apedec: 8bit and 24bit support
[libav.git] / libavcodec / apedec.c
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 Libav.
7 *
8 * Libav 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 * Libav 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 Libav; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21 */
22
23 #include "avcodec.h"
24 #include "dsputil.h"
25 #include "bytestream.h"
26 #include "libavutil/audioconvert.h"
27 #include "libavutil/avassert.h"
28
29 /**
30 * @file
31 * Monkey's Audio lossless audio decoder
32 */
33
34 #define BLOCKS_PER_LOOP 4608
35 #define MAX_CHANNELS 2
36 #define MAX_BYTESPERSAMPLE 3
37
38 #define APE_FRAMECODE_MONO_SILENCE 1
39 #define APE_FRAMECODE_STEREO_SILENCE 3
40 #define APE_FRAMECODE_PSEUDO_STEREO 4
41
42 #define HISTORY_SIZE 512
43 #define PREDICTOR_ORDER 8
44 /** Total size of all predictor histories */
45 #define PREDICTOR_SIZE 50
46
47 #define YDELAYA (18 + PREDICTOR_ORDER*4)
48 #define YDELAYB (18 + PREDICTOR_ORDER*3)
49 #define XDELAYA (18 + PREDICTOR_ORDER*2)
50 #define XDELAYB (18 + PREDICTOR_ORDER)
51
52 #define YADAPTCOEFFSA 18
53 #define XADAPTCOEFFSA 14
54 #define YADAPTCOEFFSB 10
55 #define XADAPTCOEFFSB 5
56
57 /**
58 * Possible compression levels
59 * @{
60 */
61 enum APECompressionLevel {
62 COMPRESSION_LEVEL_FAST = 1000,
63 COMPRESSION_LEVEL_NORMAL = 2000,
64 COMPRESSION_LEVEL_HIGH = 3000,
65 COMPRESSION_LEVEL_EXTRA_HIGH = 4000,
66 COMPRESSION_LEVEL_INSANE = 5000
67 };
68 /** @} */
69
70 #define APE_FILTER_LEVELS 3
71
72 /** Filter orders depending on compression level */
73 static const uint16_t ape_filter_orders[5][APE_FILTER_LEVELS] = {
74 { 0, 0, 0 },
75 { 16, 0, 0 },
76 { 64, 0, 0 },
77 { 32, 256, 0 },
78 { 16, 256, 1280 }
79 };
80
81 /** Filter fraction bits depending on compression level */
82 static const uint8_t ape_filter_fracbits[5][APE_FILTER_LEVELS] = {
83 { 0, 0, 0 },
84 { 11, 0, 0 },
85 { 11, 0, 0 },
86 { 10, 13, 0 },
87 { 11, 13, 15 }
88 };
89
90
91 /** Filters applied to the decoded data */
92 typedef struct APEFilter {
93 int16_t *coeffs; ///< actual coefficients used in filtering
94 int16_t *adaptcoeffs; ///< adaptive filter coefficients used for correcting of actual filter coefficients
95 int16_t *historybuffer; ///< filter memory
96 int16_t *delay; ///< filtered values
97
98 int avg;
99 } APEFilter;
100
101 typedef struct APERice {
102 uint32_t k;
103 uint32_t ksum;
104 } APERice;
105
106 typedef struct APERangecoder {
107 uint32_t low; ///< low end of interval
108 uint32_t range; ///< length of interval
109 uint32_t help; ///< bytes_to_follow resp. intermediate value
110 unsigned int buffer; ///< buffer for input/output
111 } APERangecoder;
112
113 /** Filter histories */
114 typedef struct APEPredictor {
115 int32_t *buf;
116
117 int32_t lastA[2];
118
119 int32_t filterA[2];
120 int32_t filterB[2];
121
122 int32_t coeffsA[2][4]; ///< adaption coefficients
123 int32_t coeffsB[2][5]; ///< adaption coefficients
124 int32_t historybuffer[HISTORY_SIZE + PREDICTOR_SIZE];
125 } APEPredictor;
126
127 /** Decoder context */
128 typedef struct APEContext {
129 AVCodecContext *avctx;
130 AVFrame frame;
131 DSPContext dsp;
132 int channels;
133 int samples; ///< samples left to decode in current frame
134 int bps;
135
136 int fileversion; ///< codec version, very important in decoding process
137 int compression_level; ///< compression levels
138 int fset; ///< which filter set to use (calculated from compression level)
139 int flags; ///< global decoder flags
140
141 uint32_t CRC; ///< frame CRC
142 int frameflags; ///< frame flags
143 APEPredictor predictor; ///< predictor used for final reconstruction
144
145 int32_t decoded0[BLOCKS_PER_LOOP]; ///< decoded data for the first channel
146 int32_t decoded1[BLOCKS_PER_LOOP]; ///< decoded data for the second channel
147
