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
33typedef 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 */
68static 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
184static 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
193static 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 = ff_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
306static 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
346const 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