Guido van Rossum | b66efa0 | 1992-06-01 16:01:24 +0000 | [diff] [blame] | 1 | /*********************************************************** |
Guido van Rossum | 524b588 | 1995-01-04 19:10:35 +0000 | [diff] [blame] | 2 | Copyright 1991-1995 by Stichting Mathematisch Centrum, Amsterdam, |
| 3 | The Netherlands. |
Guido van Rossum | b66efa0 | 1992-06-01 16:01:24 +0000 | [diff] [blame] | 4 | |
| 5 | All Rights Reserved |
| 6 | |
Guido van Rossum | d266eb4 | 1996-10-25 14:44:06 +0000 | [diff] [blame^] | 7 | Permission to use, copy, modify, and distribute this software and its |
| 8 | documentation for any purpose and without fee is hereby granted, |
Guido van Rossum | b66efa0 | 1992-06-01 16:01:24 +0000 | [diff] [blame] | 9 | provided that the above copyright notice appear in all copies and that |
Guido van Rossum | d266eb4 | 1996-10-25 14:44:06 +0000 | [diff] [blame^] | 10 | both that copyright notice and this permission notice appear in |
Guido van Rossum | b66efa0 | 1992-06-01 16:01:24 +0000 | [diff] [blame] | 11 | supporting documentation, and that the names of Stichting Mathematisch |
Guido van Rossum | d266eb4 | 1996-10-25 14:44:06 +0000 | [diff] [blame^] | 12 | Centrum or CWI or Corporation for National Research Initiatives or |
| 13 | CNRI not be used in advertising or publicity pertaining to |
| 14 | distribution of the software without specific, written prior |
| 15 | permission. |
Guido van Rossum | b66efa0 | 1992-06-01 16:01:24 +0000 | [diff] [blame] | 16 | |
Guido van Rossum | d266eb4 | 1996-10-25 14:44:06 +0000 | [diff] [blame^] | 17 | While CWI is the initial source for this software, a modified version |
| 18 | is made available by the Corporation for National Research Initiatives |
| 19 | (CNRI) at the Internet address ftp://ftp.python.org. |
| 20 | |
| 21 | STICHTING MATHEMATISCH CENTRUM AND CNRI DISCLAIM ALL WARRANTIES WITH |
| 22 | REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF |
| 23 | MERCHANTABILITY AND FITNESS, IN NO EVENT SHALL STICHTING MATHEMATISCH |
| 24 | CENTRUM OR CNRI BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL |
| 25 | DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR |
| 26 | PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER |
| 27 | TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR |
| 28 | PERFORMANCE OF THIS SOFTWARE. |
Guido van Rossum | b66efa0 | 1992-06-01 16:01:24 +0000 | [diff] [blame] | 29 | |
| 30 | ******************************************************************/ |
| 31 | |
Guido van Rossum | b6775db | 1994-08-01 11:34:53 +0000 | [diff] [blame] | 32 | /* audioopmodule - Module to detect peak values in arrays */ |
Jack Jansen | e1b4d7c | 1992-08-24 14:36:31 +0000 | [diff] [blame] | 33 | |
Guido van Rossum | b66efa0 | 1992-06-01 16:01:24 +0000 | [diff] [blame] | 34 | #include "allobjects.h" |
| 35 | #include "modsupport.h" |
| 36 | |
Guido van Rossum | 7b1e974 | 1994-08-29 10:46:42 +0000 | [diff] [blame] | 37 | #if defined(__CHAR_UNSIGNED__) |
| 38 | #if defined(signed) |
Guido van Rossum | b6775db | 1994-08-01 11:34:53 +0000 | [diff] [blame] | 39 | !ERROR!; READ THE SOURCE FILE!; |
| 40 | /* This module currently does not work on systems where only unsigned |
| 41 | characters are available. Take it out of Setup. Sorry. */ |
| 42 | #endif |
Guido van Rossum | 7b1e974 | 1994-08-29 10:46:42 +0000 | [diff] [blame] | 43 | #endif |
Guido van Rossum | b6775db | 1994-08-01 11:34:53 +0000 | [diff] [blame] | 44 | |
Guido van Rossum | a320fd3 | 1995-03-09 12:14:15 +0000 | [diff] [blame] | 45 | #include "mymath.h" |
Guido van Rossum | b6775db | 1994-08-01 11:34:53 +0000 | [diff] [blame] | 46 | |
Jack Jansen | a90805f | 1993-02-17 14:29:28 +0000 | [diff] [blame] | 47 | /* Code shamelessly stolen from sox, |
Guido van Rossum | b66efa0 | 1992-06-01 16:01:24 +0000 | [diff] [blame] | 48 | ** (c) Craig Reese, Joe Campbell and Jeff Poskanzer 1989 */ |
| 49 | |
| 50 | #define MINLIN -32768 |
| 51 | #define MAXLIN 32767 |
| 52 | #define LINCLIP(x) do { if ( x < MINLIN ) x = MINLIN ; else if ( x > MAXLIN ) x = MAXLIN; } while ( 0 ) |
| 53 | |