148 int16_t* filterbuf[APE_FILTER_LEVELS]; ///< filter memory
149
150 APERangecoder rc; ///< rangecoder used to decode actual values
151 APERice riceX; ///< rice code parameters for the second channel
152 APERice riceY; ///< rice code parameters for the first channel
153 APEFilter filters[APE_FILTER_LEVELS][2]; ///< filters used for reconstruction
154
155 uint8_t *data; ///< current frame data
156 uint8_t *data_end; ///< frame data end
157 int data_size; ///< frame data allocated size
158 const uint8_t *ptr; ///< current position in frame data
159
160 int error;
161 } APEContext;
162
163 // TODO: dsputilize
164
165 static av_cold int ape_decode_close(AVCodecContext *avctx)
166 {
167 APEContext *s = avctx->priv_data;
168 int i;
169
170 for (i = 0; i < APE_FILTER_LEVELS; i++)
171 av_freep(&s->filterbuf[i]);
172
173 av_freep(&s->data);
174 s->data_size = 0;
175
176 return 0;
177 }
178
179 static av_cold int ape_decode_init(AVCodecContext *avctx)
180 {
181 APEContext *s = avctx->priv_data;
182 int i;
183
184 if (avctx->extradata_size != 6) {
185 av_log(avctx, AV_LOG_ERROR, "Incorrect extradata\n");
186 return AVERROR(EINVAL);
187 }
188 if (avctx->channels > 2) {
189 av_log(avctx, AV_LOG_ERROR, "Only mono and stereo is supported\n");
190 return AVERROR(EINVAL);
191 }
192 s->bps = avctx->bits_per_coded_sample;
193 switch (s->bps) {
194 case 8:
195 avctx->sample_fmt = AV_SAMPLE_FMT_U8;
196 break;
197 case 16:
198 avctx->sample_fmt = AV_SAMPLE_FMT_S16;
199 break;
200 case 24:
201 avctx->sample_fmt = AV_SAMPLE_FMT_S32;
202 break;
203 default:
204 av_log_ask_for_sample(avctx, "Unsupported bits per coded sample %d\n",
205 s->bps);
206 return AVERROR_PATCHWELCOME;
207 }
208 s->avctx = avctx;
209 s->channels = avctx->channels;
210 s->fileversion = AV_RL16(avctx->extradata);
211 s->compression_level = AV_RL16(avctx->extradata + 2);
212 s->flags = AV_RL16(avctx->extradata + 4);
213
214 av_log(avctx, AV_LOG_DEBUG, "Compression Level: %d - Flags: %d\n",
215 s->compression_level, s->flags);
216 if (s->compression_level % 1000 || s->compression_level > COMPRESSION_LEVEL_INSANE) {
217 av_log(avctx, AV_LOG_ERROR, "Incorrect compression level %d\n",
218 s->compression_level);
219 return AVERROR_INVALIDDATA;
220 }
221 s->fset = s->compression_level / 1000 - 1;
222 for (i = 0; i < APE_FILTER_LEVELS; i++) {
223 if (!ape_filter_orders[s->fset][i])
224 break;
225 FF_ALLOC_OR_GOTO(avctx, s->filterbuf[i],
226 (ape_filter_orders[s->fset][i] * 3 + HISTORY_SIZE) * 4,
227 filter_alloc_fail);
228 }
229
230 dsputil_init(&s->dsp, avctx);
231 avctx->channel_layout = (avctx->channels==2) ? AV_CH_LAYOUT_STEREO : AV_CH_LAYOUT_MONO;
232
233 avcodec_get_frame_defaults(&s->frame);
234 avctx->coded_frame = &s->frame;
235
236 return 0;
237 filter_alloc_fail:
238 ape_decode_close(avctx);
239 return AVERROR(ENOMEM);
240 }
241
242 /**
243 * @name APE range decoding functions
244 * @{
245 */
246
247 #define CODE_BITS 32
248 #define TOP_VALUE ((unsigned int)1 << (CODE_BITS-1))
249 #define SHIFT_BITS (CODE_BITS - 9)
250 #define EXTRA_BITS ((CODE_BITS-2) % 8 + 1)
251 #define BOTTOM_VALUE (TOP_VALUE >> 8)
252
253 /** Start the decoder */
254 static inline void range_start_decoding(APEContext *ctx)
255 {
256 ctx->rc.buffer = bytestream_get_byte(&ctx->ptr);
257 ctx->rc.low = ctx->rc.buffer >> (8 - EXTRA_BITS);
258 ctx->rc.range = (uint32_t) 1 << EXTRA_BITS;
259 }
260
261 /** Perform normalization */
262 static inline void range_dec_normalize(APEContext *ctx)
263 {
264 while (ctx->rc.range <= BOTTOM_VALUE) {
265 ctx->rc.buffer <<= 8;
266 if(ctx->ptr < ctx->data_end) {
267 ctx->rc.buffer += *ctx->ptr;
268 ctx->ptr++;
269 } else {
270 ctx->error = 1;
271 }
272 ctx->rc.low = (ctx->rc.low << 8) | ((ctx->rc.buffer >> 1) & 0xFF);
273 ctx->rc.range <<= 8;
274 }
275 }
276
277 /**
278 * Calculate culmulative frequency for next symbol. Does NO update!
