA[0];
1207 
1208  while (count--) {
1209  A = *decoded0;
1210 
1211  p->buf[YDELAYA] = currentA;
1212  p->buf[YDELAYA - 1] = p->buf[YDELAYA] - p->buf[YDELAYA - 1];
1213 
1214  predictionA = p->buf[YDELAYA ] * p->coeffsA[0][0] +
1215  p->buf[YDELAYA - 1] * p->coeffsA[0][1] +
1216  p->buf[YDELAYA - 2] * p->coeffsA[0][2] +
1217  p->buf[YDELAYA - 3] * p->coeffsA[0][3];
1218 
1219  currentA = A + (predictionA >> 10);
1220 
1221  p->buf[YADAPTCOEFFSA] = APESIGN(p->buf[YDELAYA ]);
1222  p->buf[YADAPTCOEFFSA - 1] = APESIGN(p->buf[YDELAYA - 1]);
1223 
1224  sign = APESIGN(A);
1225  p->coeffsA[0][0] += p->buf[YADAPTCOEFFSA ] * sign;
1226  p->coeffsA[0][1] += p->buf[YADAPTCOEFFSA - 1] * sign;
1227  p->coeffsA[0][2] += p->buf[YADAPTCOEFFSA - 2] * sign;
1228  p->coeffsA[0][3] += p->buf[YADAPTCOEFFSA - 3] * sign;
1229 
1230  p->buf++;
1231 
1232  /* Have we filled the history buffer? */
1233  if (p->buf == p->historybuffer + HISTORY_SIZE) {
1234  memmove(p->historybuffer, p->buf,
1235  PREDICTOR_SIZE * sizeof(*p->historybuffer));
1236  p->buf = p->historybuffer;
1237  }
1238 
1239  p->filterA[0] = currentA + ((p->filterA[0] * 31) >> 5);
1240  *(decoded0++) = p->filterA[0];
1241  }
1242 
1243  p->lastA[0] = currentA;
1244 }
1245 
1246 static void do_init_filter(APEFilter *f, int16_t *buf, int order)
1247 {
1248  f->coeffs = buf;
1249  f->historybuffer = buf + order;
1250  f->delay = f->historybuffer + order * 2;
1251  f->adaptcoeffs = f->historybuffer + order;
1252 
1253  memset(f->historybuffer, 0, (order * 2) * sizeof(*f->historybuffer));
1254  memset(f->coeffs, 0, order * sizeof(*f->coeffs));
1255  f->avg = 0;
1256 }
1257 
1258 static void init_filter(APEContext *ctx, APEFilter *f, int16_t *buf, int order)
1259 {
1260  do_init_filter(&f[0], buf, order);
1261  do_init_filter(&f[1], buf + order * 3 + HISTORY_SIZE, order);
1262 }
1263 
1264 static void do_apply_filter(APEContext *ctx, int version, APEFilter *f,
1265  int32_t *data, int count, int order, int fracbits)
1266 {
1267  int res;
1268  int absres;
1269 
1270  while (count--) {
1271  /* round fixedpoint scalar product */
1272  res = ctx->dsp.scalarproduct_and_madd_int16(f->coeffs, f->delay - order,
1273  f->adaptcoeffs - order,
1274  order, APESIGN(*data));
1275  res = (res + (1 << (fracbits - 1))) >> fracbits;
1276  res += *data;
1277  *data++ = res;
1278 
1279  /* Update the output history */
1280  *f->delay++ = av_clip_int16(res);
1281 
1282  if (version < 3980) {
1283  /* Version ??? to < 3.98 files (untested) */
1284  f->adaptcoeffs[0] = (res == 0) ? 0 : ((res >> 28) & 8) - 4;
1285  f->adaptcoeffs[-4] >>= 1;
1286  f->adaptcoeffs[-8] >>= 1;
1287  } else {
1288  /* Version 3.98 and later files */
1289 
1290  /* Update the adaption coefficients */
1291  absres = FFABS(res);
1292  if (absres)
1293  *f->adaptcoeffs = ((res & (-1<<31)) ^ (-1<<30)) >>
1294  (25 + (absres <= f->avg*3) + (absres <= f->avg*4/3));
1295  else
1296  *f->adaptcoeffs = 0;
1297 
1298  f->avg += (absres - f->avg) / 16;
1299 
1300  f->adaptcoeffs[-1] >>= 1;
