1 /*
2 * DCA parser
3 * Copyright (C) 2004 Gildas Bazin
4 * Copyright (C) 2004 Benjamin Zores
5 * Copyright (C) 2006 Benjamin Larsson
6 * Copyright (C) 2007 Konstantin Shishkov
7 *
8 * This file is part of FFmpeg.
9 *
10 * FFmpeg is free software; you can redistribute it and/or
11 * modify it under the terms of the GNU Lesser General Public
12 * License as published by the Free Software Foundation; either
13 * version 2.1 of the License, or (at your option) any later version.
14 *
15 * FFmpeg is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
18 * Lesser General Public License for more details.
19 *
20 * You should have received a copy of the GNU Lesser General Public
21 * License along with FFmpeg; if not, write to the Free Software
22 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
23 */
24
25 #include "dca.h"
26 #include "dca_core.h"
27 #include "dca_exss.h"
28 #include "dca_lbr.h"
29 #include "dca_syncwords.h"
30 #include "get_bits.h"
31 #include "parser.h"
32
33 typedef struct DCAParseContext {
34 ParseContext pc;
35 uint32_t lastmarker;
36 int size;
37 int framesize;
38 unsigned int startpos;
39 DCAExssParser exss;
40 unsigned int sr_code;
41 } DCAParseContext;
42
43 #define IS_CORE_MARKER(state) \
44 (((state & 0xFFFFFFFFF0FF) == (((uint64_t)DCA_SYNCWORD_CORE_14B_LE << 16) | 0xF007)) || \
45 ((state & 0xFFFFFFFFFFF0) == (((uint64_t)DCA_SYNCWORD_CORE_14B_BE << 16) | 0x07F0)) || \
46 ((state & 0xFFFFFFFF00FC) == (((uint64_t)DCA_SYNCWORD_CORE_LE << 16) | 0x00FC)) || \
47 ((state & 0xFFFFFFFFFC00) == (((uint64_t)DCA_SYNCWORD_CORE_BE << 16) | 0xFC00)))
48
49 #define IS_EXSS_MARKER(state) ((state & 0xFFFFFFFF) == DCA_SYNCWORD_SUBSTREAM)
50
51 #define IS_MARKER(state) (IS_CORE_MARKER(state) || IS_EXSS_MARKER(state))
52
53 #define CORE_MARKER(state) ((state >> 16) & 0xFFFFFFFF)
54 #define EXSS_MARKER(state) (state & 0xFFFFFFFF)
55
56 #define STATE_LE(state) (((state & 0xFF00FF00) >> 8) | ((state & 0x00FF00FF) << 8))
57 #define STATE_14(state) (((state & 0x3FFF0000) >> 8) | ((state & 0x00003FFF) >> 6))
58
59 #define CORE_FRAMESIZE(state) (((state >> 4) & 0x3FFF) + 1)
60 #define EXSS_FRAMESIZE(state) ((state & 0x2000000000) ? \
61 ((state >> 5) & 0xFFFFF) + 1 : \
62 ((state >> 13) & 0x0FFFF) + 1)
63
64 /**
65 * Find the end of the current frame in the bitstream.
66 * @return the position of the first byte of the next frame, or -1
67 */
dca_find_frame_end(DCAParseContext * pc1,const uint8_t * buf,int buf_size)68 static int dca_find_frame_end(DCAParseContext *pc1, const uint8_t *buf,
69 int buf_size)
70 {
71 int start_found, size, i;
72 uint64_t state;
73 ParseContext *pc = &pc1->pc;
74
75 start_found = pc->frame_start_found;
76 state = pc->state64;
77 size = pc1->size;
78
79 i = 0;
80 if (!start_found) {
81 for (; i < buf_size; i++) {
82 size++;
83 state = (state << 8) | buf[i];
84
85 if (IS_MARKER(state) &&
86 (!pc1->lastmarker ||
87 pc1->lastmarker == CORE_MARKER(state) ||
88 pc1->lastmarker == DCA_SYNCWORD_SUBSTREAM)) {
89 if (!pc1->lastmarker)
90 pc1->startpos = IS_EXSS_MARKER(state) ? size - 4 : size - 6;
91
92 if (IS_EXSS_MARKER(state))
93 pc1->lastmarker = EXSS_MARKER(state);
94 else
95 pc1->lastmarker = CORE_MARKER(state);
96
97 start_found = 1;
98 size = 0;
99
100 i++;
101 break;
102 }
103 }
104 }
105
106 if (start_found) {
107 for (; i < buf_size; i++) {
108 size++;
109 state = (state << 8) | buf[i];
