dc4efe255dc7df99de895ded7fce3d93146103e3
[libav.git] / libavcodec / mlpdec.c
1 /*
2 * MLP decoder
3 * Copyright (c) 2007-2008 Ian Caulfield
4 *
5 * This file is part of FFmpeg.
6 *
7 * FFmpeg is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
11 *
12 * FFmpeg is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
16 *
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20 */
21
22 /**
23 * @file libavcodec/mlpdec.c
24 * MLP decoder
25 */
26
27 #include <stdint.h>
28
29 #include "avcodec.h"
30 #include "libavutil/intreadwrite.h"
31 #include "bitstream.h"
32 #include "libavutil/crc.h"
33 #include "parser.h"
34 #include "mlp_parser.h"
35 #include "mlp.h"
36
37 /** number of bits used for VLC lookup - longest Huffman code is 9 */
38 #define VLC_BITS 9
39
40
41 static const char* sample_message =
42 "Please file a bug report following the instructions at "
43 "http://ffmpeg.org/bugreports.html and include "
44 "a sample of this file.";
45
46 typedef struct SubStream {
47 //! Set if a valid restart header has been read. Otherwise the substream cannot be decoded.
48 uint8_t restart_seen;
49
50 //@{
51 /** restart header data */
52 //! The type of noise to be used in the rematrix stage.
53 uint16_t noise_type;
54
55 //! The index of the first channel coded in this substream.
56 uint8_t min_channel;
57 //! The index of the last channel coded in this substream.
58 uint8_t max_channel;
59 //! The number of channels input into the rematrix stage.
60 uint8_t max_matrix_channel;
61 //! For each channel output by the matrix, the output channel to map it to
62 uint8_t ch_assign[MAX_CHANNELS];
63
64 //! The left shift applied to random noise in 0x31ea substreams.
65 uint8_t noise_shift;
66 //! The current seed value for the pseudorandom noise generator(s).
67 uint32_t noisegen_seed;
68
69 //! Set if the substream contains extra info to check the size of VLC blocks.
70 uint8_t data_check_present;
71
72 //! Bitmask of which parameter sets are conveyed in a decoding parameter block.
73 uint8_t param_presence_flags;
74 #define PARAM_BLOCKSIZE (1 << 7)
75 #define PARAM_MATRIX (1 << 6)
76 #define PARAM_OUTSHIFT (1 << 5)
77 #define PARAM_QUANTSTEP (1 << 4)
78 #define PARAM_FIR (1 << 3)
79 #define PARAM_IIR (1 << 2)
80 #define PARAM_HUFFOFFSET (1 << 1)
81 #define PARAM_PRESENCE (1 << 0)
82 //@}
83
84 //@{
85 /** matrix data */
86
87 //! Number of matrices to be applied.
88 uint8_t num_primitive_matrices;
89
90 //! matrix output channel
91 uint8_t matrix_out_ch[MAX_MATRICES];
92
93 //! Whether the LSBs of the matrix output are encoded in the bitstream.
94 uint8_t lsb_bypass[MAX_MATRICES];
95 //! Matrix coefficients, stored as 2.14 fixed point.
96 int32_t matrix_coeff[MAX_MATRICES][MAX_CHANNELS+2];
97 //! Left shift to apply to noise values in 0x31eb substreams.
98 uint8_t matrix_noise_shift[MAX_MATRICES];
99 //@}
100
101 //! Left shift to apply to Huffman-decoded residuals.
102 uint8_t quant_step_size[MAX_CHANNELS];
103
104 //! number of PCM samples in current audio block
105 uint16_t blocksize;
106 //! Number of PCM samples decoded so far in this frame.
107 uint16_t blockpos;
108
109 //! Left shift to apply to decoded PCM values to get final 24-bit output.
110 int8_t output_shift[MAX_CHANNELS];
111
112 //! Running XOR of all output samples.
113 int32_t lossless_check_data;
114
115 } SubStream;
116
117 typedef struct MLPDecodeContext {
118 AVCodecContext *avctx;
119
120 //! Set if a valid major sync block has been read. Otherwise no decoding is possible.
121 uint8_t params_valid;
122
123 //! Number of substreams contained within this stream.
124 uint8_t num_substreams;
125
126 //! Index of the last substream to decode - further substreams are skipped.