1301  f->adaptcoeffs[-2] >>= 1;
1302  f->adaptcoeffs[-8] >>= 1;
1303  }
1304 
1305  f->adaptcoeffs++;
1306 
1307  /* Have we filled the history buffer? */
1308  if (f->delay == f->historybuffer + HISTORY_SIZE + (order * 2)) {
1309  memmove(f->historybuffer, f->delay - (order * 2),
1310  (order * 2) * sizeof(*f->historybuffer));
1311  f->delay = f->historybuffer + order * 2;
1312  f->adaptcoeffs = f->historybuffer + order;
1313  }
1314  }
1315 }
1316 
1317 static void apply_filter(APEContext *ctx, APEFilter *f,
1318  int32_t *data0, int32_t *data1,
1319  int count, int order, int fracbits)
1320 {
1321  do_apply_filter(ctx, ctx->fileversion, &f[0], data0, count, order, fracbits);
1322  if (data1)
1323  do_apply_filter(ctx, ctx->fileversion, &f[1], data1, count, order, fracbits);
1324 }
1325 
1326 static void ape_apply_filters(APEContext *ctx, int32_t *decoded0,
1327  int32_t *decoded1, int count)
1328 {
1329  int i;
1330 
1331  for (i = 0; i < APE_FILTER_LEVELS; i++) {
1332  if (!ape_filter_orders[ctx->fset][i])
1333  break;
1334  apply_filter(ctx, ctx->filters[i], decoded0, decoded1, count,
1335  ape_filter_orders[ctx->fset][i],
1336  ape_filter_fracbits[ctx->fset][i]);
1337  }
1338 }
1339 
1340 static int init_frame_decoder(APEContext *ctx)
1341 {
1342  int i, ret;
1343  if ((ret = init_entropy_decoder(ctx)) < 0)
1344  return ret;
1345  init_predictor_decoder(ctx);
1346 
1347  for (i = 0; i < APE_FILTER_LEVELS; i++) {
1348  if (!ape_filter_orders[ctx->fset][i])
1349  break;
1350  init_filter(ctx, ctx->filters[i], ctx->filterbuf[i],
1351  ape_filter_orders[ctx->fset][i]);
1352  }
1353  return 0;
1354 }
1355 
1356 static void ape_unpack_mono(APEContext *ctx, int count)
1357 {
1358  if (ctx->frameflags & APE_FRAMECODE_STEREO_SILENCE) {
1359  /* We are pure silence, so we're done. */
1360  av_log(ctx->avctx, AV_LOG_DEBUG, "pure silence mono\n");
1361  return;
1362  }
1363 
1364  ctx->entropy_decode_mono(ctx, count);
1365 
1366  /* Now apply the predictor decoding */
1367  ctx->predictor_decode_mono(ctx, count);
1368 
1369  /* Pseudo-stereo - just copy left channel to right channel */
1370  if (ctx->channels == 2) {
1371  memcpy(ctx->decoded[1], ctx->decoded[0], count * sizeof(*ctx->decoded[1]));
1372  }
1373 }
1374 
1375 static void ape_unpack_stereo(APEContext *ctx, int count)
1376 {
1377  int32_t left, right;
1378  int32_t *decoded0 = ctx->decoded[0];
1379  int32_t *decoded1 = ctx->decoded[1];
1380 
1381  if (ctx->frameflags & APE_FRAMECODE_STEREO_SILENCE) {
1382  /* We are pure silence, so we're done. */
1383  av_log(ctx->avctx, AV_LOG_DEBUG, "pure silence stereo\n");
1384  return;
1385  }
1386 
1387  ctx->entropy_decode_stereo(ctx, count);
1388 
1389  /* Now apply the predictor decoding */
1390  ctx->predictor_decode_stereo(ctx, count);
1391 
1392  /* Decorrelate and scale to output depth */
1393  while (count--) {
1394  left = *decoded1 - (*decoded0 / 2);
1395  right = left + *decoded0;
1396 
1397  *(decoded0++) = left;
1398  *(decoded1++) = right;
1399  }
1400 }
1401 
