mlpdec.c 46.4 KB
Newer Older
Ramiro Polla's avatar
Ramiro Polla committed
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22
/*
 * MLP decoder
 * Copyright (c) 2007-2008 Ian Caulfield
 *
 * This file is part of FFmpeg.
 *
 * FFmpeg is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * FFmpeg is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with FFmpeg; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

/**
23
 * @file
Ramiro Polla's avatar
Ramiro Polla committed
24 25 26
 * MLP decoder
 */

27 28
#include <stdint.h>

Ramiro Polla's avatar
Ramiro Polla committed
29
#include "avcodec.h"
30
#include "libavutil/internal.h"
Ramiro Polla's avatar
Ramiro Polla committed
31
#include "libavutil/intreadwrite.h"
32
#include "libavutil/channel_layout.h"
33
#include "get_bits.h"
34
#include "internal.h"
Ramiro Polla's avatar
Ramiro Polla committed
35 36 37
#include "libavutil/crc.h"
#include "parser.h"
#include "mlp_parser.h"
38
#include "mlpdsp.h"
39
#include "mlp.h"
Ramiro Polla's avatar
Ramiro Polla committed
40

Diego Biurrun's avatar
Diego Biurrun committed
41
/** number of bits used for VLC lookup - longest Huffman code is 9 */
Ramiro Polla's avatar
Ramiro Polla committed
42 43 44
#define VLC_BITS            9

typedef struct SubStream {
45
    /// Set if a valid restart header has been read. Otherwise the substream cannot be decoded.
Ramiro Polla's avatar
Ramiro Polla committed
46 47 48 49
    uint8_t     restart_seen;

    //@{
    /** restart header data */
50
    /// The type of noise to be used in the rematrix stage.
Ramiro Polla's avatar
Ramiro Polla committed
51 52
    uint16_t    noise_type;

53
    /// The index of the first channel coded in this substream.
Ramiro Polla's avatar
Ramiro Polla committed
54
    uint8_t     min_channel;
55
    /// The index of the last channel coded in this substream.
Ramiro Polla's avatar
Ramiro Polla committed
56
    uint8_t     max_channel;
57
    /// The number of channels input into the rematrix stage.
Ramiro Polla's avatar
Ramiro Polla committed
58
    uint8_t     max_matrix_channel;
59
    /// For each channel output by the matrix, the output channel to map it to
60
    uint8_t     ch_assign[MAX_CHANNELS];
61 62
    /// The channel layout for this substream
    uint64_t    ch_layout;
63 64
    /// The matrix encoding mode for this substream
    enum AVMatrixEncoding matrix_encoding;
Ramiro Polla's avatar
Ramiro Polla committed
65

66
    /// Channel coding parameters for channels in the substream
67 68
    ChannelParams channel_params[MAX_CHANNELS];

69
    /// The left shift applied to random noise in 0x31ea substreams.
Ramiro Polla's avatar
Ramiro Polla committed
70
    uint8_t     noise_shift;
71
    /// The current seed value for the pseudorandom noise generator(s).
Ramiro Polla's avatar
Ramiro Polla committed
72 73
    uint32_t    noisegen_seed;

74
    /// Set if the substream contains extra info to check the size of VLC blocks.
Ramiro Polla's avatar
Ramiro Polla committed
75 76
    uint8_t     data_check_present;

77
    /// Bitmask of which parameter sets are conveyed in a decoding parameter block.
Ramiro Polla's avatar
Ramiro Polla committed
78 79 80 81 82 83 84 85
    uint8_t     param_presence_flags;
#define PARAM_BLOCKSIZE     (1 << 7)
#define PARAM_MATRIX        (1 << 6)
#define PARAM_OUTSHIFT      (1 << 5)
#define PARAM_QUANTSTEP     (1 << 4)
#define PARAM_FIR           (1 << 3)
#define PARAM_IIR           (1 << 2)
#define PARAM_HUFFOFFSET    (1 << 1)
86
#define PARAM_PRESENCE      (1 << 0)
Ramiro Polla's avatar
Ramiro Polla committed
87 88 89 90 91
    //@}

    //@{
    /** matrix data */

92
    /// Number of matrices to be applied.
Ramiro Polla's avatar
Ramiro Polla committed
93 94
    uint8_t     num_primitive_matrices;

95
    /// matrix output channel
Ramiro Polla's avatar
Ramiro Polla committed
96 97
    uint8_t     matrix_out_ch[MAX_MATRICES];

98
    /// Whether the LSBs of the matrix output are encoded in the bitstream.
Ramiro Polla's avatar
Ramiro Polla committed
99
    uint8_t     lsb_bypass[MAX_MATRICES];
100
    /// Matrix coefficients, stored as 2.14 fixed point.
101
    int32_t     matrix_coeff[MAX_MATRICES][MAX_CHANNELS];
102
    /// Left shift to apply to noise values in 0x31eb substreams.
Ramiro Polla's avatar
Ramiro Polla committed
103 104 105
    uint8_t     matrix_noise_shift[MAX_MATRICES];
    //@}

106
    /// Left shift to apply to Huffman-decoded residuals.
Ramiro Polla's avatar
Ramiro Polla committed
107 108
    uint8_t     quant_step_size[MAX_CHANNELS];

109
    /// number of PCM samples in current audio block
Ramiro Polla's avatar
Ramiro Polla committed
110
    uint16_t    blocksize;
111
    /// Number of PCM samples decoded so far in this frame.
Ramiro Polla's avatar
Ramiro Polla committed
112 113
    uint16_t    blockpos;

114
    /// Left shift to apply to decoded PCM values to get final 24-bit output.
Ramiro Polla's avatar
Ramiro Polla committed
115 116
    int8_t      output_shift[MAX_CHANNELS];

117
    /// Running XOR of all output samples.
Ramiro Polla's avatar
Ramiro Polla committed
118 119 120 121 122 123 124
    int32_t     lossless_check_data;

} SubStream;

typedef struct MLPDecodeContext {
    AVCodecContext *avctx;

125
    /// Current access unit being read has a major sync.
126 127
    int         is_major_sync_unit;

128
    /// Set if a valid major sync block has been read. Otherwise no decoding is possible.
Ramiro Polla's avatar
Ramiro Polla committed
129 130
    uint8_t     params_valid;

131
    /// Number of substreams contained within this stream.
Ramiro Polla's avatar
Ramiro Polla committed
132 133
    uint8_t     num_substreams;

134
    /// Index of the last substream to decode - further substreams are skipped.
Ramiro Polla's avatar
Ramiro Polla committed
135 136
    uint8_t     max_decoded_substream;

137
    /// Stream needs channel reordering to comply with FFmpeg's channel order
138 139
    uint8_t     needs_reordering;

140
    /// number of PCM samples contained in each frame
Ramiro Polla's avatar
Ramiro Polla committed
141
    int         access_unit_size;
142
    /// next power of two above the number of samples in each frame
Ramiro Polla's avatar
Ramiro Polla committed
143 144 145 146
    int         access_unit_size_pow2;

    SubStream   substream[MAX_SUBSTREAMS];

147 148 149
    int         matrix_changed;
    int         filter_changed[MAX_CHANNELS][NUM_FILTERS];

Ramiro Polla's avatar
Ramiro Polla committed
150 151
    int8_t      noise_buffer[MAX_BLOCKSIZE_POW2];
    int8_t      bypassed_lsbs[MAX_BLOCKSIZE][MAX_CHANNELS];
152
    int32_t     sample_buffer[MAX_BLOCKSIZE][MAX_CHANNELS];
153

154
    MLPDSPContext dsp;
Ramiro Polla's avatar
Ramiro Polla committed
155 156
} MLPDecodeContext;

157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186
static const uint64_t thd_channel_order[] = {
    AV_CH_FRONT_LEFT, AV_CH_FRONT_RIGHT,                     // LR
    AV_CH_FRONT_CENTER,                                      // C
    AV_CH_LOW_FREQUENCY,                                     // LFE
    AV_CH_SIDE_LEFT, AV_CH_SIDE_RIGHT,                       // LRs
    AV_CH_TOP_FRONT_LEFT, AV_CH_TOP_FRONT_RIGHT,             // LRvh
    AV_CH_FRONT_LEFT_OF_CENTER, AV_CH_FRONT_RIGHT_OF_CENTER, // LRc
    AV_CH_BACK_LEFT, AV_CH_BACK_RIGHT,                       // LRrs
    AV_CH_BACK_CENTER,                                       // Cs
    AV_CH_TOP_CENTER,                                        // Ts
    AV_CH_SURROUND_DIRECT_LEFT, AV_CH_SURROUND_DIRECT_RIGHT, // LRsd
    AV_CH_WIDE_LEFT, AV_CH_WIDE_RIGHT,                       // LRw
    AV_CH_TOP_FRONT_CENTER,                                  // Cvh
    AV_CH_LOW_FREQUENCY_2,                                   // LFE2
};

static uint64_t thd_channel_layout_extract_channel(uint64_t channel_layout,
                                                   int index)
{
    int i;

    if (av_get_channel_layout_nb_channels(channel_layout) <= index)
        return 0;

    for (i = 0; i < FF_ARRAY_ELEMS(thd_channel_order); i++)
        if (channel_layout & thd_channel_order[i] && !index--)
            return thd_channel_order[i];
    return 0;
}

