Guido van Rossum | b66efa0 | 1992-06-01 16:01:24 +0000 | [diff] [blame] | 1 | /*********************************************************** |
Guido van Rossum | 34679b7 | 1993-01-26 13:33:44 +0000 | [diff] [blame] | 2 | Copyright 1991, 1992, 1993 by Stichting Mathematisch Centrum, |
| 3 | Amsterdam, The Netherlands. |
Guido van Rossum | b66efa0 | 1992-06-01 16:01:24 +0000 | [diff] [blame] | 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 | |
Jack Jansen | e1b4d7c | 1992-08-24 14:36:31 +0000 | [diff] [blame] | 31 | #include <math.h> |
| 32 | |
Guido van Rossum | b66efa0 | 1992-06-01 16:01:24 +0000 | [diff] [blame] | 33 | #include "allobjects.h" |
| 34 | #include "modsupport.h" |
| 35 | |
Jack Jansen | a90805f | 1993-02-17 14:29:28 +0000 | [diff] [blame] | 36 | /* Code shamelessly stolen from sox, |
Guido van Rossum | b66efa0 | 1992-06-01 16:01:24 +0000 | [diff] [blame] | 37 | ** (c) Craig Reese, Joe Campbell and Jeff Poskanzer 1989 */ |
| 38 | |
| 39 | #define MINLIN -32768 |
| 40 | #define MAXLIN 32767 |
| 41 | #define LINCLIP(x) do { if ( x < MINLIN ) x = MINLIN ; else if ( x > MAXLIN ) x = MAXLIN; } while ( 0 ) |
| 42 | |
| 43 | unsigned char st_linear_to_ulaw( /* int sample */ ); |
| 44 | |
| 45 | /* |
| 46 | ** This macro converts from ulaw to 16 bit linear, faster. |
| 47 | ** |
| 48 | ** Jef Poskanzer |
| 49 | ** 23 October 1989 |
| 50 | ** |
| 51 | ** Input: 8 bit ulaw sample |
| 52 | ** Output: signed 16 bit linear sample |
| 53 | */ |
| 54 | #define st_ulaw_to_linear(ulawbyte) ulaw_table[ulawbyte] |
| 55 | |
| 56 | static int ulaw_table[256] = { |
| 57 | -32124, -31100, -30076, -29052, -28028, -27004, -25980, -24956, |
| 58 | -23932, -22908, -21884, -20860, -19836, -18812, -17788, -16764, |
| 59 | -15996, -15484, -14972, -14460, -13948, -13436, -12924, -12412, |
| 60 | -11900, -11388, -10876, -10364, -9852, -9340, -8828, -8316, |
| 61 | -7932, -7676, -7420, -7164, -6908, -6652, -6396, -6140, |
| 62 | -5884, -5628, -5372, -5116, -4860, -4604, -4348, -4092, |
| 63 | -3900, -3772, -3644, -3516, -3388, -3260, -3132, -3004, |
| 64 | -2876, -2748, -2620, -2492, -2364, -2236, -2108, -1980, |
| 65 | -1884, -1820, -1756, -1692, -1628, -1564, -1500, -1436, |
| 66 | -1372, -1308, -1244, -1180, -1116, -1052, -988, -924, |
| 67 | -876, -844, -812, -780, -748, -716, -684, -652, |
| 68 | -620, -588, -556, -524, -492, -460, -428, -396, |
| 69 | -372, -356, -340, -324, -308, -292, -276, -260, |
| 70 | -244, -228, -212, -196, -180, -164, -148, -132, |
| 71 | -120, -112, -104, -96, -88, -80, -72, -64, |
| 72 | -56, -48, -40, -32, -24, -16, -8, 0, |
| 73 | 32124, 31100, 30076, 29052, 28028, 27004, 25980, 24956, |
| 74 | 23932, 22908, 21884, 20860, 19836, 18812, 17788, 16764, |
| 75 | 15996, 15484, 14972, 14460, 13948, 13436, 12924, 12412, |
| 76 | 11900, 11388, 10876, 10364, 9852, 9340, 8828, 8316, |
| 77 | 7932, 7676, 7420, 7164, 6908, 6652, 6396, 6140, |
| 78 | 5884, 5628, 5372, 5116, 4860, 4604, 4348, 4092, |
| 79 | 3900, 3772, 3644, 3516, 3388, 3260, 3132, 3004, |
| 80 | 2876, 2748, 2620, 2492, 2364, 2236, 2108, 1980, |
| 81 | 1884, 1820, 1756, 1692, 1628, 1564, 1500, 1436, |
| 82 | 1372, 1308, 1244, 1180, 1116, 1052, 988, 924, |
| 83 | 876, 844, 812, 780, 748, 716, 684, 652, |
| 84 | 620, 588, 556, 524, 492, 460, 428, 396, |
| 85 | 372, 356, 340, 324, 308, 292, 276, 260, |
| 86 | 244, 228, 212, 196, 180, 164, 148, 132, |
| 87 | 120, 112, 104, 96, 88, 80, 72, 64, |
| 88 | 56, 48, 40, 32, 24, 16, 8, 0 }; |
| 89 | |
| 90 | #define ZEROTRAP /* turn on the trap as per the MIL-STD */ |
| 91 | #define BIAS 0x84 /* define the add-in bias for 16 bit samples */ |
| 92 | #define CLIP 32635 |
| 93 | |
| 94 | unsigned char |
| 95 | st_linear_to_ulaw( sample ) |
| 96 | int sample; |
| 97 | { |
| 98 | static int exp_lut[256] = {0,0,1,1,2,2,2,2,3,3,3,3,3,3,3,3, |
| 99 | 4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4, |
| 100 | 5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5, |
| 101 | 5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5, |
| 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 | 6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6, |
| 105 | 6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6, |
| 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 | 7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7, |
| 113 | 7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7}; |
| 114 | int sign, exponent, mantissa; |
| 115 | unsigned char ulawbyte; |
| 116 | |
| 117 | /* Get the sample into sign-magnitude. */ |
| 118 | sign = (sample >> 8) & 0x80; /* set aside the sign */ |
| 119 | if ( sign != 0 ) sample = -sample; /* get magnitude */ |
| 120 | if ( sample > CLIP ) sample = CLIP; /* clip the magnitude */ |
| 121 | |
| 122 | /* Convert from 16 bit linear to ulaw. */ |
| 123 | sample = sample + BIAS; |
| 124 | exponent = exp_lut[( sample >> 7 ) & 0xFF]; |
| 125 | mantissa = ( sample >> ( exponent + 3 ) ) & 0x0F; |
| 126 | ulawbyte = ~ ( sign | ( exponent << 4 ) | mantissa ); |
| 127 | #ifdef ZEROTRAP |
| 128 | if ( ulawbyte == 0 ) ulawbyte = 0x02; /* optional CCITT trap */ |
| 129 | #endif |
| 130 | |
| 131 | return ulawbyte; |
| 132 | } |
| 133 | /* End of code taken from sox */ |
| 134 | |
Guido van Rossum | b64e635 | 1992-07-06 14:21:56 +0000 | [diff] [blame] | 135 | /* ADPCM-3 step variation table */ |
Guido van Rossum | 8e7a0f0 | 1992-06-23 15:23:57 +0000 | [diff] [blame] | 136 | static float newstep[5] = { 0.8, 0.9, 1.0, 1.75, 1.75 }; |
| 137 | |
Guido van Rossum | b64e635 | 1992-07-06 14:21:56 +0000 | [diff] [blame] | 138 | /* Intel ADPCM step variation table */ |
| 139 | static int indexTable[16] = { |
| 140 | -1, -1, -1, -1, 2, 4, 6, 8, |
| 141 | -1, -1, -1, -1, 2, 4, 6, 8, |
| 142 | }; |
| 143 | |
| 144 | static int stepsizeTable[89] = { |
| 145 | 7, 8, 9, 10, 11, 12, 13, 14, 16, 17, |
| 146 | 19, 21, 23, 25, 28, 31, 34, 37, 41, 45, |
| 147 | 50, 55, 60, 66, 73, 80, 88, 97, 107, 118, |
| 148 | 130, 143, 157, 173, 190, 209, 230, 253, 279, 307, |
| 149 | 337, 371, 408, 449, 494, 544, 598, 658, 724, 796, |
| 150 | 876, 963, 1060, 1166, 1282, 1411, 1552, 1707, 1878, 2066, |
| 151 | 2272, 2499, 2749, 3024, 3327, 3660, 4026, 4428, 4871, 5358, |
| 152 | 5894, 6484, 7132, 7845, 8630, 9493, 10442, 11487, 12635, 13899, |
