Coverage Report

Created: 2025-07-11 07:16

/src/vlc/modules/packetizer/dts.c
Line
Count
Source (jump to first uncovered line)
1
/*****************************************************************************
2
 * dts.c: parse DTS audio sync info and packetize the stream
3
 *****************************************************************************
4
 * Copyright (C) 2001-2016 VLC authors and VideoLAN
5
 *
6
 * Authors: Gildas Bazin <gbazin@videolan.org>
7
 *          Thomas Guillem <thomas@gllm.fr>
8
 *
9
 * This program is free software; you can redistribute it and/or modify it
10
 * under the terms of the GNU Lesser General Public License as published by
11
 * the Free Software Foundation; either version 2.1 of the License, or
12
 * (at your option) any later version.
13
 *
14
 * This program is distributed in the hope that it will be useful,
15
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17
 * GNU Lesser General Public License for more details.
18
 *
19
 * You should have received a copy of the GNU Lesser General Public License
20
 * along with this program; if not, write to the Free Software Foundation,
21
 * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
22
 *****************************************************************************/
23
24
/*****************************************************************************
25
 * Preamble
26
 *****************************************************************************/
27
#ifdef HAVE_CONFIG_H
28
# include "config.h"
29
#endif
30
31
#include <stdbit.h>
32
33
#include <vlc_common.h>
34
#include <vlc_plugin.h>
35
#include <vlc_codec.h>
36
#include <vlc_block_helper.h>
37
#include <vlc_modules.h>
38
39
#include "dts_header.h"
40
41
#include "packetizer_helper.h"
42
43
static int  Open( vlc_object_t * );
44
static void Close( vlc_object_t * );
45
46
104
vlc_module_begin ()
47
52
    set_subcategory( SUBCAT_SOUT_PACKETIZER )
48
52
    set_description( N_("DTS audio packetizer") )
49
52
    set_capability( "audio packetizer", 10 )
50
104
    set_callbacks( Open, Close )
51
52
vlc_module_end ()
52
53
typedef struct
54
{
55
    /*
56
     * Input properties
57
     */
58
    int i_state;
59
60
    block_bytestream_t bytestream;
61
    size_t i_next_offset;
62
63
    /*
64
     * Common properties
65
     */
66
    date_t  end_date;
67
    bool    b_date_set;
68
69
    vlc_tick_t i_pts;
70
    bool    b_discontinuity;
71
72
    vlc_dts_header_t first, second;
73
    size_t  i_input_size;
74
} decoder_sys_t;
75
76
enum
77
{
78
    STATE_SYNC_SUBSTREAM_EXTENSIONS = STATE_CUSTOM_FIRST,
79
    STATE_NEXT_SYNC_SUBSTREAM_EXTENSIONS,
80
};
81
82
static void PacketizeFlush( decoder_t *p_dec )
83
0
{
84
0
    decoder_sys_t *p_sys = p_dec->p_sys;
85
86
0
    p_sys->b_discontinuity = true;
87
0
    date_Set( &p_sys->end_date, VLC_TICK_INVALID );
88
0
    p_sys->i_state = STATE_NOSYNC;
89
0
    block_BytestreamEmpty( &p_sys->bytestream );
90
0
}
91
92
static block_t *GetOutBuffer( decoder_t *p_dec )
93
113k
{
94
113k
    decoder_sys_t *p_sys = p_dec->p_sys;
95
96
113k
    if( !p_sys->b_date_set
97
113k
     || p_dec->fmt_out.audio.i_rate != p_sys->first.i_rate )
98
2.30k
    {
99
2.30k
        msg_Dbg( p_dec, "DTS samplerate:%d bitrate:%d",
100
2.30k
                 p_sys->first.i_rate, p_sys->first.i_bitrate );
101
102
2.30k
        date_Init( &p_sys->end_date, p_sys->first.i_rate, 1 );