Ramiro Polla's avatar
Ramiro Polla committed
187 188 189 190
static VLC huff_vlc[3];

/** Initialize static data, constant between all invocations of the codec. */

191
static av_cold void init_static(void)
Ramiro Polla's avatar
Ramiro Polla committed
192
{
193
    if (!huff_vlc[0].bits) {
Ramiro Polla's avatar
Ramiro Polla committed
194 195 196 197 198 199 200 201 202
        INIT_VLC_STATIC(&huff_vlc[0], VLC_BITS, 18,
                    &ff_mlp_huffman_tables[0][0][1], 2, 1,
                    &ff_mlp_huffman_tables[0][0][0], 2, 1, 512);
        INIT_VLC_STATIC(&huff_vlc[1], VLC_BITS, 16,
                    &ff_mlp_huffman_tables[1][0][1], 2, 1,
                    &ff_mlp_huffman_tables[1][0][0], 2, 1, 512);
        INIT_VLC_STATIC(&huff_vlc[2], VLC_BITS, 15,
                    &ff_mlp_huffman_tables[2][0][1], 2, 1,
                    &ff_mlp_huffman_tables[2][0][0], 2, 1, 512);
203
    }
Ramiro Polla's avatar
Ramiro Polla committed
204

205
    ff_mlp_init_crc();
Ramiro Polla's avatar
Ramiro Polla committed
206 207 208 209 210 211
}

static inline int32_t calculate_sign_huff(MLPDecodeContext *m,
                                          unsigned int substr, unsigned int ch)
{
    SubStream *s = &m->substream[substr];
212
    ChannelParams *cp = &s->channel_params[ch];
213 214 215
    int lsb_bits = cp->huff_lsbs - s->quant_step_size[ch];
    int sign_shift = lsb_bits + (cp->codebook ? 2 - cp->codebook : -1);
    int32_t sign_huff_offset = cp->huff_offset;
Ramiro Polla's avatar
Ramiro Polla committed
216

217
    if (cp->codebook > 0)
Ramiro Polla's avatar
Ramiro Polla committed
218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239
        sign_huff_offset -= 7 << lsb_bits;

    if (sign_shift >= 0)
        sign_huff_offset -= 1 << sign_shift;

    return sign_huff_offset;
}

/** Read a sample, consisting of either, both or neither of entropy-coded MSBs
 *  and plain LSBs. */

static inline int read_huff_channels(MLPDecodeContext *m, GetBitContext *gbp,
                                     unsigned int substr, unsigned int pos)
{
    SubStream *s = &m->substream[substr];
    unsigned int mat, channel;

    for (mat = 0; mat < s->num_primitive_matrices; mat++)
        if (s->lsb_bypass[mat])
            m->bypassed_lsbs[pos + s->blockpos][mat] = get_bits1(gbp);

    for (channel = s->min_channel; channel <= s->max_channel; channel++) {
240
        ChannelParams *cp = &s->channel_params[channel];
241
        int codebook = cp->codebook;
Ramiro Polla's avatar
Ramiro Polla committed
242
        int quant_step_size = s->quant_step_size[channel];
243
        int lsb_bits = cp->huff_lsbs - quant_step_size;
Ramiro Polla's avatar
Ramiro Polla committed
244 245 246 247 248 249 250
        int result = 0;

        if (codebook > 0)
            result = get_vlc2(gbp, huff_vlc[codebook-1].table,
                            VLC_BITS, (9 + VLC_BITS - 1) / VLC_BITS);

        if (result < 0)
251
            return AVERROR_INVALIDDATA;
Ramiro Polla's avatar
Ramiro Polla committed
252 253 254 255

        if (lsb_bits > 0)
            result = (result << lsb_bits) + get_bits(gbp, lsb_bits);

256
        result  += cp->sign_huff_offset;
Ramiro Polla's avatar
Ramiro Polla committed
257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273
        result <<= quant_step_size;

        m->sample_buffer[pos + s->blockpos][channel] = result;
    }

    return 0;
}

static av_cold int mlp_decode_init(AVCodecContext *avctx)
{
    MLPDecodeContext *m = avctx->priv_data;
    int substr;

    init_static();
    m->avctx = avctx;
    for (substr = 0; substr < MAX_SUBSTREAMS; substr++)
        m->substream[substr].lossless_check_data = 0xffffffff;
274
    ff_mlpdsp_init(&m->dsp);
275

Ramiro Polla's avatar
Ramiro Polla committed
276 277 278 279 280 281 282 283 284 285 286
    return 0;
}

/** Read a major sync info header - contains high level information about
 *  the stream - sample rate, channel arrangement etc. Most of this
 *  information is not actually necessary for decoding, only for playback.
 */

static int read_major_sync(MLPDecodeContext *m, GetBitContext *gb)
{
    MLPHeaderInfo mh;
287
    int substr, ret;
Ramiro Polla's avatar
Ramiro Polla committed
288

289 290
    if ((ret = ff_mlp_read_major_sync(m->avctx, &mh, gb)) != 0)
        return ret;
Ramiro Polla's avatar
Ramiro Polla committed
291 292

    if (mh.group1_bits == 0) {
Diego Biurrun's avatar
Diego Biurrun committed
293
        av_log(m->avctx, AV_LOG_ERROR, "invalid/unknown bits per sample\n");
294
        return AVERROR_INVALIDDATA;
Ramiro Polla's avatar
Ramiro Polla committed
295 296 297
    }
    if (mh.group2_bits > mh.group1_bits) {
        av_log(m->avctx, AV_LOG_ERROR,
Diego Biurrun's avatar
Diego Biurrun committed
298
               "Channel group 2 cannot have more bits per sample than group 1.\n");
299
        return AVERROR_INVALIDDATA;
Ramiro Polla's avatar
Ramiro Polla committed
300 301 302 303
    }

    if (mh.group2_samplerate && mh.group2_samplerate != mh.group1_samplerate) {
        av_log(m->avctx, AV_LOG_ERROR,
Diego Biurrun's avatar
Diego Biurrun committed
304
               "Channel groups with differing sample rates are not currently supported.\n");
305
        return AVERROR_INVALIDDATA;
Ramiro Polla's avatar
Ramiro Polla committed
306 307 308
    }

    if (mh.group1_samplerate == 0) {
Diego Biurrun's avatar
Diego Biurrun committed
309
        av_log(m->avctx, AV_LOG_ERROR, "invalid/unknown sampling rate\n");
310
        return AVERROR_INVALIDDATA;
Ramiro Polla's avatar
Ramiro Polla committed
311 312 313
    }
    if (mh.group1_samplerate > MAX_SAMPLERATE) {
        av_log(m->avctx, AV_LOG_ERROR,
Diego Biurrun's avatar
Diego Biurrun committed
314
               "Sampling rate %d is greater than the supported maximum (%d).\n",
Ramiro Polla's avatar
Ramiro Polla committed
315
               mh.group1_samplerate, MAX_SAMPLERATE);
316
        return AVERROR_INVALIDDATA;
Ramiro Polla's avatar
Ramiro Polla committed
317 318 319
    }
    if (mh.access_unit_size > MAX_BLOCKSIZE) {
        av_log(m->avctx, AV_LOG_ERROR,
Diego Biurrun's avatar
Diego Biurrun committed
320
               "Block size %d is greater than the supported maximum (%d).\n",
Ramiro Polla's avatar
Ramiro Polla committed
321
               mh.access_unit_size, MAX_BLOCKSIZE);
322
        return AVERROR_INVALIDDATA;
Ramiro Polla's avatar
Ramiro Polla committed
323 324 325
    }
    if (mh.access_unit_size_pow2 > MAX_BLOCKSIZE_POW2) {
        av_log(m->avctx, AV_LOG_ERROR,
Diego Biurrun's avatar
Diego Biurrun committed
326
               "Block size pow2 %d is greater than the supported maximum (%d).\n",
Ramiro Polla's avatar
Ramiro Polla committed
327
               mh.access_unit_size_pow2, MAX_BLOCKSIZE_POW2);
328
        return AVERROR_INVALIDDATA;
Ramiro Polla's avatar
Ramiro Polla committed
329 330 331
    }

