3 * Copyright (c) 2007-2008 Ian Caulfield
5 * This file is part of FFmpeg.
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.
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.
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
30 #include "libavutil/internal.h"
31 #include "libavutil/intreadwrite.h"
32 #include "libavutil/channel_layout.h"
35 #include "libavutil/crc.h"
37 #include "mlp_parser.h"
42 /** number of bits used for VLC lookup - longest Huffman code is 9 */
45 #define VLC_STATIC_SIZE 64
48 #define VLC_STATIC_SIZE 512
51 typedef struct SubStream {
52 /// Set if a valid restart header has been read. Otherwise the substream cannot be decoded.
56 /** restart header data */
57 /// The type of noise to be used in the rematrix stage.
60 /// The index of the first channel coded in this substream.
62 /// The index of the last channel coded in this substream.
64 /// The number of channels input into the rematrix stage.
65 uint8_t max_matrix_channel;
66 /// For each channel output by the matrix, the output channel to map it to
67 uint8_t ch_assign[MAX_CHANNELS];
68 /// The channel layout for this substream
70 /// The matrix encoding mode for this substream
71 enum AVMatrixEncoding matrix_encoding;
73 /// Channel coding parameters for channels in the substream
74 ChannelParams channel_params[MAX_CHANNELS];
76 /// The left shift applied to random noise in 0x31ea substreams.
78 /// The current seed value for the pseudorandom noise generator(s).
79 uint32_t noisegen_seed;
81 /// Set if the substream contains extra info to check the size of VLC blocks.
82 uint8_t data_check_present;
84 /// Bitmask of which parameter sets are conveyed in a decoding parameter block.
85 uint8_t param_presence_flags;
86 #define PARAM_BLOCKSIZE (1 << 7)
87 #define PARAM_MATRIX (1 << 6)
88 #define PARAM_OUTSHIFT (1 << 5)
89 #define PARAM_QUANTSTEP (1 << 4)
90 #define PARAM_FIR (1 << 3)
91 #define PARAM_IIR (1 << 2)
92 #define PARAM_HUFFOFFSET (1 << 1)
93 #define PARAM_PRESENCE (1 << 0)
99 /// Number of matrices to be applied.
100 uint8_t num_primitive_matrices;
102 /// matrix output channel
103 uint8_t matrix_out_ch[MAX_MATRICES];
105 /// Whether the LSBs of the matrix output are encoded in the bitstream.
106 uint8_t lsb_bypass[MAX_MATRICES];
107 /// Matrix coefficients, stored as 2.14 fixed point.
108 int32_t matrix_coeff[MAX_MATRICES][MAX_CHANNELS];
109 /// Left shift to apply to noise values in 0x31eb substreams.
110 uint8_t matrix_noise_shift[MAX_MATRICES];
113 /// Left shift to apply to Huffman-decoded residuals.
114 uint8_t quant_step_size[MAX_CHANNELS];
116 /// number of PCM samples in current audio block
118 /// Number of PCM samples decoded so far in this frame.
121 /// Left shift to apply to decoded PCM values to get final 24-bit output.
122 int8_t output_shift[MAX_CHANNELS];
124 /// Running XOR of all output samples.
125 int32_t lossless_check_data;
129 typedef struct MLPDecodeContext {
130 AVCodecContext *avctx;
132 /// Current access unit being read has a major sync.
133 int is_major_sync_unit;
135 /// Set if a valid major sync block has been read. Otherwise no decoding is possible.
136 uint8_t params_valid;
138 /// Number of substreams contained within this stream.
139 uint8_t num_substreams;
141 /// Index of the last substream to decode - further substreams are skipped.
142 uint8_t max_decoded_substream;
144 /// Stream needs channel reordering to comply with FFmpeg's channel order
145 uint8_t needs_reordering;
147 /// number of PCM samples contained in each frame
148 int access_unit_size;
149 /// next power of two above the number of samples in each frame
150 int access_unit_size_pow2;
152 SubStream substream[MAX_SUBSTREAMS];
155 int filter_changed[MAX_CHANNELS][NUM_FILTERS];
157 int8_t noise_buffer[MAX_BLOCKSIZE_POW2];
158 int8_t bypassed_lsbs[MAX_BLOCKSIZE][MAX_CHANNELS];
159 int32_t sample_buffer[MAX_BLOCKSIZE][MAX_CHANNELS];
164 static const uint64_t thd_channel_order[] = {
165 AV_CH_FRONT_LEFT, AV_CH_FRONT_RIGHT, // LR
166 AV_CH_FRONT_CENTER, // C
167 AV_CH_LOW_FREQUENCY, // LFE
168 AV_CH_SIDE_LEFT, AV_CH_SIDE_RIGHT, // LRs
169 AV_CH_TOP_FRONT_LEFT, AV_CH_TOP_FRONT_RIGHT, // LRvh
170 AV_CH_FRONT_LEFT_OF_CENTER, AV_CH_FRONT_RIGHT_OF_CENTER, // LRc
171 AV_CH_BACK_LEFT, AV_CH_BACK_RIGHT, // LRrs
172 AV_CH_BACK_CENTER, // Cs
173 AV_CH_TOP_CENTER, // Ts
174 AV_CH_SURROUND_DIRECT_LEFT, AV_CH_SURROUND_DIRECT_RIGHT, // LRsd
175 AV_CH_WIDE_LEFT, AV_CH_WIDE_RIGHT, // LRw
176 AV_CH_TOP_FRONT_CENTER, // Cvh
177 AV_CH_LOW_FREQUENCY_2, // LFE2
180 static uint64_t thd_channel_layout_extract_channel(uint64_t channel_layout,
185 if (av_get_channel_layout_nb_channels(channel_layout) <= index)
188 for (i = 0; i < FF_ARRAY_ELEMS(thd_channel_order); i++)
189 if (channel_layout & thd_channel_order[i] && !index--)
190 return thd_channel_order[i];