103
2.30k
        date_Set( &p_sys->end_date, p_sys->i_pts );
104
2.30k
        p_sys->b_date_set = true;
105
2.30k
    }
106
107
113k
    p_dec->fmt_out.audio.i_rate     = p_sys->first.i_rate;
108
113k
    if( p_dec->fmt_out.audio.i_bytes_per_frame < p_sys->first.i_frame_size )
109
1.42k
        p_dec->fmt_out.audio.i_bytes_per_frame = p_sys->first.i_frame_size;
110
113k
    p_dec->fmt_out.audio.i_frame_length = p_sys->first.i_frame_length;
111
112
113k
    p_dec->fmt_out.audio.i_chan_mode = p_sys->first.i_chan_mode;
113
113k
    p_dec->fmt_out.audio.i_physical_channels = p_sys->first.i_physical_channels;
114
113k
    p_dec->fmt_out.audio.i_channels =
115
113k
        stdc_count_ones( p_dec->fmt_out.audio.i_physical_channels );
116
117
113k
    p_dec->fmt_out.i_bitrate = p_sys->first.i_bitrate;
118
119
113k
    block_t *p_block = block_Alloc( p_sys->i_input_size );
120
113k
    if( p_block == NULL )
121
0
        return NULL;
122
123
113k
    p_block->i_nb_samples = p_sys->first.i_frame_length;
124
113k
    p_block->i_pts = p_block->i_dts = date_Get( &p_sys->end_date );
125
113k
    p_block->i_length =
126
113k
        date_Increment( &p_sys->end_date, p_block->i_nb_samples ) - p_block->i_pts;
127
113k
    return p_block;
128
113k
}
129
130
static block_t *PacketizeBlock( decoder_t *p_dec, block_t **pp_block )
131
128k
{
132
128k
    decoder_sys_t *p_sys = p_dec->p_sys;
133
128k
    uint8_t p_header[VLC_DTS_HEADER_SIZE];
134
128k
    block_t *p_out_buffer;
135
136
128k
    block_t *p_block = pp_block ? *pp_block : NULL;
137
138
128k
    if( p_block )
139
120k
    {
140
120k
        if ( p_block->i_flags & (BLOCK_FLAG_DISCONTINUITY|BLOCK_FLAG_CORRUPTED) ) {
141
            /* First always drain complete blocks before discontinuity */
142
0
            block_t *p_drain = PacketizeBlock( p_dec, NULL );
143
0
            if(p_drain)
144
0
                return p_drain;
145
146
0
            PacketizeFlush( p_dec );
147
148
0
            if ( p_block->i_flags & BLOCK_FLAG_CORRUPTED ) {
149
0
                block_Release( p_block );
150
0
                return NULL;
151
0
            }
152
0
        }
153
154
120k
        if ( p_block->i_pts == VLC_TICK_INVALID &&
155
120k
             date_Get( &p_sys->end_date ) == VLC_TICK_INVALID ) {
156
            /* We've just started the stream, wait for the first PTS. */
157
817
            block_Release( p_block );
158
817
            return NULL;
159
817
        }
160
161
119k
        block_BytestreamPush( &p_sys->bytestream, p_block );
162
119k
    }
163
164
5.41M
    while( 1 )
165
5.41M
    {
166
5.41M
        switch( p_sys->i_state )
167
5.41M
        {
168
3.45M
        case STATE_NOSYNC:
169
72.2M
            while( block_PeekBytes( &p_sys->bytestream, p_header, 6 )
170
72.2M
                   == VLC_SUCCESS )
171
72.2M
            {
172
72.2M
                if( vlc_dts_header_IsSync( p_header, 6 ) )
173
3.45M
                {
174
3.45M
                    p_sys->i_state = STATE_SYNC;
175
3.45M
                    break;
176
3.45M
                }
177
68.8M
                block_SkipByte( &p_sys->bytestream );
178
68.8M
            }
179
3.45M
            if( p_sys->i_state != STATE_SYNC )
180
4.75k
            {
181
4.75k
                block_BytestreamFlush( &p_sys->bytestream );
182
183
                /* Need more data */
184
4.75k
