1 /* Copyright (c) 2022 Amazon */
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 COPYRIGHT OWNER
18 OR 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 #ifdef HAVE_CONFIG_H
28 #include "config.h"
29 #endif
30
31
32 #include "opus_types.h"
33 #include "opus_defines.h"
34 #include "arch.h"
35 #include "os_support.h"
36 #include "opus_private.h"
37
38
39 /* Given an extension payload, advance data to the next extension and return the
40 length of the remaining extensions. */
skip_extension(const unsigned char ** data,opus_int32 len,opus_int32 * header_size)41 opus_int32 skip_extension(const unsigned char **data, opus_int32 len, opus_int32 *header_size)
42 {
43 int id, L;
44 if (len==0)
45 return 0;
46 id = **data>>1;
47 L = **data&1;
48 if (id == 0 && L == 1)
49 {
50 *header_size = 1;
51 if (len < 1)
52 return -1;
53 (*data)++;
54 len--;
55 return len;
56 } else if (id > 0 && id < 32)
57 {
58 if (len < 1+L)
59 return -1;
60 *data += 1+L;
61 len -= 1+L;
62 *header_size = 1;
63 return len;
64 } else {
65 if (L==0)
66 {
67 *data += len;
68 *header_size = 1;
69 return 0;
70 } else {
71 opus_int32 bytes=0;
72 *header_size = 1;
73 do {
74 (*data)++;
75 len--;
76 if (len == 0)
77 return -1;
78 bytes += **data;
79 (*header_size)++;
80 } while (**data == 255);
81 (*data)++;
82 len--;
83 if (bytes <= len)
84 {
85 len -= bytes;
86 *data += bytes;
87 } else {
88 return -1;
89 }
90 return len;
91 }
92 }
93 }
94
95 /* Count the number of extensions, excluding real padding and separators. */
opus_packet_extensions_count(const unsigned char * data,opus_int32 len)96 opus_int32 opus_packet_extensions_count(const unsigned char *data, opus_int32 len)
97 {
98 opus_int32 curr_len;
99 opus_int32 count=0;
100 const unsigned char *curr_data = data;
101
102 celt_assert(len >= 0);
103 celt_assert(data != NULL || len == 0);
104
105 curr_len = len;
106 while (curr_len > 0)
107 {
108 int id;
109 opus_int32 header_size;
110 id = *curr_data>>1;
111 curr_len = skip_extension(&curr_data, curr_len, &header_size);
112 if (curr_len < 0)
113 return OPUS_INVALID_PACKET;
114 if (id > 1)
115 count++;
116 }
117 return count;
118 }
119
120 /* Extract extensions from Opus padding (excluding real padding and separators) */
opus_packet_extensions_parse(const unsigned char * data,opus_int32 len,opus_extension_data * extensions,opus_int32 * nb_extensions)121 opus_int32 opus_packet_extensions_parse(const unsigned char *data, opus_int32 len, opus_extension_data *extensions, opus_int32 *nb_extensions)
122 {
123 const unsigned char *curr_data;
124 opus_int32 curr_len;
125 int curr_frame=0;
126 opus_int32 count=0;
127
128 celt_assert(len >= 0);
129 celt_assert(data != NULL || len == 0);
130 celt_assert(nb_extensions != NULL);
131 celt_assert(extensions != NULL || *nb_extensions == 0);
132
133 curr_data = data;
134 curr_len = len;
135 while (curr_len > 0)
136 {
137 int id;
138 opus_int32 header_size;
139 opus_extension_data curr_ext;
140 id = *curr_data>>1;
141 if (id > 1)
142 {
143 curr_ext.id = id;
144 curr_ext.frame = curr_frame;
145 curr_ext.data = curr_data;
146 } else if (id == 1)
147 {
148 int L = *curr_data&1;
149 if (L==0)
150 curr_frame++;
151 else {
152 if (curr_len >= 2)
153 curr_frame += curr_data[1];
154 /* Else we're at the end and it doesn't matter. */
155 }
156 if (curr_frame >= 48)
157 {
158 *nb_extensions = count;
159 return OPUS_INVALID_PACKET;
160 }
161 }
162 curr_len = skip_extension(&curr_data, curr_len, &header_size);
163 /* printf("curr_len = %d, header_size = %d\n", curr_len, header_size); */
164 if (curr_len < 0)
165 {
166 *nb_extensions = count;
167 return OPUS_INVALID_PACKET;
168 }
169 celt_assert(curr_data - data == len - curr_len);
170 if (id > 1)
171 {
172 if (count == *nb_extensions)
173 {
174 return OPUS_BUFFER_TOO_SMALL;
175 }
176 curr_ext.len = curr_data - curr_ext.data - header_size;