194 static VLC huff_vlc[3];
196 /** Initialize static data, constant between all invocations of the codec. */
198 static av_cold void init_static(void)
200 if (!huff_vlc[0].bits) {
201 INIT_VLC_STATIC(&huff_vlc[0], VLC_BITS, 18,
202 &ff_mlp_huffman_tables[0][0][1], 2, 1,
203 &ff_mlp_huffman_tables[0][0][0], 2, 1, VLC_STATIC_SIZE);
204 INIT_VLC_STATIC(&huff_vlc[1], VLC_BITS, 16,
205 &ff_mlp_huffman_tables[1][0][1], 2, 1,
206 &ff_mlp_huffman_tables[1][0][0], 2, 1, VLC_STATIC_SIZE);
207 INIT_VLC_STATIC(&huff_vlc[2], VLC_BITS, 15,
208 &ff_mlp_huffman_tables[2][0][1], 2, 1,
209 &ff_mlp_huffman_tables[2][0][0], 2, 1, VLC_STATIC_SIZE);
215 static inline int32_t calculate_sign_huff(MLPDecodeContext *m,
216 unsigned int substr, unsigned int ch)
218 SubStream *s = &m->substream[substr];
219 ChannelParams *cp = &s->channel_params[ch];
220 int lsb_bits = cp->huff_lsbs - s->quant_step_size[ch];
221 int sign_shift = lsb_bits + (cp->codebook ? 2 - cp->codebook : -1);
222 int32_t sign_huff_offset = cp->huff_offset;
224 if (cp->codebook > 0)
225 sign_huff_offset -= 7 << lsb_bits;
228 sign_huff_offset -= 1 << sign_shift;
230 return sign_huff_offset;
233 /** Read a sample, consisting of either, both or neither of entropy-coded MSBs
236 static inline int read_huff_channels(MLPDecodeContext *m, GetBitContext *gbp,
237 unsigned int substr, unsigned int pos)
239 SubStream *s = &m->substream[substr];
240 unsigned int mat, channel;
242 for (mat = 0; mat < s->num_primitive_matrices; mat++)
243 if (s->lsb_bypass[mat])
244 m->bypassed_lsbs[pos + s->blockpos][mat] = get_bits1(gbp);
246 for (channel = s->min_channel; channel <= s->max_channel; channel++) {
247 ChannelParams *cp = &s->channel_params[channel];
248 int codebook = cp->codebook;
249 int quant_step_size = s->quant_step_size[channel];
250 int lsb_bits = cp->huff_lsbs - quant_step_size;
254 result = get_vlc2(gbp, huff_vlc[codebook-1].table,
255 VLC_BITS, (9 + VLC_BITS - 1) / VLC_BITS);
258 return AVERROR_INVALIDDATA;
261 result = (result << lsb_bits) + get_bits(gbp, lsb_bits);
263 result += cp->sign_huff_offset;
264 result <<= quant_step_size;
266 m->sample_buffer[pos + s->blockpos][channel] = result;
272 static av_cold int mlp_decode_init(AVCodecContext *avctx)
274 MLPDecodeContext *m = avctx->priv_data;
279 for (substr = 0; substr < MAX_SUBSTREAMS; substr++)
280 m->substream[substr].lossless_check_data = 0xffffffff;
281 ff_mlpdsp_init(&m->dsp);
286 /** Read a major sync info header - contains high level information about
287 * the stream - sample rate, channel arrangement etc. Most of this
288 * information is not actually necessary for decoding, only for playback.
291 static int read_major_sync(MLPDecodeContext *m, GetBitContext *gb)
296 if ((ret = ff_mlp_read_major_sync(m->avctx, &mh, gb)) != 0)
299 if (mh.group1_bits == 0) {
300 av_log(m->avctx, AV_LOG_ERROR, "invalid/unknown bits per sample\n");
301 return AVERROR_INVALIDDATA;
303 if (mh.group2_bits > mh.group1_bits) {
304 av_log(m->avctx, AV_LOG_ERROR,
305 "Channel group 2 cannot have more bits per sample than group 1.\n");
306 return AVERROR_INVALIDDATA;
309 if (mh.group2_samplerate && mh.group2_samplerate != mh.group1_samplerate) {
310 av_log(m->avctx, AV_LOG_ERROR,
311 "Channel groups with differing sample rates are not currently supported.\n");
312 return AVERROR_INVALIDDATA;
315 if (mh.group1_samplerate == 0) {
316 av_log(m->avctx, AV_LOG_ERROR, "invalid/unknown sampling rate\n");
317 return AVERROR_INVALIDDATA;
319 if (mh.group1_samplerate > MAX_SAMPLERATE) {
320 av_log(m->avctx, AV_LOG_ERROR,
321 "Sampling rate %d is greater than the supported maximum (%d).\n",
322 mh.group1_samplerate, MAX_SAMPLERATE);
323 return AVERROR_INVALIDDATA;
325 if (mh.access_unit_size > MAX_BLOCKSIZE) {
326 av_log(m->avctx, AV_LOG_ERROR,
327 "Block size %d is greater than the supported maximum (%d).\n",
328 mh.access_unit_size, MAX_BLOCKSIZE);
329 return AVERROR_INVALIDDATA;
331 if (mh.access_unit_size_pow2 > MAX_BLOCKSIZE_POW2) {
332 av_log(m->avctx, AV_LOG_ERROR,
333 "Block size pow2 %d is greater than the supported maximum (%d).\n",
334 mh.access_unit_size_pow2, MAX_BLOCKSIZE_POW2);
335 return AVERROR_INVALIDDATA;
338 if (mh.num_substreams == 0)
339 return AVERROR_INVALIDDATA;
340 if (m->avctx->codec_id == AV_CODEC_ID_MLP && mh.num_substreams > 2) {
341 av_log(m->avctx, AV_LOG_ERROR, "MLP only supports up to 2 substreams.\n");
342 return AVERROR_INVALIDDATA;
344 if (mh.num_substreams > MAX_SUBSTREAMS) {
345 avpriv_request_sample(m->avctx,
346 "%d substreams (more than the "
347 "maximum supported by the decoder)",
349 return AVERROR_PATCHWELCOME;
352 m->access_unit_size = mh.access_unit_size;
353 m->access_unit_size_pow2 = mh.access_unit_size_pow2;
355 m->num_substreams = mh.num_substreams;
356 m->max_decoded_substream = m->num_substreams - 1;
358 m->avctx->sample_rate = mh.group1_samplerate;