                return NULL;
185
4.75k
            }
186
            /* fallthrough */
187
188
3.45M
        case STATE_SYNC:
189
            /* New frame, set the Presentation Time Stamp */
190
3.45M
            p_sys->i_pts = p_sys->bytestream.p_block->i_pts;
191
3.45M
            if( p_sys->i_pts != VLC_TICK_INVALID &&
192
3.45M
                p_sys->i_pts != date_Get( &p_sys->end_date ) )
193
2.15k
            {
194
2.15k
                date_Set( &p_sys->end_date, p_sys->i_pts );
195
2.15k
            }
196
3.45M
            p_sys->i_state = STATE_HEADER;
197
            /* fallthrough */
198
199
3.45M
        case STATE_HEADER:
200
            /* Get DTS frame header (VLC_DTS_HEADER_SIZE bytes) */
201
3.45M
            if( block_PeekBytes( &p_sys->bytestream, p_header,
202
3.45M
                                 VLC_DTS_HEADER_SIZE ) != VLC_SUCCESS )
203
1.48k
            {
204
                /* Need more data */
205
1.48k
                return NULL;
206
1.48k
            }
207
208
            /* Check if frame is valid and get frame info */
209
3.45M
            if( vlc_dts_header_Parse( &p_sys->first, p_header,
210
3.45M
                                      VLC_DTS_HEADER_SIZE ) != VLC_SUCCESS
211
3.45M
             || p_sys->first.i_frame_size == 0 )
212
1.80M
            {
213
1.80M
                msg_Dbg( p_dec, "emulated sync word" );
214
1.80M
                block_SkipByte( &p_sys->bytestream );
215
1.80M
                p_sys->i_state = STATE_NOSYNC;
216
1.80M
                break;
217
1.80M
            }
218
219
1.64M
            if( p_sys->first.syncword == DTS_SYNC_SUBSTREAM )
220
1.39M
                p_sys->i_state = STATE_SYNC_SUBSTREAM_EXTENSIONS;
221
252k
            else
222
252k
                p_sys->i_state = STATE_NEXT_SYNC;
223
1.64M
            p_sys->i_input_size = p_sys->i_next_offset = p_sys->first.i_frame_size;
224
1.64M
            break;
225
226
1.39M
        case STATE_SYNC_SUBSTREAM_EXTENSIONS:
227
            /* Peek into the substream extension (sync + header size < frame_size) */
228
1.39M
            if( block_PeekOffsetBytes( &p_sys->bytestream,
229
1.39M
                                       p_sys->first.i_substream_header_size,
230
1.39M
                                       p_header,
231
1.39M
                                       VLC_DTS_HEADER_SIZE ) != VLC_SUCCESS )
232
1.27k
            {
233
                /* Need more data */
234
1.27k
                return NULL;
235
1.27k
            }
236
237
1.39M
            vlc_dts_header_t xssheader;
238
1.39M
            if( vlc_dts_header_Parse( &xssheader, p_header,
239
1.39M
                                      VLC_DTS_HEADER_SIZE ) != VLC_SUCCESS )
240
1.26M
            {
241
1.26M
                msg_Dbg( p_dec, "emulated substream sync word, can't find extension" );
242
1.26M
                block_SkipByte( &p_sys->bytestream );
243
1.26M
                p_sys->i_state = STATE_NOSYNC;
244
1.26M
                break;
245
1.26M
            }
246
247
124k
            if( xssheader.syncword == DTS_SYNC_SUBSTREAM_LBR )
248
107k
            {
249
                /*
250
                 * LBR exists as independent SUBSTREAM. It is seen valid
251
                 * only when SUBSTREAM[LBR]..SUBTREAM.
252
                 * CORE...SUBSTREAM is regular extension.
253
                 * SUBSTREAM...CORE is sync issue.