127 uint8_t max_decoded_substream;
128
129 //! number of PCM samples contained in each frame
130 int access_unit_size;
131 //! next power of two above the number of samples in each frame
132 int access_unit_size_pow2;
133
134 SubStream substream[MAX_SUBSTREAMS];
135
136 ChannelParams channel_params[MAX_CHANNELS];
137
138 int8_t noise_buffer[MAX_BLOCKSIZE_POW2];
139 int8_t bypassed_lsbs[MAX_BLOCKSIZE][MAX_CHANNELS];
140 int32_t sample_buffer[MAX_BLOCKSIZE][MAX_CHANNELS+2];
141 } MLPDecodeContext;
142
143 static VLC huff_vlc[3];
144
145 /** Initialize static data, constant between all invocations of the codec. */
146
147 static av_cold void init_static(void)
148 {
149 INIT_VLC_STATIC(&huff_vlc[0], VLC_BITS, 18,
150 &ff_mlp_huffman_tables[0][0][1], 2, 1,
151 &ff_mlp_huffman_tables[0][0][0], 2, 1, 512);
152 INIT_VLC_STATIC(&huff_vlc[1], VLC_BITS, 16,
153 &ff_mlp_huffman_tables[1][0][1], 2, 1,
154 &ff_mlp_huffman_tables[1][0][0], 2, 1, 512);
155 INIT_VLC_STATIC(&huff_vlc[2], VLC_BITS, 15,
156 &ff_mlp_huffman_tables[2][0][1], 2, 1,
157 &ff_mlp_huffman_tables[2][0][0], 2, 1, 512);
158
159 ff_mlp_init_crc();
160 }
161
162 static inline int32_t calculate_sign_huff(MLPDecodeContext *m,
163 unsigned int substr, unsigned int ch)
164 {
165 ChannelParams *cp = &m->channel_params[ch];
166 SubStream *s = &m->substream[substr];
167 int lsb_bits = cp->huff_lsbs - s->quant_step_size[ch];
168 int sign_shift = lsb_bits + (cp->codebook ? 2 - cp->codebook : -1);
169 int32_t sign_huff_offset = cp->huff_offset;
170
171 if (cp->codebook > 0)
172 sign_huff_offset -= 7 << lsb_bits;
173
174 if (sign_shift >= 0)
175 sign_huff_offset -= 1 << sign_shift;
176
177 return sign_huff_offset;
178 }
179
180 /** Read a sample, consisting of either, both or neither of entropy-coded MSBs
181 * and plain LSBs. */
182
183 static inline int read_huff_channels(MLPDecodeContext *m, GetBitContext *gbp,
184 unsigned int substr, unsigned int pos)
185 {
186 SubStream *s = &m->substream[substr];
187 unsigned int mat, channel;
188
189 for (mat = 0; mat < s->num_primitive_matrices; mat++)
190 if (s->lsb_bypass[mat])
191 m->bypassed_lsbs[pos + s->blockpos][mat] = get_bits1(gbp);
192
193 for (channel = s->min_channel; channel <= s->max_channel; channel++) {
194 ChannelParams *cp = &m->channel_params[channel];
195 int codebook = cp->codebook;
196 int quant_step_size = s->quant_step_size[channel];
197 int lsb_bits = cp->huff_lsbs - quant_step_size;
198 int result = 0;
199
200 if (codebook > 0)
201 result = get_vlc2(gbp, huff_vlc[codebook-1].table,
202 VLC_BITS, (9 + VLC_BITS - 1) / VLC_BITS);
203
204 if (result < 0)
205 return -1;
206
207 if (lsb_bits > 0)
208 result = (result << lsb_bits) + get_bits(gbp, lsb_bits);
209
210 result += cp->sign_huff_offset;
211 result <<= quant_step_size;
212
213 m->sample_buffer[pos + s->blockpos][channel] = result;
214 }
215
216 return 0;
217 }
218
219 static av_cold int mlp_decode_init(AVCodecContext *avctx)
220 {
221 MLPDecodeContext *m = avctx->priv_data;
222 int substr;
223
224 init_static();
225 m->avctx = avctx;
226 for (substr = 0; substr < MAX_SUBSTREAMS; substr++)
227 m->substream[substr].lossless_check_data = 0xffffffff;
228
229 return 0;
230 }
231
232 /** Read a major sync info header - contains high level information about
233 * the stream - sample rate, channel arrangement etc. Most of this
234 * information is not actually necessary for decoding, only for playback.
235 */
236
237 static int read_major_sync(MLPDecodeContext *m, GetBitContext *gb)
238 {
239 MLPHeaderInfo mh;
240 int substr;
241
242 if (ff_mlp_read_major_sync(m->avctx, &mh, gb) != 0)
243 return -1;
244
245 if (mh.group1_bits == 0) {
246 av_log(m->avctx, AV_LOG_ERROR, "invalid/unknown bits per sample\n");
247 return -1;
248 }
249 if (mh.group2_bits > mh.group1_bits) {
250 av_log(m->avctx, AV_LOG_ERROR,
251 "Channel group 2 cannot have more bits per sample than group 1.\n");
252 return -1;
253 }
254
255 if (mh.group2_samplerate && mh.group2_samplerate != mh.group1_samplerate) {
256 av_log(m->avctx, AV_LOG_ERROR,
257 "Channel groups with differing sample rates are not currently supported.\n");
258 return -1;
259 }
260
261 if (mh.group1_samplerate == 0) {
262 av_log(m->avctx, AV_LOG_ERROR, "invalid/unknown sampling rate\n");
263 return -1;
264 }
265 if (mh.group1_samplerate > MAX_SAMPLERATE) {
266 av_log(m->avctx, AV_LOG_ERROR,
267 "Sampling rate %d is greater than the supported maximum (%d).\n",
268 mh.group1_samplerate, MAX_SAMPLERATE);
269 return -1;
270 }
271 if (mh.access_unit_size > MAX_BLOCKSIZE) {
272 av_log(m->avctx, AV_LOG_ERROR,
273 "Block size %d is greater than the supported maximum (%d).\n",
274 mh.access_unit_size, MAX_BLOCKSIZE);
275 return -1;
276 }
277 if (mh.access_unit_size_pow2 > MAX_BLOCKSIZE_POW2) {
278 av_log(m->avctx, AV_LOG_ERROR,
279 "Block size pow2 %d is greater than the supported maximum (%d).\n",
280 mh.access_unit_size_pow2, MAX_BLOCKSIZE_POW2);
281 return -1;
282 }
283
284 if (mh.num_substreams == 0)