279 * @param ctx decoder context
280 * @param tot_f is the total frequency or (code_value)1<<shift
281 * @return the culmulative frequency
282 */
283 static inline int range_decode_culfreq(APEContext *ctx, int tot_f)
284 {
285 range_dec_normalize(ctx);
286 ctx->rc.help = ctx->rc.range / tot_f;
287 return ctx->rc.low / ctx->rc.help;
288 }
289
290 /**
291 * Decode value with given size in bits
292 * @param ctx decoder context
293 * @param shift number of bits to decode
294 */
295 static inline int range_decode_culshift(APEContext *ctx, int shift)
296 {
297 range_dec_normalize(ctx);
298 ctx->rc.help = ctx->rc.range >> shift;
299 return ctx->rc.low / ctx->rc.help;
300 }
301
302
303 /**
304 * Update decoding state
305 * @param ctx decoder context
306 * @param sy_f the interval length (frequency of the symbol)
307 * @param lt_f the lower end (frequency sum of < symbols)
308 */
309 static inline void range_decode_update(APEContext *ctx, int sy_f, int lt_f)
310 {
311 ctx->rc.low -= ctx->rc.help * lt_f;
312 ctx->rc.range = ctx->rc.help * sy_f;
313 }
314
315 /** Decode n bits (n <= 16) without modelling */
316 static inline int range_decode_bits(APEContext *ctx, int n)
317 {
318 int sym = range_decode_culshift(ctx, n);
319 range_decode_update(ctx, 1, sym);
320 return sym;
321 }
322
323
324 #define MODEL_ELEMENTS 64
325
326 /**
327 * Fixed probabilities for symbols in Monkey Audio version 3.97
328 */
329 static const uint16_t counts_3970[22] = {
330 0, 14824, 28224, 39348, 47855, 53994, 58171, 60926,
331 62682, 63786, 64463, 64878, 65126, 65276, 65365, 65419,
332 65450, 65469, 65480, 65487, 65491, 65493,
333 };
334
335 /**
336 * Probability ranges for symbols in Monkey Audio version 3.97
337 */
338 static const uint16_t counts_diff_3970[21] = {
339 14824, 13400, 11124, 8507, 6139, 4177, 2755, 1756,
340 1104, 677, 415, 248, 150, 89, 54, 31,
341 19, 11, 7, 4, 2,
342 };
343
344 /**
345 * Fixed probabilities for symbols in Monkey Audio version 3.98
346 */
347 static const uint16_t counts_3980[22] = {
348 0, 19578, 36160, 48417, 56323, 60899, 63265, 64435,
349 64971, 65232, 65351, 65416, 65447, 65466, 65476, 65482,
350 65485, 65488, 65490, 65491, 65492, 65493,
351 };
352
353 /**
354 * Probability ranges for symbols in Monkey Audio version 3.98
355 */
356 static const uint16_t counts_diff_3980[21] = {
357 19578, 16582, 12257, 7906, 4576, 2366, 1170, 536,
358 261, 119, 65, 31, 19, 10, 6, 3,
359 3, 2, 1, 1, 1,
360 };
361
362 /**
363 * Decode symbol
364 * @param ctx decoder context
365 * @param counts probability range start position
366 * @param counts_diff probability range widths
367 */
368 static inline int range_get_symbol(APEContext *ctx,
369 const uint16_t counts[],
370 const uint16_t counts_diff[])
371 {
372 int symbol, cf;
373
374 cf = range_decode_culshift(ctx, 16);
375
376 if(cf > 65492){
377 symbol= cf - 65535 + 63;
378 range_decode_update(ctx, 1, cf);
379 if(cf > 65535)
380 ctx->error=1;
381 return symbol;
382 }
383 /* figure out the symbol inefficiently; a binary search would be much better */
384 for (symbol = 0; counts[symbol + 1] <= cf; symbol++);
385
386 range_decode_update(ctx, counts_diff[symbol], counts[symbol]);
387
388 return symbol;
389 }
390 /** @} */ // group rangecoder
391
392 static inline void update_rice(APERice *rice, int x)
393 {
394 int lim = rice->k ? (1 << (rice->k + 4)) : 0;
395 rice->ksum += ((x + 1) / 2) - ((rice->ksum + 16) >> 5);