| 153 | 15289, 16818, 18500, 20350, 22385, 24623, 27086, 29794, 32767 |
| 154 | }; |
| 155 | |
Guido van Rossum | b66efa0 | 1992-06-01 16:01:24 +0000 | [diff] [blame] | 156 | #define CHARP(cp, i) ((signed char *)(cp+i)) |
| 157 | #define SHORTP(cp, i) ((short *)(cp+i)) |
| 158 | #define LONGP(cp, i) ((long *)(cp+i)) |
| 159 | |
| 160 | |
| 161 | |
| 162 | static object *AudioopError; |
| 163 | |
| 164 | static object * |
| 165 | audioop_getsample(self, args) |
| 166 | object *self; |
| 167 | object *args; |
| 168 | { |
| 169 | signed char *cp; |
| 170 | int len, size, val; |
| 171 | int i; |
| 172 | |
| 173 | if ( !getargs(args, "(s#ii)", &cp, &len, &size, &i) ) |
| 174 | return 0; |
| 175 | if ( size != 1 && size != 2 && size != 4 ) { |
| 176 | err_setstr(AudioopError, "Size should be 1, 2 or 4"); |
| 177 | return 0; |
| 178 | } |
| 179 | if ( i < 0 || i >= len/size ) { |
| 180 | err_setstr(AudioopError, "Index out of range"); |
| 181 | return 0; |
| 182 | } |
| 183 | if ( size == 1 ) val = (int)*CHARP(cp, i); |
| 184 | else if ( size == 2 ) val = (int)*SHORTP(cp, i*2); |
| 185 | else if ( size == 4 ) val = (int)*LONGP(cp, i*4); |
| 186 | return newintobject(val); |
| 187 | } |
| 188 | |
| 189 | static object * |
| 190 | audioop_max(self, args) |
| 191 | object *self; |
| 192 | object *args; |
| 193 | { |
| 194 | signed char *cp; |
| 195 | int len, size, val; |
| 196 | int i; |
| 197 | int max = 0; |
| 198 | |
| 199 | if ( !getargs(args, "(s#i)", &cp, &len, &size) ) |
| 200 | return 0; |
| 201 | if ( size != 1 && size != 2 && size != 4 ) { |
| 202 | err_setstr(AudioopError, "Size should be 1, 2 or 4"); |
| 203 | return 0; |
| 204 | } |
| 205 | for ( i=0; i<len; i+= size) { |
| 206 | if ( size == 1 ) val = (int)*CHARP(cp, i); |
| 207 | else if ( size == 2 ) val = (int)*SHORTP(cp, i); |
| 208 | else if ( size == 4 ) val = (int)*LONGP(cp, i); |
| 209 | if ( val < 0 ) val = (-val); |
| 210 | if ( val > max ) max = val; |
| 211 | } |
| 212 | return newintobject(max); |
| 213 | } |
| 214 | |
| 215 | static object * |
| 216 | audioop_avg(self, args) |
| 217 | object *self; |
| 218 | object *args; |
| 219 | { |
| 220 | signed char *cp; |
| 221 | int len, size, val; |
| 222 | int i; |
| 223 | float avg = 0.0; |
| 224 | |
| 225 | if ( !getargs(args, "(s#i)", &cp, &len, &size) ) |
| 226 | return 0; |
| 227 | if ( size != 1 && size != 2 && size != 4 ) { |
| 228 | err_setstr(AudioopError, "Size should be 1, 2 or 4"); |
| 229 | return 0; |
| 230 | } |
| 231 | for ( i=0; i<len; i+= size) { |
| 232 | if ( size == 1 ) val = (int)*CHARP(cp, i); |
| 233 | else if ( size == 2 ) val = (int)*SHORTP(cp, i); |
| 234 | else if ( size == 4 ) val = (int)*LONGP(cp, i); |
| 235 | avg += val; |
| 236 | } |
| 237 | if ( len == 0 ) |
| 238 | val = 0; |
| 239 | else |
| 240 | val = (int)(avg / (float)(len/size)); |
| 241 | return newintobject(val); |
| 242 | } |
| 243 | |
| 244 | static object * |
Jack Jansen | e1b4d7c | 1992-08-24 14:36:31 +0000 | [diff] [blame] | 245 | audioop_rms(self, args) |
| 246 | object *self; |
| 247 | object *args; |
| 248 | { |
| 249 | signed char *cp; |
| 250 | int len, size, val; |
| 251 | int i; |
| 252 | float sum_squares = 0.0; |
| 253 | |
| 254 | if ( !getargs(args, "(s#i)", &cp, &len, &size) ) |
| 255 | return 0; |
| 256 | if ( size != 1 && size != 2 && size != 4 ) { |
| 257 | err_setstr(AudioopError, "Size should be 1, 2 or 4"); |
| 258 | return 0; |
| 259 | } |
| 260 | for ( i=0; i<len; i+= size) { |
| 261 | if ( size == 1 ) val = (int)*CHARP(cp, i); |
| 262 | else if ( size == 2 ) val = (int)*SHORTP(cp, i); |
| 263 | else if ( size == 4 ) val = (int)*LONGP(cp, i); |
| 264 | sum_squares += (float)val*(float)val; |
| 265 | } |
| 266 | if ( len == 0 ) |
| 267 | val = 0; |
| 268 | else |
| 269 | val = (int)sqrt(sum_squares / (float)(len/size)); |
| 270 | return newintobject(val); |
| 271 | } |
| 272 | |
Jack Jansen | a90805f | 1993-02-17 14:29:28 +0000 | [diff] [blame] | 273 | double _sum2(a, b, len) |
| 274 | short *a; |
| 275 | short *b; |
| 276 | int len; |
| 277 | { |
| 278 | int i; |
| 279 | double sum = 0.0; |
| 280 | |
| 281 | for( i=0; i<len; i++) { |
| 282 | sum = sum + (double)a[i]*(double)b[i]; |
| 283 | } |
| 284 | return sum; |
| 285 | } |
| 286 | |
| 287 | /* |
| 288 | ** Findfit tries to locate a sample within another sample. Its main use |
| 289 | ** is in echo-cancellation (to find the feedback of the output signal in |
| 290 | ** the input signal). |
| 291 | ** The method used is as follows: |
| 292 | ** |
| 293 | ** let R be the reference signal (length n) and A the input signal (length N) |
| 294 | ** with N > n, and let all sums be over i from 0 to n-1. |
| 295 | ** |
| 296 | ** Now, for each j in {0..N-n} we compute a factor fj so that -fj*R matches A |
| 297 | ** as good as possible, i.e. sum( (A[j+i]+fj*R[i])^2 ) is minimal. This |
| 298 | ** equation gives fj = sum( A[j+i]R[i] ) / sum(R[i]^2). |
| 299 | ** |
| 300 | ** Next, we compute the relative distance between the original signal and |
| 301 | ** the modified signal and minimize that over j: |
| 302 | ** vj = sum( (A[j+i]-fj*R[i])^2 ) / sum( A[j+i]^2 ) => |
| 303 | ** vj = ( sum(A[j+i]^2)*sum(R[i]^2) - sum(A[j+i]R[i])^2 ) / sum( A[j+i]^2 ) |
| 304 | ** |
| 305 | ** In the code variables correspond as follows: |
| 306 | ** cp1 A |
| 307 | ** cp2 R |
| 308 | ** len1 N |
| 309 | ** len2 n |
| 310 | ** aj_m1 A[j-1] |
| 311 | ** aj_lm1 A[j+n-1] |
| 312 | ** sum_ri_2 sum(R[i]^2) |
| 313 | ** sum_aij_2 sum(A[i+j]^2) |
| 314 | ** sum_aij_ri sum(A[i+j]R[i]) |
| 315 | ** |
| 316 | ** sum_ri is calculated once, sum_aij_2 is updated each step and sum_aij_ri |
| 317 | ** is completely recalculated each step. |
| 318 | */ |
Jack Jansen | e1b4d7c | 1992-08-24 14:36:31 +0000 | [diff] [blame] | 319 | static object * |
Jack Jansen | a90805f | 1993-02-17 14:29:28 +0000 | [diff] [blame] | 320 | audioop_findfit(self, args) |
Jack Jansen | dd8a6ea | 1993-02-17 14:21:09 +0000 | [diff] [blame] | 321 | object *self; |
| 322 | object *args; |
| 323 | { |
Jack Jansen | a90805f | 1993-02-17 14:29:28 +0000 | [diff] [blame] | 324 | short *cp1, *cp2; |
| 325 | int len1, len2; |
| 326 | int j, best_j; |
| 327 | double aj_m1, aj_lm1; |
| 328 | double sum_ri_2, sum_aij_2, sum_aij_ri, result, best_result, factor; |
Jack Jansen | dd8a6ea | 1993-02-17 14:21:09 +0000 | [diff] [blame] | 329 | |
