Alexandre Lision | 744f742 | 2013-09-25 11:39:37 -0400 | [diff] [blame] | 1 | /* Copyright (c) 2011 Xiph.Org Foundation, Skype Limited |
| 2 | Written by Jean-Marc Valin and Koen Vos */ |
| 3 | /* |
| 4 | Redistribution and use in source and binary forms, with or without |
| 5 | modification, are permitted provided that the following conditions |
| 6 | are met: |
| 7 | |
| 8 | - Redistributions of source code must retain the above copyright |
| 9 | notice, this list of conditions and the following disclaimer. |
| 10 | |
| 11 | - Redistributions in binary form must reproduce the above copyright |
| 12 | notice, this list of conditions and the following disclaimer in the |
| 13 | documentation and/or other materials provided with the distribution. |
| 14 | |
| 15 | THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| 16 | ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| 17 | LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
| 18 | A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER |
| 19 | OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, |
| 20 | EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, |
| 21 | PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR |
| 22 | PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF |
| 23 | LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING |
| 24 | NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS |
| 25 | SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| 26 | */ |
| 27 | |
| 28 | #ifdef HAVE_CONFIG_H |
| 29 | #include "config.h" |
| 30 | #endif |
| 31 | |
| 32 | #include "opus.h" |
| 33 | #include "opus_private.h" |
| 34 | |
Alexandre Lision | 8538238 | 2014-01-27 15:54:16 -0500 | [diff] [blame] | 35 | #ifndef DISABLE_FLOAT_API |
| 36 | OPUS_EXPORT void opus_pcm_soft_clip(float *_x, int N, int C, float *declip_mem) |
| 37 | { |
| 38 | int c; |
| 39 | int i; |
| 40 | float *x; |
| 41 | |
| 42 | if (C<1 || N<1 || !_x || !declip_mem) return; |
| 43 | |
| 44 | /* First thing: saturate everything to +/- 2 which is the highest level our |
| 45 | non-linearity can handle. At the point where the signal reaches +/-2, |
| 46 | the derivative will be zero anyway, so this doesn't introduce any |
| 47 | discontinuity in the derivative. */ |
| 48 | for (i=0;i<N*C;i++) |
| 49 | _x[i] = MAX16(-2.f, MIN16(2.f, _x[i])); |
| 50 | for (c=0;c<C;c++) |
| 51 | { |
| 52 | float a; |
| 53 | float x0; |
| 54 | int curr; |
| 55 | |
| 56 | x = _x+c; |
| 57 | a = declip_mem[c]; |
| 58 | /* Continue applying the non-linearity from the previous frame to avoid |
| 59 | any discontinuity. */ |
| 60 | for (i=0;i<N;i++) |
| 61 | { |
| 62 | if (x[i*C]*a>=0) |
| 63 | break; |
| 64 | x[i*C] = x[i*C]+a*x[i*C]*x[i*C]; |
| 65 | } |
| 66 | |
| 67 | curr=0; |
| 68 | x0 = x[0]; |
| 69 | while(1) |
| 70 | { |
| 71 | int start, end; |
| 72 | float maxval; |
| 73 | int special=0; |
| 74 | int peak_pos; |
| 75 | for (i=curr;i<N;i++) |
| 76 | { |
| 77 | if (x[i*C]>1 || x[i*C]<-1) |
| 78 | break; |
| 79 | } |
| 80 | if (i==N) |
| 81 | { |
| 82 | a=0; |
| 83 | break; |
| 84 | } |
| 85 | peak_pos = i; |
| 86 | start=end=i; |
| 87 | maxval=ABS16(x[i*C]); |
| 88 | /* Look for first zero crossing before clipping */ |
| 89 | while (start>0 && x[i*C]*x[(start-1)*C]>=0) |
| 90 | start--; |
| 91 | /* Look for first zero crossing after clipping */ |
| 92 | while (end<N && x[i*C]*x[end*C]>=0) |
| 93 | { |
| 94 | /* Look for other peaks until the next zero-crossing. */ |