Guido van Rossum | cd938fc | 1995-01-17 16:13:48 +0000 | [diff] [blame] | 54 | static unsigned char st_linear_to_ulaw( /* int sample */ ); |
Guido van Rossum | b66efa0 | 1992-06-01 16:01:24 +0000 | [diff] [blame] | 55 | |
| 56 | /* |
| 57 | ** This macro converts from ulaw to 16 bit linear, faster. |
| 58 | ** |
| 59 | ** Jef Poskanzer |
| 60 | ** 23 October 1989 |
| 61 | ** |
| 62 | ** Input: 8 bit ulaw sample |
| 63 | ** Output: signed 16 bit linear sample |
| 64 | */ |
| 65 | #define st_ulaw_to_linear(ulawbyte) ulaw_table[ulawbyte] |
| 66 | |
| 67 | static int ulaw_table[256] = { |
| 68 | -32124, -31100, -30076, -29052, -28028, -27004, -25980, -24956, |
| 69 | -23932, -22908, -21884, -20860, -19836, -18812, -17788, -16764, |
| 70 | -15996, -15484, -14972, -14460, -13948, -13436, -12924, -12412, |
| 71 | -11900, -11388, -10876, -10364, -9852, -9340, -8828, -8316, |
| 72 | -7932, -7676, -7420, -7164, -6908, -6652, -6396, -6140, |
| 73 | -5884, -5628, -5372, -5116, -4860, -4604, -4348, -4092, |
| 74 | -3900, -3772, -3644, -3516, -3388, -3260, -3132, -3004, |
| 75 | -2876, -2748, -2620, -2492, -2364, -2236, -2108, -1980, |
| 76 | -1884, -1820, -1756, -1692, -1628, -1564, -1500, -1436, |
| 77 | -1372, -1308, -1244, -1180, -1116, -1052, -988, -924, |
| 78 | -876, -844, -812, -780, -748, -716, -684, -652, |
| 79 | -620, -588, -556, -524, -492, -460, -428, -396, |
| 80 | -372, -356, -340, -324, -308, -292, -276, -260, |
| 81 | -244, -228, -212, -196, -180, -164, -148, -132, |
| 82 | -120, -112, -104, -96, -88, -80, -72, -64, |
| 83 | -56, -48, -40, -32, -24, -16, -8, 0, |
| 84 | 32124, 31100, 30076, 29052, 28028, 27004, 25980, 24956, |
| 85 | 23932, 22908, 21884, 20860, 19836, 18812, 17788, 16764, |
| 86 | 15996, 15484, 14972, 14460, 13948, 13436, 12924, 12412, |
| 87 | 11900, 11388, 10876, 10364, 9852, 9340, 8828, 8316, |
| 88 | 7932, 7676, 7420, 7164, 6908, 6652, 6396, 6140, |
| 89 | 5884, 5628, 5372, 5116, 4860, 4604, 4348, 4092, |
| 90 | 3900, 3772, 3644, 3516, 3388, 3260, 3132, 3004, |
| 91 | 2876, 2748, 2620, 2492, 2364, 2236, 2108, 1980, |
| 92 | 1884, 1820, 1756, 1692, 1628, 1564, 1500, 1436, |
| 93 | 1372, 1308, 1244, 1180, 1116, 1052, 988, 924, |
| 94 | 876, 844, 812, 780, 748, 716, 684, 652, |
| 95 | 620, 588, 556, 524, 492, 460, 428, 396, |
| 96 | 372, 356, 340, 324, 308, 292, 276, 260, |
| 97 | 244, 228, 212, 196, 180, 164, 148, 132, |
| 98 | 120, 112, 104, 96, 88, 80, 72, 64, |
| 99 | 56, 48, 40, 32, 24, 16, 8, 0 }; |
| 100 | |
| 101 | #define ZEROTRAP /* turn on the trap as per the MIL-STD */ |
| 102 | #define BIAS 0x84 /* define the add-in bias for 16 bit samples */ |
| 103 | #define CLIP 32635 |
| 104 | |
Guido van Rossum | cd938fc | 1995-01-17 16:13:48 +0000 | [diff] [blame] | 105 | static unsigned char |
Guido van Rossum | b66efa0 | 1992-06-01 16:01:24 +0000 | [diff] [blame] | 106 | st_linear_to_ulaw( sample ) |
| 107 | int sample; |
| 108 | { |
| 109 | static int exp_lut[256] = {0,0,1,1,2,2,2,2,3,3,3,3,3,3,3,3, |
| 110 | 4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4, |
| 111 | 5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5, |
| 112 | 5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5, |
| 113 | 6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6, |
| 114 | 6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6, |
| 115 | 6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6, |
| 116 | 6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6, |
| 117 | 7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7, |
| 118 | 7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7, |
| 119 | 7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7, |
| 120 | 7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7, |
| 121 | 7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7, |
| 122 | 7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7, |
| 123 | 7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7, |
| 124 | 7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7}; |
| 125 | int sign, exponent, mantissa; |
| 126 | unsigned char ulawbyte; |
| 127 | |
