8bcbd2129b6e498a6f5a2d6279c96a72f8d1b134
[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 j, i;
662
663 for (j = 0; j < NUM_FILTERS; j++) {
664 memcpy(&filter_state_buffer[j][MAX_BLOCKSIZE], &fp[j]->state[0],
665 MAX_FIR_ORDER * sizeof(int32_t));
666 }
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 (j = 0; j < NUM_FILTERS; j++)
677 for (order = 0; order < fp[j]->order; order++)
678 accum += (int64_t)filter_state_buffer[j][index + order] *
679 fp[j]->coeff[order];
680
681 accum = accum >> filter_shift;
682 result = (accum + residual) & mask;
683
684 --index;
685
686 filter_state_buffer[FIR][index] = result;
687 filter_state_buffer[IIR][index] = result - accum;
688
689 m->sample_buffer[i + s->blockpos][channel] = result;
690 }
691
692 for (j = 0; j < NUM_FILTERS; j++) {
693 memcpy(&fp[j]->state[0], &filter_state_buffer[j][index],
694 MAX_FIR_ORDER * sizeof(int32_t));
695 }
696 }
697
698 /** Read a block of PCM residual data (or actual if no filtering active). */
699
700 static int read_block_data(MLPDecodeContext *m, GetBitContext *gbp,
701 unsigned int substr)
702 {
703 SubStream *s = &m->substream[substr];
704 unsigned int i, ch, expected_stream_pos = 0;
705
706 if (s->data_check_present) {
707 expected_stream_pos = get_bits_count(gbp);
708 expected_stream_pos += get_bits(gbp, 16);
709 av_log(m->avctx, AV_LOG_WARNING, "This file contains some features "
710 "we have not tested yet. %s\n", sample_message);
711 }
712
713 if (s->blockpos + s->blocksize > m->access_unit_size) {
714 av_log(m->avctx, AV_LOG_ERROR, "too many audio samples in frame\n");
715 return -1;
716 }
717
718 memset(&m->bypassed_lsbs[s->blockpos][0], 0,
719 s->blocksize * sizeof(m->bypassed_lsbs[0]));
720
721 for (i = 0; i < s->blocksize; i++) {
722 if (read_huff_channels(m, gbp, substr, i) < 0)
723 return -1;
724 }
725
726 for (ch = s->min_channel; ch <= s->max_channel; ch++) {
727 filter_channel(m, substr, ch);
728 }
729
730 s->blockpos += s->blocksize;
731
732 if (s->data_check_present) {
733 if (get_bits_count(gbp) != expected_stream_pos)
734 av_log(m->avctx, AV_LOG_ERROR, "block data length mismatch\n");
735 skip_bits(gbp, 8);
736 }
737
738 return 0;
739 }
740
741 /** Data table used for TrueHD noise generation function. */
742
743 static const int8_t noise_table[256] = {
744 30, 51, 22, 54, 3, 7, -4, 38, 14, 55, 46, 81, 22, 58, -3, 2,
745 52, 31, -7, 51, 15, 44, 74, 30, 85, -17, 10, 33, 18, 80, 28, 62,
746 10, 32, 23, 69, 72, 26, 35, 17, 73, 60, 8, 56, 2, 6, -2, -5,
747 51, 4, 11, 50, 66, 76, 21, 44, 33, 47, 1, 26, 64, 48, 57, 40,
748 38, 16, -10, -28, 92, 22, -18, 29, -10, 5, -13, 49, 19, 24, 70, 34,
749 61, 48, 30, 14, -6, 25, 58, 33, 42, 60, 67, 17, 54, 17, 22, 30,
750 67, 44, -9, 50, -11, 43, 40, 32, 59, 82, 13, 49, -14, 55, 60, 36,
751 48, 49, 31, 47, 15, 12, 4, 65, 1, 23, 29, 39, 45, -2, 84, 69,
752 0, 72, 37, 57, 27, 41, -15, -16, 35, 31, 14, 61, 24, 0, 27, 24,
753 16, 41, 55, 34, 53, 9, 56, 12, 25, 29, 53, 5, 20, -20, -8, 20,
754 13, 28, -3, 78, 38, 16, 11, 62, 46, 29, 21, 24, 46, 65, 43, -23,
755 89, 18, 74, 21, 38, -12, 19, 12, -19, 8, 15, 33, 4, 57, 9, -8,
756 36, 35, 26, 28, 7, 83, 63, 79, 75, 11, 3, 87, 37, 47, 34, 40,
757 39, 19, 20, 42, 27, 34, 39, 77, 13, 42, 59, 64, 45, -1, 32, 37,
758 45, -5, 53, -6, 7, 36, 50, 23, 6, 32, 9, -21, 18, 71, 27, 52,
759 -25, 31, 35, 42, -1, 68, 63, 52, 26, 43, 66, 37, 41, 25, 40, 70,
760 };
761
762 /** Noise generation functions.