285 return -1;
286 if (m->avctx->codec_id == CODEC_ID_MLP && mh.num_substreams > 2) {
287 av_log(m->avctx, AV_LOG_ERROR, "MLP only supports up to 2 substreams.\n");
288 return -1;
289 }
290 if (mh.num_substreams > MAX_SUBSTREAMS) {
291 av_log(m->avctx, AV_LOG_ERROR,
292 "Number of substreams %d is larger than the maximum supported "
293 "by the decoder. %s\n", mh.num_substreams, sample_message);
294 return -1;
295 }
296
297 m->access_unit_size = mh.access_unit_size;
298 m->access_unit_size_pow2 = mh.access_unit_size_pow2;
299
300 m->num_substreams = mh.num_substreams;
301 m->max_decoded_substream = m->num_substreams - 1;
302
303 m->avctx->sample_rate = mh.group1_samplerate;
304 m->avctx->frame_size = mh.access_unit_size;
305
306 m->avctx->bits_per_raw_sample = mh.group1_bits;
307 if (mh.group1_bits > 16)
308 m->avctx->sample_fmt = SAMPLE_FMT_S32;
309 else
310 m->avctx->sample_fmt = SAMPLE_FMT_S16;
311
312 m->params_valid = 1;
313 for (substr = 0; substr < MAX_SUBSTREAMS; substr++)
314 m->substream[substr].restart_seen = 0;
315
316 return 0;
317 }
318
319 /** Read a restart header from a block in a substream. This contains parameters
320 * required to decode the audio that do not change very often. Generally
321 * (always) present only in blocks following a major sync. */
322
323 static int read_restart_header(MLPDecodeContext *m, GetBitContext *gbp,
324 const uint8_t *buf, unsigned int substr)
325 {
326 SubStream *s = &m->substream[substr];
327 unsigned int ch;
328 int sync_word, tmp;
329 uint8_t checksum;
330 uint8_t lossless_check;
331 int start_count = get_bits_count(gbp);
332
333 sync_word = get_bits(gbp, 13);
334
335 if (sync_word != 0x31ea >> 1) {
336 av_log(m->avctx, AV_LOG_ERROR,
337 "restart header sync incorrect (got 0x%04x)\n", sync_word);
338 return -1;
339 }
340 s->noise_type = get_bits1(gbp);
341
342 skip_bits(gbp, 16); /* Output timestamp */
343
344 s->min_channel = get_bits(gbp, 4);
345 s->max_channel = get_bits(gbp, 4);
346 s->max_matrix_channel = get_bits(gbp, 4);
347
348 if (s->min_channel > s->max_channel) {
349 av_log(m->avctx, AV_LOG_ERROR,
350 "Substream min channel cannot be greater than max channel.\n");
351 return -1;
352 }
353
354 if (m->avctx->request_channels > 0
355 && s->max_channel + 1 >= m->avctx->request_channels
356 && substr < m->max_decoded_substream) {
357 av_log(m->avctx, AV_LOG_INFO,
358 "Extracting %d channel downmix from substream %d. "
359 "Further substreams will be skipped.\n",
360 s->max_channel + 1, substr);
361 m->max_decoded_substream = substr;
362 }
363
364 s->noise_shift = get_bits(gbp, 4);
365 s->noisegen_seed = get_bits(gbp, 23);
366
367 skip_bits(gbp, 19);
368
369 s->data_check_present = get_bits1(gbp);
370 lossless_check = get_bits(gbp, 8);
371 if (substr == m->max_decoded_substream
372 && s->lossless_check_data != 0xffffffff) {
373 tmp = xor_32_to_8(s->lossless_check_data);
374 if (tmp != lossless_check)
375 av_log(m->avctx, AV_LOG_WARNING,
376 "Lossless check failed - expected %02x, calculated %02x.\n",
377 lossless_check, tmp);
378 }
379
380 skip_bits(gbp, 16);
381
382 memset(s->ch_assign, 0, sizeof(s->ch_assign));
383
384 for (ch = 0; ch <= s->max_matrix_channel; ch++) {
385 int ch_assign = get_bits(gbp, 6);
386 if (ch_assign > s->max_matrix_channel) {
387 av_log(m->avctx, AV_LOG_ERROR,
388 "Assignment of matrix channel %d to invalid output channel %d. %s\n",
389 ch, ch_assign, sample_message);
390 return -1;
391 }
392 s->ch_assign[ch_assign] = ch;
393 }
394
395 checksum = ff_mlp_restart_checksum(buf, get_bits_count(gbp) - start_count);
396
397 if (checksum != get_bits(gbp, 8))
398 av_log(m->avctx, AV_LOG_ERROR, "restart header checksum error\n");
399
400 /* Set default decoding parameters. */
401 s->param_presence_flags = 0xff;
402 s->num_primitive_matrices = 0;
403 s->blocksize = 8;
404 s->lossless_check_data = 0;
405
406 memset(s->output_shift , 0, sizeof(s->output_shift ));
407 memset(s->quant_step_size, 0, sizeof(s->quant_step_size));
408
409 for (ch = s->min_channel; ch <= s->max_channel; ch++) {
410 ChannelParams *cp = &m->channel_params[ch];
411 cp->filter_params[FIR].order = 0;
412 cp->filter_params[IIR].order = 0;
413 cp->filter_params[FIR].shift = 0;
414 cp->filter_params[IIR].shift = 0;
415
416 /* Default audio coding is 24-bit raw PCM. */
417 cp->huff_offset = 0;
418 cp->sign_huff_offset = (-1) << 23;
419 cp->codebook = 0;
420 cp->huff_lsbs = 24;
421 }
422
423 if (substr == m->max_decoded_substream) {
424 m->avctx->channels = s->max_matrix_channel + 1;
425 }
426
427 return 0;
428 }
429
430 /** Read parameters for one of the prediction filters. */
431
432 static int read_filter_params(MLPDecodeContext *m, GetBitContext *gbp,
433 unsigned int channel, unsigned int filter)
434 {
435 FilterParams *fp = &m->channel_params[channel].filter_params[filter];
436 const int max_order = filter ? MAX_IIR_ORDER : MAX_FIR_ORDER;
437 const char fchar = filter ? 'I' : 'F';
438 int i, order;
439
440 // Filter is 0 for FIR, 1 for IIR.