| 128 | /* Get the sample into sign-magnitude. */ |
| 129 | sign = (sample >> 8) & 0x80; /* set aside the sign */ |
| 130 | if ( sign != 0 ) sample = -sample; /* get magnitude */ |
| 131 | if ( sample > CLIP ) sample = CLIP; /* clip the magnitude */ |
| 132 | |
| 133 | /* Convert from 16 bit linear to ulaw. */ |
| 134 | sample = sample + BIAS; |
| 135 | exponent = exp_lut[( sample >> 7 ) & 0xFF]; |
| 136 | mantissa = ( sample >> ( exponent + 3 ) ) & 0x0F; |
| 137 | ulawbyte = ~ ( sign | ( exponent << 4 ) | mantissa ); |
| 138 | #ifdef ZEROTRAP |
| 139 | if ( ulawbyte == 0 ) ulawbyte = 0x02; /* optional CCITT trap */ |
| 140 | #endif |
| 141 | |
| 142 | return ulawbyte; |
| 143 | } |
| 144 | /* End of code taken from sox */ |
| 145 | |
Guido van Rossum | b64e635 | 1992-07-06 14:21:56 +0000 | [diff] [blame] | 146 | /* Intel ADPCM step variation table */ |
| 147 | static int indexTable[16] = { |
| 148 | -1, -1, -1, -1, 2, 4, 6, 8, |
| 149 | -1, -1, -1, -1, 2, 4, 6, 8, |
| 150 | }; |
| 151 | |
| 152 | static int stepsizeTable[89] = { |
| 153 | 7, 8, 9, 10, 11, 12, 13, 14, 16, 17, |
| 154 | 19, 21, 23, 25, 28, 31, 34, 37, 41, 45, |
| 155 | 50, 55, 60, 66, 73, 80, 88, 97, 107, 118, |
| 156 | 130, 143, 157, 173, 190, 209, 230, 253, 279, 307, |
| 157 | 337, 371, 408, 449, 494, 544, 598, 658, 724, 796, |
| 158 | 876, 963, 1060, 1166, 1282, 1411, 1552, 1707, 1878, 2066, |
| 159 | 2272, 2499, 2749, 3024, 3327, 3660, 4026, 4428, 4871, 5358, |
| 160 | 5894, 6484, 7132, 7845, 8630, 9493, 10442, 11487, 12635, 13899, |
| 161 | 15289, 16818, 18500, 20350, 22385, 24623, 27086, 29794, 32767 |
| 162 | }; |
| 163 | |
Guido van Rossum | b66efa0 | 1992-06-01 16:01:24 +0000 | [diff] [blame] | 164 | #define CHARP(cp, i) ((signed char *)(cp+i)) |
| 165 | #define SHORTP(cp, i) ((short *)(cp+i)) |
| 166 | #define LONGP(cp, i) ((long *)(cp+i)) |
| 167 | |
| 168 | |
| 169 | |
| 170 | static object *AudioopError; |
| 171 | |
| 172 | static object * |
| 173 | audioop_getsample(self, args) |
| 174 | object *self; |
| 175 | object *args; |
| 176 | { |
| 177 | signed char *cp; |
| 178 | int len, size, val; |
| 179 | int i; |
| 180 | |
| 181 | if ( !getargs(args, "(s#ii)", &cp, &len, &size, &i) ) |
| 182 | return 0; |
| 183 | if ( size != 1 && size != 2 && size != 4 ) { |
| 184 | err_setstr(AudioopError, "Size should be 1, 2 or 4"); |
| 185 | return 0; |
| 186 | } |
| 187 | if ( i < 0 || i >= len/size ) { |
| 188 | err_setstr(AudioopError, "Index out of range"); |
| 189 | return 0; |
| 190 | } |
| 191 | if ( size == 1 ) val = (int)*CHARP(cp, i); |
| 192 | else if ( size == 2 ) val = (int)*SHORTP(cp, i*2); |
| 193 | else if ( size == 4 ) val = (int)*LONGP(cp, i*4); |
| 194 | return newintobject(val); |
| 195 | } |
| 196 | |
| 197 | static object * |
| 198 | audioop_max(self, args) |
| 199 | object *self; |
| 200 | object *args; |
| 201 | { |
| 202 | signed char *cp; |
| 203 | int len, size, val; |
| 204 | int i; |
| 205 | int max = 0; |
| 206 | |
| 207 | if ( !getargs(args, "(s#i)", &cp, &len, &size) ) |
| 208 | return 0; |
| 209 | if ( size != 1 && size != 2 && size != 4 ) { |
| 210 | err_setstr(AudioopError, "Size should be 1, 2 or 4"); |
| 211 | return 0; |
| 212 | } |
| 213 | for ( i=0; i<len; i+= size) { |
| 214 | if ( size == 1 ) val = (int)*CHARP(cp, i); |
| 215 | else if ( size == 2 ) val = (int)*SHORTP(cp, i); |
| 216 | else if ( size == 4 ) val = (int)*LONGP(cp, i); |
| 217 | if ( val < 0 ) val = (-val); |
| 218 | if ( val > max ) max = val; |
| 219 | } |
| 220 | return newintobject(max); |
| 221 | } |
| 222 | |
| 223 | static object * |
Sjoerd Mullender | a142613 | 1994-09-06 16:19:33 +0000 | [diff] [blame] | 224 | audioop_minmax(self, args) |
| 225 | object *self; |
| 226 | object *args; |
| 227 | { |
| 228 | signed char *cp; |
| 229 | int len, size, val; |
| 230 | int i; |
| 231 | int min = 0x7fffffff, max = -0x7fffffff; |
| 232 | |
| 233 | if (!getargs(args, "(s#i)", &cp, &len, &size)) |
| 234 | return NULL; |
| 235 | if (size != 1 && size != 2 && size != 4) { |
| 236 | err_setstr(AudioopError, "Size should be 1, 2 or 4"); |