763 * I'm not sure what these are for - they seem to be some kind of pseudorandom
764 * sequence generators, used to generate noise data which is used when the
765 * channels are rematrixed. I'm not sure if they provide a practical benefit
766 * to compression, or just obfuscate the decoder. Are they for some kind of
767 * dithering? */
768
769 /** Generate two channels of noise, used in the matrix when
770 * restart sync word == 0x31ea. */
771
772 static void generate_2_noise_channels(MLPDecodeContext *m, unsigned int substr)
773 {
774 SubStream *s = &m->substream[substr];
775 unsigned int i;
776 uint32_t seed = s->noisegen_seed;
777 unsigned int maxchan = s->max_matrix_channel;
778
779 for (i = 0; i < s->blockpos; i++) {
780 uint16_t seed_shr7 = seed >> 7;
781 m->sample_buffer[i][maxchan+1] = ((int8_t)(seed >> 15)) << s->noise_shift;
782 m->sample_buffer[i][maxchan+2] = ((int8_t) seed_shr7) << s->noise_shift;
783
784 seed = (seed << 16) ^ seed_shr7 ^ (seed_shr7 << 5);
785 }
786
787 s->noisegen_seed = seed;
788 }
789
790 /** Generate a block of noise, used when restart sync word == 0x31eb. */
791
792 static void fill_noise_buffer(MLPDecodeContext *m, unsigned int substr)
793 {
794 SubStream *s = &m->substream[substr];
795 unsigned int i;
796 uint32_t seed = s->noisegen_seed;
797
798 for (i = 0; i < m->access_unit_size_pow2; i++) {
799 uint8_t seed_shr15 = seed >> 15;
800 m->noise_buffer[i] = noise_table[seed_shr15];
801 seed = (seed << 8) ^ seed_shr15 ^ (seed_shr15 << 5);
802 }
803
804 s->noisegen_seed = seed;
805 }
806
807
808 /** Apply the channel matrices in turn to reconstruct the original audio
809 * samples. */
810
811 static void rematrix_channels(MLPDecodeContext *m, unsigned int substr)
812 {
813 SubStream *s = &m->substream[substr];
814 unsigned int mat, src_ch, i;
815 unsigned int maxchan;
816
817 maxchan = s->max_matrix_channel;
818 if (!s->noise_type) {
819 generate_2_noise_channels(m, substr);
820 maxchan += 2;
821 } else {
822 fill_noise_buffer(m, substr);
823 }
824
825 for (mat = 0; mat < s->num_primitive_matrices; mat++) {
826 int matrix_noise_shift = s->matrix_noise_shift[mat];
827 unsigned int dest_ch = s->matrix_out_ch[mat];
828 int32_t mask = MSB_MASK(s->quant_step_size[dest_ch]);
829
830 /* TODO: DSPContext? */
831
832 for (i = 0; i < s->blockpos; i++) {
833 int64_t accum = 0;
834 for (src_ch = 0; src_ch <= maxchan; src_ch++) {
835 accum += (int64_t)m->sample_buffer[i][src_ch]
836 * s->matrix_coeff[mat][src_ch];
837 }
838 if (matrix_noise_shift) {
839 uint32_t index = s->num_primitive_matrices - mat;
840 index = (i * (index * 2 + 1) + index) & (m->access_unit_size_pow2 - 1);
841 accum += m->noise_buffer[index] << (matrix_noise_shift + 7);
842 }
843 m->sample_buffer[i][dest_ch] = ((accum >> 14) & mask)
844 + m->bypassed_lsbs[i][mat];
845 }
846 }
847 }
848
849 /** Write the audio data into the output buffer. */
850
851 static int output_data_internal(MLPDecodeContext *m, unsigned int substr,
852 uint8_t *data, unsigned int *data_size, int is32)
853 {
854 SubStream *s = &m->substream[substr];
855 unsigned int i, out_ch = 0;
856 int32_t *data_32 = (int32_t*) data;
857 int16_t *data_16 = (int16_t*) data;
858
859 if (*data_size < (s->max_channel + 1) * s->blockpos * (is32 ? 4 : 2))
860 return -1;
861
862 for (i = 0; i < s->blockpos; i++) {
863 for (out_ch = 0; out_ch <= s->max_matrix_channel; out_ch++) {
864 int mat_ch = s->ch_assign[out_ch];
865 int32_t sample = m->sample_buffer[i][mat_ch]
866 << s->output_shift[mat_ch];
867 s->lossless_check_data ^= (sample & 0xffffff) << mat_ch;
868 if (is32) *data_32++ = sample << 8;
869 else *data_16++ = sample >> 8;
870 }
871 }
872
873 *data_size = i * out_ch * (is32 ? 4 : 2);
874
875 return 0;
876 }
877
878 static int output_data(MLPDecodeContext *m, unsigned int substr,
879 uint8_t *data, unsigned int *data_size)
880 {
881 if (m->avctx->sample_fmt == SAMPLE_FMT_S32)
882 return output_data_internal(m, substr, data, data_size, 1);
883 else
884 return output_data_internal(m, substr, data, data_size, 0);
885 }
886
887
888 /** Read an access unit from the stream.
