Merge branch 't/image-0.5'
[paraslash.git] / opus_common.c
1 /* Copyright (C)2012 Xiph.Org Foundation
2 *
3 * Redistribution and use in source and binary forms, with or without
4 * modification, are permitted provided that the following conditions
5 * are met:
6 *
7 * - Redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer.
9 *
10 * - Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13
14 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
15 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
16 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
17 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR
18 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
19 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
20 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
21 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
22 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
23 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
24 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25 */
26
27 /**
28 * \file opus_common.c Common functions of the opus decoder and audio format
29 * handler.
30 */
31
32 #include <ogg/ogg.h>
33
34 #include "para.h"
35 #include "error.h"
36 #include "opus_common.h"
37 #include "portable_io.h"
38
39 struct packet {
40 const char *data;
41 int maxlen;
42 int pos;
43 };
44
45 static int read_chars(struct packet *p, unsigned char *str, int nb_chars)
46 {
47 int i;
48
49 if (p->pos > p->maxlen - nb_chars)
50 return 0;
51 for (i = 0; i < nb_chars; i++)
52 str[i] = p->data[p->pos++];
53 return 1;
54 }
55
56 static int read_uint32(struct packet *p, ogg_uint32_t *val)
57 {
58 if (p->pos > p->maxlen - 4)
59 return 0;
60 *val = read_u32(p->data + p->pos);
61 p->pos += 4;
62 return 1;
63 }
64
65 static int read_uint16(struct packet *p, ogg_uint16_t *val)
66 {
67 if (p->pos > p->maxlen - 2)
68 return 0;
69 *val = read_u16(p->data + p->pos);
70 p->pos += 2;
71 return 1;
72 }
73
74 /**
75 * Get metadata of an opus stream.
76 *
77 * This is called from both the audio format handler (which passes ogg packet
78 * 0) and from the decoder.
79 *
80 * \param packet Start of the packet.
81 * \param len Number of bytes.
82 * \param h Result.
83 *
84 * \return Standard.
85 */
86 int opus_parse_header(const char *packet, int len, struct opus_header *h)
87 {
88 int i;
89 char str[9];
90 struct packet p;
91 unsigned char ch, channel_mapping;
92 ogg_uint16_t shortval;
93
94 p.data = packet;
95 p.maxlen = len;
96 p.pos = 0;
97 str[8] = 0;
98 if (len < 19)
99 return -E_OPUS_HEADER;
100 read_chars(&p, (unsigned char*)str, 8);
101 if (memcmp(str, "OpusHead", 8) != 0)
102 return -E_OPUS_HEADER;
103
104 if (!read_chars(&p, &ch, 1))
105 return -E_OPUS_HEADER;
106 h->version = ch;
107 if((h->version & 240) != 0) /* Only major version 0 supported. */
108 return -E_OPUS_HEADER;
109
110 if (!read_chars(&p, &ch, 1))
111 return -E_OPUS_HEADER;
112 h->channels = ch;
113 if (h->channels == 0)
114 return -E_OPUS_HEADER;
115
116 if (!read_uint16(&p, &shortval))
117 return -E_OPUS_HEADER;
118 h->preskip = shortval;
119
120 if (!read_uint32(&p, &h->input_sample_rate))
121 return -E_OPUS_HEADER;
122
123 if (!read_uint16(&p, &shortval))
124 return -E_OPUS_HEADER;
125 h->gain = (short)shortval;
126
127 if (!read_chars(&p, &ch, 1))
128 return -E_OPUS_HEADER;
129 channel_mapping = ch;
130
131 if (channel_mapping != 0) {
132 if (!read_chars(&p, &ch, 1))
133 return -E_OPUS_HEADER;
134
135 if (ch < 1)
136 return -E_OPUS_HEADER;
137 h->nb_streams = ch;
138
139 if (!read_chars(&p, &ch, 1))
140 return -E_OPUS_HEADER;
141
142 if (ch > h->nb_streams || (ch + h->nb_streams) > 255)
143 return -E_OPUS_HEADER;
144 h->nb_coupled = ch;
145
146 /* Multi-stream support */
147 for (i = 0; i < h->channels; i++) {
148 if (!read_chars(&p, &h->stream_map[i], 1))
149 return -E_OPUS_HEADER;
150 if (h->stream_map[i] > (h->nb_streams + h->nb_coupled)
151 && h->stream_map[i] != 255)
152 return -E_OPUS_HEADER;
153 }
154 } else {
155 if (h->channels > 2)
156 return -E_OPUS_HEADER;
157 h->nb_streams = 1;
158 h->nb_coupled = h->channels > 1;
159 h->stream_map[0] = 0;
160 h->stream_map[1] = 1;
161 }
162 /*
163 * For version 0/1 we know there won't be any more data so reject any
164 * that have data past the end.
165 */
166 if ((h->version == 0 || h->version == 1) && p.pos != len)
167 return -E_OPUS_HEADER;
168 return 1;
169 }