aboutsummaryrefslogtreecommitdiffstats
path: root/libavcodec/dca_exss.c
blob: 4579f2350fedb27bde061946edd908321f0c9352 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
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
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
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
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
/*
 * Copyright (C) 2016 foo86
 *
 * 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
 */

#include "dcadec.h"
#include "dcadata.h"

static int count_chs_for_mask(int mask)
{
    return av_popcount(mask) + av_popcount(mask & 0xae66);
}

static void parse_xll_parameters(DCAExssParser *s, DCAExssAsset *asset)
{
    // Size of XLL data in extension substream
    asset->xll_size = get_bits(&s->gb, s->exss_size_nbits) + 1;

    // XLL sync word present flag
    if (asset->xll_sync_present = get_bits1(&s->gb)) {
        int xll_delay_nbits;

        // Peak bit rate smoothing buffer size
        skip_bits(&s->gb, 4);

        // Number of bits for XLL decoding delay
        xll_delay_nbits = get_bits(&s->gb, 5) + 1;

        // Initial XLL decoding delay in frames
        asset->xll_delay_nframes = get_bits_long(&s->gb, xll_delay_nbits);

        // Number of bytes offset to XLL sync
        asset->xll_sync_offset = get_bits(&s->gb, s->exss_size_nbits);
    } else {
        asset->xll_delay_nframes = 0;
        asset->xll_sync_offset = 0;
    }
}

static void parse_lbr_parameters(DCAExssParser *s, DCAExssAsset *asset)
{
    // Size of LBR component in extension substream
    asset->lbr_size = get_bits(&s->gb, 14) + 1;

    // LBR sync word present flag
    if (get_bits1(&s->gb))
        // LBR sync distance
        skip_bits(&s->gb, 2);
}

static int parse_descriptor(DCAExssParser *s, DCAExssAsset *asset)
{
    int i, j, drc_present, descr_size, descr_pos = get_bits_count(&s->gb);

    // Size of audio asset descriptor in bytes
    descr_size = get_bits(&s->gb, 9) + 1;

    // Audio asset identifier
    asset->asset_index = get_bits(&s->gb, 3);

    //
    // Per stream static metadata
    //

    if (s->static_fields_present) {
        // Asset type descriptor presence
        if (get_bits1(&s->gb))
            // Asset type descriptor
            skip_bits(&s->gb, 4);

        // Language descriptor presence
        if (get_bits1(&s->gb))
            // Language descriptor
            skip_bits(&s->gb, 24);

        // Additional textual information presence
        if (get_bits1(&s->gb)) {
            // Byte size of additional text info
            int text_size = get_bits(&s->gb, 10) + 1;

            // Sanity check available size
            if (get_bits_left(&s->gb) < text_size * 8)
                return AVERROR_INVALIDDATA;

            // Additional textual information string
            skip_bits_long(&s->gb, text_size * 8);
        }

        // PCM bit resolution
        asset->pcm_bit_res = get_bits(&s->gb, 5) + 1;

        // Maximum sample rate
        asset->max_sample_rate = ff_dca_sampling_freqs[get_bits(&s->gb, 4)];

        // Total number of channels
        asset->nchannels_total = get_bits(&s->gb, 8) + 1;

        // One to one map channel to speakers
        if (asset->one_to_one_map_ch_to_spkr = get_bits1(&s->gb)) {
            int spkr_mask_nbits = 0;
            int spkr_remap_nsets;
            int nspeakers[8];

            // Embedded stereo flag
            if (asset->nchannels_total > 2)
                asset->embedded_stereo = get_bits1(&s->gb);

            // Embedded 6 channels flag
            if (asset->nchannels_total > 6)
                asset->embedded_6ch = get_bits1(&s->gb);

            // Speaker mask enabled flag
            if (asset->spkr_mask_enabled = get_bits1(&s->gb)) {
                // Number of bits for speaker activity mask
                spkr_mask_nbits = (get_bits(&s->gb, 2) + 1) << 2;

                // Loudspeaker activity mask
                asset->spkr_mask = get_bits(&s->gb, spkr_mask_nbits);
            }

            // Number of speaker remapping sets
            if ((spkr_remap_nsets = get_bits(&s->gb, 3)) && !spkr_mask_nbits) {
                av_log(s->avctx, AV_LOG_ERROR, "Speaker mask disabled yet there are remapping sets\n");
                return AVERROR_INVALIDDATA;
            }