Jack Jansen | a90805f | 1993-02-17 14:29:28 +0000 | [diff] [blame] | 330 | if ( !getargs(args, "(s#s#)", &cp1, &len1, &cp2, &len2) ) |
Jack Jansen | dd8a6ea | 1993-02-17 14:21:09 +0000 | [diff] [blame] | 331 | return 0; |
Jack Jansen | a90805f | 1993-02-17 14:29:28 +0000 | [diff] [blame] | 332 | if ( len1 & 1 || len2 & 1 ) { |
| 333 | err_setstr(AudioopError, "Strings should be even-sized"); |
| 334 | return 0; |
| 335 | } |
| 336 | len1 >>= 1; |
| 337 | len2 >>= 1; |
| 338 | |
| 339 | if ( len1 < len2 ) { |
| 340 | err_setstr(AudioopError, "First sample should be longer"); |
| 341 | return 0; |
| 342 | } |
| 343 | sum_ri_2 = _sum2(cp2, cp2, len2); |
| 344 | sum_aij_2 = _sum2(cp1, cp1, len2); |
| 345 | sum_aij_ri = _sum2(cp1, cp2, len2); |
| 346 | |
| 347 | result = (sum_ri_2*sum_aij_2 - sum_aij_ri*sum_aij_ri) / sum_aij_2; |
| 348 | |
| 349 | best_result = result; |
| 350 | best_j = 0; |
| 351 | j = 0; |
| 352 | |
| 353 | for ( j=1; j<=len1-len2; j++) { |
| 354 | aj_m1 = (double)cp1[j-1]; |
| 355 | aj_lm1 = (double)cp1[j+len2-1]; |
| 356 | |
| 357 | sum_aij_2 = sum_aij_2 + aj_lm1*aj_lm1 - aj_m1*aj_m1; |
| 358 | sum_aij_ri = _sum2(cp1+j, cp2, len2); |
| 359 | |
| 360 | result = (sum_ri_2*sum_aij_2 - sum_aij_ri*sum_aij_ri) / sum_aij_2; |
| 361 | |
| 362 | if ( result < best_result ) { |
| 363 | best_result = result; |
| 364 | best_j = j; |
| 365 | } |
| 366 | |
| 367 | } |
| 368 | |
| 369 | factor = _sum2(cp1+best_j, cp2, len2) / sum_ri_2; |
| 370 | |
| 371 | return mkvalue("(if)", best_j, factor); |
| 372 | } |
| 373 | |
| 374 | /* |
| 375 | ** findfactor finds a factor f so that the energy in A-fB is minimal. |
| 376 | ** See the comment for findfit for details. |
| 377 | */ |
| 378 | static object * |
| 379 | audioop_findfactor(self, args) |
| 380 | object *self; |
| 381 | object *args; |
| 382 | { |
| 383 | short *cp1, *cp2; |
| 384 | int len1, len2; |
| 385 | double sum_ri_2, sum_aij_ri, result; |
| 386 | |
| 387 | if ( !getargs(args, "(s#s#)", &cp1, &len1, &cp2, &len2) ) |
| 388 | return 0; |
| 389 | if ( len1 & 1 || len2 & 1 ) { |
| 390 | err_setstr(AudioopError, "Strings should be even-sized"); |
Jack Jansen | dd8a6ea | 1993-02-17 14:21:09 +0000 | [diff] [blame] | 391 | return 0; |
| 392 | } |
| 393 | if ( len1 != len2 ) { |
| 394 | err_setstr(AudioopError, "Samples should be same size"); |
| 395 | return 0; |
| 396 | } |
Jack Jansen | a90805f | 1993-02-17 14:29:28 +0000 | [diff] [blame] | 397 | len2 >>= 1; |
| 398 | sum_ri_2 = _sum2(cp2, cp2, len2); |
| 399 | sum_aij_ri = _sum2(cp1, cp2, len2); |
| 400 | |
| 401 | result = sum_aij_ri / sum_ri_2; |
| 402 | |
| 403 | return newfloatobject(result); |
| 404 | } |
| 405 | |
| 406 | /* |
| 407 | ** findmax returns the index of the n-sized segment of the input sample |
| 408 | ** that contains the most energy. |
| 409 | */ |
| 410 | static object * |
| 411 | audioop_findmax(self, args) |
| 412 | object *self; |
| 413 | object *args; |
| 414 | { |
| 415 | short *cp1; |
| 416 | int len1, len2; |
| 417 | int j, best_j; |
| 418 | double aj_m1, aj_lm1; |
| 419 | double result, best_result; |
| 420 | |
| 421 | if ( !getargs(args, "(s#i)", &cp1, &len1, &len2) ) |
| 422 | return 0; |
| 423 | if ( len1 & 1 ) { |
| 424 | err_setstr(AudioopError, "Strings should be even-sized"); |
| 425 | return 0; |
Jack Jansen | dd8a6ea | 1993-02-17 14:21:09 +0000 | [diff] [blame] | 426 | } |
Jack Jansen | a90805f | 1993-02-17 14:29:28 +0000 | [diff] [blame] | 427 | len1 >>= 1; |
| 428 | |
| 429 | if ( len1 < len2 ) { |
| 430 | err_setstr(AudioopError, "Input sample should be longer"); |
| 431 | return 0; |
| 432 | } |
| 433 | |
| 434 | result = _sum2(cp1, cp1, len2); |
| 435 | |
| 436 | best_result = result; |
| 437 | best_j = 0; |
| 438 | j = 0; |
| 439 | |
| 440 | for ( j=1; j<=len1-len2; j++) { |
| 441 | aj_m1 = (double)cp1[j-1]; |
| 442 | aj_lm1 = (double)cp1[j+len2-1]; |
| 443 | |
| 444 | result = result + aj_lm1*aj_lm1 - aj_m1*aj_m1; |
| 445 | |
| 446 | if ( result > best_result ) { |
| 447 | best_result = result; |
| 448 | best_j = j; |
| 449 | } |
| 450 | |
| 451 | } |
| 452 | |
| 453 | return newintobject(best_j); |
Jack Jansen | dd8a6ea | 1993-02-17 14:21:09 +0000 | [diff] [blame] | 454 | } |
| 455 | |
| 456 | static object * |
Jack Jansen | e1b4d7c | 1992-08-24 14:36:31 +0000 | [diff] [blame] | 457 | audioop_avgpp(self, args) |
| 458 | object *self; |
| 459 | object *args; |
| 460 | { |
| 461 | signed char *cp; |
| 462 | int len, size, val, prevval, prevextremevalid = 0, prevextreme; |
| 463 | int i; |
| 464 | float avg = 0.0; |
| 465 | int diff, prevdiff, extremediff, nextreme = 0; |
| 466 | |
| 467 | if ( !getargs(args, "(s#i)", &cp, &len, &size) ) |
| 468 | return 0; |
| 469 | if ( size != 1 && size != 2 && size != 4 ) { |
| 470 | err_setstr(AudioopError, "Size should be 1, 2 or 4"); |
| 471 | return 0; |
| 472 | } |
| 473 | /* Compute first delta value ahead. Also automatically makes us |
| 474 | ** skip the first extreme value |
| 475 | */ |
| 476 | if ( size == 1 ) prevval = (int)*CHARP(cp, 0); |
| 477 | else if ( size == 2 ) prevval = (int)*SHORTP(cp, 0); |
| 478 | else if ( size == 4 ) prevval = (int)*LONGP(cp, 0); |
| 479 | if ( size == 1 ) val = (int)*CHARP(cp, size); |
| 480 | else if ( size == 2 ) val = (int)*SHORTP(cp, size); |
| 481 | else if ( size == 4 ) val = (int)*LONGP(cp, size); |
| 482 | prevdiff = val - prevval; |
| 483 | |
| 484 | for ( i=size; i<len; i+= size) { |
| 485 | if ( size == 1 ) val = (int)*CHARP(cp, i); |
| 486 | else if ( size == 2 ) val = (int)*SHORTP(cp, i); |
| 487 | else if ( size == 4 ) val = (int)*LONGP(cp, i); |
| 488 | diff = val - prevval; |
| 489 | if ( diff*prevdiff < 0 ) { |
| 490 | /* Derivative changed sign. Compute difference to last extreme |
| 491 | ** value and remember. |
| 492 | */ |
| 493 | if ( prevextremevalid ) { |
| 494 | extremediff = prevval - prevextreme; |
| 495 | if ( extremediff < 0 ) |
| 496 | extremediff = -extremediff; |
| 497 | avg += extremediff; |
| 498 | nextreme++; |
| 499 | } |
| 500 | prevextremevalid = 1; |
| 501 | prevextreme = prevval; |
| 502 | } |
| 503 | prevval = val; |
| 504 | if ( diff != 0 ) |
| 505 | prevdiff = diff; |
| 506 | } |
| 507 | if ( nextreme == 0 ) |
| 508 | val = 0; |
| 509 | else |
| 510 | val = (int)(avg / (float)nextreme); |