359 m->avctx->frame_size = mh.access_unit_size;
361 m->avctx->bits_per_raw_sample = mh.group1_bits;
362 if (mh.group1_bits > 16)
363 m->avctx->sample_fmt = AV_SAMPLE_FMT_S32;
365 m->avctx->sample_fmt = AV_SAMPLE_FMT_S16;
366 m->dsp.mlp_pack_output = m->dsp.mlp_select_pack_output(m->substream[m->max_decoded_substream].ch_assign,
367 m->substream[m->max_decoded_substream].output_shift,
368 m->substream[m->max_decoded_substream].max_matrix_channel,
369 m->avctx->sample_fmt == AV_SAMPLE_FMT_S32);
372 for (substr = 0; substr < MAX_SUBSTREAMS; substr++)
373 m->substream[substr].restart_seen = 0;
375 /* Set the layout for each substream. When there's more than one, the first
376 * substream is Stereo. Subsequent substreams' layouts are indicated in the
378 if (m->avctx->codec_id == AV_CODEC_ID_MLP) {
379 if (mh.stream_type != 0xbb) {
380 avpriv_request_sample(m->avctx,
381 "unexpected stream_type %X in MLP",
383 return AVERROR_PATCHWELCOME;
385 if ((substr = (mh.num_substreams > 1)))
386 m->substream[0].ch_layout = AV_CH_LAYOUT_STEREO;
387 m->substream[substr].ch_layout = mh.channel_layout_mlp;
389 if (mh.stream_type != 0xba) {
390 avpriv_request_sample(m->avctx,
391 "unexpected stream_type %X in !MLP",
393 return AVERROR_PATCHWELCOME;
395 if ((substr = (mh.num_substreams > 1)))
396 m->substream[0].ch_layout = AV_CH_LAYOUT_STEREO;
397 if (mh.num_substreams > 2)
398 if (mh.channel_layout_thd_stream2)
399 m->substream[2].ch_layout = mh.channel_layout_thd_stream2;
401 m->substream[2].ch_layout = mh.channel_layout_thd_stream1;
402 m->substream[substr].ch_layout = mh.channel_layout_thd_stream1;
404 if (m->avctx->channels<=2 && m->substream[substr].ch_layout == AV_CH_LAYOUT_MONO && m->max_decoded_substream == 1) {
405 av_log(m->avctx, AV_LOG_DEBUG, "Mono stream with 2 substreams, ignoring 2nd\n");
406 m->max_decoded_substream = 0;
407 if (m->avctx->channels==2)
408 m->avctx->channel_layout = AV_CH_LAYOUT_STEREO;
412 m->needs_reordering = mh.channel_arrangement >= 18 && mh.channel_arrangement <= 20;
414 /* Parse the TrueHD decoder channel modifiers and set each substream's
415 * AVMatrixEncoding accordingly.
417 * The meaning of the modifiers depends on the channel layout:
419 * - THD_CH_MODIFIER_LTRT, THD_CH_MODIFIER_LBINRBIN only apply to 2-channel
421 * - THD_CH_MODIFIER_MONO applies to 1-channel or 2-channel (dual mono)
423 * - THD_CH_MODIFIER_SURROUNDEX, THD_CH_MODIFIER_NOTSURROUNDEX only apply to
424 * layouts with an Ls/Rs channel pair
426 for (substr = 0; substr < MAX_SUBSTREAMS; substr++)
427 m->substream[substr].matrix_encoding = AV_MATRIX_ENCODING_NONE;
428 if (m->avctx->codec_id == AV_CODEC_ID_TRUEHD) {
429 if (mh.num_substreams > 2 &&
430 mh.channel_layout_thd_stream2 & AV_CH_SIDE_LEFT &&
431 mh.channel_layout_thd_stream2 & AV_CH_SIDE_RIGHT &&
432 mh.channel_modifier_thd_stream2 == THD_CH_MODIFIER_SURROUNDEX)
433 m->substream[2].matrix_encoding = AV_MATRIX_ENCODING_DOLBYEX;
435 if (mh.num_substreams > 1 &&
436 mh.channel_layout_thd_stream1 & AV_CH_SIDE_LEFT &&
437 mh.channel_layout_thd_stream1 & AV_CH_SIDE_RIGHT &&
438 mh.channel_modifier_thd_stream1 == THD_CH_MODIFIER_SURROUNDEX)
439 m->substream[1].matrix_encoding = AV_MATRIX_ENCODING_DOLBYEX;
441 if (mh.num_substreams > 0)
442 switch (mh.channel_modifier_thd_stream0) {
443 case THD_CH_MODIFIER_LTRT:
444 m->substream[0].matrix_encoding = AV_MATRIX_ENCODING_DOLBY;
446 case THD_CH_MODIFIER_LBINRBIN:
447 m->substream[0].matrix_encoding = AV_MATRIX_ENCODING_DOLBYHEADPHONE;
457 /** Read a restart header from a block in a substream. This contains parameters
458 * required to decode the audio that do not change very often. Generally
459 * (always) present only in blocks following a major sync. */
461 static int read_restart_header(MLPDecodeContext *m, GetBitContext *gbp,
462 const uint8_t *buf, unsigned int substr)
464 SubStream *s = &m->substream[substr];
468 uint8_t lossless_check;
469 int start_count = get_bits_count(gbp);
470 int min_channel, max_channel, max_matrix_channel;
471 const int std_max_matrix_channel = m->avctx->codec_id == AV_CODEC_ID_MLP
472 ? MAX_MATRIX_CHANNEL_MLP
473 : MAX_MATRIX_CHANNEL_TRUEHD;
475 sync_word = get_bits(gbp, 13);
477 if (sync_word != 0x31ea >> 1) {
478 av_log(m->avctx, AV_LOG_ERROR,
479 "restart header sync incorrect (got 0x%04x)\n", sync_word);
480 return AVERROR_INVALIDDATA;
483 s->noise_type = get_bits1(gbp);
485 if (m->avctx->codec_id == AV_CODEC_ID_MLP && s->noise_type) {
486 av_log(m->avctx, AV_LOG_ERROR, "MLP must have 0x31ea sync word.\n");
487 return AVERROR_INVALIDDATA;
490 skip_bits(gbp, 16); /* Output timestamp */
492 min_channel = get_bits(gbp, 4);
493 max_channel = get_bits(gbp, 4);
494 max_matrix_channel = get_bits(gbp, 4);
496 if (max_matrix_channel > std_max_matrix_channel) {
497 av_log(m->avctx, AV_LOG_ERROR,