1402 static int ape_decode_frame(AVCodecContext *avctx, void *data,
1403  int *got_frame_ptr, AVPacket *avpkt)
1404 {
1405  AVFrame *frame = data;
1406  const uint8_t *buf = avpkt->data;
1407  APEContext *s = avctx->priv_data;
1408  uint8_t *sample8;
1409  int16_t *sample16;
1410  int32_t *sample24;
1411  int i, ch, ret;
1412  int blockstodecode;
1413 
1414  /* this should never be negative, but bad things will happen if it is, so
1415  check it just to make sure. */
1416  av_assert0(s->samples >= 0);
1417 
1418  if(!s->samples){
1419  uint32_t nblocks, offset;
1420  int buf_size;
1421 
1422  if (!avpkt->size) {
1423  *got_frame_ptr = 0;
1424  return 0;
1425  }
1426  if (avpkt->size < 8) {
1427  av_log(avctx, AV_LOG_ERROR, "Packet is too small\n");
1428  return AVERROR_INVALIDDATA;
1429  }
1430  buf_size = avpkt->size & ~3;
1431  if (buf_size != avpkt->size) {
1432  av_log(avctx, AV_LOG_WARNING, "packet size is not a multiple of 4. "
1433  "extra bytes at the end will be skipped.\n");
1434  }
1435  if (s->fileversion < 3950) // previous versions overread two bytes
1436  buf_size += 2;
1437  av_fast_malloc(&s->data, &s->data_size, buf_size);
1438  if (!s->data)
1439  return AVERROR(ENOMEM);
1440  s->dsp.bswap_buf((uint32_t*)s->data, (const uint32_t*)buf, buf_size >> 2);
1441  memset(s->data + (buf_size & ~3), 0, buf_size & 3);
1442  s->ptr = s->data;
1443  s->data_end = s->data + buf_size;
1444 
1445  nblocks = bytestream_get_be32(&s->ptr);
1446  offset = bytestream_get_be32(&s->ptr);
1447  if (s->fileversion >= 3900) {
1448  if (offset > 3) {
1449  av_log(avctx, AV_LOG_ERROR, "Incorrect offset passed\n");
1450  s->data = NULL;
1451  return AVERROR_INVALIDDATA;
1452  }
1453  if (s->data_end - s->ptr < offset) {
1454  av_log(avctx, AV_LOG_ERROR, "Packet is too small\n");
1455  return AVERROR_INVALIDDATA;
1456  }
1457  s->ptr += offset;
1458  } else {
1459  init_get_bits(&s->gb, s->ptr, (s->data_end - s->ptr) * 8);
1460  if (s->fileversion > 3800)
1461  skip_bits_long(&s->gb, offset * 8);
1462  else
1463  skip_bits_long(&s->gb, offset);
1464  }
1465 
1466  if (!nblocks || nblocks > INT_MAX) {
1467  av_log(avctx, AV_LOG_ERROR, "Invalid sample count: %u.\n", nblocks);
1468  return AVERROR_INVALIDDATA;
1469  }
1470  s->samples = nblocks;
1471 
1472  /* Initialize the frame decoder */
1473  if (init_frame_decoder(s) < 0) {
1474  av_log(avctx, AV_LOG_ERROR, "Error reading frame header\n");
1475  return AVERROR_INVALIDDATA;
1476  }
1477  }
1478 
1479  if (!s->data) {
1480  *got_frame_ptr = 0;
1481  return avpkt->size;
1482  }
1483 
1484  blockstodecode = FFMIN(s->blocks_per_loop, s->samples);
1485  // for old files coefficients were not interleaved,
1486  // so we need to decode all of them at once
1487  if (s->fileversion < 3930)
1488  blockstodecode = s->samples;
1489 
1490  /* reallocate decoded sample buffer if needed */
1491  av_fast_malloc(&s->decoded_buffer, &s->decoded_size,
1492  2 * FFALIGN(blockstodecode, 8) * sizeof(*s->decoded_buffer));
1493  if (!s->decoded_buffer)
1494  return AVERROR(ENOMEM);