            // Standard loudspeaker layout mask
            for (i = 0; i < spkr_remap_nsets; i++)
                nspeakers[i] = count_chs_for_mask(get_bits(&s->gb, spkr_mask_nbits));

            for (i = 0; i < spkr_remap_nsets; i++) {
                // Number of channels to be decoded for speaker remapping
                int nch_for_remaps = get_bits(&s->gb, 5) + 1;

                for (j = 0; j < nspeakers[i]; j++) {
                    // Decoded channels to output speaker mapping mask
                    int remap_ch_mask = get_bits_long(&s->gb, nch_for_remaps);

                    // Loudspeaker remapping codes
                    skip_bits_long(&s->gb, av_popcount(remap_ch_mask) * 5);
                }
            }
        } else {
            asset->embedded_stereo = 0;
            asset->embedded_6ch = 0;
            asset->spkr_mask_enabled = 0;
            asset->spkr_mask = 0;

            // Representation type
            asset->representation_type = get_bits(&s->gb, 3);
        }
    }

    //
    // DRC, DNC and mixing metadata
    //

    // Dynamic range coefficient presence flag
    drc_present = get_bits1(&s->gb);

    // Code for dynamic range coefficient
    if (drc_present)
        skip_bits(&s->gb, 8);

    // Dialog normalization presence flag
    if (get_bits1(&s->gb))
        // Dialog normalization code
        skip_bits(&s->gb, 5);

    // DRC for stereo downmix
    if (drc_present && asset->embedded_stereo)
        skip_bits(&s->gb, 8);

    // Mixing metadata presence flag
    if (s->mix_metadata_enabled && get_bits1(&s->gb)) {
        int nchannels_dmix;

        // External mixing flag
        skip_bits1(&s->gb);

        // Post mixing / replacement gain adjustment
        skip_bits(&s->gb, 6);

        // DRC prior to mixing
        if (get_bits(&s->gb, 2) == 3)
            // Custom code for mixing DRC
            skip_bits(&s->gb, 8);
        else
            // Limit for mixing DRC
            skip_bits(&s->gb, 3);

        // Scaling type for channels of main audio
        // Scaling parameters of main audio
        if (get_bits1(&s->gb))
            for (i = 0; i < s->nmixoutconfigs; i++)
                skip_bits_long(&s->gb, 6 * s->nmixoutchs[i]);
        else
            skip_bits_long(&s->gb, 6 * s->nmixoutconfigs);

        nchannels_dmix = asset->nchannels_total;
        if (asset->embedded_6ch)
            nchannels_dmix += 6;
        if (asset->embedded_stereo)
            nchannels_dmix += 2;

        for (i = 0; i < s->nmixoutconfigs; i++) {
            if (!s->nmixoutchs[i]) {
                av_log(s->avctx, AV_LOG_ERROR, "Invalid speaker layout mask for mixing configuration\n");
                return AVERROR_INVALIDDATA;
            }
            for (j = 0; j < nchannels_dmix; j++) {
                // Mix output mask
                int mix_map_mask = get_bits(&s->gb, s->nmixoutchs[i]);

                // Mixing coefficients
                skip_bits_long(&s->gb, av_popcount(mix_map_mask) * 6);
            }
        }
    }

    //
    // Decoder navigation data
    //

    // Coding mode for the asset
    asset->coding_mode = get_bits(&s->gb, 2);

    // Coding components used in asset
    switch (asset->coding_mode) {
    case 0: // Coding mode that may contain multiple coding components
        asset->extension_mask = get_bits(&s->gb, 12);

        if (asset->extension_mask & DCA_EXSS_CORE) {
            // Size of core component in extension substream
            asset->core_size = get_bits(&s->gb, 14) + 1;
            // Core sync word present flag
            if (get_bits1(&s->gb))
                // Core sync distance
                skip_bits(&s->gb, 2);
        }

        if (asset->extension_mask & DCA_EXSS_XBR)
            // Size of XBR extension in extension substream
            asset->xbr_size = get_bits(&s->gb, 14) + 1;

        if (asset->extension_mask & DCA_EXSS_XXCH)
            // Size of XXCH extension in extension substream
            asset->xxch_size = get_bits(&s->gb, 14) + 1;

