Guido van Rossum | b66efa0 | 1992-06-01 16:01:24 +0000 | [diff] [blame^] | 1 | /*********************************************************** |
| 2 | Copyright 1991 by Stichting Mathematisch Centrum, Amsterdam, The |
| 3 | Netherlands. |
| 4 | |
| 5 | All Rights Reserved |
| 6 | |
| 7 | Permission to use, copy, modify, and distribute this software and its |
| 8 | documentation for any purpose and without fee is hereby granted, |
| 9 | provided that the above copyright notice appear in all copies and that |
| 10 | both that copyright notice and this permission notice appear in |
| 11 | supporting documentation, and that the names of Stichting Mathematisch |
| 12 | Centrum or CWI not be used in advertising or publicity pertaining to |
| 13 | distribution of the software without specific, written prior permission. |
| 14 | |
| 15 | STICHTING MATHEMATISCH CENTRUM DISCLAIMS ALL WARRANTIES WITH REGARD TO |
| 16 | THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND |
| 17 | FITNESS, IN NO EVENT SHALL STICHTING MATHEMATISCH CENTRUM BE LIABLE |
| 18 | FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES |
| 19 | WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN |
| 20 | ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT |
| 21 | OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. |
| 22 | |
| 23 | ******************************************************************/ |
| 24 | |
| 25 | /* audioopmodele - Module to detect peak values in arrays */ |
| 26 | |
| 27 | #ifdef sun |
| 28 | #define signed |
| 29 | #endif |
| 30 | |
| 31 | #include "allobjects.h" |
| 32 | #include "modsupport.h" |
| 33 | |
| 34 | /* Code shamelessly stealen from sox, |
| 35 | ** (c) Craig Reese, Joe Campbell and Jeff Poskanzer 1989 */ |
| 36 | |
| 37 | #define MINLIN -32768 |
| 38 | #define MAXLIN 32767 |
| 39 | #define LINCLIP(x) do { if ( x < MINLIN ) x = MINLIN ; else if ( x > MAXLIN ) x = MAXLIN; } while ( 0 ) |
| 40 | |
| 41 | unsigned char st_linear_to_ulaw( /* int sample */ ); |
| 42 | |
| 43 | /* |
| 44 | ** This macro converts from ulaw to 16 bit linear, faster. |
| 45 | ** |
| 46 | ** Jef Poskanzer |
| 47 | ** 23 October 1989 |
| 48 | ** |
| 49 | ** Input: 8 bit ulaw sample |
| 50 | ** Output: signed 16 bit linear sample |
| 51 | */ |
| 52 | #define st_ulaw_to_linear(ulawbyte) ulaw_table[ulawbyte] |
| 53 | |
| 54 | static int ulaw_table[256] = { |
| 55 | -32124, -31100, -30076, -29052, -28028, -27004, -25980, -24956, |
| 56 | -23932, -22908, -21884, -20860, -19836, -18812, -17788, -16764, |
| 57 | -15996, -15484, -14972, -14460, -13948, -13436, -12924, -12412, |
| 58 | -11900, -11388, -10876, -10364, -9852, -9340, -8828, -8316, |
| 59 | -7932, -7676, -7420, -7164, -6908, -6652, -6396, -6140, |
| 60 | -5884, -5628, -5372, -5116, -4860, -4604, -4348, -4092, |
| 61 | -3900, -3772, -3644, -3516, -3388, -3260, -3132, -3004, |
| 62 | -2876, -2748, -2620, -2492, -2364, -2236, -2108, -1980, |
| 63 | -1884, -1820, -1756, -1692, -1628, -1564, -1500, -1436, |