441 assert(filter < 2);
442
443 order = get_bits(gbp, 4);
444 if (order > max_order) {
445 av_log(m->avctx, AV_LOG_ERROR,
446 "%cIR filter order %d is greater than maximum %d.\n",
447 fchar, order, max_order);
448 return -1;
449 }
450 fp->order = order;
451
452 if (order > 0) {
453 int coeff_bits, coeff_shift;
454
455 fp->shift = get_bits(gbp, 4);
456
457 coeff_bits = get_bits(gbp, 5);
458 coeff_shift = get_bits(gbp, 3);
459 if (coeff_bits < 1 || coeff_bits > 16) {
460 av_log(m->avctx, AV_LOG_ERROR,
461 "%cIR filter coeff_bits must be between 1 and 16.\n",
462 fchar);
463 return -1;
464 }
465 if (coeff_bits + coeff_shift > 16) {
466 av_log(m->avctx, AV_LOG_ERROR,
467 "Sum of coeff_bits and coeff_shift for %cIR filter must be 16 or less.\n",
468 fchar);
469 return -1;
470 }
471
472 for (i = 0; i < order; i++)
473 fp->coeff[i] = get_sbits(gbp, coeff_bits) << coeff_shift;
474
475 if (get_bits1(gbp)) {
476 int state_bits, state_shift;
477
478 if (filter == FIR) {
479 av_log(m->avctx, AV_LOG_ERROR,
480 "FIR filter has state data specified.\n");
481 return -1;
482 }
483
484 state_bits = get_bits(gbp, 4);
485 state_shift = get_bits(gbp, 4);
486
487 /* TODO: Check validity of state data. */
488
489 for (i = 0; i < order; i++)
490 fp->state[i] = get_sbits(gbp, state_bits) << state_shift;
491 }
492 }
493
494 return 0;
495 }
496
497 /** Read parameters for primitive matrices. */
498
499 static int read_matrix_params(MLPDecodeContext *m, SubStream *s, GetBitContext *gbp)
500 {
501 unsigned int mat, ch;
502
503 s->num_primitive_matrices = get_bits(gbp, 4);
504
505 for (mat = 0; mat < s->num_primitive_matrices; mat++) {
506 int frac_bits, max_chan;
507 s->matrix_out_ch[mat] = get_bits(gbp, 4);
508 frac_bits = get_bits(gbp, 4);
509 s->lsb_bypass [mat] = get_bits1(gbp);
510
511 if (s->matrix_out_ch[mat] > s->max_channel) {
512 av_log(m->avctx, AV_LOG_ERROR,
513 "Invalid channel %d specified as output from matrix.\n",
514 s->matrix_out_ch[mat]);
515 return -1;
516 }
517 if (frac_bits > 14) {
518 av_log(m->avctx, AV_LOG_ERROR,
519 "Too many fractional bits specified.\n");
520 return -1;
521 }
522
523 max_chan = s->max_matrix_channel;
524 if (!s->noise_type)
525 max_chan+=2;
526
527 for (ch = 0; ch <= max_chan; ch++) {
528 int coeff_val = 0;
529 if (get_bits1(gbp))
530 coeff_val = get_sbits(gbp, frac_bits + 2);
531
532 s->matrix_coeff[mat][ch] = coeff_val << (14 - frac_bits);
533 }
534
535 if (s->noise_type)
536 s->matrix_noise_shift[mat] = get_bits(gbp, 4);
537 else
538 s->matrix_noise_shift[mat] = 0;
539 }
540
541 return 0;
542 }
543
544 /** Read channel parameters. */
545
546 static int read_channel_params(MLPDecodeContext *m, unsigned int substr,
547 GetBitContext *gbp, unsigned int ch)
548 {
549 ChannelParams *cp = &m->channel_params[ch];
550 FilterParams *fir = &cp->filter_params[FIR];
551 FilterParams *iir = &cp->filter_params[IIR];
552 SubStream *s = &m->substream[substr];
553
554 if (s->param_presence_flags & PARAM_FIR)
555 if (get_bits1(gbp))
556 if (read_filter_params(m, gbp, ch, FIR) < 0)
557 return -1;
558
559 if (s->param_presence_flags & PARAM_IIR)
560 if (get_bits1(gbp))
561 if (read_filter_params(m, gbp, ch, IIR) < 0)
562 return -1;
563
564 if (fir->order && iir->order &&
565 fir->shift != iir->shift) {
566 av_log(m->avctx, AV_LOG_ERROR,
567 "FIR and IIR filters must use the same precision.\n");
568 return -1;
569 }
570 /* The FIR and IIR filters must have the same precision.