    if (mh.num_substreams == 0)
332
        return AVERROR_INVALIDDATA;
333
    if (m->avctx->codec_id == AV_CODEC_ID_MLP && mh.num_substreams > 2) {
334
        av_log(m->avctx, AV_LOG_ERROR, "MLP only supports up to 2 substreams.\n");
335
        return AVERROR_INVALIDDATA;
336
    }
Ramiro Polla's avatar
Ramiro Polla committed
337
    if (mh.num_substreams > MAX_SUBSTREAMS) {
338 339 340 341
        avpriv_request_sample(m->avctx,
                              "%d substreams (more than the "
                              "maximum supported by the decoder)",
                              mh.num_substreams);
342
        return AVERROR_PATCHWELCOME;
Ramiro Polla's avatar
Ramiro Polla committed
343 344 345 346 347 348 349 350 351 352 353
    }

    m->access_unit_size      = mh.access_unit_size;
    m->access_unit_size_pow2 = mh.access_unit_size_pow2;

    m->num_substreams        = mh.num_substreams;
    m->max_decoded_substream = m->num_substreams - 1;

    m->avctx->sample_rate    = mh.group1_samplerate;
    m->avctx->frame_size     = mh.access_unit_size;

354
    m->avctx->bits_per_raw_sample = mh.group1_bits;
355
    if (mh.group1_bits > 16)
356
        m->avctx->sample_fmt = AV_SAMPLE_FMT_S32;
357
    else
358
        m->avctx->sample_fmt = AV_SAMPLE_FMT_S16;
Ramiro Polla's avatar
Ramiro Polla committed
359 360 361 362 363

    m->params_valid = 1;
    for (substr = 0; substr < MAX_SUBSTREAMS; substr++)
        m->substream[substr].restart_seen = 0;

364 365 366 367
    /* Set the layout for each substream. When there's more than one, the first
     * substream is Stereo. Subsequent substreams' layouts are indicated in the
     * major sync. */
    if (m->avctx->codec_id == AV_CODEC_ID_MLP) {
368 369 370 371 372 373
        if (mh.stream_type != 0xbb) {
            avpriv_request_sample(m->avctx,
                        "unexpected stream_type %X in MLP",
                        mh.stream_type);
            return AVERROR_PATCHWELCOME;
        }
374 375 376 377
        if ((substr = (mh.num_substreams > 1)))
            m->substream[0].ch_layout = AV_CH_LAYOUT_STEREO;
        m->substream[substr].ch_layout = mh.channel_layout_mlp;
    } else {
378 379 380 381 382 383
        if (mh.stream_type != 0xba) {
            avpriv_request_sample(m->avctx,
                        "unexpected stream_type %X in !MLP",
                        mh.stream_type);
            return AVERROR_PATCHWELCOME;
        }
384 385 386 387 388 389 390 391
        if ((substr = (mh.num_substreams > 1)))
            m->substream[0].ch_layout = AV_CH_LAYOUT_STEREO;
        if (mh.num_substreams > 2)
            if (mh.channel_layout_thd_stream2)
                m->substream[2].ch_layout = mh.channel_layout_thd_stream2;
            else
                m->substream[2].ch_layout = mh.channel_layout_thd_stream1;
        m->substream[substr].ch_layout = mh.channel_layout_thd_stream1;
392 393 394 395 396 397 398

        if (m->avctx->channels<=2 && m->substream[substr].ch_layout == AV_CH_LAYOUT_MONO && m->max_decoded_substream == 1) {
            av_log(m->avctx, AV_LOG_DEBUG, "Mono stream with 2 substreams, ignoring 2nd\n");
            m->max_decoded_substream = 0;
            if (m->avctx->channels==2)
                m->avctx->channel_layout = AV_CH_LAYOUT_STEREO;
        }
399 400
    }

401
    m->needs_reordering = mh.channel_arrangement >= 18 && mh.channel_arrangement <= 20;
402

403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442
    /* Parse the TrueHD decoder channel modifiers and set each substream's
     * AVMatrixEncoding accordingly.
     *
     * The meaning of the modifiers depends on the channel layout:
     *
     * - THD_CH_MODIFIER_LTRT, THD_CH_MODIFIER_LBINRBIN only apply to 2-channel
     *
     * - THD_CH_MODIFIER_MONO applies to 1-channel or 2-channel (dual mono)
     *
     * - THD_CH_MODIFIER_SURROUNDEX, THD_CH_MODIFIER_NOTSURROUNDEX only apply to
     *   layouts with an Ls/Rs channel pair
     */
    for (substr = 0; substr < MAX_SUBSTREAMS; substr++)
        m->substream[substr].matrix_encoding = AV_MATRIX_ENCODING_NONE;
    if (m->avctx->codec_id == AV_CODEC_ID_TRUEHD) {
        if (mh.num_substreams > 2 &&
            mh.channel_layout_thd_stream2 & AV_CH_SIDE_LEFT &&
            mh.channel_layout_thd_stream2 & AV_CH_SIDE_RIGHT &&
            mh.channel_modifier_thd_stream2 == THD_CH_MODIFIER_SURROUNDEX)
            m->substream[2].matrix_encoding = AV_MATRIX_ENCODING_DOLBYEX;

        if (mh.num_substreams > 1 &&
            mh.channel_layout_thd_stream1 & AV_CH_SIDE_LEFT &&
            mh.channel_layout_thd_stream1 & AV_CH_SIDE_RIGHT &&
            mh.channel_modifier_thd_stream1 == THD_CH_MODIFIER_SURROUNDEX)
            m->substream[1].matrix_encoding = AV_MATRIX_ENCODING_DOLBYEX;

        if (mh.num_substreams > 0)
            switch (mh.channel_modifier_thd_stream0) {
            case THD_CH_MODIFIER_LTRT:
                m->substream[0].matrix_encoding = AV_MATRIX_ENCODING_DOLBY;
                break;
            case THD_CH_MODIFIER_LBINRBIN:
                m->substream[0].matrix_encoding = AV_MATRIX_ENCODING_DOLBYHEADPHONE;
                break;
            default:
                break;
            }
    }

Ramiro Polla's avatar
Ramiro Polla committed
443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458
    return 0;
}

/** Read a restart header from a block in a substream. This contains parameters
 *  required to decode the audio that do not change very often. Generally
 *  (always) present only in blocks following a major sync. */

static int read_restart_header(MLPDecodeContext *m, GetBitContext *gbp,
                               const uint8_t *buf, unsigned int substr)
{
    SubStream *s = &m->substream[substr];
    unsigned int ch;
    int sync_word, tmp;
    uint8_t checksum;
    uint8_t lossless_check;
    int start_count = get_bits_count(gbp);
459 460 461 462
    int min_channel, max_channel, max_matrix_channel;
    const int std_max_matrix_channel = m->avctx->codec_id == AV_CODEC_ID_MLP
                                     ? MAX_MATRIX_CHANNEL_MLP
                                     : MAX_MATRIX_CHANNEL_TRUEHD;
Ramiro Polla's avatar
Ramiro Polla committed
463 464 465

    sync_word = get_bits(gbp, 13);

466
    if (sync_word != 0x31ea >> 1) {
Ramiro Polla's avatar
Ramiro Polla committed
467
        av_log(m->avctx, AV_LOG_ERROR,
Diego Biurrun's avatar
Diego Biurrun committed
468
               "restart header sync incorrect (got 0x%04x)\n", sync_word);
469
        return AVERROR_INVALIDDATA;
Ramiro Polla's avatar
Ramiro Polla committed
470 471
    }

472 473
    s->noise_type = get_bits1(gbp);

474
    if (m->avctx->codec_id == AV_CODEC_ID_MLP && s->noise_type) {
475
        av_log(m->avctx, AV_LOG_ERROR, "MLP must have 0x31ea sync word.\n");
476
        return AVERROR_INVALIDDATA;
477 478
    }

Ramiro Polla's avatar
Ramiro Polla committed
479 480
    skip_bits(gbp, 16); /* Output timestamp */

481 482 483
    min_channel        = get_bits(gbp, 4);
    max_channel        = get_bits(gbp, 4);
    max_matrix_channel = get_bits(gbp, 4);
Ramiro Polla's avatar
Ramiro Polla committed
484

485
    if (max_matrix_channel > std_max_matrix_channel) {
486 487
        av_log(m->avctx, AV_LOG_ERROR,
               "Max matrix channel cannot be greater than %d.\n",
488
               std_max_matrix_channel);
489
        return AVERROR_INVALIDDATA;
490 491
    }