498 "Max matrix channel cannot be greater than %d.\n",
499 std_max_matrix_channel);
500 return AVERROR_INVALIDDATA;
503 if (max_channel != max_matrix_channel) {
504 av_log(m->avctx, AV_LOG_ERROR,
505 "Max channel must be equal max matrix channel.\n");
506 return AVERROR_INVALIDDATA;
509 /* This should happen for TrueHD streams with >6 channels and MLP's noise
510 * type. It is not yet known if this is allowed. */
511 if (max_channel > MAX_MATRIX_CHANNEL_MLP && !s->noise_type) {
512 avpriv_request_sample(m->avctx,
513 "%d channels (more than the "
514 "maximum supported by the decoder)",
516 return AVERROR_PATCHWELCOME;
519 if (min_channel > max_channel) {
520 av_log(m->avctx, AV_LOG_ERROR,
521 "Substream min channel cannot be greater than max channel.\n");
522 return AVERROR_INVALIDDATA;
525 s->min_channel = min_channel;
526 s->max_channel = max_channel;
527 s->max_matrix_channel = max_matrix_channel;
529 #if FF_API_REQUEST_CHANNELS
530 FF_DISABLE_DEPRECATION_WARNINGS
531 if (m->avctx->request_channels > 0 &&
532 m->avctx->request_channels <= s->max_channel + 1 &&
533 m->max_decoded_substream > substr) {
534 av_log(m->avctx, AV_LOG_DEBUG,
535 "Extracting %d-channel downmix from substream %d. "
536 "Further substreams will be skipped.\n",
537 s->max_channel + 1, substr);
538 m->max_decoded_substream = substr;
539 FF_ENABLE_DEPRECATION_WARNINGS
542 if (m->avctx->request_channel_layout && (s->ch_layout & m->avctx->request_channel_layout) ==
543 m->avctx->request_channel_layout && m->max_decoded_substream > substr) {
544 av_log(m->avctx, AV_LOG_DEBUG,
545 "Extracting %d-channel downmix (0x%"PRIx64") from substream %d. "
546 "Further substreams will be skipped.\n",
547 s->max_channel + 1, s->ch_layout, substr);
548 m->max_decoded_substream = substr;
551 s->noise_shift = get_bits(gbp, 4);
552 s->noisegen_seed = get_bits(gbp, 23);
556 s->data_check_present = get_bits1(gbp);
557 lossless_check = get_bits(gbp, 8);
558 if (substr == m->max_decoded_substream
559 && s->lossless_check_data != 0xffffffff) {
560 tmp = xor_32_to_8(s->lossless_check_data);
561 if (tmp != lossless_check)
562 av_log(m->avctx, AV_LOG_WARNING,
563 "Lossless check failed - expected %02x, calculated %02x.\n",
564 lossless_check, tmp);
569 memset(s->ch_assign, 0, sizeof(s->ch_assign));
571 for (ch = 0; ch <= s->max_matrix_channel; ch++) {
572 int ch_assign = get_bits(gbp, 6);
573 if (m->avctx->codec_id == AV_CODEC_ID_TRUEHD) {
574 uint64_t channel = thd_channel_layout_extract_channel(s->ch_layout,
576 ch_assign = av_get_channel_layout_channel_index(s->ch_layout,
579 if ((unsigned)ch_assign > s->max_matrix_channel) {
580 avpriv_request_sample(m->avctx,
581 "Assignment of matrix channel %d to invalid output channel %d",
583 return AVERROR_PATCHWELCOME;
585 s->ch_assign[ch_assign] = ch;
588 checksum = ff_mlp_restart_checksum(buf, get_bits_count(gbp) - start_count);
590 if (checksum != get_bits(gbp, 8))
591 av_log(m->avctx, AV_LOG_ERROR, "restart header checksum error\n");
593 /* Set default decoding parameters. */
594 s->param_presence_flags = 0xff;
595 s->num_primitive_matrices = 0;
597 s->lossless_check_data = 0;
599 memset(s->output_shift , 0, sizeof(s->output_shift ));
600 memset(s->quant_step_size, 0, sizeof(s->quant_step_size));
602 for (ch = s->min_channel; ch <= s->max_channel; ch++) {
603 ChannelParams *cp = &s->channel_params[ch];
604 cp->filter_params[FIR].order = 0;
605 cp->filter_params[IIR].order = 0;
606 cp->filter_params[FIR].shift = 0;
607 cp->filter_params[IIR].shift = 0;
609 /* Default audio coding is 24-bit raw PCM. */
611 cp->sign_huff_offset = (-1) << 23;
616 if (substr == m->max_decoded_substream) {
617 m->avctx->channels = s->max_matrix_channel + 1;
618 m->avctx->channel_layout = s->ch_layout;
619 m->dsp.mlp_pack_output = m->dsp.mlp_select_pack_output(s->ch_assign,
621 s->max_matrix_channel,
622 m->avctx->sample_fmt == AV_SAMPLE_FMT_S32);
624 if (m->avctx->codec_id == AV_CODEC_ID_MLP && m->needs_reordering) {
625 if (m->avctx->channel_layout == (AV_CH_LAYOUT_QUAD|AV_CH_LOW_FREQUENCY) ||
626 m->avctx->channel_layout == AV_CH_LAYOUT_5POINT0_BACK) {
627 int i = s->ch_assign[4];
628 s->ch_assign[4] = s->ch_assign[3];
629 s->ch_assign[3] = s->ch_assign[2];
631 } else if (m->avctx->channel_layout == AV_CH_LAYOUT_5POINT1_BACK) {
632 FFSWAP(int, s->ch_assign[2], s->ch_assign[4]);
633 FFSWAP(int, s->ch_assign[3], s->ch_assign[5]);
642 /** Read parameters for one of the prediction filters. */
644 static int read_filter_params(MLPDecodeContext *m, GetBitContext *gbp,
645 unsigned int substr, unsigned int channel,
648 SubStream *s = &m->substream[substr];
649 FilterParams *fp = &s->channel_params[channel].filter_params[filter];
650 const int max_order = filter ? MAX_IIR_ORDER : MAX_FIR_ORDER;
651 const char fchar = filter ? 'I' : 'F';
654 // Filter is 0 for FIR, 1 for IIR.