| 237 | return NULL; |
| 238 | } |
| 239 | for (i = 0; i < len; i += size) { |
| 240 | if (size == 1) val = (int) *CHARP(cp, i); |
| 241 | else if (size == 2) val = (int) *SHORTP(cp, i); |
| 242 | else if (size == 4) val = (int) *LONGP(cp, i); |
| 243 | if (val > max) max = val; |
| 244 | if (val < min) min = val; |
| 245 | } |
| 246 | return mkvalue("(ii)", min, max); |
| 247 | } |
| 248 | |
| 249 | static object * |
Guido van Rossum | b66efa0 | 1992-06-01 16:01:24 +0000 | [diff] [blame] | 250 | audioop_avg(self, args) |
| 251 | object *self; |
| 252 | object *args; |
| 253 | { |
| 254 | signed char *cp; |
| 255 | int len, size, val; |
| 256 | int i; |
| 257 | float avg = 0.0; |
| 258 | |
| 259 | if ( !getargs(args, "(s#i)", &cp, &len, &size) ) |
| 260 | return 0; |
| 261 | if ( size != 1 && size != 2 && size != 4 ) { |
| 262 | err_setstr(AudioopError, "Size should be 1, 2 or 4"); |
| 263 | return 0; |
| 264 | } |
| 265 | for ( i=0; i<len; i+= size) { |
| 266 | if ( size == 1 ) val = (int)*CHARP(cp, i); |
| 267 | else if ( size == 2 ) val = (int)*SHORTP(cp, i); |
| 268 | else if ( size == 4 ) val = (int)*LONGP(cp, i); |
| 269 | avg += val; |
| 270 | } |
| 271 | if ( len == 0 ) |
| 272 | val = 0; |
| 273 | else |
| 274 | val = (int)(avg / (float)(len/size)); |
| 275 | return newintobject(val); |
| 276 | } |
| 277 | |
| 278 | static object * |
Jack Jansen | e1b4d7c | 1992-08-24 14:36:31 +0000 | [diff] [blame] | 279 | audioop_rms(self, args) |
| 280 | object *self; |
| 281 | object *args; |
| 282 | { |
| 283 | signed char *cp; |
| 284 | int len, size, val; |
| 285 | int i; |
| 286 | float sum_squares = 0.0; |
| 287 | |
| 288 | if ( !getargs(args, "(s#i)", &cp, &len, &size) ) |
| 289 | return 0; |
| 290 | if ( size != 1 && size != 2 && size != 4 ) { |
| 291 | err_setstr(AudioopError, "Size should be 1, 2 or 4"); |
| 292 | return 0; |
| 293 | } |
| 294 | for ( i=0; i<len; i+= size) { |
| 295 | if ( size == 1 ) val = (int)*CHARP(cp, i); |
| 296 | else if ( size == 2 ) val = (int)*SHORTP(cp, i); |
| 297 | else if ( size == 4 ) val = (int)*LONGP(cp, i); |
| 298 | sum_squares += (float)val*(float)val; |
| 299 | } |
| 300 | if ( len == 0 ) |
| 301 | val = 0; |
| 302 | else |
| 303 | val = (int)sqrt(sum_squares / (float)(len/size)); |
| 304 | return newintobject(val); |
| 305 | } |
| 306 | |
Guido van Rossum | cd938fc | 1995-01-17 16:13:48 +0000 | [diff] [blame] | 307 | static double _sum2(a, b, len) |
Jack Jansen | a90805f | 1993-02-17 14:29:28 +0000 | [diff] [blame] | 308 | short *a; |
| 309 | short *b; |
| 310 | int len; |
| 311 | { |
| 312 | int i; |
| 313 | double sum = 0.0; |
| 314 | |
| 315 | for( i=0; i<len; i++) { |
| 316 | sum = sum + (double)a[i]*(double)b[i]; |
| 317 | } |
| 318 | return sum; |
| 319 | } |
| 320 | |
| 321 | /* |
| 322 | ** Findfit tries to locate a sample within another sample. Its main use |
| 323 | ** is in echo-cancellation (to find the feedback of the output signal in |
| 324 | ** the input signal). |
| 325 | ** The method used is as follows: |
| 326 | ** |
| 327 | ** let R be the reference signal (length n) and A the input signal (length N) |
| 328 | ** with N > n, and let all sums be over i from 0 to n-1. |
| 329 | ** |
| 330 | ** Now, for each j in {0..N-n} we compute a factor fj so that -fj*R matches A |
| 331 | ** as good as possible, i.e. sum( (A[j+i]+fj*R[i])^2 ) is minimal. This |
| 332 | ** equation gives fj = sum( A[j+i]R[i] ) / sum(R[i]^2). |
| 333 | ** |
| 334 | ** Next, we compute the relative distance between the original signal and |
| 335 | ** the modified signal and minimize that over j: |
| 336 | ** vj = sum( (A[j+i]-fj*R[i])^2 ) / sum( A[j+i]^2 ) => |
| 337 | ** vj = ( sum(A[j+i]^2)*sum(R[i]^2) - sum(A[j+i]R[i])^2 ) / sum( A[j+i]^2 ) |
| 338 | ** |
| 339 | ** In the code variables correspond as follows: |
| 340 | ** cp1 A |
| 341 | ** cp2 R |
| 342 | ** len1 N |
| 343 | ** len2 n |
| 344 | ** aj_m1 A[j-1] |
| 345 | ** aj_lm1 A[j+n-1] |
| 346 | ** sum_ri_2 sum(R[i]^2) |
| 347 | ** sum_aij_2 sum(A[i+j]^2) |
| 348 | ** sum_aij_ri sum(A[i+j]R[i]) |