492
    if (max_channel != max_matrix_channel) {
493 494
        av_log(m->avctx, AV_LOG_ERROR,
               "Max channel must be equal max matrix channel.\n");
495
        return AVERROR_INVALIDDATA;
496 497
    }

498 499
    /* This should happen for TrueHD streams with >6 channels and MLP's noise
     * type. It is not yet known if this is allowed. */
500
    if (max_channel > MAX_MATRIX_CHANNEL_MLP && !s->noise_type) {
501 502 503
        avpriv_request_sample(m->avctx,
                              "%d channels (more than the "
                              "maximum supported by the decoder)",
504
                              max_channel + 2);
505
        return AVERROR_PATCHWELCOME;
506 507
    }

508
    if (min_channel > max_channel) {
Ramiro Polla's avatar
Ramiro Polla committed
509 510
        av_log(m->avctx, AV_LOG_ERROR,
               "Substream min channel cannot be greater than max channel.\n");
511
        return AVERROR_INVALIDDATA;
Ramiro Polla's avatar
Ramiro Polla committed
512 513
    }

514 515 516
    s->min_channel        = min_channel;
    s->max_channel        = max_channel;
    s->max_matrix_channel = max_matrix_channel;
517

518
#if FF_API_REQUEST_CHANNELS
519
FF_DISABLE_DEPRECATION_WARNINGS
520 521 522
    if (m->avctx->request_channels > 0 &&
        m->avctx->request_channels <= s->max_channel + 1 &&
        m->max_decoded_substream > substr) {
523
        av_log(m->avctx, AV_LOG_DEBUG,
524
               "Extracting %d-channel downmix from substream %d. "
Ramiro Polla's avatar
Ramiro Polla committed
525 526 527
               "Further substreams will be skipped.\n",
               s->max_channel + 1, substr);
        m->max_decoded_substream = substr;
528
FF_ENABLE_DEPRECATION_WARNINGS
529
    } else
530
#endif
531
    if (m->avctx->request_channel_layout && (s->ch_layout & m->avctx->request_channel_layout) ==
532
        m->avctx->request_channel_layout && m->max_decoded_substream > substr) {
533 534 535 536 537
        av_log(m->avctx, AV_LOG_DEBUG,
               "Extracting %d-channel downmix (0x%"PRIx64") from substream %d. "
               "Further substreams will be skipped.\n",
               s->max_channel + 1, s->ch_layout, substr);
        m->max_decoded_substream = substr;
Ramiro Polla's avatar
Ramiro Polla committed
538 539 540 541 542 543 544 545 546 547 548
    }

    s->noise_shift   = get_bits(gbp,  4);
    s->noisegen_seed = get_bits(gbp, 23);

    skip_bits(gbp, 19);

    s->data_check_present = get_bits1(gbp);
    lossless_check = get_bits(gbp, 8);
    if (substr == m->max_decoded_substream
        && s->lossless_check_data != 0xffffffff) {
549
        tmp = xor_32_to_8(s->lossless_check_data);
Ramiro Polla's avatar
Ramiro Polla committed
550 551
        if (tmp != lossless_check)
            av_log(m->avctx, AV_LOG_WARNING,
Diego Biurrun's avatar
Diego Biurrun committed
552
                   "Lossless check failed - expected %02x, calculated %02x.\n",
Ramiro Polla's avatar
Ramiro Polla committed
553 554 555 556 557
                   lossless_check, tmp);
    }

    skip_bits(gbp, 16);

558 559
    memset(s->ch_assign, 0, sizeof(s->ch_assign));

Ramiro Polla's avatar
Ramiro Polla committed
560 561
    for (ch = 0; ch <= s->max_matrix_channel; ch++) {
        int ch_assign = get_bits(gbp, 6);
562 563 564 565 566 567
        if (m->avctx->codec_id == AV_CODEC_ID_TRUEHD) {
            uint64_t channel = thd_channel_layout_extract_channel(s->ch_layout,
                                                                  ch_assign);
            ch_assign = av_get_channel_layout_channel_index(s->ch_layout,
                                                            channel);
        }
568
        if ((unsigned)ch_assign > s->max_matrix_channel) {
569 570 571
            avpriv_request_sample(m->avctx,
                                  "Assignment of matrix channel %d to invalid output channel %d",
                                  ch, ch_assign);
572
            return AVERROR_PATCHWELCOME;
Ramiro Polla's avatar
Ramiro Polla committed
573
        }
574
        s->ch_assign[ch_assign] = ch;
Ramiro Polla's avatar
Ramiro Polla committed
575 576
    }

577
    checksum = ff_mlp_restart_checksum(buf, get_bits_count(gbp) - start_count);
Ramiro Polla's avatar
Ramiro Polla committed
578 579

    if (checksum != get_bits(gbp, 8))
Diego Biurrun's avatar
Diego Biurrun committed
580
        av_log(m->avctx, AV_LOG_ERROR, "restart header checksum error\n");
Ramiro Polla's avatar
Ramiro Polla committed
581

Diego Biurrun's avatar
Diego Biurrun committed
582
    /* Set default decoding parameters. */
Ramiro Polla's avatar
Ramiro Polla committed
583 584 585 586 587 588 589 590 591
    s->param_presence_flags   = 0xff;
    s->num_primitive_matrices = 0;
    s->blocksize              = 8;
    s->lossless_check_data    = 0;

    memset(s->output_shift   , 0, sizeof(s->output_shift   ));
    memset(s->quant_step_size, 0, sizeof(s->quant_step_size));

    for (ch = s->min_channel; ch <= s->max_channel; ch++) {
592
        ChannelParams *cp = &s->channel_params[ch];
593 594 595 596
        cp->filter_params[FIR].order = 0;
        cp->filter_params[IIR].order = 0;
        cp->filter_params[FIR].shift = 0;
        cp->filter_params[IIR].shift = 0;
Ramiro Polla's avatar
Ramiro Polla committed
597

Diego Biurrun's avatar
Diego Biurrun committed
598
        /* Default audio coding is 24-bit raw PCM. */
599 600 601 602
        cp->huff_offset      = 0;
        cp->sign_huff_offset = (-1) << 23;
        cp->codebook         = 0;
        cp->huff_lsbs        = 24;
Ramiro Polla's avatar
Ramiro Polla committed
603 604
    }

605 606 607
    if (substr == m->max_decoded_substream) {
        m->avctx->channels       = s->max_matrix_channel + 1;
        m->avctx->channel_layout = s->ch_layout;
608 609 610 611 612 613 614 615 616 617 618 619 620 621

        if (m->avctx->codec_id == AV_CODEC_ID_MLP && m->needs_reordering) {
            if (m->avctx->channel_layout == (AV_CH_LAYOUT_QUAD|AV_CH_LOW_FREQUENCY) ||
                m->avctx->channel_layout == AV_CH_LAYOUT_5POINT0_BACK) {
                int i = s->ch_assign[4];
                s->ch_assign[4] = s->ch_assign[3];
                s->ch_assign[3] = s->ch_assign[2];
                s->ch_assign[2] = i;
            } else if (m->avctx->channel_layout == AV_CH_LAYOUT_5POINT1_BACK) {
                FFSWAP(int, s->ch_assign[2], s->ch_assign[4]);
                FFSWAP(int, s->ch_assign[3], s->ch_assign[5]);
            }
        }

622
    }
Ramiro Polla's avatar
Ramiro Polla committed
623 624 625 626 627 628 629

    return 0;
}

/** Read parameters for one of the prediction filters. */

static int read_filter_params(MLPDecodeContext *m, GetBitContext *gbp,
630 631
                              unsigned int substr, unsigned int channel,
                              unsigned int filter)
Ramiro Polla's avatar
Ramiro Polla committed
632
{
633 634
    SubStream *s = &m->substream[substr];
    FilterParams *fp = &s->channel_params[channel].filter_params[filter];
635
    const int max_order = filter ? MAX_IIR_ORDER : MAX_FIR_ORDER;
Ramiro Polla's avatar
Ramiro Polla committed
636 637 638
    const char fchar = filter ? 'I' : 'F';
    int i, order;

Diego Biurrun's avatar
Diego Biurrun committed
639
    // Filter is 0 for FIR, 1 for IIR.
640
    av_assert0(filter < 2);
Ramiro Polla's avatar
Ramiro Polla committed
641

642 643
    if (m->filter_changed[channel][filter]++ > 1) {
        av_log(m->avctx, AV_LOG_ERROR, "Filters may change only once per access unit.\n");
644
        return AVERROR_INVALIDDATA;
645
    }
646