571 * To simplify the filtering code, only the precision of the
572 * FIR filter is considered. If only the IIR filter is employed,
573 * the FIR filter precision is set to that of the IIR filter, so
574 * that the filtering code can use it. */
575 if (!fir->order && iir->order)
576 fir->shift = iir->shift;
577
578 if (s->param_presence_flags & PARAM_HUFFOFFSET)
579 if (get_bits1(gbp))
580 cp->huff_offset = get_sbits(gbp, 15);
581
582 cp->codebook = get_bits(gbp, 2);
583 cp->huff_lsbs = get_bits(gbp, 5);
584
585 cp->sign_huff_offset = calculate_sign_huff(m, substr, ch);
586
587 /* TODO: validate */
588
589 return 0;
590 }
591
592 /** Read decoding parameters that change more often than those in the restart
593 * header. */
594
595 static int read_decoding_params(MLPDecodeContext *m, GetBitContext *gbp,
596 unsigned int substr)
597 {
598 SubStream *s = &m->substream[substr];
599 unsigned int ch;
600
601 if (s->param_presence_flags & PARAM_PRESENCE)
602 if (get_bits1(gbp))
603 s->param_presence_flags = get_bits(gbp, 8);
604
605 if (s->param_presence_flags & PARAM_BLOCKSIZE)
606 if (get_bits1(gbp)) {
607 s->blocksize = get_bits(gbp, 9);
608 if (s->blocksize < 8 || s->blocksize > m->access_unit_size) {
609 av_log(m->avctx, AV_LOG_ERROR, "Invalid blocksize.");
610 s->blocksize = 0;
611 return -1;
612 }
613 }
614
615 if (s->param_presence_flags & PARAM_MATRIX)
616 if (get_bits1(gbp)) {
617 if (read_matrix_params(m, s, gbp) < 0)
618 return -1;
619 }
620
621 if (s->param_presence_flags & PARAM_OUTSHIFT)
622 if (get_bits1(gbp))
623 for (ch = 0; ch <= s->max_matrix_channel; ch++) {
624 s->output_shift[ch] = get_sbits(gbp, 4);
625 }
626
627 if (s->param_presence_flags & PARAM_QUANTSTEP)
628 if (get_bits1(gbp))
629 for (ch = 0; ch <= s->max_channel; ch++) {
630 ChannelParams *cp = &m->channel_params[ch];
631
632 s->quant_step_size[ch] = get_bits(gbp, 4);
633
634 cp->sign_huff_offset = calculate_sign_huff(m, substr, ch);
635 }
636
637 for (ch = s->min_channel; ch <= s->max_channel; ch++)
638 if (get_bits1(gbp)) {
639 if (read_channel_params(m, substr, gbp, ch) < 0)
640 return -1;
641 }
642
643 return 0;
644 }
645
646 #define MSB_MASK(bits) (-1u << bits)
647
648 /** Generate PCM samples using the prediction filters and residual values
649 * read from the data stream, and update the filter state. */
650
651 static void filter_channel(MLPDecodeContext *m, unsigned int substr,
652 unsigned int channel)
653 {
654 SubStream *s = &m->substream[substr];
655 int32_t filter_state_buffer[NUM_FILTERS][MAX_BLOCKSIZE + MAX_FIR_ORDER];
656 FilterParams *fp[NUM_FILTERS] = { &m->channel_params[channel].filter_params[FIR],
657 &m->channel_params[channel].filter_params[IIR], };
658 unsigned int filter_shift = fp[FIR]->shift;
659 int32_t mask = MSB_MASK(s->quant_step_size[channel]);
660 int index = MAX_BLOCKSIZE;
661 int i;
662
663 memcpy(&filter_state_buffer[FIR][MAX_BLOCKSIZE], &fp[FIR]->state[0],
664 MAX_FIR_ORDER * sizeof(int32_t));
665 memcpy(&filter_state_buffer[IIR][MAX_BLOCKSIZE], &fp[IIR]->state[0],
666 MAX_IIR_ORDER * sizeof(int32_t));
667
668 for (i = 0; i < s->blocksize; i++) {
669 int32_t residual = m->sample_buffer[i + s->blockpos][channel];
670 unsigned int order;
671 int64_t accum = 0;
672 int32_t result;
673
674 /* TODO: Move this code to DSPContext? */
675
676 for (order = 0; order < fp[FIR]->order; order++)
677 accum += (int64_t)filter_state_buffer[FIR][index + order] *
678 fp[FIR]->coeff[order];
679 for (order = 0; order < fp[IIR]->order; order++)
680 accum += (int64_t)filter_state_buffer[IIR][index + order] *
681 fp[IIR]->coeff[order];
682
683 accum = accum >> filter_shift;
684 result = (accum + residual) & mask;
685
686 --index;
687
688 filter_state_buffer[FIR][index] = result;
689 filter_state_buffer[IIR][index] = result - accum;
690
691 m->sample_buffer[i + s->blockpos][channel] = result;
692 }
693
694 memcpy(&fp[FIR]->state[0], &filter_state_buffer[FIR][index],
695 MAX_FIR_ORDER * sizeof(int32_t));
696 memcpy(&fp[IIR]->state[0], &filter_state_buffer[IIR][index],
697 MAX_IIR_ORDER * sizeof(int32_t));
698 }
699
700 /** Read a block of PCM residual data (or actual if no filtering active). */