| 349 | ** |
| 350 | ** sum_ri is calculated once, sum_aij_2 is updated each step and sum_aij_ri |
| 351 | ** is completely recalculated each step. |
| 352 | */ |
Jack Jansen | e1b4d7c | 1992-08-24 14:36:31 +0000 | [diff] [blame] | 353 | static object * |
Jack Jansen | a90805f | 1993-02-17 14:29:28 +0000 | [diff] [blame] | 354 | audioop_findfit(self, args) |
Jack Jansen | dd8a6ea | 1993-02-17 14:21:09 +0000 | [diff] [blame] | 355 | object *self; |
| 356 | object *args; |
| 357 | { |
Jack Jansen | a90805f | 1993-02-17 14:29:28 +0000 | [diff] [blame] | 358 | short *cp1, *cp2; |
| 359 | int len1, len2; |
| 360 | int j, best_j; |
| 361 | double aj_m1, aj_lm1; |
| 362 | 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] | 363 | |
Jack Jansen | a90805f | 1993-02-17 14:29:28 +0000 | [diff] [blame] | 364 | if ( !getargs(args, "(s#s#)", &cp1, &len1, &cp2, &len2) ) |
Jack Jansen | dd8a6ea | 1993-02-17 14:21:09 +0000 | [diff] [blame] | 365 | return 0; |
Jack Jansen | a90805f | 1993-02-17 14:29:28 +0000 | [diff] [blame] | 366 | if ( len1 & 1 || len2 & 1 ) { |
| 367 | err_setstr(AudioopError, "Strings should be even-sized"); |
| 368 | return 0; |
| 369 | } |
| 370 | len1 >>= 1; |
| 371 | len2 >>= 1; |
| 372 | |
| 373 | if ( len1 < len2 ) { |
| 374 | err_setstr(AudioopError, "First sample should be longer"); |
| 375 | return 0; |
| 376 | } |
| 377 | sum_ri_2 = _sum2(cp2, cp2, len2); |
| 378 | sum_aij_2 = _sum2(cp1, cp1, len2); |
| 379 | sum_aij_ri = _sum2(cp1, cp2, len2); |
| 380 | |
| 381 | result = (sum_ri_2*sum_aij_2 - sum_aij_ri*sum_aij_ri) / sum_aij_2; |
| 382 | |
| 383 | best_result = result; |
| 384 | best_j = 0; |
| 385 | j = 0; |
| 386 | |
| 387 | for ( j=1; j<=len1-len2; j++) { |
| 388 | aj_m1 = (double)cp1[j-1]; |
| 389 | aj_lm1 = (double)cp1[j+len2-1]; |
| 390 | |
| 391 | sum_aij_2 = sum_aij_2 + aj_lm1*aj_lm1 - aj_m1*aj_m1; |
| 392 | sum_aij_ri = _sum2(cp1+j, cp2, len2); |
| 393 | |
| 394 | result = (sum_ri_2*sum_aij_2 - sum_aij_ri*sum_aij_ri) / sum_aij_2; |
| 395 | |
| 396 | if ( result < best_result ) { |
| 397 | best_result = result; |
| 398 | best_j = j; |
| 399 | } |
| 400 | |
| 401 | } |
| 402 | |
| 403 | factor = _sum2(cp1+best_j, cp2, len2) / sum_ri_2; |
| 404 | |
| 405 | return mkvalue("(if)", best_j, factor); |
| 406 | } |
| 407 | |
| 408 | /* |
| 409 | ** findfactor finds a factor f so that the energy in A-fB is minimal. |
| 410 | ** See the comment for findfit for details. |
| 411 | */ |
| 412 | static object * |
| 413 | audioop_findfactor(self, args) |
| 414 | object *self; |
| 415 | object *args; |
| 416 | { |
| 417 | short *cp1, *cp2; |
| 418 | int len1, len2; |
| 419 | double sum_ri_2, sum_aij_ri, result; |
| 420 | |
| 421 | if ( !getargs(args, "(s#s#)", &cp1, &len1, &cp2, &len2) ) |
| 422 | return 0; |
| 423 | if ( len1 & 1 || len2 & 1 ) { |
| 424 | err_setstr(AudioopError, "Strings should be even-sized"); |
Jack Jansen | dd8a6ea | 1993-02-17 14:21:09 +0000 | [diff] [blame] | 425 | return 0; |
| 426 | } |
| 427 | if ( len1 != len2 ) { |
| 428 | err_setstr(AudioopError, "Samples should be same size"); |
| 429 | return 0; |
| 430 | } |
Jack Jansen | a90805f | 1993-02-17 14:29:28 +0000 | [diff] [blame] | 431 | len2 >>= 1; |
| 432 | sum_ri_2 = _sum2(cp2, cp2, len2); |
| 433 | sum_aij_ri = _sum2(cp1, cp2, len2); |
| 434 | |
| 435 | result = sum_aij_ri / sum_ri_2; |
| 436 | |
| 437 | return newfloatobject(result); |
| 438 | } |
| 439 | |
| 440 | /* |
| 441 | ** findmax returns the index of the n-sized segment of the input sample |
| 442 | ** that contains the most energy. |
| 443 | */ |
| 444 | static object * |
| 445 | audioop_findmax(self, args) |
| 446 | object *self; |
| 447 | object *args; |
| 448 | { |
| 449 | short *cp1; |
| 450 | int len1, len2; |
| 451 | int j, best_j; |
| 452 | double aj_m1, aj_lm1; |
| 453 | double result, best_result; |
| 454 | |
| 455 | if ( !getargs(args, "(s#i)", &cp1, &len1, &len2) ) |
| 456 | return 0; |
| 457 | if ( len1 & 1 ) { |
| 458 | err_setstr(AudioopError, "Strings should be even-sized"); |
| 459 | return 0; |