254
                 */
255
107k
                p_dec->fmt_out.i_profile = PROFILE_DTS_EXPRESS;
256
107k
                p_sys->first.i_rate = xssheader.i_rate;
257
107k
                p_sys->first.i_frame_length = xssheader.i_frame_length;
258
107k
                p_sys->i_state = STATE_NEXT_SYNC;
259
107k
                break;
260
107k
            }
261
262
17.0k
            msg_Warn( p_dec, "substream without the paired core stream, skip it" );
263
17.0k
            p_sys->i_state = STATE_NOSYNC;
264
17.0k
            p_dec->fmt_out.i_profile = PROFILE_DTS;
265
17.0k
            if( block_SkipBytes( &p_sys->bytestream,
266
17.0k
                                 p_sys->first.i_frame_size ) != VLC_SUCCESS )
267
1.46k
                return NULL;
268
15.6k
            break;
269
270
395k
        case STATE_NEXT_SYNC:
271
            /* Check if next expected frame contains the sync word */
272
47.5M
            while( p_sys->i_state == STATE_NEXT_SYNC )
273
47.3M
            {
274
47.3M
                if( block_PeekOffsetBytes( &p_sys->bytestream,
275
47.3M
                                           p_sys->i_next_offset, p_header,
276
47.3M
                                           VLC_DTS_HEADER_SIZE )
277
47.3M
                                           != VLC_SUCCESS )
278
4.65k
                {
279
4.65k
                    if( p_block == NULL ) /* drain */
280
746
                    {
281
746
                        p_sys->i_state = STATE_GET_DATA;
282
746
                        break;
283
746
                    }
284
                    /* Need more data */
285
3.91k
                    return NULL;
286
4.65k
                }
287
288
47.3M
                if( p_header[0] == 0 )
289
46.9M
                {
290
                    /* DTS wav files, audio CD's and some mkvs use stuffing */
291
46.9M
                    p_sys->i_next_offset++;
292
46.9M
                    continue;
293
46.9M
                }
294
295
391k
                if( !vlc_dts_header_IsSync( p_header, VLC_DTS_HEADER_SIZE ) )
296
277k
                {
297
                    /* Even frame size is likely incorrect FSIZE #18166 */
298
277k
                    if( (p_sys->first.i_frame_size % 2) && p_sys->i_next_offset > 0 &&
299
277k
                        block_PeekOffsetBytes( &p_sys->bytestream,
300
118k
                                               p_sys->i_next_offset - 1, p_header,
301
118k
                                               VLC_DTS_HEADER_SIZE ) == 0 &&
302
277k
                         vlc_dts_header_IsSync( p_header, VLC_DTS_HEADER_SIZE ) )
303
31.9k
                    {
304
31.9k
                        p_sys->i_input_size = p_sys->i_next_offset = p_sys->first.i_frame_size - 1;
305
                        /* reenter */
306
31.9k
                        break;
307
31.9k
                    }
308
245k
                    msg_Dbg( p_dec, "emulated sync word "
309
245k
                             "(no sync on following frame)" );
310
245k
                    p_sys->i_state = STATE_NOSYNC;
311
245k
                    block_SkipByte( &p_sys->bytestream );
312
245k
                    break;
313
277k
                }
314
315
                /* Check if a DTS substream packet is located just after
316
                 * the core packet */
317
113k
                if( p_sys->i_next_offset == p_sys->first.i_frame_size &&
318
113k
                    vlc_dts_header_Parse( &p_sys->second,
319
72.6k
                                          p_header, VLC_DTS_HEADER_SIZE ) == VLC_SUCCESS &&
320
113k
                    p_sys->second.syncword == DTS_SYNC_SUBSTREAM )
321
54.3k
                {
322
54.3k
                    p_sys->i_state = STATE_NEXT_SYNC_SUBSTREAM_EXTENSIONS;
323
54.3k
                }
324
59.3k
                else
325
59.3k
                {
326
59.3k
                    p_dec->fmt_out.i_profile = PROFILE_DTS;
327
59.3k
                    p_sys->i_state = STATE_GET_DATA;
328
59.3k
                }
329
113k
            }
330
391k
            break;
331
332
391k