396
397 if (rice->ksum < lim)
398 rice->k--;
399 else if (rice->ksum >= (1 << (rice->k + 5)))
400 rice->k++;
401 }
402
403 static inline int ape_decode_value(APEContext *ctx, APERice *rice)
404 {
405 int x, overflow;
406
407 if (ctx->fileversion < 3990) {
408 int tmpk;
409
410 overflow = range_get_symbol(ctx, counts_3970, counts_diff_3970);
411
412 if (overflow == (MODEL_ELEMENTS - 1)) {
413 tmpk = range_decode_bits(ctx, 5);
414 overflow = 0;
415 } else
416 tmpk = (rice->k < 1) ? 0 : rice->k - 1;
417
418 if (tmpk <= 16)
419 x = range_decode_bits(ctx, tmpk);
420 else {
421 x = range_decode_bits(ctx, 16);
422 x |= (range_decode_bits(ctx, tmpk - 16) << 16);
423 }
424 x += overflow << tmpk;
425 } else {
426 int base, pivot;
427
428 pivot = rice->ksum >> 5;
429 if (pivot == 0)
430 pivot = 1;
431
432 overflow = range_get_symbol(ctx, counts_3980, counts_diff_3980);
433
434 if (overflow == (MODEL_ELEMENTS - 1)) {
435 overflow = range_decode_bits(ctx, 16) << 16;
436 overflow |= range_decode_bits(ctx, 16);
437 }
438
439 if (pivot < 0x10000) {
440 base = range_decode_culfreq(ctx, pivot);
441 range_decode_update(ctx, 1, base);
442 } else {
443 int base_hi = pivot, base_lo;
444 int bbits = 0;
445
446 while (base_hi & ~0xFFFF) {
447 base_hi >>= 1;
448 bbits++;
449 }
450 base_hi = range_decode_culfreq(ctx, base_hi + 1);
451 range_decode_update(ctx, 1, base_hi);
452 base_lo = range_decode_culfreq(ctx, 1 << bbits);
453 range_decode_update(ctx, 1, base_lo);
454
455 base = (base_hi << bbits) + base_lo;
456 }
457
458 x = base + overflow * pivot;
459 }
460
461 update_rice(rice, x);
462
463 /* Convert to signed */
464 if (x & 1)
465 return (x >> 1) + 1;
466 else
467 return -(x >> 1);
468 }
469
470 static void entropy_decode(APEContext *ctx, int blockstodecode, int stereo)
471 {
472 int32_t *decoded0 = ctx->decoded0;
473 int32_t *decoded1 = ctx->decoded1;
474
475 if (ctx->frameflags & APE_FRAMECODE_STEREO_SILENCE) {
476 /* We are pure silence, just memset the output buffer. */
477 memset(decoded0, 0, blockstodecode * sizeof(int32_t));
478 memset(decoded1, 0, blockstodecode * sizeof(int32_t));
479 } else {
480 while (blockstodecode--) {
481 *decoded0++ = ape_decode_value(ctx, &ctx->riceY);
482 if (stereo)
483 *decoded1++ = ape_decode_value(ctx, &ctx->riceX);
484 }
485 }
486 }
487
488 static int init_entropy_decoder(APEContext *ctx)
489 {
490 /* Read the CRC */
491 if (ctx->data_end - ctx->ptr < 6)
492 return AVERROR_INVALIDDATA;
493 ctx->CRC = bytestream_get_be32(&ctx->ptr);
494
495 /* Read the frame flags if they exist */
496 ctx->frameflags = 0;
497 if ((ctx->fileversion > 3820) && (ctx->CRC & 0x80000000)) {
498 ctx->CRC &= ~0x80000000;
499
500 if (ctx->data_end - ctx->ptr < 6)
501 return AVERROR_INVALIDDATA;
502 ctx->frameflags = bytestream_get_be32(&ctx->ptr);
503 }
504
505 /* Initialize the rice structs */
506 ctx->riceX.k = 10;
507 ctx->riceX.ksum = (1 << ctx->riceX.k) * 16;
508 ctx->riceY.k = 10;
509 ctx->riceY.ksum = (1 << ctx->riceY.k) * 16;
510
511 /* The first 8 bits of input are ignored. */
512 ctx->ptr++;
513
514 range_start_decoding(ctx);
515
516 return 0;
517 }
518
519 static const int32_t initial_coeffs[4] = {
520 360, 317, -109, 98
521 };
522
523 static void init_predictor_decoder(APEContext *ctx)
524 {
525 APEPredictor *p = &ctx->predictor;
526
527 /* Zero the history buffers */