| 64 | -1372, -1308, -1244, -1180, -1116, -1052, -988, -924, |
| 65 | -876, -844, -812, -780, -748, -716, -684, -652, |
| 66 | -620, -588, -556, -524, -492, -460, -428, -396, |
| 67 | -372, -356, -340, -324, -308, -292, -276, -260, |
| 68 | -244, -228, -212, -196, -180, -164, -148, -132, |
| 69 | -120, -112, -104, -96, -88, -80, -72, -64, |
| 70 | -56, -48, -40, -32, -24, -16, -8, 0, |
| 71 | 32124, 31100, 30076, 29052, 28028, 27004, 25980, 24956, |
| 72 | 23932, 22908, 21884, 20860, 19836, 18812, 17788, 16764, |
| 73 | 15996, 15484, 14972, 14460, 13948, 13436, 12924, 12412, |
| 74 | 11900, 11388, 10876, 10364, 9852, 9340, 8828, 8316, |
| 75 | 7932, 7676, 7420, 7164, 6908, 6652, 6396, 6140, |
| 76 | 5884, 5628, 5372, 5116, 4860, 4604, 4348, 4092, |
| 77 | 3900, 3772, 3644, 3516, 3388, 3260, 3132, 3004, |
| 78 | 2876, 2748, 2620, 2492, 2364, 2236, 2108, 1980, |
| 79 | 1884, 1820, 1756, 1692, 1628, 1564, 1500, 1436, |
| 80 | 1372, 1308, 1244, 1180, 1116, 1052, 988, 924, |
| 81 | 876, 844, 812, 780, 748, 716, 684, 652, |
| 82 | 620, 588, 556, 524, 492, 460, 428, 396, |
| 83 | 372, 356, 340, 324, 308, 292, 276, 260, |
| 84 | 244, 228, 212, 196, 180, 164, 148, 132, |
| 85 | 120, 112, 104, 96, 88, 80, 72, 64, |
| 86 | 56, 48, 40, 32, 24, 16, 8, 0 }; |
| 87 | |
| 88 | #define ZEROTRAP /* turn on the trap as per the MIL-STD */ |
| 89 | #define BIAS 0x84 /* define the add-in bias for 16 bit samples */ |
| 90 | #define CLIP 32635 |
| 91 | |
| 92 | unsigned char |
| 93 | st_linear_to_ulaw( sample ) |
| 94 | int sample; |
| 95 | { |
| 96 | static int exp_lut[256] = {0,0,1,1,2,2,2,2,3,3,3,3,3,3,3,3, |
| 97 | 4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4, |
| 98 | 5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5, |
| 99 | 5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5, |
| 100 | 6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6, |
| 101 | 6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6, |
| 102 | 6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6, |
| 103 | 6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6, |
| 104 | 7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7, |
| 105 | 7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7, |
| 106 | 7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7, |
| 107 | 7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7, |
| 108 | 7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7, |
| 109 | 7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7, |
| 110 | 7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7, |
| 111 | 7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7}; |
| 112 | int sign, exponent, mantissa; |
| 113 | unsigned char ulawbyte; |
| 114 | |
| 115 | /* Get the sample into sign-magnitude. */ |
| 116 | sign = (sample >> 8) & 0x80; /* set aside the sign */ |
| 117 | if ( sign != 0 ) sample = -sample; /* get magnitude */ |
| 118 | if ( sample > CLIP ) sample = CLIP; /* clip the magnitude */ |