701
702 static int read_block_data(MLPDecodeContext *m, GetBitContext *gbp,
703 unsigned int substr)
704 {
705 SubStream *s = &m->substream[substr];
706 unsigned int i, ch, expected_stream_pos = 0;
707
708 if (s->data_check_present) {
709 expected_stream_pos = get_bits_count(gbp);
710 expected_stream_pos += get_bits(gbp, 16);
711 av_log(m->avctx, AV_LOG_WARNING, "This file contains some features "
712 "we have not tested yet. %s\n", sample_message);
713 }
714
715 if (s->blockpos + s->blocksize > m->access_unit_size) {
716 av_log(m->avctx, AV_LOG_ERROR, "too many audio samples in frame\n");
717 return -1;
718 }
719
720 memset(&m->bypassed_lsbs[s->blockpos][0], 0,
721 s->blocksize * sizeof(m->bypassed_lsbs[0]));
722
723 for (i = 0; i < s->blocksize; i++) {
724 if (read_huff_channels(m, gbp, substr, i) < 0)
725 return -1;
726 }
727
728 for (ch = s->min_channel; ch <= s->max_channel; ch++) {
729 filter_channel(m, substr, ch);
730 }
731
732 s->blockpos += s->blocksize;
733
734 if (s->data_check_present) {
735 if (get_bits_count(gbp) != expected_stream_pos)
736 av_log(m->avctx, AV_LOG_ERROR, "block data length mismatch\n");
737 skip_bits(gbp, 8);
738 }
739
740 return 0;
741 }
742
743 /** Data table used for TrueHD noise generation function. */
744
745 static const int8_t noise_table[256] = {
746 30, 51, 22, 54, 3, 7, -4, 38, 14, 55, 46, 81, 22, 58, -3, 2,
747 52, 31, -7, 51, 15, 44, 74, 30, 85, -17, 10, 33, 18, 80, 28, 62,
748 10, 32, 23, 69, 72, 26, 35, 17, 73, 60, 8, 56, 2, 6, -2, -5,
749 51, 4, 11, 50, 66, 76, 21, 44, 33, 47, 1, 26, 64, 48, 57, 40,
750 38, 16, -10, -28, 92, 22, -18, 29, -10, 5, -13, 49, 19, 24, 70, 34,
751 61, 48, 30, 14, -6, 25, 58, 33, 42, 60, 67, 17, 54, 17, 22, 30,
752 67, 44, -9, 50, -11, 43, 40, 32, 59, 82, 13, 49, -14, 55, 60, 36,
753 48, 49, 31, 47, 15, 12, 4, 65, 1, 23, 29, 39, 45, -2, 84, 69,
754 0, 72, 37, 57, 27, 41, -15, -16, 35, 31, 14, 61, 24, 0, 27, 24,
755 16, 41, 55, 34, 53, 9, 56, 12, 25, 29, 53, 5, 20, -20, -8, 20,
756 13, 28, -3, 78, 38, 16, 11, 62, 46, 29, 21, 24, 46, 65, 43, -23,
757 89, 18, 74, 21, 38, -12, 19, 12, -19, 8, 15, 33, 4, 57, 9, -8,
758 36, 35, 26, 28, 7, 83, 63, 79, 75, 11, 3, 87, 37, 47, 34, 40,
759 39, 19, 20, 42, 27, 34, 39, 77, 13, 42, 59, 64, 45, -1, 32, 37,
760 45, -5, 53, -6, 7, 36, 50, 23, 6, 32, 9, -21, 18, 71, 27, 52,
761 -25, 31, 35, 42, -1, 68, 63, 52, 26, 43, 66, 37, 41, 25, 40, 70,
762 };
763
764 /** Noise generation functions.
765 * I'm not sure what these are for - they seem to be some kind of pseudorandom
766 * sequence generators, used to generate noise data which is used when the
767 * channels are rematrixed. I'm not sure if they provide a practical benefit
768 * to compression, or just obfuscate the decoder. Are they for some kind of
769 * dithering? */
770
771 /** Generate two channels of noise, used in the matrix when
772 * restart sync word == 0x31ea. */
773
774 static void generate_2_noise_channels(MLPDecodeContext *m, unsigned int substr)
775 {
776 SubStream *s = &m->substream[substr];
777 unsigned int i;
778 uint32_t seed = s->noisegen_seed;
779 unsigned int maxchan = s->max_matrix_channel;
780
781 for (i = 0; i < s->blockpos; i++) {
782 uint16_t seed_shr7 = seed >> 7;
783 m->sample_buffer[i][maxchan+1] = ((int8_t)(seed >> 15)) << s->noise_shift;
784 m->sample_buffer[i][maxchan+2] = ((int8_t) seed_shr7) << s->noise_shift;
785
786 seed = (seed << 16) ^ seed_shr7 ^ (seed_shr7 << 5);
787 }
788
789 s->noisegen_seed = seed;
790 }
791
792 /** Generate a block of noise, used when restart sync word == 0x31eb. */
793
794 static void fill_noise_buffer(MLPDecodeContext *m, unsigned int substr)
795 {
796 SubStream *s = &m->substream[substr];
797 unsigned int i;
798 uint32_t seed = s->noisegen_seed;
799
800 for (i = 0; i < m->access_unit_size_pow2; i++) {
801 uint8_t seed_shr15 = seed >> 15;
802 m->noise_buffer[i] = noise_table[seed_shr15];
803 seed = (seed << 8) ^ seed_shr15 ^ (seed_shr15 << 5);
804 }
805
806 s->noisegen_seed = seed;
807 }
808
809
810 /** Apply the channel matrices in turn to reconstruct the original audio
811 * samples. */