| 511 | return newintobject(val); |
| 512 | } |
| 513 | |
| 514 | static object * |
| 515 | audioop_maxpp(self, args) |
| 516 | object *self; |
| 517 | object *args; |
| 518 | { |
| 519 | signed char *cp; |
| 520 | int len, size, val, prevval, prevextremevalid = 0, prevextreme; |
| 521 | int i; |
| 522 | int max = 0; |
| 523 | int diff, prevdiff, extremediff; |
| 524 | |
| 525 | if ( !getargs(args, "(s#i)", &cp, &len, &size) ) |
| 526 | return 0; |
| 527 | if ( size != 1 && size != 2 && size != 4 ) { |
| 528 | err_setstr(AudioopError, "Size should be 1, 2 or 4"); |
| 529 | return 0; |
| 530 | } |
| 531 | /* Compute first delta value ahead. Also automatically makes us |
| 532 | ** skip the first extreme value |
| 533 | */ |
| 534 | if ( size == 1 ) prevval = (int)*CHARP(cp, 0); |
| 535 | else if ( size == 2 ) prevval = (int)*SHORTP(cp, 0); |
| 536 | else if ( size == 4 ) prevval = (int)*LONGP(cp, 0); |
| 537 | if ( size == 1 ) val = (int)*CHARP(cp, size); |
| 538 | else if ( size == 2 ) val = (int)*SHORTP(cp, size); |
| 539 | else if ( size == 4 ) val = (int)*LONGP(cp, size); |
| 540 | prevdiff = val - prevval; |
| 541 | |
| 542 | for ( i=size; i<len; i+= size) { |
| 543 | if ( size == 1 ) val = (int)*CHARP(cp, i); |
| 544 | else if ( size == 2 ) val = (int)*SHORTP(cp, i); |
| 545 | else if ( size == 4 ) val = (int)*LONGP(cp, i); |
| 546 | diff = val - prevval; |
| 547 | if ( diff*prevdiff < 0 ) { |
| 548 | /* Derivative changed sign. Compute difference to last extreme |
| 549 | ** value and remember. |
| 550 | */ |
| 551 | if ( prevextremevalid ) { |
| 552 | extremediff = prevval - prevextreme; |
| 553 | if ( extremediff < 0 ) |
| 554 | extremediff = -extremediff; |
| 555 | if ( extremediff > max ) |
| 556 | max = extremediff; |
| 557 | } |
| 558 | prevextremevalid = 1; |
| 559 | prevextreme = prevval; |
| 560 | } |
| 561 | prevval = val; |
| 562 | if ( diff != 0 ) |
| 563 | prevdiff = diff; |
| 564 | } |
| 565 | return newintobject(max); |
| 566 | } |
| 567 | |
| 568 | static object * |
Guido van Rossum | b66efa0 | 1992-06-01 16:01:24 +0000 | [diff] [blame] | 569 | audioop_cross(self, args) |
| 570 | object *self; |
| 571 | object *args; |
| 572 | { |
| 573 | signed char *cp; |
| 574 | int len, size, val; |
| 575 | int i; |
| 576 | int cross, prevval, ncross; |
| 577 | |
| 578 | if ( !getargs(args, "(s#i)", &cp, &len, &size) ) |
| 579 | return 0; |
| 580 | if ( size != 1 && size != 2 && size != 4 ) { |
| 581 | err_setstr(AudioopError, "Size should be 1, 2 or 4"); |
| 582 | return 0; |
| 583 | } |
| 584 | ncross = -1; |
| 585 | prevval = 17; /* Anything <> 0,1 */ |
| 586 | for ( i=0; i<len; i+= size) { |
| 587 | if ( size == 1 ) val = ((int)*CHARP(cp, i)) >> 7; |
| 588 | else if ( size == 2 ) val = ((int)*SHORTP(cp, i)) >> 15; |
| 589 | else if ( size == 4 ) val = ((int)*LONGP(cp, i)) >> 31; |
| 590 | val = val & 1; |
| 591 | if ( val != prevval ) ncross++; |
| 592 | prevval = val; |
| 593 | } |
| 594 | return newintobject(ncross); |
| 595 | } |
| 596 | |
| 597 | static object * |
| 598 | audioop_mul(self, args) |
| 599 | object *self; |
| 600 | object *args; |
| 601 | { |
| 602 | signed char *cp, *ncp; |
| 603 | int len, size, val; |
| 604 | double factor, fval, maxval; |
| 605 | object *rv; |
| 606 | int i; |
| 607 | |
| 608 | if ( !getargs(args, "(s#id)", &cp, &len, &size, &factor ) ) |
| 609 | return 0; |
| 610 | |
| 611 | if ( size == 1 ) maxval = (double) 0x7f; |
| 612 | else if ( size == 2 ) maxval = (double) 0x7fff; |
| 613 | else if ( size == 4 ) maxval = (double) 0x7fffffff; |
| 614 | else { |
| 615 | err_setstr(AudioopError, "Size should be 1, 2 or 4"); |
| 616 | return 0; |
| 617 | } |
| 618 | |
| 619 | rv = newsizedstringobject(NULL, len); |
| 620 | if ( rv == 0 ) |
| 621 | return 0; |
| 622 | ncp = (signed char *)getstringvalue(rv); |
| 623 | |
| 624 | |
| 625 | for ( i=0; i < len; i += size ) { |
| 626 | if ( size == 1 ) val = (int)*CHARP(cp, i); |
| 627 | else if ( size == 2 ) val = (int)*SHORTP(cp, i); |
| 628 | else if ( size == 4 ) val = (int)*LONGP(cp, i); |
| 629 | fval = (double)val*factor; |
| 630 | if ( fval > maxval ) fval = maxval; |
| 631 | else if ( fval < -maxval ) fval = -maxval; |
| 632 | val = (int)fval; |
| 633 | if ( size == 1 ) *CHARP(ncp, i) = (signed char)val; |
| 634 | else if ( size == 2 ) *SHORTP(ncp, i) = (short)val; |
| 635 | else if ( size == 4 ) *LONGP(ncp, i) = (long)val; |
| 636 | } |
| 637 | return rv; |
| 638 | } |
| 639 | |
| 640 | static object * |
| 641 | audioop_tomono(self, args) |
| 642 | object *self; |
| 643 | object *args; |
| 644 | { |
| 645 | signed char *cp, *ncp; |
| 646 | int len, size, val1, val2; |
| 647 | double fac1, fac2, fval, maxval; |
| 648 | object *rv; |
| 649 | int i; |
| 650 | |
| 651 | if ( !getargs(args, "(s#idd)", &cp, &len, &size, &fac1, &fac2 ) ) |
| 652 | return 0; |
| 653 | |
| 654 | if ( size == 1 ) maxval = (double) 0x7f; |
| 655 | else if ( size == 2 ) maxval = (double) 0x7fff; |
| 656 | else if ( size == 4 ) maxval = (double) 0x7fffffff; |
| 657 | else { |
| 658 | err_setstr(AudioopError, "Size should be 1, 2 or 4"); |
| 659 | return 0; |
| 660 | } |
| 661 | |
| 662 | rv = newsizedstringobject(NULL, len/2); |
| 663 | if ( rv == 0 ) |
| 664 | return 0; |
| 665 | ncp = (signed char *)getstringvalue(rv); |
| 666 | |
| 667 | |
| 668 | for ( i=0; i < len; i += size*2 ) { |
| 669 | if ( size == 1 ) val1 = (int)*CHARP(cp, i); |
| 670 | else if ( size == 2 ) val1 = (int)*SHORTP(cp, i); |
| 671 | else if ( size == 4 ) val1 = (int)*LONGP(cp, i); |
| 672 | if ( size == 1 ) val2 = (int)*CHARP(cp, i+1); |
| 673 | else if ( size == 2 ) val2 = (int)*SHORTP(cp, i+2); |
| 674 | else if ( size == 4 ) val2 = (int)*LONGP(cp, i+4); |
| 675 | fval = (double)val1*fac1 + (double)val2*fac2; |
| 676 | if ( fval > maxval ) fval = maxval; |
| 677 | else if ( fval < -maxval ) fval = -maxval; |
| 678 | val1 = (int)fval; |
| 679 | if ( size == 1 ) *CHARP(ncp, i/2) = (signed char)val1; |
| 680 | else if ( size == 2 ) *SHORTP(ncp, i/2) = (short)val1; |
| 681 | else if ( size == 4 ) *LONGP(ncp, i/2)= (long)val1; |
| 682 | } |
| 683 | return rv; |
| 684 | } |
| 685 | |
| 686 | static object * |
| 687 | audioop_tostereo(self, args) |
| 688 | object *self; |
| 689 | object *args; |
| 690 | { |
| 691 | signed char *cp, *ncp; |