1495  memset(s->decoded_buffer, 0, s->decoded_size);
1496  s->decoded[0] = s->decoded_buffer;
1497  s->decoded[1] = s->decoded_buffer + FFALIGN(blockstodecode, 8);
1498 
1499  /* get output buffer */
1500  frame->nb_samples = blockstodecode;
1501  if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
1502  return ret;
1503 
1504  s->error=0;
1505 
1506  if ((s->channels == 1) || (s->frameflags & APE_FRAMECODE_PSEUDO_STEREO))
1507  ape_unpack_mono(s, blockstodecode);
1508  else
1509  ape_unpack_stereo(s, blockstodecode);
1510  emms_c();
1511 
1512  if (s->error) {
1513  s->samples=0;
1514  av_log(avctx, AV_LOG_ERROR, "Error decoding frame\n");
1515  return AVERROR_INVALIDDATA;
1516  }
1517 
1518  switch (s->bps) {
1519  case 8:
1520  for (ch = 0; ch < s->channels; ch++) {
1521  sample8 = (uint8_t *)frame->data[ch];
1522  for (i = 0; i < blockstodecode; i++)
1523  *sample8++ = (s->decoded[ch][i] + 0x80) & 0xff;
1524  }
1525  break;
1526  case 16:
1527  for (ch = 0; ch < s->channels; ch++) {
1528  sample16 = (int16_t *)frame->data[ch];
1529  for (i = 0; i < blockstodecode; i++)
1530  *sample16++ = s->decoded[ch][i];
1531  }
1532  break;
1533  case 24:
1534  for (ch = 0; ch < s->channels; ch++) {
1535  sample24 = (int32_t *)frame->data[ch];
1536  for (i = 0; i < blockstodecode; i++)
1537  *sample24++ = s->decoded[ch][i] << 8;
1538  }
1539  break;
1540  }
1541 
1542  s->samples -= blockstodecode;
1543 
1544  *got_frame_ptr = 1;
1545 
1546  return !s->samples ? avpkt->size : 0;
1547 }
1548 
1549 static void ape_flush(AVCodecContext *avctx)
1550 {
1551  APEContext *s = avctx->priv_data;
1552  s->samples= 0;
1553 }
1554 
1555 #define OFFSET(x) offsetof(APEContext, x)
1556 #define PAR (AV_OPT_FLAG_DECODING_PARAM | AV_OPT_FLAG_AUDIO_PARAM)
1557 static const AVOption options[] = {
1558  { "max_samples", "maximum number of samples decoded per call", OFFSET(blocks_per_loop), AV_OPT_TYPE_INT, { .i64 = 4608 }, 1, INT_MAX, PAR, "max_samples" },
1559  { "all", "no maximum. decode all samples for each packet at once", 0, AV_OPT_TYPE_CONST, { .i64 = INT_MAX }, INT_MIN, INT_MAX, PAR, "max_samples" },
1560  { NULL},
1561 };
1562 
1563 static const AVClass ape_decoder_class = {
1564  .class_name = "APE decoder",
1565  .item_name = av_default_item_name,
1566  .option = options,
1567  .version = LIBAVUTIL_VERSION_INT,
1568 };
1569 
1570 AVCodec ff_ape_decoder = {
1571  .name = "ape",
1572  .type = AVMEDIA_TYPE_AUDIO,
1573  .id = AV_CODEC_ID_APE,
1574  .priv_data_size = sizeof(APEContext),
1575  .init = ape_decode_init,
1576  .close = ape_decode_close,
1577  .decode = ape_decode_frame,
1578  .capabilities = CODEC_CAP_SUBFRAMES | CODEC_CAP_DELAY | CODEC_CAP_DR1,
1579  .flush = ape_flush,
1580  .long_name = NULL_IF_CONFIG_SMALL("Monkey's Audio"),
1581  .sample_fmts = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_U8P,
1582  AV_SAMPLE_FMT_S16P,
1583  AV_SAMPLE_FMT_S32P,
1584  AV_SAMPLE_FMT_NONE },
1585  .priv_class = &ape_decoder_class,
1586 };
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