| 119 | |
| 120 | /* Convert from 16 bit linear to ulaw. */ |
| 121 | sample = sample + BIAS; |
| 122 | exponent = exp_lut[( sample >> 7 ) & 0xFF]; |
| 123 | mantissa = ( sample >> ( exponent + 3 ) ) & 0x0F; |
| 124 | ulawbyte = ~ ( sign | ( exponent << 4 ) | mantissa ); |
| 125 | #ifdef ZEROTRAP |
| 126 | if ( ulawbyte == 0 ) ulawbyte = 0x02; /* optional CCITT trap */ |
| 127 | #endif |
| 128 | |
| 129 | return ulawbyte; |
| 130 | } |
| 131 | /* End of code taken from sox */ |
| 132 | |
| 133 | #define CHARP(cp, i) ((signed char *)(cp+i)) |
| 134 | #define SHORTP(cp, i) ((short *)(cp+i)) |
| 135 | #define LONGP(cp, i) ((long *)(cp+i)) |
| 136 | |
| 137 | |
| 138 | |
| 139 | static object *AudioopError; |
| 140 | |
| 141 | static object * |
| 142 | audioop_getsample(self, args) |
| 143 | object *self; |
| 144 | object *args; |
| 145 | { |
| 146 | signed char *cp; |
| 147 | int len, size, val; |
| 148 | int i; |
| 149 | |
| 150 | if ( !getargs(args, "(s#ii)", &cp, &len, &size, &i) ) |
| 151 | return 0; |
| 152 | if ( size != 1 && size != 2 && size != 4 ) { |
| 153 | err_setstr(AudioopError, "Size should be 1, 2 or 4"); |
| 154 | return 0; |
| 155 | } |
| 156 | if ( i < 0 || i >= len/size ) { |
| 157 | err_setstr(AudioopError, "Index out of range"); |
| 158 | return 0; |
| 159 | } |
| 160 | if ( size == 1 ) val = (int)*CHARP(cp, i); |
| 161 | else if ( size == 2 ) val = (int)*SHORTP(cp, i*2); |
| 162 | else if ( size == 4 ) val = (int)*LONGP(cp, i*4); |
| 163 | return newintobject(val); |
| 164 | } |
| 165 | |
| 166 | static object * |
| 167 | audioop_max(self, args) |
| 168 | object *self; |
| 169 | object *args; |
| 170 | { |
| 171 | signed char *cp; |
| 172 | int len, size, val; |
| 173 | int i; |
| 174 | int max = 0; |
| 175 | |
| 176 | if ( !getargs(args, "(s#i)", &cp, &len, &size) ) |
| 177 | return 0; |
| 178 | if ( size != 1 && size != 2 && size != 4 ) { |
| 179 | err_setstr(AudioopError, "Size should be 1, 2 or 4"); |
| 180 | return 0; |
| 181 | } |
| 182 | for ( i=0; i<len; i+= size) { |
| 183 | if ( size == 1 ) val = (int)*CHARP(cp, i); |
| 184 | else if ( size == 2 ) val = (int)*SHORTP(cp, i); |
| 185 | else if ( size == 4 ) val = (int)*LONGP(cp, i); |
| 186 | if ( val < 0 ) val = (-val); |
| 187 | if ( val > max ) max = val; |
| 188 | } |
| 189 | return newintobject(max); |
| 190 | } |
| 191 | |
| 192 | static object * |
| 193 | audioop_avg(self, args) |
| 194 | object *self; |
| 195 | object *args; |
| 196 | { |
| 197 | signed char *cp; |
| 198 | int len, size, val; |
| 199 | int i; |
| 200 | float avg = 0.0; |
| 201 | |
| 202 | if ( !getargs(args, "(s#i)", &cp, &len, &size) ) |
| 203 | return 0; |
| 204 | if ( size != 1 && size != 2 && size != 4 ) { |
| 205 | err_setstr(AudioopError, "Size should be 1, 2 or 4"); |
| 206 | return 0; |
| 207 | } |
| 208 | for ( i=0; i<len; i+= size) { |
| 209 | if ( size == 1 ) val = (int)*CHARP(cp, i); |
| 210 | else if ( size == 2 ) val = (int)*SHORTP(cp, i); |