655 av_assert0(filter < 2);
657 if (m->filter_changed[channel][filter]++ > 1) {
658 av_log(m->avctx, AV_LOG_ERROR, "Filters may change only once per access unit.\n");
659 return AVERROR_INVALIDDATA;
662 order = get_bits(gbp, 4);
663 if (order > max_order) {
664 av_log(m->avctx, AV_LOG_ERROR,
665 "%cIR filter order %d is greater than maximum %d.\n",
666 fchar, order, max_order);
667 return AVERROR_INVALIDDATA;
672 int32_t *fcoeff = s->channel_params[channel].coeff[filter];
673 int coeff_bits, coeff_shift;
675 fp->shift = get_bits(gbp, 4);
677 coeff_bits = get_bits(gbp, 5);
678 coeff_shift = get_bits(gbp, 3);
679 if (coeff_bits < 1 || coeff_bits > 16) {
680 av_log(m->avctx, AV_LOG_ERROR,
681 "%cIR filter coeff_bits must be between 1 and 16.\n",
683 return AVERROR_INVALIDDATA;
685 if (coeff_bits + coeff_shift > 16) {
686 av_log(m->avctx, AV_LOG_ERROR,
687 "Sum of coeff_bits and coeff_shift for %cIR filter must be 16 or less.\n",
689 return AVERROR_INVALIDDATA;
692 for (i = 0; i < order; i++)
693 fcoeff[i] = get_sbits(gbp, coeff_bits) << coeff_shift;
695 if (get_bits1(gbp)) {
696 int state_bits, state_shift;
699 av_log(m->avctx, AV_LOG_ERROR,
700 "FIR filter has state data specified.\n");
701 return AVERROR_INVALIDDATA;
704 state_bits = get_bits(gbp, 4);
705 state_shift = get_bits(gbp, 4);
707 /* TODO: Check validity of state data. */
709 for (i = 0; i < order; i++)
710 fp->state[i] = state_bits ? get_sbits(gbp, state_bits) << state_shift : 0;
717 /** Read parameters for primitive matrices. */
719 static int read_matrix_params(MLPDecodeContext *m, unsigned int substr, GetBitContext *gbp)
721 SubStream *s = &m->substream[substr];
722 unsigned int mat, ch;
723 const int max_primitive_matrices = m->avctx->codec_id == AV_CODEC_ID_MLP
725 : MAX_MATRICES_TRUEHD;
727 if (m->matrix_changed++ > 1) {
728 av_log(m->avctx, AV_LOG_ERROR, "Matrices may change only once per access unit.\n");
729 return AVERROR_INVALIDDATA;
732 s->num_primitive_matrices = get_bits(gbp, 4);
734 if (s->num_primitive_matrices > max_primitive_matrices) {
735 av_log(m->avctx, AV_LOG_ERROR,
736 "Number of primitive matrices cannot be greater than %d.\n",
737 max_primitive_matrices);
738 return AVERROR_INVALIDDATA;
741 for (mat = 0; mat < s->num_primitive_matrices; mat++) {
742 int frac_bits, max_chan;
743 s->matrix_out_ch[mat] = get_bits(gbp, 4);
744 frac_bits = get_bits(gbp, 4);
745 s->lsb_bypass [mat] = get_bits1(gbp);
747 if (s->matrix_out_ch[mat] > s->max_matrix_channel) {
748 av_log(m->avctx, AV_LOG_ERROR,
749 "Invalid channel %d specified as output from matrix.\n",
750 s->matrix_out_ch[mat]);
751 return AVERROR_INVALIDDATA;
753 if (frac_bits > 14) {
754 av_log(m->avctx, AV_LOG_ERROR,
755 "Too many fractional bits specified.\n");
756 return AVERROR_INVALIDDATA;
759 max_chan = s->max_matrix_channel;
763 for (ch = 0; ch <= max_chan; ch++) {
766 coeff_val = get_sbits(gbp, frac_bits + 2);
768 s->matrix_coeff[mat][ch] = coeff_val << (14 - frac_bits);
772 s->matrix_noise_shift[mat] = get_bits(gbp, 4);
774 s->matrix_noise_shift[mat] = 0;
780 /** Read channel parameters. */
782 static int read_channel_params(MLPDecodeContext *m, unsigned int substr,
783 GetBitContext *gbp, unsigned int ch)
785 SubStream *s = &m->substream[substr];
786 ChannelParams *cp = &s->channel_params[ch];
787 FilterParams *fir = &cp->filter_params[FIR];
788 FilterParams *iir = &cp->filter_params[IIR];
791 if (s->param_presence_flags & PARAM_FIR)
793 if ((ret = read_filter_params(m, gbp, substr, ch, FIR)) < 0)
796 if (s->param_presence_flags & PARAM_IIR)
798 if ((ret = read_filter_params(m, gbp, substr, ch, IIR)) < 0)
801 if (fir->order + iir->order > 8) {
802 av_log(m->avctx, AV_LOG_ERROR, "Total filter orders too high.\n");
803 return AVERROR_INVALIDDATA;
806 if (fir->order && iir->order &&
807 fir->shift != iir->shift) {
808 av_log(m->avctx, AV_LOG_ERROR,
809 "FIR and IIR filters must use the same precision.\n");
810 return AVERROR_INVALIDDATA;
812 /* The FIR and IIR filters must have the same precision.