528 memset(p->historybuffer, 0, PREDICTOR_SIZE * sizeof(int32_t));
529 p->buf = p->historybuffer;
530
531 /* Initialize and zero the coefficients */
532 memcpy(p->coeffsA[0], initial_coeffs, sizeof(initial_coeffs));
533 memcpy(p->coeffsA[1], initial_coeffs, sizeof(initial_coeffs));
534 memset(p->coeffsB, 0, sizeof(p->coeffsB));
535
536 p->filterA[0] = p->filterA[1] = 0;
537 p->filterB[0] = p->filterB[1] = 0;
538 p->lastA[0] = p->lastA[1] = 0;
539 }
540
541 /** Get inverse sign of integer (-1 for positive, 1 for negative and 0 for zero) */
542 static inline int APESIGN(int32_t x) {
543 return (x < 0) - (x > 0);
544 }
545
546 static av_always_inline int predictor_update_filter(APEPredictor *p,
547 const int decoded, const int filter,
548 const int delayA, const int delayB,
549 const int adaptA, const int adaptB)
550 {
551 int32_t predictionA, predictionB, sign;
552
553 p->buf[delayA] = p->lastA[filter];
554 p->buf[adaptA] = APESIGN(p->buf[delayA]);
555 p->buf[delayA - 1] = p->buf[delayA] - p->buf[delayA - 1];
556 p->buf[adaptA - 1] = APESIGN(p->buf[delayA - 1]);
557
558 predictionA = p->buf[delayA ] * p->coeffsA[filter][0] +
559 p->buf[delayA - 1] * p->coeffsA[filter][1] +
560 p->buf[delayA - 2] * p->coeffsA[filter][2] +
561 p->buf[delayA - 3] * p->coeffsA[filter][3];
562
563 /* Apply a scaled first-order filter compression */
564 p->buf[delayB] = p->filterA[filter ^ 1] - ((p->filterB[filter] * 31) >> 5);
565 p->buf[adaptB] = APESIGN(p->buf[delayB]);
566 p->buf[delayB - 1] = p->buf[delayB] - p->buf[delayB - 1];
567 p->buf[adaptB - 1] = APESIGN(p->buf[delayB - 1]);
568 p->filterB[filter] = p->filterA[filter ^ 1];
569
570 predictionB = p->buf[delayB ] * p->coeffsB[filter][0] +
571 p->buf[delayB - 1] * p->coeffsB[filter][1] +
572 p->buf[delayB - 2] * p->coeffsB[filter][2] +
573 p->buf[delayB - 3] * p->coeffsB[filter][3] +
574 p->buf[delayB - 4] * p->coeffsB[filter][4];
575
576 p->lastA[filter] = decoded + ((predictionA + (predictionB >> 1)) >> 10);
577 p->filterA[filter] = p->lastA[filter] + ((p->filterA[filter] * 31) >> 5);
578
579 sign = APESIGN(decoded);
580 p->coeffsA[filter][0] += p->buf[adaptA ] * sign;
581 p->coeffsA[filter][1] += p->buf[adaptA - 1] * sign;
582 p->coeffsA[filter][2] += p->buf[adaptA - 2] * sign;
583 p->coeffsA[filter][3] += p->buf[adaptA - 3] * sign;
584 p->coeffsB[filter][0] += p->buf[adaptB ] * sign;
585 p->coeffsB[filter][1] += p->buf[adaptB - 1] * sign;
586 p->coeffsB[filter][2] += p->buf[adaptB - 2] * sign;
587 p->coeffsB[filter][3] += p->buf[adaptB - 3] * sign;
588 p->coeffsB[filter][4] += p->buf[adaptB - 4] * sign;
589
590 return p->filterA[filter];
591 }
592
593 static void predictor_decode_stereo(APEContext *ctx, int count)
594 {
595 APEPredictor *p = &ctx->predictor;
596 int32_t *decoded0 = ctx->decoded0;
597 int32_t *decoded1 = ctx->decoded1;
598
599 while (count--) {
600 /* Predictor Y */
601 *decoded0 = predictor_update_filter(p, *decoded0, 0, YDELAYA, YDELAYB,
602 YADAPTCOEFFSA, YADAPTCOEFFSB);
603 decoded0++;
604 *decoded1 = predictor_update_filter(p, *decoded1, 1, XDELAYA, XDELAYB,
605 XADAPTCOEFFSA, XADAPTCOEFFSB);
606 decoded1++;
607
608 /* Combined */
609 p->buf++;
610
611 /* Have we filled the history buffer? */
612 if (p->buf == p->historybuffer + HISTORY_SIZE) {
613 memmove(p->historybuffer, p->buf, PREDICTOR_SIZE * sizeof(int32_t));
614 p->buf = p->historybuffer;
615 }
616 }
617 }
618