| 211 | else if ( size == 4 ) val = (int)*LONGP(cp, i); |
| 212 | avg += val; |
| 213 | } |
| 214 | if ( len == 0 ) |
| 215 | val = 0; |
| 216 | else |
| 217 | val = (int)(avg / (float)(len/size)); |
| 218 | return newintobject(val); |
| 219 | } |
| 220 | |
| 221 | static object * |
| 222 | audioop_cross(self, args) |
| 223 | object *self; |
| 224 | object *args; |
| 225 | { |
| 226 | signed char *cp; |
| 227 | int len, size, val; |
| 228 | int i; |
| 229 | int cross, prevval, ncross; |
| 230 | |
| 231 | if ( !getargs(args, "(s#i)", &cp, &len, &size) ) |
| 232 | return 0; |
| 233 | if ( size != 1 && size != 2 && size != 4 ) { |
| 234 | err_setstr(AudioopError, "Size should be 1, 2 or 4"); |
| 235 | return 0; |
| 236 | } |
| 237 | ncross = -1; |
| 238 | prevval = 17; /* Anything <> 0,1 */ |
| 239 | for ( i=0; i<len; i+= size) { |
| 240 | if ( size == 1 ) val = ((int)*CHARP(cp, i)) >> 7; |
| 241 | else if ( size == 2 ) val = ((int)*SHORTP(cp, i)) >> 15; |
| 242 | else if ( size == 4 ) val = ((int)*LONGP(cp, i)) >> 31; |
| 243 | val = val & 1; |
| 244 | if ( val != prevval ) ncross++; |
| 245 | prevval = val; |
| 246 | } |
| 247 | return newintobject(ncross); |
| 248 | } |
| 249 | |
| 250 | static object * |
| 251 | audioop_mul(self, args) |
| 252 | object *self; |
| 253 | object *args; |
| 254 | { |
| 255 | signed char *cp, *ncp; |
| 256 | int len, size, val; |
| 257 | double factor, fval, maxval; |
| 258 | object *rv; |
| 259 | int i; |
| 260 | |
| 261 | if ( !getargs(args, "(s#id)", &cp, &len, &size, &factor ) ) |
| 262 | return 0; |
| 263 | |
| 264 | if ( size == 1 ) maxval = (double) 0x7f; |
| 265 | else if ( size == 2 ) maxval = (double) 0x7fff; |
| 266 | else if ( size == 4 ) maxval = (double) 0x7fffffff; |
| 267 | else { |
| 268 | err_setstr(AudioopError, "Size should be 1, 2 or 4"); |
| 269 | return 0; |
| 270 | } |
| 271 | |
| 272 | rv = newsizedstringobject(NULL, len); |
| 273 | if ( rv == 0 ) |
| 274 | return 0; |
| 275 | ncp = (signed char *)getstringvalue(rv); |
| 276 | |
| 277 | |
| 278 | for ( i=0; i < len; i += size ) { |
| 279 | if ( size == 1 ) val = (int)*CHARP(cp, i); |
| 280 | else if ( size == 2 ) val = (int)*SHORTP(cp, i); |
| 281 | else if ( size == 4 ) val = (int)*LONGP(cp, i); |
| 282 | fval = (double)val*factor; |
| 283 | if ( fval > maxval ) fval = maxval; |
| 284 | else if ( fval < -maxval ) fval = -maxval; |
| 285 | val = (int)fval; |
| 286 | if ( size == 1 ) *CHARP(ncp, i) = (signed char)val; |
| 287 | else if ( size == 2 ) *SHORTP(ncp, i) = (short)val; |
| 288 | else if ( size == 4 ) *LONGP(ncp, i) = (long)val; |
| 289 | } |
| 290 | return rv; |
| 291 | } |
| 292 | |
| 293 | static object * |
| 294 | audioop_tomono(self, args) |
| 295 | object *self; |
| 296 | object *args; |
| 297 | { |
| 298 | signed char *cp, *ncp; |
| 299 | int len, size, val1, val2; |
| 300 | double fac1, fac2, fval, maxval; |
| 301 | object *rv; |
| 302 | int i; |
| 303 | |
| 304 | if ( !getargs(args, "(s#idd)", &cp, &len, &size, &fac1, &fac2 ) ) |