        if (asset->extension_mask & DCA_EXSS_X96)
            // Size of X96 extension in extension substream
            asset->x96_size = get_bits(&s->gb, 12) + 1;

        if (asset->extension_mask & DCA_EXSS_LBR)
            parse_lbr_parameters(s, asset);

        if (asset->extension_mask & DCA_EXSS_XLL)
            parse_xll_parameters(s, asset);

        if (asset->extension_mask & DCA_EXSS_RSV1)
            skip_bits(&s->gb, 16);

        if (asset->extension_mask & DCA_EXSS_RSV2)
            skip_bits(&s->gb, 16);
        break;

    case 1: // Loss-less coding mode without CBR component
        asset->extension_mask = DCA_EXSS_XLL;
        parse_xll_parameters(s, asset);
        break;

    case 2: // Low bit rate mode
        asset->extension_mask = DCA_EXSS_LBR;
        parse_lbr_parameters(s, asset);
        break;

    case 3: // Auxiliary coding mode
        asset->extension_mask = 0;

        // Size of auxiliary coded data
        skip_bits(&s->gb, 14);

        // Auxiliary codec identification
        skip_bits(&s->gb, 8);

        // Aux sync word present flag
        if (get_bits1(&s->gb))
            // Aux sync distance
            skip_bits(&s->gb, 3);
        break;
    }

    if (asset->extension_mask & DCA_EXSS_XLL)
        // DTS-HD stream ID
        asset->hd_stream_id = get_bits(&s->gb, 3);

    // One to one mixing flag
    // Per channel main audio scaling flag
    // Main audio scaling codes
    // Decode asset in secondary decoder flag
    // Revision 2 DRC metadata
    // Reserved
    // Zero pad
    if (ff_dca_seek_bits(&s->gb, descr_pos + descr_size * 8)) {
        av_log(s->avctx, AV_LOG_ERROR, "Read past end of EXSS asset descriptor\n");
        return AVERROR_INVALIDDATA;
    }

    return 0;
}

static int set_exss_offsets(DCAExssAsset *asset)
{
    int offs = asset->asset_offset;
    int size = asset->asset_size;

    if (asset->extension_mask & DCA_EXSS_CORE) {
        asset->core_offset = offs;
        if (asset->core_size > size)
            return AVERROR_INVALIDDATA;
        offs += asset->core_size;
        size -= asset->core_size;
    }

    if (asset->extension_mask & DCA_EXSS_XBR) {
        asset->xbr_offset = offs;
        if (asset->xbr_size > size)
            return AVERROR_INVALIDDATA;
        offs += asset->xbr_size;
        size -= asset->xbr_size;
    }

    if (asset->extension_mask & DCA_EXSS_XXCH) {
        asset->xxch_offset = offs;
        if (asset->xxch_size > size)
            return AVERROR_INVALIDDATA;
        offs += asset->xxch_size;
        size -= asset->xxch_size;
    }

    if (asset->extension_mask & DCA_EXSS_X96) {
        asset->x96_offset = offs;
        if (asset->x96_size > size)
            return AVERROR_INVALIDDATA;
        offs += asset->x96_size;
        size -= asset->x96_size;
    }

    if (asset->extension_mask & DCA_EXSS_LBR) {
        asset->lbr_offset = offs;
        if (asset->lbr_size > size)
            return AVERROR_INVALIDDATA;
        offs += asset->lbr_size;
        size -= asset->lbr_size;
    }

    if (asset->extension_mask & DCA_EXSS_XLL) {
        asset->xll_offset = offs;
        if (asset->xll_size > size)
            return AVERROR_INVALIDDATA;
        offs += asset->xll_size;
        size -= asset->xll_size;
    }

    return 0;
}

int ff_dca_exss_parse(DCAExssParser *s, uint8_t *data, int size)
{
    int i, ret, offset, wide_hdr, header_size;

    if ((ret = init_get_bits8(&s->gb, data, size)) < 0)
        return ret;

    // Extension substream sync word
    skip_bits_long(&s->gb, 32);

    // User defined bits
    skip_bits(&s->gb, 8);

    // Extension substream index
    s->exss_index = get_bits(&s->gb, 2);

    // Flag indicating short or long header size
    wide_hdr = get_bits1(&s->gb);