889 * Returns < 0 on error, 0 if not enough data is present in the input stream
890 * otherwise returns the number of bytes consumed. */
891
892 static int read_access_unit(AVCodecContext *avctx, void* data, int *data_size,
893 const uint8_t *buf, int buf_size)
894 {
895 MLPDecodeContext *m = avctx->priv_data;
896 GetBitContext gb;
897 unsigned int length, substr;
898 unsigned int substream_start;
899 unsigned int header_size = 4;
900 unsigned int substr_header_size = 0;
901 uint8_t substream_parity_present[MAX_SUBSTREAMS];
902 uint16_t substream_data_len[MAX_SUBSTREAMS];
903 uint8_t parity_bits;
904
905 if (buf_size < 4)
906 return 0;
907
908 length = (AV_RB16(buf) & 0xfff) * 2;
909
910 if (length > buf_size)
911 return -1;
912
913 init_get_bits(&gb, (buf + 4), (length - 4) * 8);
914
915 if (show_bits_long(&gb, 31) == (0xf8726fba >> 1)) {
916 if (read_major_sync(m, &gb) < 0)
917 goto error;
918 header_size += 28;
919 }
920
921 if (!m->params_valid) {
922 av_log(m->avctx, AV_LOG_WARNING,
923 "Stream parameters not seen; skipping frame.\n");
924 *data_size = 0;
925 return length;
926 }
927
928 substream_start = 0;
929
930 for (substr = 0; substr < m->num_substreams; substr++) {
931 int extraword_present, checkdata_present, end;
932
933 extraword_present = get_bits1(&gb);
934 skip_bits1(&gb);
935 checkdata_present = get_bits1(&gb);
936 skip_bits1(&gb);
937
938 end = get_bits(&gb, 12) * 2;
939
940 substr_header_size += 2;
941
942 if (extraword_present) {
943 skip_bits(&gb, 16);
944 substr_header_size += 2;
945 }
946
947 if (end + header_size + substr_header_size > length) {
948 av_log(m->avctx, AV_LOG_ERROR,
949 "Indicated length of substream %d data goes off end of "
950 "packet.\n", substr);
951 end = length - header_size - substr_header_size;
952 }
953
954 if (end < substream_start) {
955 av_log(avctx, AV_LOG_ERROR,
956 "Indicated end offset of substream %d data "
957 "is smaller than calculated start offset.\n",
958 substr);
959 goto error;
960 }
961
962 if (substr > m->max_decoded_substream)
963 continue;
964
965 substream_parity_present[substr] = checkdata_present;
966 substream_data_len[substr] = end - substream_start;
967 substream_start = end;
968 }
969
970 parity_bits = ff_mlp_calculate_parity(buf, 4);
971 parity_bits ^= ff_mlp_calculate_parity(buf + header_size, substr_header_size);
972
973 if ((((parity_bits >> 4) ^ parity_bits) & 0xF) != 0xF) {
974 av_log(avctx, AV_LOG_ERROR, "Parity check failed.\n");
975 goto error;
976 }
977
978 buf += header_size + substr_header_size;
979
980 for (substr = 0; substr <= m->max_decoded_substream; substr++) {
981 SubStream *s = &m->substream[substr];
982 init_get_bits(&gb, buf, substream_data_len[substr] * 8);
983
984 s->blockpos = 0;
985 do {
986 if (get_bits1(&gb)) {
987 if (get_bits1(&gb)) {
988 /* A restart header should be present. */
989 if (read_restart_header(m, &gb, buf, substr) < 0)