Ramiro Polla's avatar
Ramiro Polla committed
647
    order = get_bits(gbp, 4);
648
    if (order > max_order) {
Ramiro Polla's avatar
Ramiro Polla committed
649
        av_log(m->avctx, AV_LOG_ERROR,
Diego Biurrun's avatar
Diego Biurrun committed
650
               "%cIR filter order %d is greater than maximum %d.\n",
651
               fchar, order, max_order);
652
        return AVERROR_INVALIDDATA;
Ramiro Polla's avatar
Ramiro Polla committed
653
    }
654
    fp->order = order;
Ramiro Polla's avatar
Ramiro Polla committed
655 656

    if (order > 0) {
657
        int32_t *fcoeff = s->channel_params[channel].coeff[filter];
Ramiro Polla's avatar
Ramiro Polla committed
658 659
        int coeff_bits, coeff_shift;

660
        fp->shift = get_bits(gbp, 4);
Ramiro Polla's avatar
Ramiro Polla committed
661 662 663 664 665

        coeff_bits  = get_bits(gbp, 5);
        coeff_shift = get_bits(gbp, 3);
        if (coeff_bits < 1 || coeff_bits > 16) {
            av_log(m->avctx, AV_LOG_ERROR,
Diego Biurrun's avatar
Diego Biurrun committed
666
                   "%cIR filter coeff_bits must be between 1 and 16.\n",
Ramiro Polla's avatar
Ramiro Polla committed
667
                   fchar);
668
            return AVERROR_INVALIDDATA;
Ramiro Polla's avatar
Ramiro Polla committed
669 670 671
        }
        if (coeff_bits + coeff_shift > 16) {
            av_log(m->avctx, AV_LOG_ERROR,
Diego Biurrun's avatar
Diego Biurrun committed
672
                   "Sum of coeff_bits and coeff_shift for %cIR filter must be 16 or less.\n",
Ramiro Polla's avatar
Ramiro Polla committed
673
                   fchar);
674
            return AVERROR_INVALIDDATA;
Ramiro Polla's avatar
Ramiro Polla committed
675 676 677
        }

        for (i = 0; i < order; i++)
678
            fcoeff[i] = get_sbits(gbp, coeff_bits) << coeff_shift;
Ramiro Polla's avatar
Ramiro Polla committed
679 680 681 682 683 684

        if (get_bits1(gbp)) {
            int state_bits, state_shift;

            if (filter == FIR) {
                av_log(m->avctx, AV_LOG_ERROR,
Diego Biurrun's avatar
Diego Biurrun committed
685
                       "FIR filter has state data specified.\n");
686
                return AVERROR_INVALIDDATA;
Ramiro Polla's avatar
Ramiro Polla committed
687 688 689 690 691
            }

            state_bits  = get_bits(gbp, 4);
            state_shift = get_bits(gbp, 4);

Diego Biurrun's avatar
Diego Biurrun committed
692
            /* TODO: Check validity of state data. */
Ramiro Polla's avatar
Ramiro Polla committed
693 694

            for (i = 0; i < order; i++)
695
                fp->state[i] = state_bits ? get_sbits(gbp, state_bits) << state_shift : 0;
Ramiro Polla's avatar
Ramiro Polla committed
696 697 698 699 700 701
        }
    }

    return 0;
}

702 703
/** Read parameters for primitive matrices. */

704
static int read_matrix_params(MLPDecodeContext *m, unsigned int substr, GetBitContext *gbp)
705
{
706
    SubStream *s = &m->substream[substr];
707
    unsigned int mat, ch;
708
    const int max_primitive_matrices = m->avctx->codec_id == AV_CODEC_ID_MLP
709 710
                                     ? MAX_MATRICES_MLP
                                     : MAX_MATRICES_TRUEHD;
711

712 713
    if (m->matrix_changed++ > 1) {
        av_log(m->avctx, AV_LOG_ERROR, "Matrices may change only once per access unit.\n");
714
        return AVERROR_INVALIDDATA;
715 716
    }

717 718
    s->num_primitive_matrices = get_bits(gbp, 4);

719 720 721 722
    if (s->num_primitive_matrices > max_primitive_matrices) {
        av_log(m->avctx, AV_LOG_ERROR,
               "Number of primitive matrices cannot be greater than %d.\n",
               max_primitive_matrices);
723
        return AVERROR_INVALIDDATA;
724 725
    }

726 727 728 729 730 731
    for (mat = 0; mat < s->num_primitive_matrices; mat++) {
        int frac_bits, max_chan;
        s->matrix_out_ch[mat] = get_bits(gbp, 4);
        frac_bits             = get_bits(gbp, 4);
        s->lsb_bypass   [mat] = get_bits1(gbp);

732
        if (s->matrix_out_ch[mat] > s->max_matrix_channel) {
733 734 735
            av_log(m->avctx, AV_LOG_ERROR,
                    "Invalid channel %d specified as output from matrix.\n",
                    s->matrix_out_ch[mat]);
736
            return AVERROR_INVALIDDATA;
737 738 739 740
        }
        if (frac_bits > 14) {
            av_log(m->avctx, AV_LOG_ERROR,
                    "Too many fractional bits specified.\n");
741
            return AVERROR_INVALIDDATA;
742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764
        }

        max_chan = s->max_matrix_channel;
        if (!s->noise_type)
            max_chan+=2;

        for (ch = 0; ch <= max_chan; ch++) {
            int coeff_val = 0;
            if (get_bits1(gbp))
                coeff_val = get_sbits(gbp, frac_bits + 2);

            s->matrix_coeff[mat][ch] = coeff_val << (14 - frac_bits);
        }

        if (s->noise_type)
            s->matrix_noise_shift[mat] = get_bits(gbp, 4);
        else
            s->matrix_noise_shift[mat] = 0;
    }

    return 0;
}

765 766 767 768 769
/** Read channel parameters. */

static int read_channel_params(MLPDecodeContext *m, unsigned int substr,
                               GetBitContext *gbp, unsigned int ch)
{
770 771
    SubStream *s = &m->substream[substr];
    ChannelParams *cp = &s->channel_params[ch];
772 773
    FilterParams *fir = &cp->filter_params[FIR];
    FilterParams *iir = &cp->filter_params[IIR];
774
    int ret;
775 776 777

    if (s->param_presence_flags & PARAM_FIR)
        if (get_bits1(gbp))
778 779
            if ((ret = read_filter_params(m, gbp, substr, ch, FIR)) < 0)
                return ret;
780 781 782

    if (s->param_presence_flags & PARAM_IIR)
        if (get_bits1(gbp))
783 784
            if ((ret = read_filter_params(m, gbp, substr, ch, IIR)) < 0)
                return ret;
785

786 787
    if (fir->order + iir->order > 8) {
        av_log(m->avctx, AV_LOG_ERROR, "Total filter orders too high.\n");
788
        return AVERROR_INVALIDDATA;
789 790
    }

791 792 793 794
    if (fir->order && iir->order &&
        fir->shift != iir->shift) {
        av_log(m->avctx, AV_LOG_ERROR,
                "FIR and IIR filters must use the same precision.\n");
795
        return AVERROR_INVALIDDATA;
796 797
    }
    /* The FIR and IIR filters must have the same precision.
798 799 800 801
     * To simplify the filtering code, only the precision of the
     * FIR filter is considered. If only the IIR filter is employed,
     * the FIR filter precision is set to that of the IIR filter, so
     * that the filtering code can use it. */
802 803 804 805 806 807 808 809 810 811
    if (!fir->order && iir->order)
        fir->shift = iir->shift;

    if (s->param_presence_flags & PARAM_HUFFOFFSET)
        if (get_bits1(gbp))
            cp->huff_offset = get_sbits(gbp, 15);

    cp->codebook  = get_bits(gbp, 2);
    cp->huff_lsbs = get_bits(gbp, 5);

812 813
    if (cp->huff_lsbs > 24) {
        av_log(m->avctx, AV_LOG_ERROR, "Invalid huff_lsbs.\n");
814
        cp->huff_lsbs = 0;
815
        return AVERROR_INVALIDDATA;
816
    }
817

818
    cp->sign_huff_offset = calculate_sign_huff(m, substr, ch);
819 820 821 822

    return 0;
}

Ramiro Polla's avatar
Ramiro Polla committed
823 824 825 826 827 828 829
/** Read decoding parameters that change more often than those in the restart
 *  header. */

static int read_decoding_params(MLPDecodeContext *m, GetBitContext *gbp,
                                unsigned int substr)
{
    SubStream *s = &m->substream[substr];
830
    unsigned int ch;
831
    int ret;
Ramiro Polla's avatar
Ramiro Polla committed
832