    // Extension substream header length
    header_size = get_bits(&s->gb, 8 + 4 * wide_hdr) + 1;

    // Check CRC
    if ((s->avctx->err_recognition & (AV_EF_CRCCHECK | AV_EF_CAREFUL))
        && ff_dca_check_crc(&s->gb, 32 + 8, header_size * 8)) {
        av_log(s->avctx, AV_LOG_ERROR, "Invalid EXSS header checksum\n");
        return AVERROR_INVALIDDATA;
    }

    s->exss_size_nbits = 16 + 4 * wide_hdr;

    // Number of bytes of extension substream
    s->exss_size = get_bits(&s->gb, s->exss_size_nbits) + 1;
    if (s->exss_size > size) {
        av_log(s->avctx, AV_LOG_ERROR, "Packet too short for EXSS frame\n");
        return AVERROR_INVALIDDATA;
    }

    // Per stream static fields presence flag
    if (s->static_fields_present = get_bits1(&s->gb)) {
        int active_exss_mask[8];

        // Reference clock code
        skip_bits(&s->gb, 2);

        // Extension substream frame duration
        skip_bits(&s->gb, 3);

        // Timecode presence flag
        if (get_bits1(&s->gb))
            // Timecode data
            skip_bits_long(&s->gb, 36);

        // Number of defined audio presentations
        s->npresents = get_bits(&s->gb, 3) + 1;
        if (s->npresents > 1) {
            avpriv_request_sample(s->avctx, "%d audio presentations", s->npresents);
            return AVERROR_PATCHWELCOME;
        }

        // Number of audio assets in extension substream
        s->nassets = get_bits(&s->gb, 3) + 1;
        if (s->nassets > 1) {
            avpriv_request_sample(s->avctx, "%d audio assets", s->nassets);
            return AVERROR_PATCHWELCOME;
        }

        // Active extension substream mask for audio presentation
        for (i = 0; i < s->npresents; i++)
            active_exss_mask[i] = get_bits(&s->gb, s->exss_index + 1);

        // Active audio asset mask
        for (i = 0; i < s->npresents; i++)
            skip_bits_long(&s->gb, av_popcount(active_exss_mask[i]) * 8);

        // Mixing metadata enable flag
        if (s->mix_metadata_enabled = get_bits1(&s->gb)) {
            int spkr_mask_nbits;

            // Mixing metadata adjustment level
            skip_bits(&s->gb, 2);

            // Number of bits for mixer output speaker activity mask
            spkr_mask_nbits = (get_bits(&s->gb, 2) + 1) << 2;

            // Number of mixing configurations
            s->nmixoutconfigs = get_bits(&s->gb, 2) + 1;

            // Speaker layout mask for mixer output channels
            for (i = 0; i < s->nmixoutconfigs; i++)
                s->nmixoutchs[i] = count_chs_for_mask(get_bits(&s->gb, spkr_mask_nbits));
        }
    } else {
        s->npresents = 1;
        s->nassets = 1;
    }

    // Size of encoded asset data in bytes
    offset = header_size;
    for (i = 0; i < s->nassets; i++) {
        s->assets[i].asset_offset = offset;
        s->assets[i].asset_size = get_bits(&s->gb, s->exss_size_nbits) + 1;
        offset += s->assets[i].asset_size;
        if (offset > s->exss_size) {
            av_log(s->avctx, AV_LOG_ERROR, "EXSS asset out of bounds\n");
            return AVERROR_INVALIDDATA;
        }
    }

    // Audio asset descriptor
    for (i = 0; i < s->nassets; i++) {
        if ((ret = parse_descriptor(s, &s->assets[i])) < 0)
            return ret;
        if ((ret = set_exss_offsets(&s->assets[i])) < 0) {
            av_log(s->avctx, AV_LOG_ERROR, "Invalid extension size in EXSS asset descriptor\n");
            return ret;
        }
    }

    // Backward compatible core present
    // Backward compatible core substream index
    // Backward compatible core asset index
    // Reserved
    // Byte align
    // CRC16 of extension substream header
    if (ff_dca_seek_bits(&s->gb, header_size * 8)) {
        av_log(s->avctx, AV_LOG_ERROR, "Read past end of EXSS header\n");
        return AVERROR_INVALIDDATA;
    }

    return 0;
}