| 305 | return 0; |
| 306 | |
| 307 | if ( size == 1 ) maxval = (double) 0x7f; |
| 308 | else if ( size == 2 ) maxval = (double) 0x7fff; |
| 309 | else if ( size == 4 ) maxval = (double) 0x7fffffff; |
| 310 | else { |
| 311 | err_setstr(AudioopError, "Size should be 1, 2 or 4"); |
| 312 | return 0; |
| 313 | } |
| 314 | |
| 315 | rv = newsizedstringobject(NULL, len/2); |
| 316 | if ( rv == 0 ) |
| 317 | return 0; |
| 318 | ncp = (signed char *)getstringvalue(rv); |
| 319 | |
| 320 | |
| 321 | for ( i=0; i < len; i += size*2 ) { |
| 322 | if ( size == 1 ) val1 = (int)*CHARP(cp, i); |
| 323 | else if ( size == 2 ) val1 = (int)*SHORTP(cp, i); |
| 324 | else if ( size == 4 ) val1 = (int)*LONGP(cp, i); |
| 325 | if ( size == 1 ) val2 = (int)*CHARP(cp, i+1); |
| 326 | else if ( size == 2 ) val2 = (int)*SHORTP(cp, i+2); |
| 327 | else if ( size == 4 ) val2 = (int)*LONGP(cp, i+4); |
| 328 | fval = (double)val1*fac1 + (double)val2*fac2; |
| 329 | if ( fval > maxval ) fval = maxval; |
| 330 | else if ( fval < -maxval ) fval = -maxval; |
| 331 | val1 = (int)fval; |
| 332 | if ( size == 1 ) *CHARP(ncp, i/2) = (signed char)val1; |
| 333 | else if ( size == 2 ) *SHORTP(ncp, i/2) = (short)val1; |
| 334 | else if ( size == 4 ) *LONGP(ncp, i/2)= (long)val1; |
| 335 | } |
| 336 | return rv; |
| 337 | } |
| 338 | |
| 339 | static object * |
| 340 | audioop_tostereo(self, args) |
| 341 | object *self; |
| 342 | object *args; |
| 343 | { |
| 344 | signed char *cp, *ncp; |
| 345 | int len, size, val1, val2, val; |
| 346 | double fac1, fac2, fval, maxval; |
| 347 | object *rv; |
| 348 | int i; |
| 349 | |
| 350 | if ( !getargs(args, "(s#idd)", &cp, &len, &size, &fac1, &fac2 ) ) |
| 351 | return 0; |
| 352 | |
| 353 | if ( size == 1 ) maxval = (double) 0x7f; |
| 354 | else if ( size == 2 ) maxval = (double) 0x7fff; |
| 355 | else if ( size == 4 ) maxval = (double) 0x7fffffff; |
| 356 | else { |
| 357 | err_setstr(AudioopError, "Size should be 1, 2 or 4"); |
| 358 | return 0; |
| 359 | } |
| 360 | |
| 361 | rv = newsizedstringobject(NULL, len*2); |
| 362 | if ( rv == 0 ) |
| 363 | return 0; |
| 364 | ncp = (signed char *)getstringvalue(rv); |
| 365 | |
| 366 | |
| 367 | for ( i=0; i < len; i += size ) { |
| 368 | if ( size == 1 ) val = (int)*CHARP(cp, i); |
| 369 | else if ( size == 2 ) val = (int)*SHORTP(cp, i); |
| 370 | else if ( size == 4 ) val = (int)*LONGP(cp, i); |
| 371 | |
| 372 | fval = (double)val*fac1; |
| 373 | if ( fval > maxval ) fval = maxval; |
| 374 | else if ( fval < -maxval ) fval = -maxval; |
| 375 | val1 = (int)fval; |
| 376 | |
| 377 | fval = (double)val*fac2; |
| 378 | if ( fval > maxval ) fval = maxval; |
| 379 | else if ( fval < -maxval ) fval = -maxval; |
| 380 | val2 = (int)fval; |
| 381 | |
| 382 | if ( size == 1 ) *CHARP(ncp, i*2) = (signed char)val1; |
| 383 | else if ( size == 2 ) *SHORTP(ncp, i*2) = (short)val1; |
| 384 | else if ( size == 4 ) *LONGP(ncp, i*2) = (long)val1; |