| 95 | if (ABS16(x[end*C])>maxval) |
| 96 | { |
| 97 | maxval = ABS16(x[end*C]); |
| 98 | peak_pos = end; |
| 99 | } |
| 100 | end++; |
| 101 | } |
| 102 | /* Detect the special case where we clip before the first zero crossing */ |
| 103 | special = (start==0 && x[i*C]*x[0]>=0); |
| 104 | |
| 105 | /* Compute a such that maxval + a*maxval^2 = 1 */ |
| 106 | a=(maxval-1)/(maxval*maxval); |
| 107 | if (x[i*C]>0) |
| 108 | a = -a; |
| 109 | /* Apply soft clipping */ |
| 110 | for (i=start;i<end;i++) |
| 111 | x[i*C] = x[i*C]+a*x[i*C]*x[i*C]; |
| 112 | |
| 113 | if (special && peak_pos>=2) |
| 114 | { |
| 115 | /* Add a linear ramp from the first sample to the signal peak. |
| 116 | This avoids a discontinuity at the beginning of the frame. */ |
| 117 | float delta; |
| 118 | float offset = x0-x[0]; |
| 119 | delta = offset / peak_pos; |
| 120 | for (i=curr;i<peak_pos;i++) |
| 121 | { |
| 122 | offset -= delta; |
| 123 | x[i*C] += offset; |
| 124 | x[i*C] = MAX16(-1.f, MIN16(1.f, x[i*C])); |
| 125 | } |
| 126 | } |
| 127 | curr = end; |
| 128 | if (curr==N) |
| 129 | break; |
| 130 | } |
| 131 | declip_mem[c] = a; |
| 132 | } |
| 133 | } |
| 134 | #endif |
| 135 | |
Alexandre Lision | 744f742 | 2013-09-25 11:39:37 -0400 | [diff] [blame] | 136 | int encode_size(int size, unsigned char *data) |
| 137 | { |
| 138 | if (size < 252) |
| 139 | { |
| 140 | data[0] = size; |
| 141 | return 1; |
| 142 | } else { |
| 143 | data[0] = 252+(size&0x3); |
| 144 | data[1] = (size-(int)data[0])>>2; |
| 145 | return 2; |
| 146 | } |
| 147 | } |
| 148 | |
Alexandre Lision | 8538238 | 2014-01-27 15:54:16 -0500 | [diff] [blame] | 149 | static int parse_size(const unsigned char *data, opus_int32 len, opus_int16 *size) |
| 150 | { |
| 151 | if (len<1) |
| 152 | { |
| 153 | *size = -1; |
| 154 | return -1; |
| 155 | } else if (data[0]<252) |
| 156 | { |
| 157 | *size = data[0]; |
| 158 | return 1; |
| 159 | } else if (len<2) |
| 160 | { |
| 161 | *size = -1; |
| 162 | return -1; |
| 163 | } else { |
| 164 | *size = 4*data[1] + data[0]; |
| 165 | return 2; |
| 166 | } |
| 167 | } |
| 168 | |
| 169 | int opus_packet_parse_impl(const unsigned char *data, opus_int32 len, |
| 170 | int self_delimited, unsigned char *out_toc, |
| 171 | const unsigned char *frames[48], opus_int16 size[48], |
| 172 | int *payload_offset, opus_int32 *packet_offset) |
| 173 | { |
| 174 | int i, bytes; |
| 175 | int count; |
| 176 | int cbr; |
| 177 | unsigned char ch, toc; |
| 178 | int framesize; |
| 179 | opus_int32 last_size; |
| 180 | opus_int32 pad = 0; |
| 181 | const unsigned char *data0 = data; |
| 182 | |
| 183 | if (size==NULL) |
| 184 | return OPUS_BAD_ARG; |
| 185 | |
| 186 | framesize = opus_packet_get_samples_per_frame(data, 48000); |
| 187 | |
| 188 | cbr = 0; |
| 189 | toc = *data++; |
| 190 | len--; |
| 191 | last_size = len; |
| 192 | switch (toc&0x3) |
| 193 | { |
| 194 | /* One frame */ |
| 195 | case 0: |
| 196 | count=1; |
| 197 | break; |
| 198 | /* Two CBR frames */ |
| 199 | case 1: |
| 200 | count=2; |
| 201 | cbr = 1; |
| 202 | if (!self_delimited) |
| 203 | { |
| 204 | if (len&0x1) |
| 205 | return OPUS_INVALID_PACKET; |
| 206 | last_size = len/2; |
| 207 | /* If last_size doesn't fit in size[0], we'll catch it later */ |
| 208 | size[0] = (opus_int16)last_size; |
| 209 | } |
| 210 | break; |
| 211 | /* Two VBR frames */ |
| 212 | case 2: |
| 213 | count = 2; |
| 214 | bytes = parse_size(data, len, size); |
| 215 | len -= bytes; |