110
111 if (start_found == 1) {
112 switch (pc1->lastmarker) {
113 case DCA_SYNCWORD_CORE_BE:
114 if (size == 2) {
115 pc1->framesize = CORE_FRAMESIZE(state);
116 start_found = 2;
117 }
118 break;
119 case DCA_SYNCWORD_CORE_LE:
120 if (size == 2) {
121 pc1->framesize = CORE_FRAMESIZE(STATE_LE(state));
122 start_found = 4;
123 }
124 break;
125 case DCA_SYNCWORD_CORE_14B_BE:
126 if (size == 4) {
127 pc1->framesize = CORE_FRAMESIZE(STATE_14(state));
128 start_found = 4;
129 }
130 break;
131 case DCA_SYNCWORD_CORE_14B_LE:
132 if (size == 4) {
133 pc1->framesize = CORE_FRAMESIZE(STATE_14(STATE_LE(state)));
134 start_found = 4;
135 }
136 break;
137 case DCA_SYNCWORD_SUBSTREAM:
138 if (size == 6) {
139 pc1->framesize = EXSS_FRAMESIZE(state);
140 start_found = 4;
141 }
142 break;
143 default:
144 av_assert0(0);
145 }
146 continue;
147 }
148
149 if (start_found == 2 && IS_EXSS_MARKER(state) &&
150 pc1->framesize <= size + 2) {
151 pc1->framesize = size + 2;
152 start_found = 3;
153 continue;
154 }
155
156 if (start_found == 3) {
157 if (size == pc1->framesize + 4) {
158 pc1->framesize += EXSS_FRAMESIZE(state);
159 start_found = 4;
160 }
161 continue;
162 }
163
164 if (pc1->framesize > size)
165 continue;
166
167 if (IS_MARKER(state) &&
168 (pc1->lastmarker == CORE_MARKER(state) ||
169 pc1->lastmarker == DCA_SYNCWORD_SUBSTREAM)) {
170 pc->frame_start_found = 0;
171 pc->state64 = -1;
172 pc1->size = 0;
173 return IS_EXSS_MARKER(state) ? i - 3 : i - 5;
174 }
175 }
176 }
177
178 pc->frame_start_found = start_found;
179 pc->state64 = state;
180 pc1->size = size;
181 return END_NOT_FOUND;
182 }
183
dca_parse_init(AVCodecParserContext * s)184 static av_cold int dca_parse_init(AVCodecParserContext *s)
185 {
186 DCAParseContext *pc1 = s->priv_data;
187
188 pc1->lastmarker = 0;
189 pc1->sr_code = -1;
190 return 0;
191 }
192
dca_parse_params(DCAParseContext * pc1,const uint8_t * buf,int buf_size,int * duration,int * sample_rate,int * profile)193 static int dca_parse_params(DCAParseContext *pc1, const uint8_t *buf,
194 int buf_size, int *duration, int *sample_rate,
195 int *profile)
196 {
197 DCAExssAsset *asset = &pc1->exss.assets[0];
198 GetBitContext gb;
199 DCACoreFrameHeader h;
200 uint8_t hdr[DCA_CORE_FRAME_HEADER_SIZE + AV_INPUT_BUFFER_PADDING_SIZE] = { 0 };
201 int ret, frame_size;
202
203 if (buf_size < DCA_CORE_FRAME_HEADER_SIZE)
204 return AVERROR_INVALIDDATA;
205
206 if (AV_RB32(buf) == DCA_SYNCWORD_SUBSTREAM) {
207 if ((ret = ff_dca_exss_parse(&pc1->exss, buf, buf_size)) < 0)
208 return ret;
209
210 if (asset->extension_mask & DCA_EXSS_LBR) {
211 if ((ret = init_get_bits8(&gb, buf + asset->lbr_offset, asset->lbr_size)) < 0)
212 return ret;
213
214 if (get_bits_long(&gb, 32) != DCA_SYNCWORD_LBR)
215 return AVERROR_INVALIDDATA;
216
217 switch (get_bits(&gb, 8)) {
218 case DCA_LBR_HEADER_DECODER_INIT:
219 pc1->sr_code = get_bits(&gb, 8);
220 case DCA_LBR_HEADER_SYNC_ONLY:
221 break;
222 default:
223 return AVERROR_INVALIDDATA;
224 }
225
226 if (pc1->sr_code >= FF_ARRAY_ELEMS(ff_dca_sampling_freqs))
227 return AVERROR_INVALIDDATA;
228
229 *sample_rate = ff_dca_sampling_freqs[pc1->sr_code];
230 *duration = 1024 << ff_dca_freq_ranges[pc1->sr_code];
231 *profile = FF_PROFILE_DTS_EXPRESS;
232 return 0;
233 }
234
235 if (asset->extension_mask & DCA_EXSS_XLL) {
236 int nsamples_log2;
237