| 692 | int len, size, val1, val2, val; |
| 693 | double fac1, fac2, fval, maxval; |
| 694 | object *rv; |
| 695 | int i; |
| 696 | |
| 697 | if ( !getargs(args, "(s#idd)", &cp, &len, &size, &fac1, &fac2 ) ) |
| 698 | return 0; |
| 699 | |
| 700 | if ( size == 1 ) maxval = (double) 0x7f; |
| 701 | else if ( size == 2 ) maxval = (double) 0x7fff; |
| 702 | else if ( size == 4 ) maxval = (double) 0x7fffffff; |
| 703 | else { |
| 704 | err_setstr(AudioopError, "Size should be 1, 2 or 4"); |
| 705 | return 0; |
| 706 | } |
| 707 | |
| 708 | rv = newsizedstringobject(NULL, len*2); |
| 709 | if ( rv == 0 ) |
| 710 | return 0; |
| 711 | ncp = (signed char *)getstringvalue(rv); |
| 712 | |
| 713 | |
| 714 | for ( i=0; i < len; i += size ) { |
| 715 | if ( size == 1 ) val = (int)*CHARP(cp, i); |
| 716 | else if ( size == 2 ) val = (int)*SHORTP(cp, i); |
| 717 | else if ( size == 4 ) val = (int)*LONGP(cp, i); |
| 718 | |
| 719 | fval = (double)val*fac1; |
| 720 | if ( fval > maxval ) fval = maxval; |
| 721 | else if ( fval < -maxval ) fval = -maxval; |
| 722 | val1 = (int)fval; |
| 723 | |
| 724 | fval = (double)val*fac2; |
| 725 | if ( fval > maxval ) fval = maxval; |
| 726 | else if ( fval < -maxval ) fval = -maxval; |
| 727 | val2 = (int)fval; |
| 728 | |
| 729 | if ( size == 1 ) *CHARP(ncp, i*2) = (signed char)val1; |
| 730 | else if ( size == 2 ) *SHORTP(ncp, i*2) = (short)val1; |
| 731 | else if ( size == 4 ) *LONGP(ncp, i*2) = (long)val1; |
| 732 | |
| 733 | if ( size == 1 ) *CHARP(ncp, i*2+1) = (signed char)val2; |
| 734 | else if ( size == 2 ) *SHORTP(ncp, i*2+2) = (short)val2; |
| 735 | else if ( size == 4 ) *LONGP(ncp, i*2+4) = (long)val2; |
| 736 | } |
| 737 | return rv; |
| 738 | } |
| 739 | |
| 740 | static object * |
| 741 | audioop_add(self, args) |
| 742 | object *self; |
| 743 | object *args; |
| 744 | { |
| 745 | signed char *cp1, *cp2, *ncp; |
| 746 | int len1, len2, size, val1, val2; |
| 747 | object *rv; |
| 748 | int i; |
| 749 | |
| 750 | if ( !getargs(args, "(s#s#i)", |
| 751 | &cp1, &len1, &cp2, &len2, &size ) ) |
| 752 | return 0; |
| 753 | |
| 754 | if ( len1 != len2 ) { |
| 755 | err_setstr(AudioopError, "Lengths should be the same"); |
| 756 | return 0; |
| 757 | } |
| 758 | |
| 759 | if ( size != 1 && size != 2 && size != 4) { |
| 760 | err_setstr(AudioopError, "Size should be 1, 2 or 4"); |
| 761 | return 0; |
| 762 | } |
| 763 | |
| 764 | rv = newsizedstringobject(NULL, len1); |
| 765 | if ( rv == 0 ) |
| 766 | return 0; |
| 767 | ncp = (signed char *)getstringvalue(rv); |
| 768 | |
| 769 | |
| 770 | for ( i=0; i < len1; i += size ) { |
| 771 | if ( size == 1 ) val1 = (int)*CHARP(cp1, i); |
| 772 | else if ( size == 2 ) val1 = (int)*SHORTP(cp1, i); |
| 773 | else if ( size == 4 ) val1 = (int)*LONGP(cp1, i); |
| 774 | |
| 775 | if ( size == 1 ) val2 = (int)*CHARP(cp2, i); |
| 776 | else if ( size == 2 ) val2 = (int)*SHORTP(cp2, i); |
| 777 | else if ( size == 4 ) val2 = (int)*LONGP(cp2, i); |
| 778 | |
| 779 | if ( size == 1 ) *CHARP(ncp, i) = (signed char)(val1+val2); |
| 780 | else if ( size == 2 ) *SHORTP(ncp, i) = (short)(val1+val2); |
| 781 | else if ( size == 4 ) *LONGP(ncp, i) = (long)(val1+val2); |
| 782 | } |
| 783 | return rv; |
| 784 | } |
| 785 | |
| 786 | static object * |
| 787 | audioop_bias(self, args) |
| 788 | object *self; |
| 789 | object *args; |
| 790 | { |
| 791 | signed char *cp, *ncp; |
| 792 | int len, size, val; |
| 793 | object *rv; |
| 794 | int i; |
| 795 | int bias; |
| 796 | |
| 797 | if ( !getargs(args, "(s#ii)", |
| 798 | &cp, &len, &size , &bias) ) |
| 799 | return 0; |
| 800 | |
| 801 | if ( size != 1 && size != 2 && size != 4) { |
| 802 | err_setstr(AudioopError, "Size should be 1, 2 or 4"); |
| 803 | return 0; |
| 804 | } |
| 805 | |
| 806 | rv = newsizedstringobject(NULL, len); |
| 807 | if ( rv == 0 ) |
| 808 | return 0; |
| 809 | ncp = (signed char *)getstringvalue(rv); |
| 810 | |
| 811 | |
| 812 | for ( i=0; i < len; i += size ) { |
| 813 | if ( size == 1 ) val = (int)*CHARP(cp, i); |
| 814 | else if ( size == 2 ) val = (int)*SHORTP(cp, i); |
| 815 | else if ( size == 4 ) val = (int)*LONGP(cp, i); |
| 816 | |
| 817 | if ( size == 1 ) *CHARP(ncp, i) = (signed char)(val+bias); |
| 818 | else if ( size == 2 ) *SHORTP(ncp, i) = (short)(val+bias); |
| 819 | else if ( size == 4 ) *LONGP(ncp, i) = (long)(val+bias); |
| 820 | } |
| 821 | return rv; |
| 822 | } |
| 823 | |
| 824 | static object * |
Jack Jansen | a90805f | 1993-02-17 14:29:28 +0000 | [diff] [blame] | 825 | audioop_lin2lin(self, args) |
| 826 | object *self; |
| 827 | object *args; |
| 828 | { |
| 829 | signed char *cp; |
| 830 | unsigned char *ncp; |
| 831 | int len, size, size2, val; |
| 832 | object *rv; |
| 833 | int i, j; |
| 834 | |
| 835 | if ( !getargs(args, "(s#ii)", |
| 836 | &cp, &len, &size, &size2) ) |
| 837 | return 0; |
| 838 | |
| 839 | if ( (size != 1 && size != 2 && size != 4) || |
| 840 | (size2 != 1 && size2 != 2 && size2 != 4)) { |
| 841 | err_setstr(AudioopError, "Size should be 1, 2 or 4"); |
| 842 | return 0; |
| 843 | } |
| 844 | |
| 845 | rv = newsizedstringobject(NULL, (len/size)*size2); |
| 846 | if ( rv == 0 ) |
| 847 | return 0; |
| 848 | ncp = (unsigned char *)getstringvalue(rv); |
| 849 | |
| 850 | for ( i=0, j=0; i < len; i += size, j += size2 ) { |
| 851 | if ( size == 1 ) val = ((int)*CHARP(cp, i)) << 8; |
| 852 | else if ( size == 2 ) val = (int)*SHORTP(cp, i); |
| 853 | else if ( size == 4 ) val = ((int)*LONGP(cp, i)) >> 16; |
| 854 | |
| 855 | if ( size2 == 1 ) *CHARP(ncp, j) = (signed char)(val >> 8); |
| 856 | else if ( size2 == 2 ) *SHORTP(ncp, j) = (short)(val); |
| 857 | else if ( size2 == 4 ) *LONGP(ncp, j) = (long)(val<<16); |
| 858 | } |
| 859 | return rv; |
| 860 | } |
| 861 | |
| 862 | static object * |
Guido van Rossum | b66efa0 | 1992-06-01 16:01:24 +0000 | [diff] [blame] | 863 | audioop_lin2ulaw(self, args) |
| 864 | object *self; |
| 865 | object *args; |
| 866 | { |
| 867 | signed char *cp; |
| 868 | unsigned char *ncp; |
| 869 | int len, size, val; |
| 870 | object *rv; |
| 871 | int i; |
| 872 | |
| 873 | if ( !getargs(args, "(s#i)", |
| 874 | &cp, &len, &size) ) |
| 875 | return 0; |
| 876 | |
| 877 | if ( size != 1 && size != 2 && size != 4) { |
| 878 | err_setstr(AudioopError, "Size should be 1, 2 or 4"); |