| 216 | if (size[0]<0 || size[0] > len) |
| 217 | return OPUS_INVALID_PACKET; |
| 218 | data += bytes; |
| 219 | last_size = len-size[0]; |
| 220 | break; |
| 221 | /* Multiple CBR/VBR frames (from 0 to 120 ms) */ |
| 222 | default: /*case 3:*/ |
| 223 | if (len<1) |
| 224 | return OPUS_INVALID_PACKET; |
| 225 | /* Number of frames encoded in bits 0 to 5 */ |
| 226 | ch = *data++; |
| 227 | count = ch&0x3F; |
| 228 | if (count <= 0 || framesize*count > 5760) |
| 229 | return OPUS_INVALID_PACKET; |
| 230 | len--; |
| 231 | /* Padding flag is bit 6 */ |
| 232 | if (ch&0x40) |
| 233 | { |
| 234 | int p; |
| 235 | do { |
| 236 | int tmp; |
| 237 | if (len<=0) |
| 238 | return OPUS_INVALID_PACKET; |
| 239 | p = *data++; |
| 240 | len--; |
| 241 | tmp = p==255 ? 254: p; |
| 242 | len -= tmp; |
| 243 | pad += tmp; |
| 244 | } while (p==255); |
| 245 | } |
| 246 | if (len<0) |
| 247 | return OPUS_INVALID_PACKET; |
| 248 | /* VBR flag is bit 7 */ |
| 249 | cbr = !(ch&0x80); |
| 250 | if (!cbr) |
| 251 | { |
| 252 | /* VBR case */ |
| 253 | last_size = len; |
| 254 | for (i=0;i<count-1;i++) |
| 255 | { |
| 256 | bytes = parse_size(data, len, size+i); |
| 257 | len -= bytes; |
| 258 | if (size[i]<0 || size[i] > len) |
| 259 | return OPUS_INVALID_PACKET; |
| 260 | data += bytes; |
| 261 | last_size -= bytes+size[i]; |
| 262 | } |
| 263 | if (last_size<0) |
| 264 | return OPUS_INVALID_PACKET; |
| 265 | } else if (!self_delimited) |
| 266 | { |
| 267 | /* CBR case */ |
| 268 | last_size = len/count; |
| 269 | if (last_size*count!=len) |
| 270 | return OPUS_INVALID_PACKET; |
| 271 | for (i=0;i<count-1;i++) |
| 272 | size[i] = (opus_int16)last_size; |
| 273 | } |
| 274 | break; |
| 275 | } |
| 276 | /* Self-delimited framing has an extra size for the last frame. */ |
| 277 | if (self_delimited) |
| 278 | { |
| 279 | bytes = parse_size(data, len, size+count-1); |
| 280 | len -= bytes; |
| 281 | if (size[count-1]<0 || size[count-1] > len) |
| 282 | return OPUS_INVALID_PACKET; |
| 283 | data += bytes; |
| 284 | /* For CBR packets, apply the size to all the frames. */ |
| 285 | if (cbr) |
| 286 | { |
| 287 | if (size[count-1]*count > len) |
| 288 | return OPUS_INVALID_PACKET; |
| 289 | for (i=0;i<count-1;i++) |
| 290 | size[i] = size[count-1]; |
| 291 | } else if (bytes+size[count-1] > last_size) |
| 292 | return OPUS_INVALID_PACKET; |
| 293 | } else |
| 294 | { |
| 295 | /* Because it's not encoded explicitly, it's possible the size of the |
| 296 | last packet (or all the packets, for the CBR case) is larger than |
| 297 | 1275. Reject them here.*/ |
| 298 | if (last_size > 1275) |
| 299 | return OPUS_INVALID_PACKET; |
| 300 | size[count-1] = (opus_int16)last_size; |
| 301 | } |
| 302 | |
| 303 | if (payload_offset) |
| 304 | *payload_offset = (int)(data-data0); |
| 305 | |
| 306 | for (i=0;i<count;i++) |
| 307 | { |
| 308 | if (frames) |
| 309 | frames[i] = data; |
| 310 | data += size[i]; |
| 311 | } |
| 312 | |
| 313 | if (packet_offset) |
| 314 | *packet_offset = pad+(opus_int32)(data-data0); |
| 315 | |
| 316 | if (out_toc) |
| 317 | *out_toc = toc; |
| 318 | |
| 319 | return count; |
| 320 | } |
| 321 | |
| 322 | int opus_packet_parse(const unsigned char *data, opus_int32 len, |
| 323 | unsigned char *out_toc, const unsigned char *frames[48], |
| 324 | opus_int16 size[48], int *payload_offset) |
| 325 | { |
| 326 | return opus_packet_parse_impl(data, len, 0, out_toc, |
| 327 | frames, size, payload_offset, NULL); |
| 328 | } |
| 329 | |