990 goto next_substr;
991 s->restart_seen = 1;
992 }
993
994 if (!s->restart_seen) {
995 av_log(m->avctx, AV_LOG_ERROR,
996 "No restart header present in substream %d.\n",
997 substr);
998 goto next_substr;
999 }
1000
1001 if (read_decoding_params(m, &gb, substr) < 0)
1002 goto next_substr;
1003 }
1004
1005 if (!s->restart_seen) {
1006 av_log(m->avctx, AV_LOG_ERROR,
1007 "No restart header present in substream %d.\n",
1008 substr);
1009 goto next_substr;
1010 }
1011
1012 if (read_block_data(m, &gb, substr) < 0)
1013 return -1;
1014
1015 } while ((get_bits_count(&gb) < substream_data_len[substr] * 8)
1016 && get_bits1(&gb) == 0);
1017
1018 skip_bits(&gb, (-get_bits_count(&gb)) & 15);
1019 if (substream_data_len[substr] * 8 - get_bits_count(&gb) >= 32 &&
1020 (show_bits_long(&gb, 32) == END_OF_STREAM ||
1021 show_bits_long(&gb, 20) == 0xd234e)) {
1022 skip_bits(&gb, 18);
1023 if (substr == m->max_decoded_substream)
1024 av_log(m->avctx, AV_LOG_INFO, "End of stream indicated.\n");
1025
1026 if (get_bits1(&gb)) {
1027 int shorten_by = get_bits(&gb, 13);
1028 shorten_by = FFMIN(shorten_by, s->blockpos);
1029 s->blockpos -= shorten_by;
1030 } else
1031 skip_bits(&gb, 13);
1032 }
1033 if (substream_data_len[substr] * 8 - get_bits_count(&gb) >= 16 &&
1034 substream_parity_present[substr]) {
1035 uint8_t parity, checksum;
1036
1037 parity = ff_mlp_calculate_parity(buf, substream_data_len[substr] - 2);
1038 if ((parity ^ get_bits(&gb, 8)) != 0xa9)
1039 av_log(m->avctx, AV_LOG_ERROR,
1040 "Substream %d parity check failed.\n", substr);
1041
1042 checksum = ff_mlp_checksum8(buf, substream_data_len[substr] - 2);
1043 if (checksum != get_bits(&gb, 8))
1044 av_log(m->avctx, AV_LOG_ERROR, "Substream %d checksum failed.\n",
1045 substr);
1046 }
1047 if (substream_data_len[substr] * 8 != get_bits_count(&gb)) {
1048 av_log(m->avctx, AV_LOG_ERROR, "substream %d length mismatch\n",
1049 substr);
1050 return -1;
1051 }
1052
1053 next_substr:
1054 buf += substream_data_len[substr];
1055 }
1056
1057 rematrix_channels(m, m->max_decoded_substream);
1058
1059 if (output_data(m, m->max_decoded_substream, data, data_size) < 0)
1060 return -1;
1061
1062 return length;
1063
1064 error:
1065 m->params_valid = 0;
1066 return -1;
1067 }
1068
1069 #if CONFIG_MLP_DECODER
1070 AVCodec mlp_decoder = {
1071 "mlp",
1072 CODEC_TYPE_AUDIO,
1073 CODEC_ID_MLP,
1074 sizeof(MLPDecodeContext),
1075 mlp_decode_init,
1076 NULL,
1077 NULL,
1078 read_access_unit,
1079 .long_name = NULL_IF_CONFIG_SMALL("MLP (Meridian Lossless Packing)"),
1080 };
1081 #endif /* CONFIG_MLP_DECODER */
1082
1083 #if CONFIG_TRUEHD_DECODER
1084 AVCodec truehd_decoder = {
1085 "truehd",
1086 CODEC_TYPE_AUDIO,
1087 CODEC_ID_TRUEHD,
1088 sizeof(MLPDecodeContext),
1089 mlp_decode_init,
1090 NULL,
1091 NULL,
1092 read_access_unit,
1093 .long_name = NULL_IF_CONFIG_SMALL("TrueHD"),
1094 };
1095 #endif /* CONFIG_TRUEHD_DECODER */