Jack Jansen | dd8a6ea | 1993-02-17 14:21:09 +0000 | [diff] [blame] | 460 | } |
Jack Jansen | a90805f | 1993-02-17 14:29:28 +0000 | [diff] [blame] | 461 | len1 >>= 1; |
| 462 | |
| 463 | if ( len1 < len2 ) { |
| 464 | err_setstr(AudioopError, "Input sample should be longer"); |
| 465 | return 0; |
| 466 | } |
| 467 | |
| 468 | result = _sum2(cp1, cp1, len2); |
| 469 | |
| 470 | best_result = result; |
| 471 | best_j = 0; |
| 472 | j = 0; |
| 473 | |
| 474 | for ( j=1; j<=len1-len2; j++) { |
| 475 | aj_m1 = (double)cp1[j-1]; |
| 476 | aj_lm1 = (double)cp1[j+len2-1]; |
| 477 | |
| 478 | result = result + aj_lm1*aj_lm1 - aj_m1*aj_m1; |
| 479 | |
| 480 | if ( result > best_result ) { |
| 481 | best_result = result; |
| 482 | best_j = j; |
| 483 | } |
| 484 | |
| 485 | } |
| 486 | |
| 487 | return newintobject(best_j); |
Jack Jansen | dd8a6ea | 1993-02-17 14:21:09 +0000 | [diff] [blame] | 488 | } |
| 489 | |
| 490 | static object * |
Jack Jansen | e1b4d7c | 1992-08-24 14:36:31 +0000 | [diff] [blame] | 491 | audioop_avgpp(self, args) |
| 492 | object *self; |
| 493 | object *args; |
| 494 | { |
| 495 | signed char *cp; |
| 496 | int len, size, val, prevval, prevextremevalid = 0, prevextreme; |
| 497 | int i; |
| 498 | float avg = 0.0; |
| 499 | int diff, prevdiff, extremediff, nextreme = 0; |
| 500 | |
| 501 | if ( !getargs(args, "(s#i)", &cp, &len, &size) ) |
| 502 | return 0; |
| 503 | if ( size != 1 && size != 2 && size != 4 ) { |
| 504 | err_setstr(AudioopError, "Size should be 1, 2 or 4"); |
| 505 | return 0; |
| 506 | } |
| 507 | /* Compute first delta value ahead. Also automatically makes us |
| 508 | ** skip the first extreme value |
| 509 | */ |
| 510 | if ( size == 1 ) prevval = (int)*CHARP(cp, 0); |
| 511 | else if ( size == 2 ) prevval = (int)*SHORTP(cp, 0); |
| 512 | else if ( size == 4 ) prevval = (int)*LONGP(cp, 0); |
| 513 | if ( size == 1 ) val = (int)*CHARP(cp, size); |
| 514 | else if ( size == 2 ) val = (int)*SHORTP(cp, size); |
| 515 | else if ( size == 4 ) val = (int)*LONGP(cp, size); |
| 516 | prevdiff = val - prevval; |
| 517 | |
| 518 | for ( i=size; i<len; i+= size) { |
| 519 | if ( size == 1 ) val = (int)*CHARP(cp, i); |
| 520 | else if ( size == 2 ) val = (int)*SHORTP(cp, i); |
| 521 | else if ( size == 4 ) val = (int)*LONGP(cp, i); |
| 522 | diff = val - prevval; |
| 523 | if ( diff*prevdiff < 0 ) { |
| 524 | /* Derivative changed sign. Compute difference to last extreme |
| 525 | ** value and remember. |
| 526 | */ |
| 527 | if ( prevextremevalid ) { |
| 528 | extremediff = prevval - prevextreme; |
| 529 | if ( extremediff < 0 ) |
| 530 | extremediff = -extremediff; |
| 531 | avg += extremediff; |
| 532 | nextreme++; |
| 533 | } |
| 534 | prevextremevalid = 1; |
| 535 | prevextreme = prevval; |
| 536 | } |
| 537 | prevval = val; |
| 538 | if ( diff != 0 ) |
| 539 | prevdiff = diff; |
| 540 | } |
| 541 | if ( nextreme == 0 ) |
| 542 | val = 0; |
| 543 | else |
| 544 | val = (int)(avg / (float)nextreme); |
| 545 | return newintobject(val); |
| 546 | } |
| 547 | |
| 548 | static object * |
| 549 | audioop_maxpp(self, args) |
| 550 | object *self; |
| 551 | object *args; |
| 552 | { |
| 553 | signed char *cp; |
| 554 | int len, size, val, prevval, prevextremevalid = 0, prevextreme; |
| 555 | int i; |
| 556 | int max = 0; |
| 557 | int diff, prevdiff, extremediff; |
| 558 | |
| 559 | if ( !getargs(args, "(s#i)", &cp, &len, &size) ) |
| 560 | return 0; |
| 561 | if ( size != 1 && size != 2 && size != 4 ) { |
| 562 | err_setstr(AudioopError, "Size should be 1, 2 or 4"); |
| 563 | return 0; |
| 564 | } |
| 565 | /* Compute first delta value ahead. Also automatically makes us |
| 566 | ** skip the first extreme value |
| 567 | */ |
| 568 | if ( size == 1 ) prevval = (int)*CHARP(cp, 0); |
| 569 | else if ( size == 2 ) prevval = (int)*SHORTP(cp, 0); |
| 570 | else if ( size == 4 ) prevval = (int)*LONGP(cp, 0); |
| 571 | if ( size == 1 ) val = (int)*CHARP(cp, size); |
| 572 | else if ( size == 2 ) val = (int)*SHORTP(cp, size); |
| 573 | else if ( size == 4 ) val = (int)*LONGP(cp, size); |
| 574 | prevdiff = val - prevval; |