| 879 | return 0; |
| 880 | } |
| 881 | |
| 882 | rv = newsizedstringobject(NULL, len/size); |
| 883 | if ( rv == 0 ) |
| 884 | return 0; |
| 885 | ncp = (unsigned char *)getstringvalue(rv); |
| 886 | |
| 887 | for ( i=0; i < len; i += size ) { |
| 888 | if ( size == 1 ) val = ((int)*CHARP(cp, i)) << 8; |
| 889 | else if ( size == 2 ) val = (int)*SHORTP(cp, i); |
| 890 | else if ( size == 4 ) val = ((int)*LONGP(cp, i)) >> 16; |
| 891 | |
| 892 | *ncp++ = st_linear_to_ulaw(val); |
| 893 | } |
| 894 | return rv; |
| 895 | } |
| 896 | |
| 897 | static object * |
| 898 | audioop_ulaw2lin(self, args) |
| 899 | object *self; |
| 900 | object *args; |
| 901 | { |
| 902 | unsigned char *cp; |
| 903 | unsigned char cval; |
| 904 | signed char *ncp; |
| 905 | int len, size, val; |
| 906 | object *rv; |
| 907 | int i; |
| 908 | |
| 909 | if ( !getargs(args, "(s#i)", |
| 910 | &cp, &len, &size) ) |
| 911 | return 0; |
| 912 | |
| 913 | if ( size != 1 && size != 2 && size != 4) { |
| 914 | err_setstr(AudioopError, "Size should be 1, 2 or 4"); |
| 915 | return 0; |
| 916 | } |
| 917 | |
| 918 | rv = newsizedstringobject(NULL, len*size); |
| 919 | if ( rv == 0 ) |
| 920 | return 0; |
| 921 | ncp = (signed char *)getstringvalue(rv); |
| 922 | |
| 923 | for ( i=0; i < len*size; i += size ) { |
| 924 | cval = *cp++; |
| 925 | val = st_ulaw_to_linear(cval); |
| 926 | |
| 927 | if ( size == 1 ) *CHARP(ncp, i) = (signed char)(val >> 8); |
| 928 | else if ( size == 2 ) *SHORTP(ncp, i) = (short)(val); |
Guido van Rossum | aad5344 | 1992-06-05 15:11:56 +0000 | [diff] [blame] | 929 | else if ( size == 4 ) *LONGP(ncp, i) = (long)(val<<16); |
Guido van Rossum | b66efa0 | 1992-06-01 16:01:24 +0000 | [diff] [blame] | 930 | } |
| 931 | return rv; |
| 932 | } |
| 933 | |
Guido van Rossum | 8e7a0f0 | 1992-06-23 15:23:57 +0000 | [diff] [blame] | 934 | static object * |
Guido van Rossum | b64e635 | 1992-07-06 14:21:56 +0000 | [diff] [blame] | 935 | audioop_lin2adpcm3(self, args) |
Guido van Rossum | 8e7a0f0 | 1992-06-23 15:23:57 +0000 | [diff] [blame] | 936 | object *self; |
| 937 | object *args; |
| 938 | { |
| 939 | signed char *cp; |
| 940 | signed char *ncp; |
| 941 | int len, size, val, step, valprev, delta; |
| 942 | object *rv, *state, *str; |
| 943 | int i; |
| 944 | |
| 945 | if ( !getargs(args, "(s#iO)", |
| 946 | &cp, &len, &size, &state) ) |
| 947 | return 0; |
| 948 | |
| 949 | |
| 950 | if ( size != 1 && size != 2 && size != 4) { |
| 951 | err_setstr(AudioopError, "Size should be 1, 2 or 4"); |
| 952 | return 0; |
| 953 | } |
| 954 | |
Jack Jansen | dd8a6ea | 1993-02-17 14:21:09 +0000 | [diff] [blame] | 955 | str = newsizedstringobject(NULL, len/size); |
| 956 | if ( str == 0 ) |
| 957 | return 0; |
| 958 | ncp = (signed char *)getstringvalue(str); |
| 959 | |
Guido van Rossum | 8e7a0f0 | 1992-06-23 15:23:57 +0000 | [diff] [blame] | 960 | /* Decode state, should have (value, step) */ |
| 961 | if ( state == None ) { |
| 962 | /* First time, it seems. Set defaults */ |
| 963 | valprev = 0; |
| 964 | step = 4; /* The '4' is magic. Dunno it's significance */ |
| 965 | } else if ( !getargs(state, "(ii)", &valprev, &step) ) |
| 966 | return 0; |
| 967 | |
| 968 | for ( i=0; i < len; i += size ) { |
| 969 | if ( size == 1 ) val = ((int)*CHARP(cp, i)) << 8; |
| 970 | else if ( size == 2 ) val = (int)*SHORTP(cp, i); |
| 971 | else if ( size == 4 ) val = ((int)*LONGP(cp, i)) >> 16; |
| 972 | |
| 973 | /* Step 1 - compute difference with previous value */ |
| 974 | delta = (val - valprev)/step; |
| 975 | |
| 976 | /* Step 2 - Clamp */ |
| 977 | if ( delta < -4 ) |
| 978 | delta = -4; |
| 979 | else if ( delta > 3 ) |
| 980 | delta = 3; |
| 981 | |
| 982 | /* Step 3 - Update previous value */ |
| 983 | valprev += delta*step; |
| 984 | |
| 985 | /* Step 4 - Clamp previous value to 16 bits */ |
| 986 | if ( valprev > 32767 ) |
| 987 | valprev = 32767; |
| 988 | else if ( valprev < -32768 ) |
| 989 | valprev = -32768; |
| 990 | |
| 991 | /* Step 5 - Update step value */ |
| 992 | step = step * newstep[abs(delta)]; |
| 993 | step++; /* Don't understand this. */ |
| 994 | |
| 995 | /* Step 6 - Output value (as a whole byte, currently) */ |
| 996 | *ncp++ = delta; |
| 997 | } |
| 998 | rv = mkvalue("(O(ii))", str, valprev, step); |
| 999 | DECREF(str); |
| 1000 | return rv; |
| 1001 | } |
| 1002 | |
| 1003 | static object * |
Guido van Rossum | b64e635 | 1992-07-06 14:21:56 +0000 | [diff] [blame] | 1004 | audioop_adpcm32lin(self, args) |
Guido van Rossum | 8e7a0f0 | 1992-06-23 15:23:57 +0000 | [diff] [blame] | 1005 | object *self; |
| 1006 | object *args; |
| 1007 | { |
| 1008 | signed char *cp; |
| 1009 | signed char *ncp; |
| 1010 | int len, size, val, valprev, step, delta; |
| 1011 | object *rv, *str, *state; |
| 1012 | int i; |
| 1013 | |
| 1014 | if ( !getargs(args, "(s#iO)", |
| 1015 | &cp, &len, &size, &state) ) |
| 1016 | return 0; |
| 1017 | |
| 1018 | if ( size != 1 && size != 2 && size != 4) { |
| 1019 | err_setstr(AudioopError, "Size should be 1, 2 or 4"); |
| 1020 | return 0; |
| 1021 | } |
| 1022 | |
| 1023 | /* Decode state, should have (value, step) */ |
| 1024 | if ( state == None ) { |
| 1025 | /* First time, it seems. Set defaults */ |
| 1026 | valprev = 0; |
| 1027 | step = 4; /* The '4' is magic. Dunno it's significance */ |
| 1028 | } else if ( !getargs(state, "(ii)", &valprev, &step) ) |
| 1029 | return 0; |
| 1030 | |
| 1031 | str = newsizedstringobject(NULL, len*size); |
| 1032 | if ( str == 0 ) |
| 1033 | return 0; |
| 1034 | ncp = (signed char *)getstringvalue(str); |
| 1035 | |
| 1036 | for ( i=0; i < len*size; i += size ) { |
| 1037 | /* Step 1 - get the delta value */ |
| 1038 | delta = *cp++; |
| 1039 | |
| 1040 | /* Step 2 - update output value */ |
| 1041 | valprev = valprev + delta*step; |
| 1042 | |
| 1043 | /* Step 3 - clamp output value */ |
| 1044 | if ( valprev > 32767 ) |
| 1045 | valprev = 32767; |
| 1046 | else if ( valprev < -32768 ) |
| 1047 | valprev = -32768; |
| 1048 | |
| 1049 | /* Step 4 - Update step value */ |
| 1050 | step = step * newstep[abs(delta)]; |
| 1051 | step++; |
| 1052 | |
| 1053 | /* Step 5 - Output value */ |
| 1054 | if ( size == 1 ) *CHARP(ncp, i) = (signed char)(valprev >> 8); |
| 1055 | else if ( size == 2 ) *SHORTP(ncp, i) = (short)(valprev); |