812
813 static void rematrix_channels(MLPDecodeContext *m, unsigned int substr)
814 {
815 SubStream *s = &m->substream[substr];
816 unsigned int mat, src_ch, i;
817 unsigned int maxchan;
818
819 maxchan = s->max_matrix_channel;
820 if (!s->noise_type) {
821 generate_2_noise_channels(m, substr);
822 maxchan += 2;
823 } else {
824 fill_noise_buffer(m, substr);
825 }
826
827 for (mat = 0; mat < s->num_primitive_matrices; mat++) {
828 int matrix_noise_shift = s->matrix_noise_shift[mat];
829 unsigned int dest_ch = s->matrix_out_ch[mat];
830 int32_t mask = MSB_MASK(s->quant_step_size[dest_ch]);
831
832 /* TODO: DSPContext? */
833
834 for (i = 0; i < s->blockpos; i++) {
835 int64_t accum = 0;
836 for (src_ch = 0; src_ch <= maxchan; src_ch++) {
837 accum += (int64_t)m->sample_buffer[i][src_ch]
838 * s->matrix_coeff[mat][src_ch];
839 }
840 if (matrix_noise_shift) {
841 uint32_t index = s->num_primitive_matrices - mat;
842 index = (i * (index * 2 + 1) + index) & (m->access_unit_size_pow2 - 1);
843 accum += m->noise_buffer[index] << (matrix_noise_shift + 7);
844 }
845 m->sample_buffer[i][dest_ch] = ((accum >> 14) & mask)
846 + m->bypassed_lsbs[i][mat];
847 }
848 }
849 }
850
851 /** Write the audio data into the output buffer. */
852
853 static int output_data_internal(MLPDecodeContext *m, unsigned int substr,
854 uint8_t *data, unsigned int *data_size, int is32)
855 {
856 SubStream *s = &m->substream[substr];
857 unsigned int i, out_ch = 0;
858 int32_t *data_32 = (int32_t*) data;
859 int16_t *data_16 = (int16_t*) data;
860
861 if (*data_size < (s->max_channel + 1) * s->blockpos * (is32 ? 4 : 2))
862 return -1;
863
864 for (i = 0; i < s->blockpos; i++) {
865 for (out_ch = 0; out_ch <= s->max_matrix_channel; out_ch++) {
866 int mat_ch = s->ch_assign[out_ch];
867 int32_t sample = m->sample_buffer[i][mat_ch]
868 << s->output_shift[mat_ch];
869 s->lossless_check_data ^= (sample & 0xffffff) << mat_ch;
870 if (is32) *data_32++ = sample << 8;
871 else *data_16++ = sample >> 8;
872 }
873 }
874
875 *data_size = i * out_ch * (is32 ? 4 : 2);
876
877 return 0;
878 }
879
880 static int output_data(MLPDecodeContext *m, unsigned int substr,
881 uint8_t *data, unsigned int *data_size)
882 {
883 if (m->avctx->sample_fmt == SAMPLE_FMT_S32)
884 return output_data_internal(m, substr, data, data_size, 1);
885 else
886 return output_data_internal(m, substr, data, data_size, 0);
887 }
888
889
890 /** Read an access unit from the stream.
891 * Returns < 0 on error, 0 if not enough data is present in the input stream
892 * otherwise returns the number of bytes consumed. */
893
894 static int read_access_unit(AVCodecContext *avctx, void* data, int *data_size,
895 const uint8_t *buf, int buf_size)
896 {
897 MLPDecodeContext *m = avctx->priv_data;
898 GetBitContext gb;
899 unsigned int length, substr;
900 unsigned int substream_start;
901 unsigned int header_size = 4;
902 unsigned int substr_header_size = 0;
903 uint8_t substream_parity_present[MAX_SUBSTREAMS];
904 uint16_t substream_data_len[MAX_SUBSTREAMS];
905 uint8_t parity_bits;
906
907 if (buf_size < 4)
908 return 0;
909
910 length = (AV_RB16(buf) & 0xfff) * 2;
911
912 if (length > buf_size)
913 return -1;
914
915 init_get_bits(&gb, (buf + 4), (length - 4) * 8);
916
917 if (show_bits_long(&gb, 31) == (0xf8726fba >> 1)) {
918 if (read_major_sync(m, &gb) < 0)
919 goto error;
920 header_size += 28;
921 }
922
923 if (!m->params_valid) {
924 av_log(m->avctx, AV_LOG_WARNING,
925 "Stream parameters not seen; skipping frame.\n");
926 *data_size = 0;
927 return length;
928 }
929
930 substream_start = 0;
931
932 for (substr = 0; substr < m->num_substreams; substr++) {
933 int extraword_present, checkdata_present, end;
934
935 extraword_present = get_bits1(&gb);
936 skip_bits1(&gb);
937 checkdata_present = get_bits1(&gb);
938 skip_bits1(&gb);
939
940 end = get_bits(&gb, 12) * 2;
941
942 substr_header_size += 2;
943
944 if (extraword_present) {
945 skip_bits(&gb, 16);
946 substr_header_size += 2;
947 }
948
949 if (end + header_size + substr_header_size > length) {
950 av_log(m->avctx, AV_LOG_ERROR,
951 "Indicated length of substream %d data goes off end of "