813 * To simplify the filtering code, only the precision of the
814 * FIR filter is considered. If only the IIR filter is employed,
815 * the FIR filter precision is set to that of the IIR filter, so
816 * that the filtering code can use it. */
817 if (!fir->order && iir->order)
818 fir->shift = iir->shift;
820 if (s->param_presence_flags & PARAM_HUFFOFFSET)
822 cp->huff_offset = get_sbits(gbp, 15);
824 cp->codebook = get_bits(gbp, 2);
825 cp->huff_lsbs = get_bits(gbp, 5);
827 if (cp->huff_lsbs > 24) {
828 av_log(m->avctx, AV_LOG_ERROR, "Invalid huff_lsbs.\n");
830 return AVERROR_INVALIDDATA;
833 cp->sign_huff_offset = calculate_sign_huff(m, substr, ch);
838 /** Read decoding parameters that change more often than those in the restart
841 static int read_decoding_params(MLPDecodeContext *m, GetBitContext *gbp,
844 SubStream *s = &m->substream[substr];
848 if (s->param_presence_flags & PARAM_PRESENCE)
850 s->param_presence_flags = get_bits(gbp, 8);
852 if (s->param_presence_flags & PARAM_BLOCKSIZE)
853 if (get_bits1(gbp)) {
854 s->blocksize = get_bits(gbp, 9);
855 if (s->blocksize < 8 || s->blocksize > m->access_unit_size) {
856 av_log(m->avctx, AV_LOG_ERROR, "Invalid blocksize.\n");
858 return AVERROR_INVALIDDATA;
862 if (s->param_presence_flags & PARAM_MATRIX)
864 if ((ret = read_matrix_params(m, substr, gbp)) < 0)
867 if (s->param_presence_flags & PARAM_OUTSHIFT)
868 if (get_bits1(gbp)) {
869 for (ch = 0; ch <= s->max_matrix_channel; ch++)
870 s->output_shift[ch] = get_sbits(gbp, 4);
871 if (substr == m->max_decoded_substream)
872 m->dsp.mlp_pack_output = m->dsp.mlp_select_pack_output(s->ch_assign,
874 s->max_matrix_channel,
875 m->avctx->sample_fmt == AV_SAMPLE_FMT_S32);
878 if (s->param_presence_flags & PARAM_QUANTSTEP)
880 for (ch = 0; ch <= s->max_channel; ch++) {
881 ChannelParams *cp = &s->channel_params[ch];
883 s->quant_step_size[ch] = get_bits(gbp, 4);
885 cp->sign_huff_offset = calculate_sign_huff(m, substr, ch);
888 for (ch = s->min_channel; ch <= s->max_channel; ch++)
890 if ((ret = read_channel_params(m, substr, gbp, ch)) < 0)
896 #define MSB_MASK(bits) (-1u << bits)
898 /** Generate PCM samples using the prediction filters and residual values
899 * read from the data stream, and update the filter state. */
901 static void filter_channel(MLPDecodeContext *m, unsigned int substr,
902 unsigned int channel)
904 SubStream *s = &m->substream[substr];
905 const int32_t *fircoeff = s->channel_params[channel].coeff[FIR];
906 int32_t state_buffer[NUM_FILTERS][MAX_BLOCKSIZE + MAX_FIR_ORDER];
907 int32_t *firbuf = state_buffer[FIR] + MAX_BLOCKSIZE;
908 int32_t *iirbuf = state_buffer[IIR] + MAX_BLOCKSIZE;
909 FilterParams *fir = &s->channel_params[channel].filter_params[FIR];
910 FilterParams *iir = &s->channel_params[channel].filter_params[IIR];
911 unsigned int filter_shift = fir->shift;
912 int32_t mask = MSB_MASK(s->quant_step_size[channel]);
914 memcpy(firbuf, fir->state, MAX_FIR_ORDER * sizeof(int32_t));
915 memcpy(iirbuf, iir->state, MAX_IIR_ORDER * sizeof(int32_t));
917 m->dsp.mlp_filter_channel(firbuf, fircoeff,
918 fir->order, iir->order,
919 filter_shift, mask, s->blocksize,
920 &m->sample_buffer[s->blockpos][channel]);
922 memcpy(fir->state, firbuf - s->blocksize, MAX_FIR_ORDER * sizeof(int32_t));
923 memcpy(iir->state, iirbuf - s->blocksize, MAX_IIR_ORDER * sizeof(int32_t));
926 /** Read a block of PCM residual data (or actual if no filtering active). */
928 static int read_block_data(MLPDecodeContext *m, GetBitContext *gbp,
931 SubStream *s = &m->substream[substr];
932 unsigned int i, ch, expected_stream_pos = 0;
935 if (s->data_check_present) {
936 expected_stream_pos = get_bits_count(gbp);
937 expected_stream_pos += get_bits(gbp, 16);
938 avpriv_request_sample(m->avctx,
939 "Substreams with VLC block size check info");
942 if (s->blockpos + s->blocksize > m->access_unit_size) {
943 av_log(m->avctx, AV_LOG_ERROR, "too many audio samples in frame\n");
944 return AVERROR_INVALIDDATA;
947 memset(&m->bypassed_lsbs[s->blockpos][0], 0,
948 s->blocksize * sizeof(m->bypassed_lsbs[0]));
950 for (i = 0; i < s->blocksize; i++)
951 if ((ret = read_huff_channels(m, gbp, substr, i)) < 0)
954 for (ch = s->min_channel; ch <= s->max_channel; ch++)
955 filter_channel(m, substr, ch);
957 s->blockpos += s->blocksize;
959 if (s->data_check_present) {
960 if (get_bits_count(gbp) != expected_stream_pos)
961 av_log(m->avctx, AV_LOG_ERROR, "block data length mismatch\n");
968 /** Data table used for TrueHD noise generation function. */
970 static const int8_t noise_table[256] = {
971 30, 51, 22, 54, 3, 7, -4, 38, 14, 55, 46, 81, 22, 58, -3, 2,
972 52, 31, -7, 51, 15, 44, 74, 30, 85, -17, 10, 33, 18, 80, 28, 62,
973 10, 32, 23, 69, 72, 26, 35, 17, 73, 60, 8, 56, 2, 6, -2, -5,
974 51, 4, 11, 50, 66, 76, 21, 44, 33, 47, 1, 26, 64, 48, 57, 40,
975 38, 16, -10, -28, 92, 22, -18, 29, -10, 5, -13, 49, 19, 24, 70, 34,
976 61, 48, 30, 14, -6, 25, 58, 33, 42, 60, 67, 17, 54, 17, 22, 30,
977 67, 44, -9, 50, -11, 43, 40, 32, 59, 82, 13, 49, -14, 55, 60, 36,
978 48, 49, 31, 47, 15, 12, 4, 65, 1, 23, 29, 39, 45, -2, 84, 69,
979 0, 72, 37, 57, 27, 41, -15, -16, 35, 31, 14, 61, 24, 0, 27, 24,
980 16, 41, 55, 34, 53, 9, 56, 12, 25, 29, 53, 5, 20, -20, -8, 20,
981 13, 28, -3, 78, 38, 16, 11, 62, 46, 29, 21, 24, 46, 65, 43, -23,
982 89, 18, 74, 21, 38, -12, 19, 12, -19, 8, 15, 33, 4, 57, 9, -8,
983 36, 35, 26, 28, 7, 83, 63, 79, 75, 11, 3, 87, 37, 47, 34, 40,
984 39, 19, 20, 42, 27, 34, 39, 77, 13, 42, 59, 64, 45, -1, 32, 37,
985 45, -5, 53, -6, 7, 36, 50, 23, 6, 32, 9, -21, 18, 71, 27, 52,
986 -25, 31, 35, 42, -1, 68, 63, 52, 26, 43, 66, 37, 41, 25, 40, 70,
989 /** Noise generation functions.