833
    if (s->param_presence_flags & PARAM_PRESENCE)
834 835
        if (get_bits1(gbp))
            s->param_presence_flags = get_bits(gbp, 8);
Ramiro Polla's avatar
Ramiro Polla committed
836 837 838 839

    if (s->param_presence_flags & PARAM_BLOCKSIZE)
        if (get_bits1(gbp)) {
            s->blocksize = get_bits(gbp, 9);
840
            if (s->blocksize < 8 || s->blocksize > m->access_unit_size) {
841
                av_log(m->avctx, AV_LOG_ERROR, "Invalid blocksize.\n");
Ramiro Polla's avatar
Ramiro Polla committed
842
                s->blocksize = 0;
843
                return AVERROR_INVALIDDATA;
Ramiro Polla's avatar
Ramiro Polla committed
844 845 846 847
            }
        }

    if (s->param_presence_flags & PARAM_MATRIX)
848
        if (get_bits1(gbp))
849 850
            if ((ret = read_matrix_params(m, substr, gbp)) < 0)
                return ret;
Ramiro Polla's avatar
Ramiro Polla committed
851 852 853

    if (s->param_presence_flags & PARAM_OUTSHIFT)
        if (get_bits1(gbp))
854
            for (ch = 0; ch <= s->max_matrix_channel; ch++)
855
                s->output_shift[ch] = get_sbits(gbp, 4);
Ramiro Polla's avatar
Ramiro Polla committed
856 857 858 859

    if (s->param_presence_flags & PARAM_QUANTSTEP)
        if (get_bits1(gbp))
            for (ch = 0; ch <= s->max_channel; ch++) {
860
                ChannelParams *cp = &s->channel_params[ch];
861

Ramiro Polla's avatar
Ramiro Polla committed
862 863
                s->quant_step_size[ch] = get_bits(gbp, 4);

864
                cp->sign_huff_offset = calculate_sign_huff(m, substr, ch);
Ramiro Polla's avatar
Ramiro Polla committed
865 866 867
            }

    for (ch = s->min_channel; ch <= s->max_channel; ch++)
868
        if (get_bits1(gbp))
869 870
            if ((ret = read_channel_params(m, substr, gbp, ch)) < 0)
                return ret;
Ramiro Polla's avatar
Ramiro Polla committed
871 872 873 874 875 876 877 878 879 880 881 882 883

    return 0;
}

#define MSB_MASK(bits)  (-1u << bits)

/** Generate PCM samples using the prediction filters and residual values
 *  read from the data stream, and update the filter state. */

static void filter_channel(MLPDecodeContext *m, unsigned int substr,
                           unsigned int channel)
{
    SubStream *s = &m->substream[substr];
884
    const int32_t *fircoeff = s->channel_params[channel].coeff[FIR];
885 886 887
    int32_t state_buffer[NUM_FILTERS][MAX_BLOCKSIZE + MAX_FIR_ORDER];
    int32_t *firbuf = state_buffer[FIR] + MAX_BLOCKSIZE;
    int32_t *iirbuf = state_buffer[IIR] + MAX_BLOCKSIZE;
888 889
    FilterParams *fir = &s->channel_params[channel].filter_params[FIR];
    FilterParams *iir = &s->channel_params[channel].filter_params[IIR];
890
    unsigned int filter_shift = fir->shift;
Ramiro Polla's avatar
Ramiro Polla committed
891 892
    int32_t mask = MSB_MASK(s->quant_step_size[channel]);

893 894
    memcpy(firbuf, fir->state, MAX_FIR_ORDER * sizeof(int32_t));
    memcpy(iirbuf, iir->state, MAX_IIR_ORDER * sizeof(int32_t));
Ramiro Polla's avatar
Ramiro Polla committed
895

896 897
    m->dsp.mlp_filter_channel(firbuf, fircoeff,
                              fir->order, iir->order,
898 899
                              filter_shift, mask, s->blocksize,
                              &m->sample_buffer[s->blockpos][channel]);
Ramiro Polla's avatar
Ramiro Polla committed
900

901 902
    memcpy(fir->state, firbuf - s->blocksize, MAX_FIR_ORDER * sizeof(int32_t));
    memcpy(iir->state, iirbuf - s->blocksize, MAX_IIR_ORDER * sizeof(int32_t));
Ramiro Polla's avatar
Ramiro Polla committed
903 904 905 906 907 908 909 910 911
}

/** Read a block of PCM residual data (or actual if no filtering active). */

static int read_block_data(MLPDecodeContext *m, GetBitContext *gbp,
                           unsigned int substr)
{
    SubStream *s = &m->substream[substr];
    unsigned int i, ch, expected_stream_pos = 0;
912
    int ret;
Ramiro Polla's avatar
Ramiro Polla committed
913 914 915 916

    if (s->data_check_present) {
        expected_stream_pos  = get_bits_count(gbp);
        expected_stream_pos += get_bits(gbp, 16);
917 918
        avpriv_request_sample(m->avctx,
                              "Substreams with VLC block size check info");
Ramiro Polla's avatar
Ramiro Polla committed
919 920 921
    }

    if (s->blockpos + s->blocksize > m->access_unit_size) {
Diego Biurrun's avatar
Diego Biurrun committed
922
        av_log(m->avctx, AV_LOG_ERROR, "too many audio samples in frame\n");
923
        return AVERROR_INVALIDDATA;
Ramiro Polla's avatar
Ramiro Polla committed
924 925 926 927 928
    }

    memset(&m->bypassed_lsbs[s->blockpos][0], 0,
           s->blocksize * sizeof(m->bypassed_lsbs[0]));

929
    for (i = 0; i < s->blocksize; i++)
930 931
        if ((ret = read_huff_channels(m, gbp, substr, i)) < 0)
            return ret;
Ramiro Polla's avatar
Ramiro Polla committed
932

933
    for (ch = s->min_channel; ch <= s->max_channel; ch++)
Ramiro Polla's avatar
Ramiro Polla committed
934 935 936 937 938 939
        filter_channel(m, substr, ch);

    s->blockpos += s->blocksize;

    if (s->data_check_present) {
        if (get_bits_count(gbp) != expected_stream_pos)
Diego Biurrun's avatar
Diego Biurrun committed
940
            av_log(m->avctx, AV_LOG_ERROR, "block data length mismatch\n");
Ramiro Polla's avatar
Ramiro Polla committed
941 942 943 944 945 946
        skip_bits(gbp, 8);
    }

    return 0;
}

Diego Biurrun's avatar
Diego Biurrun committed
947
/** Data table used for TrueHD noise generation function. */
Ramiro Polla's avatar
Ramiro Polla committed
948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034

static const int8_t noise_table[256] = {
     30,  51,  22,  54,   3,   7,  -4,  38,  14,  55,  46,  81,  22,  58,  -3,   2,
     52,  31,  -7,  51,  15,  44,  74,  30,  85, -17,  10,  33,  18,  80,  28,  62,
     10,  32,  23,  69,  72,  26,  35,  17,  73,  60,   8,  56,   2,   6,  -2,  -5,
     51,   4,  11,  50,  66,  76,  21,  44,  33,  47,   1,  26,  64,  48,  57,  40,
     38,  16, -10, -28,  92,  22, -18,  29, -10,   5, -13,  49,  19,  24,  70,  34,
     61,  48,  30,  14,  -6,  25,  58,  33,  42,  60,  67,  17,  54,  17,  22,  30,
     67,  44,  -9,  50, -11,  43,  40,  32,  59,  82,  13,  49, -14,  55,  60,  36,
     48,  49,  31,  47,  15,  12,   4,  65,   1,  23,  29,  39,  45,  -2,  84,  69,
      0,  72,  37,  57,  27,  41, -15, -16,  35,  31,  14,  61,  24,   0,  27,  24,
     16,  41,  55,  34,  53,   9,  56,  12,  25,  29,  53,   5,  20, -20,  -8,  20,
     13,  28,  -3,  78,  38,  16,  11,  62,  46,  29,  21,  24,  46,  65,  43, -23,
     89,  18,  74,  21,  38, -12,  19,  12, -19,   8,  15,  33,   4,  57,   9,  -8,
     36,  35,  26,  28,   7,  83,  63,  79,  75,  11,   3,  87,  37,  47,  34,  40,
     39,  19,  20,  42,  27,  34,  39,  77,  13,  42,  59,  64,  45,  -1,  32,  37,
     45,  -5,  53,  -6,   7,  36,  50,  23,   6,  32,   9, -21,  18,  71,  27,  52,
    -25,  31,  35,  42,  -1,  68,  63,  52,  26,  43,  66,  37,  41,  25,  40,  70,
};