| 575 | |
| 576 | for ( i=size; i<len; i+= size) { |
| 577 | if ( size == 1 ) val = (int)*CHARP(cp, i); |
| 578 | else if ( size == 2 ) val = (int)*SHORTP(cp, i); |
| 579 | else if ( size == 4 ) val = (int)*LONGP(cp, i); |
| 580 | diff = val - prevval; |
| 581 | if ( diff*prevdiff < 0 ) { |
| 582 | /* Derivative changed sign. Compute difference to last extreme |
| 583 | ** value and remember. |
| 584 | */ |
| 585 | if ( prevextremevalid ) { |
| 586 | extremediff = prevval - prevextreme; |
| 587 | if ( extremediff < 0 ) |
| 588 | extremediff = -extremediff; |
| 589 | if ( extremediff > max ) |
| 590 | max = extremediff; |
| 591 | } |
| 592 | prevextremevalid = 1; |
| 593 | prevextreme = prevval; |
| 594 | } |
| 595 | prevval = val; |
| 596 | if ( diff != 0 ) |
| 597 | prevdiff = diff; |
| 598 | } |
| 599 | return newintobject(max); |
| 600 | } |
| 601 | |
| 602 | static object * |
Guido van Rossum | b66efa0 | 1992-06-01 16:01:24 +0000 | [diff] [blame] | 603 | audioop_cross(self, args) |
| 604 | object *self; |
| 605 | object *args; |
| 606 | { |
| 607 | signed char *cp; |
| 608 | int len, size, val; |
| 609 | int i; |
Guido van Rossum | 3bbc62e | 1995-01-02 19:30:30 +0000 | [diff] [blame] | 610 | int prevval, ncross; |
Guido van Rossum | b66efa0 | 1992-06-01 16:01:24 +0000 | [diff] [blame] | 611 | |
| 612 | if ( !getargs(args, "(s#i)", &cp, &len, &size) ) |
| 613 | return 0; |
| 614 | if ( size != 1 && size != 2 && size != 4 ) { |
| 615 | err_setstr(AudioopError, "Size should be 1, 2 or 4"); |
| 616 | return 0; |
| 617 | } |
| 618 | ncross = -1; |
| 619 | prevval = 17; /* Anything <> 0,1 */ |
| 620 | for ( i=0; i<len; i+= size) { |
| 621 | if ( size == 1 ) val = ((int)*CHARP(cp, i)) >> 7; |
| 622 | else if ( size == 2 ) val = ((int)*SHORTP(cp, i)) >> 15; |
| 623 | else if ( size == 4 ) val = ((int)*LONGP(cp, i)) >> 31; |
| 624 | val = val & 1; |
| 625 | if ( val != prevval ) ncross++; |
| 626 | prevval = val; |
| 627 | } |
| 628 | return newintobject(ncross); |
| 629 | } |
| 630 | |
| 631 | static object * |
| 632 | audioop_mul(self, args) |
| 633 | object *self; |
| 634 | object *args; |
| 635 | { |
| 636 | signed char *cp, *ncp; |
| 637 | int len, size, val; |
| 638 | double factor, fval, maxval; |
| 639 | object *rv; |
| 640 | int i; |
| 641 | |
| 642 | if ( !getargs(args, "(s#id)", &cp, &len, &size, &factor ) ) |
| 643 | return 0; |
| 644 | |
| 645 | if ( size == 1 ) maxval = (double) 0x7f; |
| 646 | else if ( size == 2 ) maxval = (double) 0x7fff; |
| 647 | else if ( size == 4 ) maxval = (double) 0x7fffffff; |
| 648 | else { |
| 649 | err_setstr(AudioopError, "Size should be 1, 2 or 4"); |
| 650 | return 0; |
| 651 | } |
| 652 | |
| 653 | rv = newsizedstringobject(NULL, len); |
| 654 | if ( rv == 0 ) |
| 655 | return 0; |
| 656 | ncp = (signed char *)getstringvalue(rv); |
| 657 | |
| 658 | |
| 659 | for ( i=0; i < len; i += size ) { |
| 660 | if ( size == 1 ) val = (int)*CHARP(cp, i); |
| 661 | else if ( size == 2 ) val = (int)*SHORTP(cp, i); |
| 662 | else if ( size == 4 ) val = (int)*LONGP(cp, i); |
| 663 | fval = (double)val*factor; |
| 664 | if ( fval > maxval ) fval = maxval; |
| 665 | else if ( fval < -maxval ) fval = -maxval; |
| 666 | val = (int)fval; |
| 667 | if ( size == 1 ) *CHARP(ncp, i) = (signed char)val; |
| 668 | else if ( size == 2 ) *SHORTP(ncp, i) = (short)val; |
| 669 | else if ( size == 4 ) *LONGP(ncp, i) = (long)val; |
| 670 | } |
| 671 | return rv; |
| 672 | } |
| 673 | |
| 674 | static object * |
| 675 | audioop_tomono(self, args) |
| 676 | object *self; |
| 677 | object *args; |
| 678 | { |
| 679 | signed char *cp, *ncp; |
| 680 | int len, size, val1, val2; |
| 681 | double fac1, fac2, fval, maxval; |
| 682 | object *rv; |
| 683 | int i; |
| 684 | |
| 685 | if ( !getargs(args, "(s#idd)", &cp, &len, &size, &fac1, &fac2 ) ) |
| 686 | return 0; |
| 687 | |
| 688 | if ( size == 1 ) maxval = (double) 0x7f; |
| 689 | else if ( size == 2 ) maxval = (double) 0x7fff; |
| 690 | else if ( size == 4 ) maxval = (double) 0x7fffffff; |
| 691 | else { |