| 385 | |
| 386 | if ( size == 1 ) *CHARP(ncp, i*2+1) = (signed char)val2; |
| 387 | else if ( size == 2 ) *SHORTP(ncp, i*2+2) = (short)val2; |
| 388 | else if ( size == 4 ) *LONGP(ncp, i*2+4) = (long)val2; |
| 389 | } |
| 390 | return rv; |
| 391 | } |
| 392 | |
| 393 | static object * |
| 394 | audioop_add(self, args) |
| 395 | object *self; |
| 396 | object *args; |
| 397 | { |
| 398 | signed char *cp1, *cp2, *ncp; |
| 399 | int len1, len2, size, val1, val2; |
| 400 | object *rv; |
| 401 | int i; |
| 402 | |
| 403 | if ( !getargs(args, "(s#s#i)", |
| 404 | &cp1, &len1, &cp2, &len2, &size ) ) |
| 405 | return 0; |
| 406 | |
| 407 | if ( len1 != len2 ) { |
| 408 | err_setstr(AudioopError, "Lengths should be the same"); |
| 409 | return 0; |
| 410 | } |
| 411 | |
| 412 | if ( size != 1 && size != 2 && size != 4) { |
| 413 | err_setstr(AudioopError, "Size should be 1, 2 or 4"); |
| 414 | return 0; |
| 415 | } |
| 416 | |
| 417 | rv = newsizedstringobject(NULL, len1); |
| 418 | if ( rv == 0 ) |
| 419 | return 0; |
| 420 | ncp = (signed char *)getstringvalue(rv); |
| 421 | |
| 422 | |
| 423 | for ( i=0; i < len1; i += size ) { |
| 424 | if ( size == 1 ) val1 = (int)*CHARP(cp1, i); |
| 425 | else if ( size == 2 ) val1 = (int)*SHORTP(cp1, i); |
| 426 | else if ( size == 4 ) val1 = (int)*LONGP(cp1, i); |
| 427 | |
| 428 | if ( size == 1 ) val2 = (int)*CHARP(cp2, i); |
| 429 | else if ( size == 2 ) val2 = (int)*SHORTP(cp2, i); |
| 430 | else if ( size == 4 ) val2 = (int)*LONGP(cp2, i); |
| 431 | |
| 432 | if ( size == 1 ) *CHARP(ncp, i) = (signed char)(val1+val2); |
| 433 | else if ( size == 2 ) *SHORTP(ncp, i) = (short)(val1+val2); |
| 434 | else if ( size == 4 ) *LONGP(ncp, i) = (long)(val1+val2); |
| 435 | } |
| 436 | return rv; |
| 437 | } |
| 438 | |
| 439 | static object * |
| 440 | audioop_bias(self, args) |
| 441 | object *self; |
| 442 | object *args; |
| 443 | { |
| 444 | signed char *cp, *ncp; |
| 445 | int len, size, val; |
| 446 | object *rv; |
| 447 | int i; |
| 448 | int bias; |
| 449 | |
| 450 | if ( !getargs(args, "(s#ii)", |
| 451 | &cp, &len, &size , &bias) ) |
| 452 | return 0; |
| 453 | |
| 454 | if ( size != 1 && size != 2 && size != 4) { |
| 455 | err_setstr(AudioopError, "Size should be 1, 2 or 4"); |
| 456 | return 0; |
| 457 | } |
| 458 | |
| 459 | rv = newsizedstringobject(NULL, len); |
| 460 | if ( rv == 0 ) |
| 461 | return 0; |
| 462 | ncp = (signed char *)getstringvalue(rv); |
| 463 | |
| 464 | |
| 465 | for ( i=0; i < len; i += size ) { |
| 466 | if ( size == 1 ) val = (int)*CHARP(cp, i); |
| 467 | else if ( size == 2 ) val = (int)*SHORTP(cp, i); |
| 468 | else if ( size == 4 ) val = (int)*LONGP(cp, i); |
| 469 | |
| 470 | if ( size == 1 ) *CHARP(ncp, i) = (signed char)(val+bias); |
| 471 | else if ( size == 2 ) *SHORTP(ncp, i) = (short)(val+bias); |
| 472 | else if ( size == 4 ) *LONGP(ncp, i) = (long)(val+bias); |
| 473 | } |
| 474 | return rv; |
| 475 | } |
| 476 | |
| 477 | static object * |