619 static void predictor_decode_mono(APEContext *ctx, int count)
620 {
621 APEPredictor *p = &ctx->predictor;
622 int32_t *decoded0 = ctx->decoded0;
623 int32_t predictionA, currentA, A, sign;
624
625 currentA = p->lastA[0];
626
627 while (count--) {
628 A = *decoded0;
629
630 p->buf[YDELAYA] = currentA;
631 p->buf[YDELAYA - 1] = p->buf[YDELAYA] - p->buf[YDELAYA - 1];
632
633 predictionA = p->buf[YDELAYA ] * p->coeffsA[0][0] +
634 p->buf[YDELAYA - 1] * p->coeffsA[0][1] +
635 p->buf[YDELAYA - 2] * p->coeffsA[0][2] +
636 p->buf[YDELAYA - 3] * p->coeffsA[0][3];
637
638 currentA = A + (predictionA >> 10);
639
640 p->buf[YADAPTCOEFFSA] = APESIGN(p->buf[YDELAYA ]);
641 p->buf[YADAPTCOEFFSA - 1] = APESIGN(p->buf[YDELAYA - 1]);
642
643 sign = APESIGN(A);
644 p->coeffsA[0][0] += p->buf[YADAPTCOEFFSA ] * sign;
645 p->coeffsA[0][1] += p->buf[YADAPTCOEFFSA - 1] * sign;
646 p->coeffsA[0][2] += p->buf[YADAPTCOEFFSA - 2] * sign;
647 p->coeffsA[0][3] += p->buf[YADAPTCOEFFSA - 3] * sign;
648
649 p->buf++;
650
651 /* Have we filled the history buffer? */
652 if (p->buf == p->historybuffer + HISTORY_SIZE) {
653 memmove(p->historybuffer, p->buf, PREDICTOR_SIZE * sizeof(int32_t));
654 p->buf = p->historybuffer;
655 }
656
657 p->filterA[0] = currentA + ((p->filterA[0] * 31) >> 5);
658 *(decoded0++) = p->filterA[0];
659 }
660
661 p->lastA[0] = currentA;
662 }
663
664 static void do_init_filter(APEFilter *f, int16_t *buf, int order)
665 {
666 f->coeffs = buf;
667 f->historybuffer = buf + order;
668 f->delay = f->historybuffer + order * 2;
669 f->adaptcoeffs = f->historybuffer + order;
670
671 memset(f->historybuffer, 0, (order * 2) * sizeof(int16_t));
672 memset(f->coeffs, 0, order * sizeof(int16_t));
673 f->avg = 0;
674 }
675
676 static void init_filter(APEContext *ctx, APEFilter *f, int16_t *buf, int order)
677 {
678 do_init_filter(&f[0], buf, order);
679 do_init_filter(&f[1], buf + order * 3 + HISTORY_SIZE, order);
680 }
681
682 static void do_apply_filter(APEContext *ctx, int version, APEFilter *f,
683 int32_t *data, int count, int order, int fracbits)
684 {
685 int res;
686 int absres;
687
688 while (count--) {
689 /* round fixedpoint scalar product */
690 res = ctx->dsp.scalarproduct_and_madd_int16(f->coeffs, f->delay - order,
691 f->adaptcoeffs - order,
692 order, APESIGN(*data));
693 res = (res + (1 << (fracbits - 1))) >> fracbits;
694 res += *data;
695 *data++ = res;
696
697 /* Update the output history */
698 *f->delay++ = av_clip_int16(res);
699
700 if (version < 3980) {
701 /* Version ??? to < 3.98 files (untested) */
702 f->adaptcoeffs[0] = (res == 0) ? 0 : ((res >> 28) & 8) - 4;
703 f->adaptcoeffs[-4] >>= 1;
704 f->adaptcoeffs[-8] >>= 1;
705 } else {
706 /* Version 3.98 and later files */
707
708 /* Update the adaption coefficients */
709 absres = FFABS(res);
710 if (absres)
711 *f->adaptcoeffs = ((res & (-1<<31)) ^ (-1<<30)) >>
712 (25 + (absres <= f->avg*3) + (absres <= f->avg*4/3));
713 else
714 *f->adaptcoeffs = 0;
715
716 f->avg += (absres - f->avg) / 16;
717
718 f->adaptcoeffs[-1] >>= 1;
719 f->adaptcoeffs[-2] >>= 1;
720 f->adaptcoeffs[-8] >>= 1;
721 }
722
723 f->adaptcoeffs++;
724
725 /* Have we filled the history buffer? */
726 if (f->delay == f->historybuffer + HISTORY_SIZE + (order * 2)) {
727 memmove(f->historybuffer, f->delay - (order * 2),
728 (order * 2) * sizeof(int16_t));
729 f->delay = f->historybuffer + order * 2;
730 f->adaptcoeffs = f->historybuffer + order;