| 1056 | else if ( size == 4 ) *LONGP(ncp, i) = (long)(valprev<<16); |
| 1057 | } |
| 1058 | |
| 1059 | rv = mkvalue("(O(ii))", str, valprev, step); |
| 1060 | DECREF(str); |
| 1061 | return rv; |
| 1062 | } |
| 1063 | |
Guido van Rossum | b64e635 | 1992-07-06 14:21:56 +0000 | [diff] [blame] | 1064 | static object * |
| 1065 | audioop_lin2adpcm(self, args) |
| 1066 | object *self; |
| 1067 | object *args; |
| 1068 | { |
| 1069 | signed char *cp; |
| 1070 | signed char *ncp; |
Jack Jansen | d513f0b | 1993-01-08 14:40:53 +0000 | [diff] [blame] | 1071 | int len, size, val, step, valpred, delta, index, sign, vpdiff, diff; |
Guido van Rossum | b64e635 | 1992-07-06 14:21:56 +0000 | [diff] [blame] | 1072 | object *rv, *state, *str; |
| 1073 | int i, outputbuffer, bufferstep; |
| 1074 | |
| 1075 | if ( !getargs(args, "(s#iO)", |
| 1076 | &cp, &len, &size, &state) ) |
| 1077 | return 0; |
| 1078 | |
| 1079 | |
| 1080 | if ( size != 1 && size != 2 && size != 4) { |
| 1081 | err_setstr(AudioopError, "Size should be 1, 2 or 4"); |
| 1082 | return 0; |
| 1083 | } |
| 1084 | |
Jack Jansen | dd8a6ea | 1993-02-17 14:21:09 +0000 | [diff] [blame] | 1085 | str = newsizedstringobject(NULL, len/(size*2)); |
| 1086 | if ( str == 0 ) |
| 1087 | return 0; |
| 1088 | ncp = (signed char *)getstringvalue(str); |
| 1089 | |
Guido van Rossum | b64e635 | 1992-07-06 14:21:56 +0000 | [diff] [blame] | 1090 | /* Decode state, should have (value, step) */ |
| 1091 | if ( state == None ) { |
| 1092 | /* First time, it seems. Set defaults */ |
Jack Jansen | d513f0b | 1993-01-08 14:40:53 +0000 | [diff] [blame] | 1093 | valpred = 0; |
Guido van Rossum | b64e635 | 1992-07-06 14:21:56 +0000 | [diff] [blame] | 1094 | step = 7; |
| 1095 | index = 0; |
Jack Jansen | 55cea47 | 1993-02-10 13:21:59 +0000 | [diff] [blame] | 1096 | } else if ( !getargs(state, "(ii)", &valpred, &index) ) |
Guido van Rossum | b64e635 | 1992-07-06 14:21:56 +0000 | [diff] [blame] | 1097 | return 0; |
| 1098 | |
Jack Jansen | 55cea47 | 1993-02-10 13:21:59 +0000 | [diff] [blame] | 1099 | step = stepsizeTable[index]; |
Guido van Rossum | b64e635 | 1992-07-06 14:21:56 +0000 | [diff] [blame] | 1100 | bufferstep = 1; |
| 1101 | |
| 1102 | for ( i=0; i < len; i += size ) { |
| 1103 | if ( size == 1 ) val = ((int)*CHARP(cp, i)) << 8; |
| 1104 | else if ( size == 2 ) val = (int)*SHORTP(cp, i); |
| 1105 | else if ( size == 4 ) val = ((int)*LONGP(cp, i)) >> 16; |
| 1106 | |
| 1107 | /* Step 1 - compute difference with previous value */ |
Jack Jansen | d513f0b | 1993-01-08 14:40:53 +0000 | [diff] [blame] | 1108 | diff = val - valpred; |
| 1109 | sign = (diff < 0) ? 8 : 0; |
| 1110 | if ( sign ) diff = (-diff); |
Guido van Rossum | b64e635 | 1992-07-06 14:21:56 +0000 | [diff] [blame] | 1111 | |
| 1112 | /* Step 2 - Divide and clamp */ |
Jack Jansen | d513f0b | 1993-01-08 14:40:53 +0000 | [diff] [blame] | 1113 | /* Note: |
| 1114 | ** This code *approximately* computes: |
| 1115 | ** delta = diff*4/step; |
| 1116 | ** vpdiff = (delta+0.5)*step/4; |
| 1117 | ** but in shift step bits are dropped. The net result of this is |
| 1118 | ** that even if you have fast mul/div hardware you cannot put it to |
| 1119 | ** good use since the fixup would be too expensive. |
| 1120 | */ |
| 1121 | delta = 0; |
| 1122 | vpdiff = (step >> 3); |
| 1123 | |
| 1124 | if ( diff >= step ) { |
| 1125 | delta = 4; |
| 1126 | diff -= step; |
| 1127 | vpdiff += step; |
| 1128 | } |
| 1129 | step >>= 1; |
| 1130 | if ( diff >= step ) { |
| 1131 | delta |= 2; |
| 1132 | diff -= step; |
| 1133 | vpdiff += step; |
| 1134 | } |
| 1135 | step >>= 1; |
| 1136 | if ( diff >= step ) { |
| 1137 | delta |= 1; |
| 1138 | vpdiff += step; |
| 1139 | } |
| 1140 | |
Guido van Rossum | b64e635 | 1992-07-06 14:21:56 +0000 | [diff] [blame] | 1141 | /* Step 3 - Update previous value */ |
| 1142 | if ( sign ) |
Jack Jansen | d513f0b | 1993-01-08 14:40:53 +0000 | [diff] [blame] | 1143 | valpred -= vpdiff; |
Guido van Rossum | b64e635 | 1992-07-06 14:21:56 +0000 | [diff] [blame] | 1144 | else |
Jack Jansen | d513f0b | 1993-01-08 14:40:53 +0000 | [diff] [blame] | 1145 | valpred += vpdiff; |
Guido van Rossum | b64e635 | 1992-07-06 14:21:56 +0000 | [diff] [blame] | 1146 | |
| 1147 | /* Step 4 - Clamp previous value to 16 bits */ |
Jack Jansen | d513f0b | 1993-01-08 14:40:53 +0000 | [diff] [blame] | 1148 | if ( valpred > 32767 ) |
| 1149 | valpred = 32767; |
| 1150 | else if ( valpred < -32768 ) |
| 1151 | valpred = -32768; |
Guido van Rossum | b64e635 | 1992-07-06 14:21:56 +0000 | [diff] [blame] | 1152 | |
| 1153 | /* Step 5 - Assemble value, update index and step values */ |
| 1154 | delta |= sign; |
| 1155 | |
| 1156 | index += indexTable[delta]; |
| 1157 | if ( index < 0 ) index = 0; |
| 1158 | if ( index > 88 ) index = 88; |
| 1159 | step = stepsizeTable[index]; |
| 1160 | |
Jack Jansen | d513f0b | 1993-01-08 14:40:53 +0000 | [diff] [blame] | 1161 | /* Step 6 - Output value */ |
Guido van Rossum | b64e635 | 1992-07-06 14:21:56 +0000 | [diff] [blame] | 1162 | if ( bufferstep ) { |
Jack Jansen | d513f0b | 1993-01-08 14:40:53 +0000 | [diff] [blame] | 1163 | outputbuffer = (delta << 4) & 0xf0; |
Guido van Rossum | b64e635 | 1992-07-06 14:21:56 +0000 | [diff] [blame] | 1164 | } else { |
Jack Jansen | d513f0b | 1993-01-08 14:40:53 +0000 | [diff] [blame] | 1165 | *ncp++ = (delta & 0x0f) | outputbuffer; |
Guido van Rossum | b64e635 | 1992-07-06 14:21:56 +0000 | [diff] [blame] | 1166 | } |
| 1167 | bufferstep = !bufferstep; |
| 1168 | } |
Jack Jansen | 55cea47 | 1993-02-10 13:21:59 +0000 | [diff] [blame] | 1169 | rv = mkvalue("(O(ii))", str, valpred, index); |
Guido van Rossum | b64e635 | 1992-07-06 14:21:56 +0000 | [diff] [blame] | 1170 | DECREF(str); |
| 1171 | return rv; |
| 1172 | } |
| 1173 | |
| 1174 | static object * |
| 1175 | audioop_adpcm2lin(self, args) |
| 1176 | object *self; |
| 1177 | object *args; |
| 1178 | { |
| 1179 | signed char *cp; |
| 1180 | signed char *ncp; |
Jack Jansen | d513f0b | 1993-01-08 14:40:53 +0000 | [diff] [blame] | 1181 | int len, size, val, valpred, step, delta, index, sign, vpdiff; |
Guido van Rossum | b64e635 | 1992-07-06 14:21:56 +0000 | [diff] [blame] | 1182 | object *rv, *str, *state; |
| 1183 | int i, inputbuffer, bufferstep; |
| 1184 | |