| 478 | audioop_lin2ulaw(self, args) |
| 479 | object *self; |
| 480 | object *args; |
| 481 | { |
| 482 | signed char *cp; |
| 483 | unsigned char *ncp; |
| 484 | int len, size, val; |
| 485 | object *rv; |
| 486 | int i; |
| 487 | |
| 488 | if ( !getargs(args, "(s#i)", |
| 489 | &cp, &len, &size) ) |
| 490 | return 0; |
| 491 | |
| 492 | if ( size != 1 && size != 2 && size != 4) { |
| 493 | err_setstr(AudioopError, "Size should be 1, 2 or 4"); |
| 494 | return 0; |
| 495 | } |
| 496 | |
| 497 | rv = newsizedstringobject(NULL, len/size); |
| 498 | if ( rv == 0 ) |
| 499 | return 0; |
| 500 | ncp = (unsigned char *)getstringvalue(rv); |
| 501 | |
| 502 | for ( i=0; i < len; i += size ) { |
| 503 | if ( size == 1 ) val = ((int)*CHARP(cp, i)) << 8; |
| 504 | else if ( size == 2 ) val = (int)*SHORTP(cp, i); |
| 505 | else if ( size == 4 ) val = ((int)*LONGP(cp, i)) >> 16; |
| 506 | |
| 507 | *ncp++ = st_linear_to_ulaw(val); |
| 508 | } |
| 509 | return rv; |
| 510 | } |
| 511 | |
| 512 | static object * |
| 513 | audioop_ulaw2lin(self, args) |
| 514 | object *self; |
| 515 | object *args; |
| 516 | { |
| 517 | unsigned char *cp; |
| 518 | unsigned char cval; |
| 519 | signed char *ncp; |
| 520 | int len, size, val; |
| 521 | object *rv; |
| 522 | int i; |
| 523 | |
| 524 | if ( !getargs(args, "(s#i)", |
| 525 | &cp, &len, &size) ) |
| 526 | return 0; |
| 527 | |
| 528 | if ( size != 1 && size != 2 && size != 4) { |
| 529 | err_setstr(AudioopError, "Size should be 1, 2 or 4"); |
| 530 | return 0; |
| 531 | } |
| 532 | |
| 533 | rv = newsizedstringobject(NULL, len*size); |
| 534 | if ( rv == 0 ) |
| 535 | return 0; |
| 536 | ncp = (signed char *)getstringvalue(rv); |
| 537 | |
| 538 | for ( i=0; i < len*size; i += size ) { |
| 539 | cval = *cp++; |
| 540 | val = st_ulaw_to_linear(cval); |
| 541 | |
| 542 | if ( size == 1 ) *CHARP(ncp, i) = (signed char)(val >> 8); |
| 543 | else if ( size == 2 ) *SHORTP(ncp, i) = (short)(val); |
| 544 | else if ( size == 4 ) *LONGP(ncp, i) = (long)(val>>16); |
| 545 | } |
| 546 | return rv; |
| 547 | } |
| 548 | |
| 549 | static struct methodlist audioop_methods[] = { |
| 550 | { "max", audioop_max }, |
| 551 | { "avg", audioop_avg }, |
| 552 | { "cross", audioop_cross }, |
| 553 | { "mul", audioop_mul }, |
| 554 | { "add", audioop_add }, |
| 555 | { "bias", audioop_bias }, |
| 556 | { "ulaw2lin", audioop_ulaw2lin }, |
| 557 | { "lin2ulaw", audioop_lin2ulaw }, |
| 558 | { "tomono", audioop_tomono }, |
| 559 | { "tostereo", audioop_tostereo }, |
| 560 | { "getsample", audioop_getsample }, |
| 561 | { 0, 0 } |
| 562 | }; |
| 563 | |
| 564 | |
| 565 | void |
| 566 | initaudioop() |
| 567 | { |
| 568 | object *m, *d; |
| 569 | m = initmodule("audioop", audioop_methods); |
| 570 | d = getmoduledict(m); |
| 571 | AudioopError = newstringobject("audioop.error"); |
| 572 | if ( AudioopError == NULL || dictinsert(d,"error",AudioopError) ) |
| 573 | fatal("can't define audioop.error"); |
| 574 | } |