731 }
732 }
733 }
734
735 static void apply_filter(APEContext *ctx, APEFilter *f,
736 int32_t *data0, int32_t *data1,
737 int count, int order, int fracbits)
738 {
739 do_apply_filter(ctx, ctx->fileversion, &f[0], data0, count, order, fracbits);
740 if (data1)
741 do_apply_filter(ctx, ctx->fileversion, &f[1], data1, count, order, fracbits);
742 }
743
744 static void ape_apply_filters(APEContext *ctx, int32_t *decoded0,
745 int32_t *decoded1, int count)
746 {
747 int i;
748
749 for (i = 0; i < APE_FILTER_LEVELS; i++) {
750 if (!ape_filter_orders[ctx->fset][i])
751 break;
752 apply_filter(ctx, ctx->filters[i], decoded0, decoded1, count,
753 ape_filter_orders[ctx->fset][i],
754 ape_filter_fracbits[ctx->fset][i]);
755 }
756 }
757
758 static int init_frame_decoder(APEContext *ctx)
759 {
760 int i, ret;
761 if ((ret = init_entropy_decoder(ctx)) < 0)
762 return ret;
763 init_predictor_decoder(ctx);
764
765 for (i = 0; i < APE_FILTER_LEVELS; i++) {
766 if (!ape_filter_orders[ctx->fset][i])
767 break;
768 init_filter(ctx, ctx->filters[i], ctx->filterbuf[i],
769 ape_filter_orders[ctx->fset][i]);
770 }
771 return 0;
772 }
773
774 static void ape_unpack_mono(APEContext *ctx, int count)
775 {
776 int32_t *decoded0 = ctx->decoded0;
777 int32_t *decoded1 = ctx->decoded1;
778
779 if (ctx->frameflags & APE_FRAMECODE_STEREO_SILENCE) {
780 entropy_decode(ctx, count, 0);
781 /* We are pure silence, so we're done. */
782 av_log(ctx->avctx, AV_LOG_DEBUG, "pure silence mono\n");
783 return;
784 }
785
786 entropy_decode(ctx, count, 0);
787 ape_apply_filters(ctx, decoded0, NULL, count);
788
789 /* Now apply the predictor decoding */
790 predictor_decode_mono(ctx, count);
791
792 /* Pseudo-stereo - just copy left channel to right channel */
793 if (ctx->channels == 2) {
794 memcpy(decoded1, decoded0, count * sizeof(*decoded1));
795 }
796 }
797
798 static void ape_unpack_stereo(APEContext *ctx, int count)
799 {
800 int32_t left, right;
801 int32_t *decoded0 = ctx->decoded0;
802 int32_t *decoded1 = ctx->decoded1;
803
804 if (ctx->frameflags & APE_FRAMECODE_STEREO_SILENCE) {
805 /* We are pure silence, so we're done. */
806 av_log(ctx->avctx, AV_LOG_DEBUG, "pure silence stereo\n");
807 return;
808 }
809
810 entropy_decode(ctx, count, 1);
811 ape_apply_filters(ctx, decoded0, decoded1, count);
812
813 /* Now apply the predictor decoding */
814 predictor_decode_stereo(ctx, count);
815
816 /* Decorrelate and scale to output depth */
817 while (count--) {
818 left = *decoded1 - (*decoded0 / 2);
819 right = left + *decoded0;
820
821 *(decoded0++) = left;
822 *(decoded1++) = right;
823 }
824 }
825
826 static int ape_decode_frame(AVCodecContext *avctx, void *data,
827 int *got_frame_ptr, AVPacket *avpkt)
828 {
829 const uint8_t *buf = avpkt->data;
830 APEContext *s = avctx->priv_data;
831 uint8_t *sample8;
832 int16_t *sample16;
833 int32_t *sample24;
834 int i, ret;
835 int blockstodecode;
836 int bytes_used = 0;
837
838 /* this should never be negative, but bad things will happen if it is, so
839 check it just to make sure. */
840 av_assert0(s->samples >= 0);
841
842 if(!s->samples){
843 uint32_t nblocks, offset;
844 int buf_size;
845
846 if (!avpkt->size) {
847 *got_frame_ptr = 0;
848 return 0;
849 }
850 if (avpkt->size < 8) {
851 av_log(avctx, AV_LOG_ERROR, "Packet is too small\n");
852 return AVERROR_INVALIDDATA;
853 }
