dca: K&R formatting cosmetics
[libav.git] / libavcodec / dca_parser.c
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 Libav.
9 *
10 * Libav 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 * Libav 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 Libav; 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 "get_bits.h"
27 #include "parser.h"
28
29 typedef 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) \
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)
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 */
46 static int dca_find_frame_end(DCAParseContext *pc1, const uint8_t *buf,
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;
54 state = pc->state;
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) {
62 start_found = 1;
63 i++;
64 break;
65 } else if (!pc1->lastmarker) {
66 start_found = 1;
67 pc1->lastmarker = state;
68 i++;
69 break;
70 }
71 }
72 }
73 }
74 if (start_found) {
75 for (; i < buf_size; i++) {
76 pc1->size++;
77 state = (state << 8) | buf[i];
78 if (state == DCA_HD_MARKER && !pc1->hd_pos)
79 pc1->hd_pos = pc1->size;
80 if (state == pc1->lastmarker && IS_MARKER(state, i, buf, buf_size)) {
81 if (pc1->framesize > pc1->size)
82 continue;
83 pc->frame_start_found = 0;
84 pc->state = -1;
85 pc1->size = 0;
86 return i - 3;
87 }
88 }
89 }
90 pc->frame_start_found = start_found;
91 pc->state = state;
92 return END_NOT_FOUND;
93 }
94
95 static av_cold int dca_parse_init(AVCodecParserContext *s)
96 {
97 DCAParseContext *pc1 = s->priv_data;
98
99 pc1->lastmarker = 0;
100 return 0;
101 }
102
103 static int dca_parse_params(const uint8_t *buf, int buf_size, int *duration,
104 int *sample_rate, int *framesize)
105 {
106 GetBitContext gb;
107 uint8_t hdr[12 + FF_INPUT_BUFFER_PADDING_SIZE] = { 0 };
108 int ret, sample_blocks, sr_code;
109
110 if (buf_size < 12)
111 return AVERROR_INVALIDDATA;
112
113 if ((ret = ff_dca_convert_bitstream(buf, 12, hdr, 12)) < 0)
114 return ret;
115
116 init_get_bits(&gb, hdr, 96);
117
118 skip_bits_long(&gb, 39);
119 sample_blocks = get_bits(&gb, 7) + 1;
120 if (sample_blocks < 8)
121 return AVERROR_INVALIDDATA;
122 *duration = 256 * (sample_blocks / 8);
123
124 *framesize = get_bits(&gb, 14) + 1;
125 if (*framesize < 95)
126 return AVERROR_INVALIDDATA;
127
128 skip_bits(&gb, 6);
129 sr_code = get_bits(&gb, 4);
130 *sample_rate = avpriv_dca_sample_rates[sr_code];
131 if (*sample_rate == 0)
132 return AVERROR_INVALIDDATA;
133
134 return 0;
135 }
136
137 static int dca_parse(AVCodecParserContext *s, AVCodecContext *avctx,
138 const uint8_t **poutbuf, int *poutbuf_size,
139 const uint8_t *buf, int buf_size)
140 {
141 DCAParseContext *pc1 = s->priv_data;
142 ParseContext *pc = &pc1->pc;
143 int next, duration, sample_rate;
144
145 if (s->flags & PARSER_FLAG_COMPLETE_FRAMES) {
146 next = buf_size;
147 } else {
148 next = dca_find_frame_end(pc1, buf, buf_size);
149
150 if (ff_combine_frame(pc, next, &buf, &buf_size) < 0) {
151 *poutbuf = NULL;
152 *poutbuf_size = 0;
153 return buf_size;
154 }
155 }
156
157 /* read the duration and sample rate from the frame header */
158 if (!dca_parse_params(buf, buf_size, &duration, &sample_rate, &pc1->framesize)) {
159 s->duration = duration;
160 avctx->sample_rate = sample_rate;
161 } else
162 s->duration = 0;
163
164 *poutbuf = buf;
165 *poutbuf_size = buf_size;
166 return next;
167 }
168
169 AVCodecParser ff_dca_parser = {
170 .codec_ids = { AV_CODEC_ID_DTS },
171 .priv_data_size = sizeof(DCAParseContext),
172 .parser_init = dca_parse_init,
173 .parser_parse = dca_parse,
174 .parser_close = ff_parse_close,
175 };