Imported Debian version 2.5.3~trusty1
[deb_ffmpeg.git] / ffmpeg / libavcodec / dca_parser.c
CommitLineData
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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
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25#include "dca.h"
26#include "get_bits.h"
f6fa7814 27#include "parser.h"
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28
29typedef struct DCAParseContext {
30 ParseContext pc;
31 uint32_t lastmarker;
32 int size;
33 int framesize;
34 int hd_pos;
35} DCAParseContext;
36
37#define IS_MARKER(state, i, buf, buf_size) \
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38 ((state == DCA_MARKER_14B_LE && (i < buf_size - 2) && (buf[i + 1] & 0xF0) == 0xF0 && buf[i + 2] == 0x07) || \
39 (state == DCA_MARKER_14B_BE && (i < buf_size - 2) && buf[i + 1] == 0x07 && (buf[i + 2] & 0xF0) == 0xF0) || \
40 state == DCA_MARKER_RAW_LE || state == DCA_MARKER_RAW_BE || state == DCA_HD_MARKER)
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41
42/**
43 * Find the end of the current frame in the bitstream.
44 * @return the position of the first byte of the next frame, or -1
45 */
f6fa7814 46static int dca_find_frame_end(DCAParseContext *pc1, const uint8_t *buf,
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47 int buf_size)
48{
49 int start_found, i;
50 uint32_t state;
51 ParseContext *pc = &pc1->pc;
52
53 start_found = pc->frame_start_found;
f6fa7814 54 state = pc->state;
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55
56 i = 0;
57 if (!start_found) {
58 for (i = 0; i < buf_size; i++) {
59 state = (state << 8) | buf[i];
60 if (IS_MARKER(state, i, buf, buf_size)) {
61 if (!pc1->lastmarker || state == pc1->lastmarker || pc1->lastmarker == DCA_HD_MARKER) {
f6fa7814 62 start_found = 1;
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63 pc1->lastmarker = state;
64 i++;
65 break;
66 }
67 }
68 }
69 }
70 if (start_found) {
71 for (; i < buf_size; i++) {
72 pc1->size++;
73 state = (state << 8) | buf[i];
74 if (state == DCA_HD_MARKER && !pc1->hd_pos)
75 pc1->hd_pos = pc1->size;
76 if (IS_MARKER(state, i, buf, buf_size) && (state == pc1->lastmarker || pc1->lastmarker == DCA_HD_MARKER)) {
f6fa7814 77 if (pc1->framesize > pc1->size)
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78 continue;
79 pc->frame_start_found = 0;
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80 pc->state = -1;
81 pc1->size = 0;
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82 return i - 3;
83 }
84 }
85 }
86 pc->frame_start_found = start_found;
f6fa7814 87 pc->state = state;
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88 return END_NOT_FOUND;
89}
90
f6fa7814 91static av_cold int dca_parse_init(AVCodecParserContext *s)
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92{
93 DCAParseContext *pc1 = s->priv_data;
94
95 pc1->lastmarker = 0;
96 return 0;
97}
98
99static int dca_parse_params(const uint8_t *buf, int buf_size, int *duration,
100 int *sample_rate, int *framesize)
101{
102 GetBitContext gb;
103 uint8_t hdr[12 + FF_INPUT_BUFFER_PADDING_SIZE] = { 0 };
104 int ret, sample_blocks, sr_code;
105
106 if (buf_size < 12)
107 return AVERROR_INVALIDDATA;
108
109 if ((ret = avpriv_dca_convert_bitstream(buf, 12, hdr, 12)) < 0)
110 return ret;
111
112 init_get_bits(&gb, hdr, 96);
113
114 skip_bits_long(&gb, 39);
115 sample_blocks = get_bits(&gb, 7) + 1;
116 if (sample_blocks < 8)
117 return AVERROR_INVALIDDATA;
118 *duration = 256 * (sample_blocks / 8);
119
120 *framesize = get_bits(&gb, 14) + 1;
121 if (*framesize < 95)
122 return AVERROR_INVALIDDATA;
123
124 skip_bits(&gb, 6);
f6fa7814 125 sr_code = get_bits(&gb, 4);
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126 *sample_rate = avpriv_dca_sample_rates[sr_code];
127 if (*sample_rate == 0)
128 return AVERROR_INVALIDDATA;
129
130 return 0;
131}
132
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133static int dca_parse(AVCodecParserContext *s, AVCodecContext *avctx,
134 const uint8_t **poutbuf, int *poutbuf_size,
135 const uint8_t *buf, int buf_size)
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136{
137 DCAParseContext *pc1 = s->priv_data;
138 ParseContext *pc = &pc1->pc;
139 int next, duration, sample_rate;
140
141 if (s->flags & PARSER_FLAG_COMPLETE_FRAMES) {
142 next = buf_size;
143 } else {
144 next = dca_find_frame_end(pc1, buf, buf_size);
145
146 if (ff_combine_frame(pc, next, &buf, &buf_size) < 0) {
f6fa7814 147 *poutbuf = NULL;
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148 *poutbuf_size = 0;
149 return buf_size;
150 }
151 }
152
153 /* read the duration and sample rate from the frame header */
154 if (!dca_parse_params(buf, buf_size, &duration, &sample_rate, &pc1->framesize)) {
f6fa7814 155 s->duration = duration;
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156 avctx->sample_rate = sample_rate;
157 } else
158 s->duration = 0;
159
f6fa7814 160 *poutbuf = buf;
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161 *poutbuf_size = buf_size;
162 return next;
163}
164
165AVCodecParser ff_dca_parser = {
166 .codec_ids = { AV_CODEC_ID_DTS },
167 .priv_data_size = sizeof(DCAParseContext),
168 .parser_init = dca_parse_init,
169 .parser_parse = dca_parse,
170 .parser_close = ff_parse_close,
171};