        case STATE_NEXT_SYNC_SUBSTREAM_EXTENSIONS:
333
54.3k
            assert(p_sys->second.syncword == DTS_SYNC_SUBSTREAM);
334
54.3k
            if( p_sys->first.syncword == DTS_SYNC_SUBSTREAM )
335
52.5k
            {
336
                /* First substream must have been LBR */
337
52.5k
                p_dec->fmt_out.i_profile = PROFILE_DTS_EXPRESS;
338
52.5k
            }
339
1.81k
            else /* Otherwise that's core + extensions, we need to output both */
340
1.81k
            {
341
1.81k
                p_dec->fmt_out.i_profile = PROFILE_DTS_HD;
342
1.81k
                p_sys->i_input_size += p_sys->second.i_frame_size;
343
1.81k
            }
344
54.3k
            p_sys->i_state = STATE_GET_DATA;
345
54.3k
            break;
346
347
115k
        case STATE_GET_DATA:
348
            /* Make sure we have enough data. */
349
115k
            if( block_WaitBytes( &p_sys->bytestream,
350
115k
                                 p_sys->i_input_size ) != VLC_SUCCESS )
351
1.24k
            {
352
                /* Need more data */
353
1.24k
                return NULL;
354
1.24k
            }
355
113k
            p_sys->i_state = STATE_SEND_DATA;
356
            /* fallthrough */
357
358
113k
        case STATE_SEND_DATA:
359
113k
            if( !(p_out_buffer = GetOutBuffer( p_dec )) )
360
0
            {
361
0
                return NULL;
362
0
            }
363
364
            /* Copy the whole frame into the buffer. When we reach this point
365
             * we already know we have enough data available. */
366
113k
            block_GetBytes( &p_sys->bytestream, p_out_buffer->p_buffer,
367
113k
                            p_out_buffer->i_buffer );
368
369
            /* Make sure we don't reuse the same pts twice */
370
113k
            if( p_sys->i_pts == p_sys->bytestream.p_block->i_pts )
371
113k
                p_sys->i_pts = p_sys->bytestream.p_block->i_pts = VLC_TICK_INVALID;
372
373
113k
            if( p_sys->b_discontinuity )
374
0
            {
375
0
                p_sys->b_discontinuity = false;
376
0
                p_out_buffer->i_flags |= BLOCK_FLAG_DISCONTINUITY;
377
0
            }
378
379
            /* So p_block doesn't get re-added several times */
380
113k
            if( pp_block )
381
109k
                *pp_block = block_BytestreamPop( &p_sys->bytestream );
382
383
113k
            p_sys->i_state = STATE_NOSYNC;
384
385
113k
            return p_out_buffer;
386
5.41M
        }
387
5.41M
    }
388
128k
}
389
390
static void Close( vlc_object_t *p_this )
391
3.97k
{
392
3.97k
    decoder_t *p_dec = (decoder_t*)p_this;
393
3.97k
    decoder_sys_t *p_sys = p_dec->p_sys;
394
395
3.97k
    block_BytestreamRelease( &p_sys->bytestream );
396
397
3.97k
    free( p_sys );
398
3.97k
}
399
400
static int Open( vlc_object_t *p_this )
401
3.45M
{
402
3.45M
    decoder_t *p_dec = (decoder_t*)p_this;
403
3.45M
    decoder_sys_t *p_sys;
404
405
3.45M
    if( p_dec->fmt_in->i_codec != VLC_CODEC_DTS )
406
3.45M
        return VLC_EGENERIC;
407
408
    /* Allocate the memory needed to store the decoder's structure */
409
3.97k
    if( ( p_dec->p_sys = p_sys = malloc(sizeof(decoder_sys_t)) ) == NULL )
410
0
        return VLC_ENOMEM;
411
412
    /* Misc init */
413
3.97k
    p_sys->i_state = STATE_NOSYNC;
414
3.97k
    date_Set( &p_sys->end_date, VLC_TICK_INVALID );
415
3.97k
    p_sys->i_pts = VLC_TICK_INVALID;
416
3.97k
    p_sys->b_date_set = false;
417
3.97k
    p_sys->b_discontinuity = false;
418
3.97k
    memset(&p_sys->first, 0, sizeof(vlc_dts_header_t));
419
3.97k
    memset(&p_sys->second, 0, sizeof(vlc_dts_header_t));
420
3.97k
    block_BytestreamInit( &p_sys->bytestream );
421
422
    /* Set output properties (passthrough only) */
423
3.97k
    p_dec->fmt_out.i_codec = p_dec->fmt_in->i_codec;
424
3.97k
    p_dec->fmt_out.audio = p_dec->fmt_in->audio;
425
426
    /* Set callback */
427
3.97k
    p_dec->pf_packetize = PacketizeBlock;
428
3.97k
    p_dec->pf_flush     = PacketizeFlush;
429
3.97k
    p_dec->pf_get_cc    = NULL;
430
3.97k
    return VLC_SUCCESS;
431
3.97k
}