952 "packet.\n", substr);
953 end = length - header_size - substr_header_size;
954 }
955
956 if (end < substream_start) {
957 av_log(avctx, AV_LOG_ERROR,
958 "Indicated end offset of substream %d data "
959 "is smaller than calculated start offset.\n",
960 substr);
961 goto error;
962 }
963
964 if (substr > m->max_decoded_substream)
965 continue;
966
967 substream_parity_present[substr] = checkdata_present;
968 substream_data_len[substr] = end - substream_start;
969 substream_start = end;
970 }
971
972 parity_bits = ff_mlp_calculate_parity(buf, 4);
973 parity_bits ^= ff_mlp_calculate_parity(buf + header_size, substr_header_size);
974
975 if ((((parity_bits >> 4) ^ parity_bits) & 0xF) != 0xF) {
976 av_log(avctx, AV_LOG_ERROR, "Parity check failed.\n");
977 goto error;
978 }
979
980 buf += header_size + substr_header_size;
981
982 for (substr = 0; substr <= m->max_decoded_substream; substr++) {
983 SubStream *s = &m->substream[substr];
984 init_get_bits(&gb, buf, substream_data_len[substr] * 8);
985
986 s->blockpos = 0;
987 do {
988 if (get_bits1(&gb)) {
989 if (get_bits1(&gb)) {
990 /* A restart header should be present. */
991 if (read_restart_header(m, &gb, buf, substr) < 0)
992 goto next_substr;
993 s->restart_seen = 1;
994 }
995
996 if (!s->restart_seen) {
997 av_log(m->avctx, AV_LOG_ERROR,
998 "No restart header present in substream %d.\n",
999 substr);
1000 goto next_substr;
1001 }
1002
1003 if (read_decoding_params(m, &gb, substr) < 0)
1004 goto next_substr;
1005 }
1006
1007 if (!s->restart_seen) {
1008 av_log(m->avctx, AV_LOG_ERROR,
1009 "No restart header present in substream %d.\n",
1010 substr);
1011 goto next_substr;
1012 }
1013
1014 if (read_block_data(m, &gb, substr) < 0)
1015 return -1;
1016
1017 } while ((get_bits_count(&gb) < substream_data_len[substr] * 8)
1018 && get_bits1(&gb) == 0);
1019
1020 skip_bits(&gb, (-get_bits_count(&gb)) & 15);
1021 if (substream_data_len[substr] * 8 - get_bits_count(&gb) >= 32 &&
1022 (show_bits_long(&gb, 32) == END_OF_STREAM ||
1023 show_bits_long(&gb, 20) == 0xd234e)) {
1024 skip_bits(&gb, 18);
1025 if (substr == m->max_decoded_substream)
1026 av_log(m->avctx, AV_LOG_INFO, "End of stream indicated.\n");
1027
1028 if (get_bits1(&gb)) {
1029 int shorten_by = get_bits(&gb, 13);
1030 shorten_by = FFMIN(shorten_by, s->blockpos);
1031 s->blockpos -= shorten_by;
1032 } else
1033 skip_bits(&gb, 13);
1034 }
1035 if (substream_data_len[substr] * 8 - get_bits_count(&gb) >= 16 &&
1036 substream_parity_present[substr]) {
1037 uint8_t parity, checksum;
1038
1039 parity = ff_mlp_calculate_parity(buf, substream_data_len[substr] - 2);
1040 if ((parity ^ get_bits(&gb, 8)) != 0xa9)
1041 av_log(m->avctx, AV_LOG_ERROR,
1042 "Substream %d parity check failed.\n", substr);
1043
1044 checksum = ff_mlp_checksum8(buf, substream_data_len[substr] - 2);
1045 if (checksum != get_bits(&gb, 8))
1046 av_log(m->avctx, AV_LOG_ERROR, "Substream %d checksum failed.\n",
1047 substr);
1048 }
1049 if (substream_data_len[substr] * 8 != get_bits_count(&gb)) {
1050 av_log(m->avctx, AV_LOG_ERROR, "substream %d length mismatch\n",
1051 substr);
1052 return -1;
1053 }
1054
1055 next_substr:
1056 buf += substream_data_len[substr];
1057 }
1058
1059 rematrix_channels(m, m->max_decoded_substream);
1060
1061 if (output_data(m, m->max_decoded_substream, data, data_size) < 0)
1062 return -1;
1063
1064 return length;
1065
1066 error:
1067 m->params_valid = 0;
1068 return -1;
1069 }
1070
1071 #if CONFIG_MLP_DECODER
1072 AVCodec mlp_decoder = {
1073 "mlp",
1074 CODEC_TYPE_AUDIO,
1075 CODEC_ID_MLP,
1076 sizeof(MLPDecodeContext),
1077 mlp_decode_init,
1078 NULL,
1079 NULL,
1080 read_access_unit,
1081 .long_name = NULL_IF_CONFIG_SMALL("MLP (Meridian Lossless Packing)"),
1082 };
1083 #endif /* CONFIG_MLP_DECODER */
1084
1085 #if CONFIG_TRUEHD_DECODER
1086 AVCodec truehd_decoder = {
1087 "truehd",
1088 CODEC_TYPE_AUDIO,
1089 CODEC_ID_TRUEHD,
1090 sizeof(MLPDecodeContext),
1091 mlp_decode_init,
1092 NULL,
1093 NULL,
1094 read_access_unit,
1095 .long_name = NULL_IF_CONFIG_SMALL("TrueHD"),
1096 };
1097 #endif /* CONFIG_TRUEHD_DECODER */