854 buf_size = avpkt->size & ~3;
855 if (buf_size != avpkt->size) {
856 av_log(avctx, AV_LOG_WARNING, "packet size is not a multiple of 4. "
857 "extra bytes at the end will be skipped.\n");
858 }
859
860 av_fast_malloc(&s->data, &s->data_size, buf_size);
861 if (!s->data)
862 return AVERROR(ENOMEM);
863 s->dsp.bswap_buf((uint32_t*)s->data, (const uint32_t*)buf, buf_size >> 2);
864 s->ptr = s->data;
865 s->data_end = s->data + buf_size;
866
867 nblocks = bytestream_get_be32(&s->ptr);
868 offset = bytestream_get_be32(&s->ptr);
869 if (offset > 3) {
870 av_log(avctx, AV_LOG_ERROR, "Incorrect offset passed\n");
871 s->data = NULL;
872 return AVERROR_INVALIDDATA;
873 }
874 if (s->data_end - s->ptr < offset) {
875 av_log(avctx, AV_LOG_ERROR, "Packet is too small\n");
876 return AVERROR_INVALIDDATA;
877 }
878 s->ptr += offset;
879
880 if (!nblocks || nblocks > INT_MAX) {
881 av_log(avctx, AV_LOG_ERROR, "Invalid sample count: %u.\n", nblocks);
882 return AVERROR_INVALIDDATA;
883 }
884 s->samples = nblocks;
885
886 memset(s->decoded0, 0, sizeof(s->decoded0));
887 memset(s->decoded1, 0, sizeof(s->decoded1));
888
889 /* Initialize the frame decoder */
890 if (init_frame_decoder(s) < 0) {
891 av_log(avctx, AV_LOG_ERROR, "Error reading frame header\n");
892 return AVERROR_INVALIDDATA;
893 }
894
895 bytes_used = avpkt->size;
896 }
897
898 if (!s->data) {
899 *got_frame_ptr = 0;
900 return avpkt->size;
901 }
902
903 blockstodecode = FFMIN(BLOCKS_PER_LOOP, s->samples);
904
905 /* get output buffer */
906 s->frame.nb_samples = blockstodecode;
907 if ((ret = avctx->get_buffer(avctx, &s->frame)) < 0) {
908 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
909 return ret;
910 }
911
912 s->error=0;
913
914 if ((s->channels == 1) || (s->frameflags & APE_FRAMECODE_PSEUDO_STEREO))
915 ape_unpack_mono(s, blockstodecode);
916 else
917 ape_unpack_stereo(s, blockstodecode);
918 emms_c();
919
920 if (s->error) {
921 s->samples=0;
922 av_log(avctx, AV_LOG_ERROR, "Error decoding frame\n");
923 return AVERROR_INVALIDDATA;
924 }
925
926 switch (s->bps) {
927 case 8:
928 sample8 = (uint8_t *)s->frame.data[0];
929 for (i = 0; i < blockstodecode; i++) {
930 *sample8++ = (s->decoded0[i] + 0x80) & 0xff;
931 if (s->channels == 2)
932 *sample8++ = (s->decoded1[i] + 0x80) & 0xff;
933 }
934 break;
935 case 16:
936 sample16 = (int16_t *)s->frame.data[0];
937 for (i = 0; i < blockstodecode; i++) {
938 *sample16++ = s->decoded0[i];
939 if (s->channels == 2)
940 *sample16++ = s->decoded1[i];
941 }
942 break;
943 case 24:
944 sample24 = (int32_t *)s->frame.data[0];
945 for (i = 0; i < blockstodecode; i++) {
946 *sample24++ = s->decoded0[i] << 8;
947 if (s->channels == 2)
948 *sample24++ = s->decoded1[i] << 8;
949 }
950 break;
951 }
952
953 s->samples -= blockstodecode;
954
955 *got_frame_ptr = 1;
956 *(AVFrame *)data = s->frame;
957
958 return bytes_used;
959 }
960
961 static void ape_flush(AVCodecContext *avctx)
962 {
963 APEContext *s = avctx->priv_data;
964 s->samples= 0;
965 }
966
967 AVCodec ff_ape_decoder = {
968 .name = "ape",
969 .type = AVMEDIA_TYPE_AUDIO,
970 .id = CODEC_ID_APE,
971 .priv_data_size = sizeof(APEContext),
972 .init = ape_decode_init,
973 .close = ape_decode_close,
974 .decode = ape_decode_frame,
975 .capabilities = CODEC_CAP_SUBFRAMES | CODEC_CAP_DELAY | CODEC_CAP_DR1,
976 .flush = ape_flush,
977 .long_name = NULL_IF_CONFIG_SMALL("Monkey's Audio"),
978 };