238 if ((ret = init_get_bits8(&gb, buf + asset->xll_offset, asset->xll_size)) < 0)
239 return ret;
240
241 if (get_bits_long(&gb, 32) != DCA_SYNCWORD_XLL)
242 return AVERROR_INVALIDDATA;
243
244 if (get_bits(&gb, 4))
245 return AVERROR_INVALIDDATA;
246
247 skip_bits(&gb, 8);
248 skip_bits_long(&gb, get_bits(&gb, 5) + 1);
249 skip_bits(&gb, 4);
250 nsamples_log2 = get_bits(&gb, 4) + get_bits(&gb, 4);
251 if (nsamples_log2 > 24)
252 return AVERROR_INVALIDDATA;
253
254 *sample_rate = asset->max_sample_rate;
255 *duration = (1 + (*sample_rate > 96000)) << nsamples_log2;
256 *profile = FF_PROFILE_DTS_HD_MA;
257 return 0;
258 }
259
260 return AVERROR_INVALIDDATA;
261 }
262
263 if ((ret = avpriv_dca_convert_bitstream(buf, DCA_CORE_FRAME_HEADER_SIZE,
264 hdr, DCA_CORE_FRAME_HEADER_SIZE)) < 0)
265 return ret;
266 if (avpriv_dca_parse_core_frame_header(&h, hdr, ret) < 0)
267 return AVERROR_INVALIDDATA;
268
269 *duration = h.npcmblocks * DCA_PCMBLOCK_SAMPLES;
270 *sample_rate = avpriv_dca_sample_rates[h.sr_code];
271 if (*profile != FF_PROFILE_UNKNOWN)
272 return 0;
273
274 *profile = FF_PROFILE_DTS;
275 if (h.ext_audio_present) {
276 switch (h.ext_audio_type) {
277 case DCA_EXT_AUDIO_XCH:
278 case DCA_EXT_AUDIO_XXCH:
279 *profile = FF_PROFILE_DTS_ES;
280 break;
281 case DCA_EXT_AUDIO_X96:
282 *profile = FF_PROFILE_DTS_96_24;
283 break;
284 }
285 }
286
287 frame_size = FFALIGN(h.frame_size, 4);
288 if (buf_size - 4 < frame_size)
289 return 0;
290
291 buf += frame_size;
292 buf_size -= frame_size;
293 if (AV_RB32(buf) != DCA_SYNCWORD_SUBSTREAM)
294 return 0;
295 if (ff_dca_exss_parse(&pc1->exss, buf, buf_size) < 0)
296 return 0;
297
298 if (asset->extension_mask & DCA_EXSS_XLL)
299 *profile = FF_PROFILE_DTS_HD_MA;
300 else if (asset->extension_mask & (DCA_EXSS_XBR | DCA_EXSS_XXCH | DCA_EXSS_X96))
301 *profile = FF_PROFILE_DTS_HD_HRA;
302
303 return 0;
304 }
305
dca_parse(AVCodecParserContext * s,AVCodecContext * avctx,const uint8_t ** poutbuf,int * poutbuf_size,const uint8_t * buf,int buf_size)306 static int dca_parse(AVCodecParserContext *s, AVCodecContext *avctx,
307 const uint8_t **poutbuf, int *poutbuf_size,
308 const uint8_t *buf, int buf_size)
309 {
310 DCAParseContext *pc1 = s->priv_data;
311 ParseContext *pc = &pc1->pc;
312 int next, duration, sample_rate;
313
314 if (s->flags & PARSER_FLAG_COMPLETE_FRAMES) {
315 next = buf_size;
316 } else {
317 next = dca_find_frame_end(pc1, buf, buf_size);
318
319 if (ff_combine_frame(pc, next, &buf, &buf_size) < 0) {
320 *poutbuf = NULL;
321 *poutbuf_size = 0;
322 return buf_size;
323 }
324
325 /* skip initial padding */
326 if (buf_size > pc1->startpos) {
327 buf += pc1->startpos;
328 buf_size -= pc1->startpos;
329 }
330 pc1->startpos = 0;
331 }
332
333 /* read the duration and sample rate from the frame header */
334 if (!dca_parse_params(pc1, buf, buf_size, &duration, &sample_rate, &avctx->profile)) {
335 if (!avctx->sample_rate)
336 avctx->sample_rate = sample_rate;
337 s->duration = av_rescale(duration, avctx->sample_rate, sample_rate);
338 } else
339 s->duration = 0;
340
341 *poutbuf = buf;
342 *poutbuf_size = buf_size;
343 return next;
344 }
345
346 AVCodecParser ff_dca_parser = {
347 .codec_ids = { AV_CODEC_ID_DTS },
348 .priv_data_size = sizeof(DCAParseContext),
349 .parser_init = dca_parse_init,
350 .parser_parse = dca_parse,
351 .parser_close = ff_parse_close,
352 };
353