990 * I'm not sure what these are for - they seem to be some kind of pseudorandom
991 * sequence generators, used to generate noise data which is used when the
992 * channels are rematrixed. I'm not sure if they provide a practical benefit
993 * to compression, or just obfuscate the decoder. Are they for some kind of
996 /** Generate two channels of noise, used in the matrix when
997 * restart sync word == 0x31ea. */
999 static void generate_2_noise_channels(MLPDecodeContext *m, unsigned int substr)
1001 SubStream *s = &m->substream[substr];
1003 uint32_t seed = s->noisegen_seed;
1004 unsigned int maxchan = s->max_matrix_channel;
1006 for (i = 0; i < s->blockpos; i++) {
1007 uint16_t seed_shr7 = seed >> 7;
1008 m->sample_buffer[i][maxchan+1] = ((int8_t)(seed >> 15)) << s->noise_shift;
1009 m->sample_buffer[i][maxchan+2] = ((int8_t) seed_shr7) << s->noise_shift;
1011 seed = (seed << 16) ^ seed_shr7 ^ (seed_shr7 << 5);
1014 s->noisegen_seed = seed;
1017 /** Generate a block of noise, used when restart sync word == 0x31eb. */
1019 static void fill_noise_buffer(MLPDecodeContext *m, unsigned int substr)
1021 SubStream *s = &m->substream[substr];
1023 uint32_t seed = s->noisegen_seed;
1025 for (i = 0; i < m->access_unit_size_pow2; i++) {
1026 uint8_t seed_shr15 = seed >> 15;
1027 m->noise_buffer[i] = noise_table[seed_shr15];
1028 seed = (seed << 8) ^ seed_shr15 ^ (seed_shr15 << 5);
1031 s->noisegen_seed = seed;
1035 /** Apply the channel matrices in turn to reconstruct the original audio
1038 static void rematrix_channels(MLPDecodeContext *m, unsigned int substr)
1040 SubStream *s = &m->substream[substr];
1042 unsigned int maxchan;
1044 maxchan = s->max_matrix_channel;
1045 if (!s->noise_type) {
1046 generate_2_noise_channels(m, substr);
1049 fill_noise_buffer(m, substr);
1052 for (mat = 0; mat < s->num_primitive_matrices; mat++) {
1053 unsigned int dest_ch = s->matrix_out_ch[mat];
1054 m->dsp.mlp_rematrix_channel(&m->sample_buffer[0][0],
1055 s->matrix_coeff[mat],
1056 &m->bypassed_lsbs[0][mat],
1058 s->num_primitive_matrices - mat,
1062 s->matrix_noise_shift[mat],
1063 m->access_unit_size_pow2,
1064 MSB_MASK(s->quant_step_size[dest_ch]));
1068 /** Write the audio data into the output buffer. */
1070 static int output_data(MLPDecodeContext *m, unsigned int substr,
1071 AVFrame *frame, int *got_frame_ptr)
1073 AVCodecContext *avctx = m->avctx;
1074 SubStream *s = &m->substream[substr];
1076 int is32 = (m->avctx->sample_fmt == AV_SAMPLE_FMT_S32);
1078 if (m->avctx->channels != s->max_matrix_channel + 1) {
1079 av_log(m->avctx, AV_LOG_ERROR, "channel count mismatch\n");
1080 return AVERROR_INVALIDDATA;
1084 av_log(avctx, AV_LOG_ERROR, "No samples to output.\n");
1085 return AVERROR_INVALIDDATA;
1088 /* get output buffer */
1089 frame->nb_samples = s->blockpos;
1090 if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
1092 s->lossless_check_data = m->dsp.mlp_pack_output(s->lossless_check_data,
1098 s->max_matrix_channel,
1101 /* Update matrix encoding side data */
1102 if ((ret = ff_side_data_update_matrix_encoding(frame, s->matrix_encoding)) < 0)
1110 /** Read an access unit from the stream.