/** Noise generation functions.
 *  I'm not sure what these are for - they seem to be some kind of pseudorandom
 *  sequence generators, used to generate noise data which is used when the
 *  channels are rematrixed. I'm not sure if they provide a practical benefit
 *  to compression, or just obfuscate the decoder. Are they for some kind of
 *  dithering? */

/** Generate two channels of noise, used in the matrix when
 *  restart sync word == 0x31ea. */

static void generate_2_noise_channels(MLPDecodeContext *m, unsigned int substr)
{
    SubStream *s = &m->substream[substr];
    unsigned int i;
    uint32_t seed = s->noisegen_seed;
    unsigned int maxchan = s->max_matrix_channel;

    for (i = 0; i < s->blockpos; i++) {
        uint16_t seed_shr7 = seed >> 7;
        m->sample_buffer[i][maxchan+1] = ((int8_t)(seed >> 15)) << s->noise_shift;
        m->sample_buffer[i][maxchan+2] = ((int8_t) seed_shr7)   << s->noise_shift;

        seed = (seed << 16) ^ seed_shr7 ^ (seed_shr7 << 5);
    }

    s->noisegen_seed = seed;
}

/** Generate a block of noise, used when restart sync word == 0x31eb. */

static void fill_noise_buffer(MLPDecodeContext *m, unsigned int substr)
{
    SubStream *s = &m->substream[substr];
    unsigned int i;
    uint32_t seed = s->noisegen_seed;

    for (i = 0; i < m->access_unit_size_pow2; i++) {
        uint8_t seed_shr15 = seed >> 15;
        m->noise_buffer[i] = noise_table[seed_shr15];
        seed = (seed << 8) ^ seed_shr15 ^ (seed_shr15 << 5);
    }

    s->noisegen_seed = seed;
}


/** Apply the channel matrices in turn to reconstruct the original audio
 *  samples. */

static void rematrix_channels(MLPDecodeContext *m, unsigned int substr)
{
    SubStream *s = &m->substream[substr];
    unsigned int mat, src_ch, i;
    unsigned int maxchan;

    maxchan = s->max_matrix_channel;
    if (!s->noise_type) {
        generate_2_noise_channels(m, substr);
        maxchan += 2;
    } else {
        fill_noise_buffer(m, substr);
    }

    for (mat = 0; mat < s->num_primitive_matrices; mat++) {
        int matrix_noise_shift = s->matrix_noise_shift[mat];
        unsigned int dest_ch = s->matrix_out_ch[mat];
        int32_t mask = MSB_MASK(s->quant_step_size[dest_ch]);
1035
        int32_t *coeffs = s->matrix_coeff[mat];
1036 1037
        int index  = s->num_primitive_matrices - mat;
        int index2 = 2 * index + 1;
Ramiro Polla's avatar
Ramiro Polla committed
1038 1039 1040 1041

        /* TODO: DSPContext? */

        for (i = 0; i < s->blockpos; i++) {
1042
            int32_t bypassed_lsb = m->bypassed_lsbs[i][mat];
1043
            int32_t *samples = m->sample_buffer[i];
Ramiro Polla's avatar
Ramiro Polla committed
1044
            int64_t accum = 0;
1045 1046 1047 1048

            for (src_ch = 0; src_ch <= maxchan; src_ch++)
                accum += (int64_t) samples[src_ch] * coeffs[src_ch];

Ramiro Polla's avatar
Ramiro Polla committed
1049
            if (matrix_noise_shift) {
1050
                index &= m->access_unit_size_pow2 - 1;
Ramiro Polla's avatar
Ramiro Polla committed
1051
                accum += m->noise_buffer[index] << (matrix_noise_shift + 7);
1052
                index += index2;
Ramiro Polla's avatar
Ramiro Polla committed
1053
            }
1054

1055
            samples[dest_ch] = ((accum >> 14) & mask) + bypassed_lsb;
Ramiro Polla's avatar
Ramiro Polla committed
1056 1057 1058 1059 1060 1061
        }
    }
}

/** Write the audio data into the output buffer. */

1062
static int output_data(MLPDecodeContext *m, unsigned int substr,
1063
                       AVFrame *frame, int *got_frame_ptr)
Ramiro Polla's avatar
Ramiro Polla committed
1064
{
1065
    AVCodecContext *avctx = m->avctx;
Ramiro Polla's avatar
Ramiro Polla committed
1066
    SubStream *s = &m->substream[substr];
1067
    unsigned int i, out_ch = 0;
1068 1069 1070
    int32_t *data_32;
    int16_t *data_16;
    int ret;
1071
    int is32 = (m->avctx->sample_fmt == AV_SAMPLE_FMT_S32);
Ramiro Polla's avatar
Ramiro Polla committed
1072

1073 1074 1075 1076 1077
    if (m->avctx->channels != s->max_matrix_channel + 1) {
        av_log(m->avctx, AV_LOG_ERROR, "channel count mismatch\n");
        return AVERROR_INVALIDDATA;
    }

1078 1079 1080 1081
    if (!s->blockpos) {
        av_log(avctx, AV_LOG_ERROR, "No samples to output.\n");
        return AVERROR_INVALIDDATA;
    }
1082

1083
    /* get output buffer */
1084
    frame->nb_samples = s->blockpos;
1085
    if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
1086
        return ret;
1087 1088
    data_32 = (int32_t *)frame->data[0];
    data_16 = (int16_t *)frame->data[0];
Ramiro Polla's avatar
Ramiro Polla committed
1089 1090

    for (i = 0; i < s->blockpos; i++) {
1091 1092 1093 1094 1095
        for (out_ch = 0; out_ch <= s->max_matrix_channel; out_ch++) {
            int mat_ch = s->ch_assign[out_ch];
            int32_t sample = m->sample_buffer[i][mat_ch]
                          << s->output_shift[mat_ch];
            s->lossless_check_data ^= (sample & 0xffffff) << mat_ch;
Ramiro Polla's avatar
Ramiro Polla committed
1096 1097 1098 1099 1100
            if (is32) *data_32++ = sample << 8;
            else      *data_16++ = sample >> 8;
        }
    }

1101 1102 1103 1104
    /* Update matrix encoding side data */
    if ((ret = ff_side_data_update_matrix_encoding(frame, s->matrix_encoding)) < 0)
        return ret;

1105
    *got_frame_ptr = 1;
Ramiro Polla's avatar
Ramiro Polla committed
1106 1107 1108 1109 1110

    return 0;
}

/** Read an access unit from the stream.
1111 1112
 *  @return negative on error, 0 if not enough data is present in the input stream,
 *  otherwise the number of bytes consumed. */
Ramiro Polla's avatar
Ramiro Polla committed
1113

1114 1115
static int read_access_unit(AVCodecContext *avctx, void* data,
                            int *got_frame_ptr, AVPacket *avpkt)
Ramiro Polla's avatar
Ramiro Polla committed
1116
{
1117 1118
    const uint8_t *buf = avpkt->data;
    int buf_size = avpkt->size;
Ramiro Polla's avatar
Ramiro Polla committed
1119 1120 1121 1122 1123 1124 1125 1126 1127
    MLPDecodeContext *m = avctx->priv_data;
    GetBitContext gb;
    unsigned int length, substr;
    unsigned int substream_start;
    unsigned int header_size = 4;
    unsigned int substr_header_size = 0;
    uint8_t substream_parity_present[MAX_SUBSTREAMS];
    uint16_t substream_data_len[MAX_SUBSTREAMS];
    uint8_t parity_bits;
1128
    int ret;
Ramiro Polla's avatar
Ramiro Polla committed
1129 1130

    if (buf_size < 4)
1131
        return AVERROR_INVALIDDATA;
Ramiro Polla's avatar
Ramiro Polla committed
1132 1133 1134

    length = (AV_RB16(buf) & 0xfff) * 2;

1135
    if (length < 4 || length > buf_size)
1136
        return AVERROR_INVALIDDATA;
Ramiro Polla's avatar
Ramiro Polla committed
1137 1138 1139

    init_get_bits(&gb, (buf + 4), (length - 4) * 8);