| 1185 | if ( !getargs(args, "(s#iO)", |
| 1186 | &cp, &len, &size, &state) ) |
| 1187 | return 0; |
| 1188 | |
| 1189 | if ( size != 1 && size != 2 && size != 4) { |
| 1190 | err_setstr(AudioopError, "Size should be 1, 2 or 4"); |
| 1191 | return 0; |
| 1192 | } |
| 1193 | |
| 1194 | /* Decode state, should have (value, step) */ |
| 1195 | if ( state == None ) { |
| 1196 | /* First time, it seems. Set defaults */ |
Jack Jansen | d513f0b | 1993-01-08 14:40:53 +0000 | [diff] [blame] | 1197 | valpred = 0; |
Guido van Rossum | b64e635 | 1992-07-06 14:21:56 +0000 | [diff] [blame] | 1198 | step = 7; |
| 1199 | index = 0; |
Jack Jansen | 55cea47 | 1993-02-10 13:21:59 +0000 | [diff] [blame] | 1200 | } else if ( !getargs(state, "(ii)", &valpred, &index) ) |
Guido van Rossum | b64e635 | 1992-07-06 14:21:56 +0000 | [diff] [blame] | 1201 | return 0; |
| 1202 | |
| 1203 | str = newsizedstringobject(NULL, len*size*2); |
| 1204 | if ( str == 0 ) |
| 1205 | return 0; |
| 1206 | ncp = (signed char *)getstringvalue(str); |
| 1207 | |
Jack Jansen | 55cea47 | 1993-02-10 13:21:59 +0000 | [diff] [blame] | 1208 | step = stepsizeTable[index]; |
Guido van Rossum | b64e635 | 1992-07-06 14:21:56 +0000 | [diff] [blame] | 1209 | bufferstep = 0; |
| 1210 | |
| 1211 | for ( i=0; i < len*size*2; i += size ) { |
| 1212 | /* Step 1 - get the delta value and compute next index */ |
| 1213 | if ( bufferstep ) { |
| 1214 | delta = inputbuffer & 0xf; |
| 1215 | } else { |
| 1216 | inputbuffer = *cp++; |
| 1217 | delta = (inputbuffer >> 4) & 0xf; |
| 1218 | } |
| 1219 | |
| 1220 | bufferstep = !bufferstep; |
| 1221 | |
Jack Jansen | d513f0b | 1993-01-08 14:40:53 +0000 | [diff] [blame] | 1222 | /* Step 2 - Find new index value (for later) */ |
Guido van Rossum | b64e635 | 1992-07-06 14:21:56 +0000 | [diff] [blame] | 1223 | index += indexTable[delta]; |
| 1224 | if ( index < 0 ) index = 0; |
| 1225 | if ( index > 88 ) index = 88; |
| 1226 | |
Jack Jansen | d513f0b | 1993-01-08 14:40:53 +0000 | [diff] [blame] | 1227 | /* Step 3 - Separate sign and magnitude */ |
Guido van Rossum | b64e635 | 1992-07-06 14:21:56 +0000 | [diff] [blame] | 1228 | sign = delta & 8; |
| 1229 | delta = delta & 7; |
| 1230 | |
Jack Jansen | d513f0b | 1993-01-08 14:40:53 +0000 | [diff] [blame] | 1231 | /* Step 4 - Compute difference and new predicted value */ |
| 1232 | /* |
| 1233 | ** Computes 'vpdiff = (delta+0.5)*step/4', but see comment |
| 1234 | ** in adpcm_coder. |
| 1235 | */ |
| 1236 | vpdiff = step >> 3; |
| 1237 | if ( delta & 4 ) vpdiff += step; |
| 1238 | if ( delta & 2 ) vpdiff += step>>1; |
| 1239 | if ( delta & 1 ) vpdiff += step>>2; |
| 1240 | |
Guido van Rossum | b64e635 | 1992-07-06 14:21:56 +0000 | [diff] [blame] | 1241 | if ( sign ) |
Jack Jansen | d513f0b | 1993-01-08 14:40:53 +0000 | [diff] [blame] | 1242 | valpred -= vpdiff; |
Guido van Rossum | b64e635 | 1992-07-06 14:21:56 +0000 | [diff] [blame] | 1243 | else |
Jack Jansen | d513f0b | 1993-01-08 14:40:53 +0000 | [diff] [blame] | 1244 | valpred += vpdiff; |
Guido van Rossum | b64e635 | 1992-07-06 14:21:56 +0000 | [diff] [blame] | 1245 | |
Jack Jansen | d513f0b | 1993-01-08 14:40:53 +0000 | [diff] [blame] | 1246 | /* Step 5 - clamp output value */ |
| 1247 | if ( valpred > 32767 ) |
| 1248 | valpred = 32767; |
| 1249 | else if ( valpred < -32768 ) |
| 1250 | valpred = -32768; |
Guido van Rossum | b64e635 | 1992-07-06 14:21:56 +0000 | [diff] [blame] | 1251 | |
Jack Jansen | d513f0b | 1993-01-08 14:40:53 +0000 | [diff] [blame] | 1252 | /* Step 6 - Update step value */ |
Guido van Rossum | b64e635 | 1992-07-06 14:21:56 +0000 | [diff] [blame] | 1253 | step = stepsizeTable[index]; |
| 1254 | |
| 1255 | /* Step 6 - Output value */ |
Jack Jansen | d513f0b | 1993-01-08 14:40:53 +0000 | [diff] [blame] | 1256 | if ( size == 1 ) *CHARP(ncp, i) = (signed char)(valpred >> 8); |
| 1257 | else if ( size == 2 ) *SHORTP(ncp, i) = (short)(valpred); |
| 1258 | else if ( size == 4 ) *LONGP(ncp, i) = (long)(valpred<<16); |
Guido van Rossum | b64e635 | 1992-07-06 14:21:56 +0000 | [diff] [blame] | 1259 | } |
| 1260 | |
Jack Jansen | 55cea47 | 1993-02-10 13:21:59 +0000 | [diff] [blame] | 1261 | rv = mkvalue("(O(ii))", str, valpred, index); |
Guido van Rossum | b64e635 | 1992-07-06 14:21:56 +0000 | [diff] [blame] | 1262 | DECREF(str); |
| 1263 | return rv; |
| 1264 | } |
| 1265 | |
Guido van Rossum | b66efa0 | 1992-06-01 16:01:24 +0000 | [diff] [blame] | 1266 | static struct methodlist audioop_methods[] = { |
| 1267 | { "max", audioop_max }, |
| 1268 | { "avg", audioop_avg }, |
Jack Jansen | e1b4d7c | 1992-08-24 14:36:31 +0000 | [diff] [blame] | 1269 | { "maxpp", audioop_maxpp }, |
| 1270 | { "avgpp", audioop_avgpp }, |
| 1271 | { "rms", audioop_rms }, |
Jack Jansen | a90805f | 1993-02-17 14:29:28 +0000 | [diff] [blame] | 1272 | { "findfit", audioop_findfit }, |
| 1273 | { "findmax", audioop_findmax }, |
| 1274 | { "findfactor", audioop_findfactor }, |
Guido van Rossum | b66efa0 | 1992-06-01 16:01:24 +0000 | [diff] [blame] | 1275 | { "cross", audioop_cross }, |
| 1276 | { "mul", audioop_mul }, |
| 1277 | { "add", audioop_add }, |
| 1278 | { "bias", audioop_bias }, |
| 1279 | { "ulaw2lin", audioop_ulaw2lin }, |
| 1280 | { "lin2ulaw", audioop_lin2ulaw }, |
Jack Jansen | a90805f | 1993-02-17 14:29:28 +0000 | [diff] [blame] | 1281 | { "lin2lin", audioop_lin2lin }, |
Guido van Rossum | 8e7a0f0 | 1992-06-23 15:23:57 +0000 | [diff] [blame] | 1282 | { "adpcm2lin", audioop_adpcm2lin }, |
| 1283 | { "lin2adpcm", audioop_lin2adpcm }, |
Guido van Rossum | b64e635 | 1992-07-06 14:21:56 +0000 | [diff] [blame] | 1284 | { "adpcm32lin", audioop_adpcm32lin }, |
| 1285 | { "lin2adpcm3", audioop_lin2adpcm3 }, |
Guido van Rossum | b66efa0 | 1992-06-01 16:01:24 +0000 | [diff] [blame] | 1286 | { "tomono", audioop_tomono }, |
| 1287 | { "tostereo", audioop_tostereo }, |
| 1288 | { "getsample", audioop_getsample }, |
| 1289 | { 0, 0 } |
| 1290 | }; |
| 1291 | |
| 1292 | |
| 1293 | void |
| 1294 | initaudioop() |
| 1295 | { |
| 1296 | object *m, *d; |
| 1297 | m = initmodule("audioop", audioop_methods); |
| 1298 | d = getmoduledict(m); |
| 1299 | AudioopError = newstringobject("audioop.error"); |
| 1300 | if ( AudioopError == NULL || dictinsert(d,"error",AudioopError) ) |
| 1301 | fatal("can't define audioop.error"); |
| 1302 | } |