1111 * @return negative on error, 0 if not enough data is present in the input stream,
1112 * otherwise the number of bytes consumed. */
1114 static int read_access_unit(AVCodecContext *avctx, void* data,
1115 int *got_frame_ptr, AVPacket *avpkt)
1117 const uint8_t *buf = avpkt->data;
1118 int buf_size = avpkt->size;
1119 MLPDecodeContext *m = avctx->priv_data;
1121 unsigned int length, substr;
1122 unsigned int substream_start;
1123 unsigned int header_size = 4;
1124 unsigned int substr_header_size = 0;
1125 uint8_t substream_parity_present[MAX_SUBSTREAMS];
1126 uint16_t substream_data_len[MAX_SUBSTREAMS];
1127 uint8_t parity_bits;
1131 return AVERROR_INVALIDDATA;
1133 length = (AV_RB16(buf) & 0xfff) * 2;
1135 if (length < 4 || length > buf_size)
1136 return AVERROR_INVALIDDATA;
1138 init_get_bits(&gb, (buf + 4), (length - 4) * 8);
1140 m->is_major_sync_unit = 0;
1141 if (show_bits_long(&gb, 31) == (0xf8726fba >> 1)) {
1142 if (read_major_sync(m, &gb) < 0)
1144 m->is_major_sync_unit = 1;
1148 if (!m->params_valid) {
1149 av_log(m->avctx, AV_LOG_WARNING,
1150 "Stream parameters not seen; skipping frame.\n");
1155 substream_start = 0;
1157 for (substr = 0; substr < m->num_substreams; substr++) {
1158 int extraword_present, checkdata_present, end, nonrestart_substr;
1160 extraword_present = get_bits1(&gb);
1161 nonrestart_substr = get_bits1(&gb);
1162 checkdata_present = get_bits1(&gb);
1165 end = get_bits(&gb, 12) * 2;
1167 substr_header_size += 2;
1169 if (extraword_present) {
1170 if (m->avctx->codec_id == AV_CODEC_ID_MLP) {
1171 av_log(m->avctx, AV_LOG_ERROR, "There must be no extraword for MLP.\n");
1175 substr_header_size += 2;
1178 if (!(nonrestart_substr ^ m->is_major_sync_unit)) {
1179 av_log(m->avctx, AV_LOG_ERROR, "Invalid nonrestart_substr.\n");
1183 if (end + header_size + substr_header_size > length) {
1184 av_log(m->avctx, AV_LOG_ERROR,
1185 "Indicated length of substream %d data goes off end of "
1186 "packet.\n", substr);
1187 end = length - header_size - substr_header_size;
1190 if (end < substream_start) {
1191 av_log(avctx, AV_LOG_ERROR,
1192 "Indicated end offset of substream %d data "
1193 "is smaller than calculated start offset.\n",
1198 if (substr > m->max_decoded_substream)
1201 substream_parity_present[substr] = checkdata_present;
1202 substream_data_len[substr] = end - substream_start;
1203 substream_start = end;
1206 parity_bits = ff_mlp_calculate_parity(buf, 4);
1207 parity_bits ^= ff_mlp_calculate_parity(buf + header_size, substr_header_size);
1209 if ((((parity_bits >> 4) ^ parity_bits) & 0xF) != 0xF) {
1210 av_log(avctx, AV_LOG_ERROR, "Parity check failed.\n");
1214 buf += header_size + substr_header_size;
1216 for (substr = 0; substr <= m->max_decoded_substream; substr++) {
1217 SubStream *s = &m->substream[substr];
1218 init_get_bits(&gb, buf, substream_data_len[substr] * 8);
1220 m->matrix_changed = 0;
1221 memset(m->filter_changed, 0, sizeof(m->filter_changed));
1225 if (get_bits1(&gb)) {
1226 if (get_bits1(&gb)) {
1227 /* A restart header should be present. */
1228 if (read_restart_header(m, &gb, buf, substr) < 0)
1230 s->restart_seen = 1;
1233 if (!s->restart_seen)
1235 if (read_decoding_params(m, &gb, substr) < 0)
1239 if (!s->restart_seen)
1242 if ((ret = read_block_data(m, &gb, substr)) < 0)
1245 if (get_bits_count(&gb) >= substream_data_len[substr] * 8)
1246 goto substream_length_mismatch;
1248 } while (!get_bits1(&gb));
1250 skip_bits(&gb, (-get_bits_count(&gb)) & 15);
1252 if (substream_data_len[substr] * 8 - get_bits_count(&gb) >= 32) {
1255 if (get_bits(&gb, 16) != 0xD234)
1256 return AVERROR_INVALIDDATA;
1258 shorten_by = get_bits(&gb, 16);
1259 if (m->avctx->codec_id == AV_CODEC_ID_TRUEHD && shorten_by & 0x2000)
1260 s->blockpos -= FFMIN(shorten_by & 0x1FFF, s->blockpos);
1261 else if (m->avctx->codec_id == AV_CODEC_ID_MLP && shorten_by != 0xD234)
1262 return AVERROR_INVALIDDATA;
1264 if (substr == m->max_decoded_substream)
1265 av_log(m->avctx, AV_LOG_INFO, "End of stream indicated.\n");
1268 if (substream_parity_present[substr]) {
1269 uint8_t parity, checksum;
1271 if (substream_data_len[substr] * 8 - get_bits_count(&gb) != 16)
1272 goto substream_length_mismatch;
1274 parity = ff_mlp_calculate_parity(buf, substream_data_len[substr] - 2);
1275 checksum = ff_mlp_checksum8 (buf, substream_data_len[substr] - 2);
1277 if ((get_bits(&gb, 8) ^ parity) != 0xa9 )
1278 av_log(m->avctx, AV_LOG_ERROR, "Substream %d parity check failed.\n", substr);
1279 if ( get_bits(&gb, 8) != checksum)
1280 av_log(m->avctx, AV_LOG_ERROR, "Substream %d checksum failed.\n" , substr);
1283 if (substream_data_len[substr] * 8 != get_bits_count(&gb))
1284 goto substream_length_mismatch;
1287 if (!s->restart_seen)
1288 av_log(m->avctx, AV_LOG_ERROR,
1289 "No restart header present in substream %d.\n", substr);
1291 buf += substream_data_len[substr];
1294 rematrix_channels(m, m->max_decoded_substream);
1296 if ((ret = output_data(m, m->max_decoded_substream, data, got_frame_ptr)) < 0)
1301 substream_length_mismatch:
1302 av_log(m->avctx, AV_LOG_ERROR, "substream %d length mismatch\n", substr);
1303 return AVERROR_INVALIDDATA;
1306 m->params_valid = 0;
1307 return AVERROR_INVALIDDATA;
1310 #if CONFIG_MLP_DECODER
1311 AVCodec ff_mlp_decoder = {
1313 .long_name = NULL_IF_CONFIG_SMALL("MLP (Meridian Lossless Packing)"),
1314 .type = AVMEDIA_TYPE_AUDIO,
1315 .id = AV_CODEC_ID_MLP,
1316 .priv_data_size = sizeof(MLPDecodeContext),
1317 .init = mlp_decode_init,
1318 .decode = read_access_unit,
1319 .capabilities = CODEC_CAP_DR1,
1322 #if CONFIG_TRUEHD_DECODER
1323 AVCodec ff_truehd_decoder = {
1325 .long_name = NULL_IF_CONFIG_SMALL("TrueHD"),
1326 .type = AVMEDIA_TYPE_AUDIO,
1327 .id = AV_CODEC_ID_TRUEHD,
1328 .priv_data_size = sizeof(MLPDecodeContext),
1329 .init = mlp_decode_init,
1330 .decode = read_access_unit,
1331 .capabilities = CODEC_CAP_DR1,
1333 #endif /* CONFIG_TRUEHD_DECODER */