1140
    m->is_major_sync_unit = 0;
Ramiro Polla's avatar
Ramiro Polla committed
1141 1142 1143
    if (show_bits_long(&gb, 31) == (0xf8726fba >> 1)) {
        if (read_major_sync(m, &gb) < 0)
            goto error;
1144
        m->is_major_sync_unit = 1;
Ramiro Polla's avatar
Ramiro Polla committed
1145 1146 1147 1148 1149
        header_size += 28;
    }

    if (!m->params_valid) {
        av_log(m->avctx, AV_LOG_WARNING,
Diego Biurrun's avatar
Diego Biurrun committed
1150
               "Stream parameters not seen; skipping frame.\n");
1151
        *got_frame_ptr = 0;
Ramiro Polla's avatar
Ramiro Polla committed
1152 1153 1154 1155 1156 1157
        return length;
    }

    substream_start = 0;

    for (substr = 0; substr < m->num_substreams; substr++) {
1158
        int extraword_present, checkdata_present, end, nonrestart_substr;
Ramiro Polla's avatar
Ramiro Polla committed
1159 1160

        extraword_present = get_bits1(&gb);
1161
        nonrestart_substr = get_bits1(&gb);
Ramiro Polla's avatar
Ramiro Polla committed
1162 1163 1164 1165 1166 1167 1168 1169
        checkdata_present = get_bits1(&gb);
        skip_bits1(&gb);

        end = get_bits(&gb, 12) * 2;

        substr_header_size += 2;

        if (extraword_present) {
1170
            if (m->avctx->codec_id == AV_CODEC_ID_MLP) {
1171 1172 1173
                av_log(m->avctx, AV_LOG_ERROR, "There must be no extraword for MLP.\n");
                goto error;
            }
Ramiro Polla's avatar
Ramiro Polla committed
1174 1175 1176 1177
            skip_bits(&gb, 16);
            substr_header_size += 2;
        }

1178 1179 1180 1181 1182
        if (!(nonrestart_substr ^ m->is_major_sync_unit)) {
            av_log(m->avctx, AV_LOG_ERROR, "Invalid nonrestart_substr.\n");
            goto error;
        }

Ramiro Polla's avatar
Ramiro Polla committed
1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205
        if (end + header_size + substr_header_size > length) {
            av_log(m->avctx, AV_LOG_ERROR,
                   "Indicated length of substream %d data goes off end of "
                   "packet.\n", substr);
            end = length - header_size - substr_header_size;
        }

        if (end < substream_start) {
            av_log(avctx, AV_LOG_ERROR,
                   "Indicated end offset of substream %d data "
                   "is smaller than calculated start offset.\n",
                   substr);
            goto error;
        }

        if (substr > m->max_decoded_substream)
            continue;

        substream_parity_present[substr] = checkdata_present;
        substream_data_len[substr] = end - substream_start;
        substream_start = end;
    }

1206 1207
    parity_bits  = ff_mlp_calculate_parity(buf, 4);
    parity_bits ^= ff_mlp_calculate_parity(buf + header_size, substr_header_size);
Ramiro Polla's avatar
Ramiro Polla committed
1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219

    if ((((parity_bits >> 4) ^ parity_bits) & 0xF) != 0xF) {
        av_log(avctx, AV_LOG_ERROR, "Parity check failed.\n");
        goto error;
    }

    buf += header_size + substr_header_size;

    for (substr = 0; substr <= m->max_decoded_substream; substr++) {
        SubStream *s = &m->substream[substr];
        init_get_bits(&gb, buf, substream_data_len[substr] * 8);

1220 1221 1222
        m->matrix_changed = 0;
        memset(m->filter_changed, 0, sizeof(m->filter_changed));

Ramiro Polla's avatar
Ramiro Polla committed
1223 1224 1225 1226
        s->blockpos = 0;
        do {
            if (get_bits1(&gb)) {
                if (get_bits1(&gb)) {
Diego Biurrun's avatar
Diego Biurrun committed
1227
                    /* A restart header should be present. */
Ramiro Polla's avatar
Ramiro Polla committed
1228 1229 1230 1231 1232
                    if (read_restart_header(m, &gb, buf, substr) < 0)
                        goto next_substr;
                    s->restart_seen = 1;
                }

1233
                if (!s->restart_seen)
Ramiro Polla's avatar
Ramiro Polla committed
1234 1235 1236 1237 1238
                    goto next_substr;
                if (read_decoding_params(m, &gb, substr) < 0)
                    goto next_substr;
            }

1239
            if (!s->restart_seen)
Ramiro Polla's avatar
Ramiro Polla committed
1240 1241
                goto next_substr;

1242 1243
            if ((ret = read_block_data(m, &gb, substr)) < 0)
                return ret;
Ramiro Polla's avatar
Ramiro Polla committed
1244

1245 1246 1247 1248
            if (get_bits_count(&gb) >= substream_data_len[substr] * 8)
                goto substream_length_mismatch;

        } while (!get_bits1(&gb));
Ramiro Polla's avatar
Ramiro Polla committed
1249 1250

        skip_bits(&gb, (-get_bits_count(&gb)) & 15);
1251

1252 1253 1254 1255
        if (substream_data_len[substr] * 8 - get_bits_count(&gb) >= 32) {
            int shorten_by;

            if (get_bits(&gb, 16) != 0xD234)
1256
                return AVERROR_INVALIDDATA;
1257 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;
1263

Ramiro Polla's avatar
Ramiro Polla committed
1264
            if (substr == m->max_decoded_substream)
Diego Biurrun's avatar
Diego Biurrun committed
1265
                av_log(m->avctx, AV_LOG_INFO, "End of stream indicated.\n");
Ramiro Polla's avatar
Ramiro Polla committed
1266
        }
1267

1268
        if (substream_parity_present[substr]) {
Ramiro Polla's avatar
Ramiro Polla committed
1269 1270
            uint8_t parity, checksum;

1271 1272 1273
            if (substream_data_len[substr] * 8 - get_bits_count(&gb) != 16)
                goto substream_length_mismatch;

1274 1275
            parity   = ff_mlp_calculate_parity(buf, substream_data_len[substr] - 2);
            checksum = ff_mlp_checksum8       (buf, substream_data_len[substr] - 2);
Ramiro Polla's avatar
Ramiro Polla committed
1276

1277 1278 1279 1280
            if ((get_bits(&gb, 8) ^ parity) != 0xa9    )
                av_log(m->avctx, AV_LOG_ERROR, "Substream %d parity check failed.\n", substr);
            if ( get_bits(&gb, 8)           != checksum)
                av_log(m->avctx, AV_LOG_ERROR, "Substream %d checksum failed.\n"    , substr);
Ramiro Polla's avatar
Ramiro Polla committed
1281
        }
1282 1283

        if (substream_data_len[substr] * 8 != get_bits_count(&gb))
1284
            goto substream_length_mismatch;
Ramiro Polla's avatar
Ramiro Polla committed
1285 1286

next_substr:
1287
        if (!s->restart_seen)
1288 1289 1290
            av_log(m->avctx, AV_LOG_ERROR,
                   "No restart header present in substream %d.\n", substr);

Ramiro Polla's avatar
Ramiro Polla committed
1291 1292 1293 1294 1295
        buf += substream_data_len[substr];
    }

    rematrix_channels(m, m->max_decoded_substream);

1296
    if ((ret = output_data(m, m->max_decoded_substream, data, got_frame_ptr)) < 0)
1297
        return ret;
Ramiro Polla's avatar
Ramiro Polla committed
1298 1299 1300

    return length;

1301 1302
substream_length_mismatch:
    av_log(m->avctx, AV_LOG_ERROR, "substream %d length mismatch\n", substr);
1303
    return AVERROR_INVALIDDATA;
1304

Ramiro Polla's avatar
Ramiro Polla committed
1305 1306
error:
    m->params_valid = 0;
1307
    return AVERROR_INVALIDDATA;
Ramiro Polla's avatar
Ramiro Polla committed
1308 1309
}

1310
#if CONFIG_MLP_DECODER
1311
AVCodec ff_mlp_decoder = {
1312
    .name           = "mlp",
1313
    .long_name      = NULL_IF_CONFIG_SMALL("MLP (Meridian Lossless Packing)"),
1314
    .type           = AVMEDIA_TYPE_AUDIO,
1315
    .id             = AV_CODEC_ID_MLP,
1316 1317 1318
    .priv_data_size = sizeof(MLPDecodeContext),
    .init           = mlp_decode_init,
    .decode         = read_access_unit,
1319
    .capabilities   = CODEC_CAP_DR1,
Ramiro Polla's avatar
Ramiro Polla committed
1320
};
1321
#endif
1322
#if CONFIG_TRUEHD_DECODER
1323
AVCodec ff_truehd_decoder = {
1324
    .name           = "truehd",
1325
    .long_name      = NULL_IF_CONFIG_SMALL("TrueHD"),
1326
    .type           = AVMEDIA_TYPE_AUDIO,
1327
    .id             = AV_CODEC_ID_TRUEHD,
1328 1329 1330
    .priv_data_size = sizeof(MLPDecodeContext),
    .init           = mlp_decode_init,
    .decode         = read_access_unit,
1331
    .capabilities   = CODEC_CAP_DR1,
1332 1333
};
#endif /* CONFIG_TRUEHD_DECODER */