177 curr_ext.data += header_size;
178 extensions[count++] = curr_ext;
179 }
180 }
181 celt_assert(curr_len == 0);
182 *nb_extensions = count;
183 return OPUS_OK;
184 }
185
opus_packet_extensions_generate(unsigned char * data,opus_int32 len,const opus_extension_data * extensions,opus_int32 nb_extensions,int pad)186 opus_int32 opus_packet_extensions_generate(unsigned char *data, opus_int32 len, const opus_extension_data *extensions, opus_int32 nb_extensions, int pad)
187 {
188 int max_frame=0;
189 opus_int32 i;
190 int frame;
191 int curr_frame = 0;
192 opus_int32 pos = 0;
193 opus_int32 written = 0;
194
195 celt_assert(len >= 0);
196
197 for (i=0;i<nb_extensions;i++)
198 {
199 max_frame = IMAX(max_frame, extensions[i].frame);
200 if (extensions[i].id < 2 || extensions[i].id > 127)
201 return OPUS_BAD_ARG;
202 }
203 if (max_frame >= 48) return OPUS_BAD_ARG;
204 for (frame=0;frame<=max_frame;frame++)
205 {
206 for (i=0;i<nb_extensions;i++)
207 {
208 if (extensions[i].frame == frame)
209 {
210 /* Insert separator when needed. */
211 if (frame != curr_frame) {
212 int diff = frame - curr_frame;
213 if (len-pos < 2)
214 return OPUS_BUFFER_TOO_SMALL;
215 if (diff == 1) {
216 if (data) data[pos] = 0x02;
217 pos++;
218 } else {
219 if (data) data[pos] = 0x03;
220 pos++;
221 if (data) data[pos] = diff;
222 pos++;
223 }
224 curr_frame = frame;
225 }
226 if (extensions[i].id < 32)
227 {
228 if (extensions[i].len < 0 || extensions[i].len > 1)
229 return OPUS_BAD_ARG;
230 if (len-pos < extensions[i].len+1)
231 return OPUS_BUFFER_TOO_SMALL;
232 if (data) data[pos] = (extensions[i].id<<1) + extensions[i].len;
233 pos++;
234 if (extensions[i].len > 0) {
235 if (data) data[pos] = extensions[i].data[0];
236 pos++;
237 }
238 } else {
239 int last;
240 opus_int32 length_bytes;
241 if (extensions[i].len < 0)
242 return OPUS_BAD_ARG;
243 last = (written == nb_extensions - 1);
244 length_bytes = 1 + extensions[i].len/255;
245 if (last)
246 length_bytes = 0;
247 if (len-pos < 1 + length_bytes + extensions[i].len)
248 return OPUS_BUFFER_TOO_SMALL;
249 if (data) data[pos] = (extensions[i].id<<1) + !last;
250 pos++;
251 if (!last)
252 {
253 opus_int32 j;
254 for (j=0;j<extensions[i].len/255;j++) {
255 if (data) data[pos] = 255;
256 pos++;
257 }
258 if (data) data[pos] = extensions[i].len % 255;
259 pos++;
260 }
261 if (data) OPUS_COPY(&data[pos], extensions[i].data, extensions[i].len);
262 pos += extensions[i].len;
263 }
264 written++;
265 }
266 }
267 }
268 /* If we need to pad, just prepend 0x01 bytes. Even better would be to fill the
269 end with zeros, but that requires checking that turning the last extesion into
270 an L=1 case still fits. */
271 if (pad && pos < len)
272 {
273 opus_int32 padding = len - pos;
274 if (data) {
275 OPUS_MOVE(data+padding, data, pos);
276 for (i=0;i<padding;i++)
277 data[i] = 0x01;
278 }
279 pos += padding;
280 }
281 return pos;
282 }
283
284 #if 0
285 #include <stdio.h>
286 int main()
287 {
288 opus_extension_data ext[] = {{2, 0, (const unsigned char *)"a", 1},
289 {32, 10, (const unsigned char *)"DRED", 4},
290 {33, 1, (const unsigned char *)"NOT DRED", 8},
291 {3, 4, (const unsigned char *)NULL, 0}
292 };
293 opus_extension_data ext2[10];
294 int i, len;
295 int nb_ext = 10;
296 unsigned char packet[10000];
297 len = opus_packet_extensions_generate(packet, 32, ext, 4, 1);
298 for (i=0;i<len;i++)
299 {
300 printf("%#04x ", packet[i]);
301 if (i%16 == 15)
302 printf("\n");
303 }
304 printf("\n");
305 printf("count = %d\n", opus_packet_extensions_count(packet, len));
306 opus_packet_extensions_parse(packet, len, ext2, &nb_ext);
307 for (i=0;i<nb_ext;i++)
308 {
309 int j;
310 printf("%d %d {", ext2[i].id, ext2[i].frame);
311 for (j=0;j<ext2[i].len;j++) printf("%#04x ", ext2[i].data[j]);
312 printf("} %d\n", ext2[i].len);
313 }
314 }
315 #endif
316