| 692 | err_setstr(AudioopError, "Size should be 1, 2 or 4"); |
| 693 | return 0; |
| 694 | } |
| 695 | |
| 696 | rv = newsizedstringobject(NULL, len/2); |
| 697 | if ( rv == 0 ) |
| 698 | return 0; |
| 699 | ncp = (signed char *)getstringvalue(rv); |
| 700 | |
| 701 | |
| 702 | for ( i=0; i < len; i += size*2 ) { |
| 703 | if ( size == 1 ) val1 = (int)*CHARP(cp, i); |
| 704 | else if ( size == 2 ) val1 = (int)*SHORTP(cp, i); |
| 705 | else if ( size == 4 ) val1 = (int)*LONGP(cp, i); |
| 706 | if ( size == 1 ) val2 = (int)*CHARP(cp, i+1); |
| 707 | else if ( size == 2 ) val2 = (int)*SHORTP(cp, i+2); |
| 708 | else if ( size == 4 ) val2 = (int)*LONGP(cp, i+4); |
| 709 | fval = (double)val1*fac1 + (double)val2*fac2; |
| 710 | if ( fval > maxval ) fval = maxval; |
| 711 | else if ( fval < -maxval ) fval = -maxval; |
| 712 | val1 = (int)fval; |
| 713 | if ( size == 1 ) *CHARP(ncp, i/2) = (signed char)val1; |
| 714 | else if ( size == 2 ) *SHORTP(ncp, i/2) = (short)val1; |
| 715 | else if ( size == 4 ) *LONGP(ncp, i/2)= (long)val1; |
| 716 | } |
| 717 | return rv; |
| 718 | } |
| 719 | |
| 720 | static object * |
| 721 | audioop_tostereo(self, args) |
| 722 | object *self; |
| 723 | object *args; |
| 724 | { |
| 725 | signed char *cp, *ncp; |
| 726 | int len, size, val1, val2, val; |
| 727 | double fac1, fac2, fval, maxval; |
| 728 | object *rv; |
| 729 | int i; |
| 730 | |
| 731 | if ( !getargs(args, "(s#idd)", &cp, &len, &size, &fac1, &fac2 ) ) |
| 732 | return 0; |
| 733 | |
| 734 | if ( size == 1 ) maxval = (double) 0x7f; |
| 735 | else if ( size == 2 ) maxval = (double) 0x7fff; |
| 736 | else if ( size == 4 ) maxval = (double) 0x7fffffff; |
| 737 | else { |
| 738 | err_setstr(AudioopError, "Size should be 1, 2 or 4"); |
| 739 | return 0; |
| 740 | } |
| 741 | |
| 742 | rv = newsizedstringobject(NULL, len*2); |
| 743 | if ( rv == 0 ) |
| 744 | return 0; |
| 745 | ncp = (signed char *)getstringvalue(rv); |
| 746 | |
| 747 | |
| 748 | for ( i=0; i < len; i += size ) { |
| 749 | if ( size == 1 ) val = (int)*CHARP(cp, i); |
| 750 | else if ( size == 2 ) val = (int)*SHORTP(cp, i); |
| 751 | else if ( size == 4 ) val = (int)*LONGP(cp, i); |
| 752 | |
| 753 | fval = (double)val*fac1; |
| 754 | if ( fval > maxval ) fval = maxval; |
| 755 | else if ( fval < -maxval ) fval = -maxval; |
| 756 | val1 = (int)fval; |
| 757 | |
| 758 | fval = (double)val*fac2; |
| 759 | if ( fval > maxval ) fval = maxval; |
| 760 | else if ( fval < -maxval ) fval = -maxval; |
| 761 | val2 = (int)fval; |
| 762 | |
| 763 | if ( size == 1 ) *CHARP(ncp, i*2) = (signed char)val1; |
| 764 | else if ( size == 2 ) *SHORTP(ncp, i*2) = (short)val1; |
| 765 | else if ( size == 4 ) *LONGP(ncp, i*2) = (long)val1; |
| 766 | |
| 767 | if ( size == 1 ) *CHARP(ncp, i*2+1) = (signed char)val2; |
| 768 | else if ( size == 2 ) *SHORTP(ncp, i*2+2) = (short)val2; |
| 769 | else if ( size == 4 ) *LONGP(ncp, i*2+4) = (long)val2; |
| 770 | } |
| 771 | return rv; |
| 772 | } |
| 773 | |
| 774 | static object * |
| 775 | audioop_add(self, args) |
| 776 | object *self; |
| 777 | object *args; |
| 778 | { |
| 779 | signed char *cp1, *cp2, *ncp; |
| 780 | int len1, len2, size, val1, val2; |
| 781 | object *rv; |
| 782 | int i; |
| 783 | |
| 784 | if ( !getargs(args, "(s#s#i)", |
| 785 | &cp1, &len1, &cp2, &len2, &size ) ) |
| 786 | return 0; |
| 787 | |
| 788 | if ( len1 != len2 ) { |
| 789 | err_setstr(AudioopError, "Lengths should be the same"); |
| 790 | return 0; |
| 791 | } |
| 792 | |
| 793 | if ( size != 1 && size != 2 && size != 4) { |
| 794 | err_setstr(AudioopError, "Size should be 1, 2 or 4"); |
| 795 | return 0; |
| 796 | } |
| 797 | |
| 798 | rv = newsizedstringobject(NULL, len1); |
| 799 | if ( rv == 0 ) |
| 800 | return 0; |
| 801 | ncp = (signed char *)getstringvalue(rv); |
| 802 | |
| 803 | |
| 804 | for ( i=0; i < len1; i += size ) { |
| 805 | if ( size == 1 ) val1 = (int)*CHARP(cp1, i); |
| 806 | else if ( size == 2 ) val1 = (int)*SHORTP(cp1, i); |
| 807 | else if ( size == 4 ) val1 = (int)*LONGP(cp1, i); |
| 808 | |
| 809 | if ( size == 1 ) val2 = (int)*CHARP(cp2, i); |
| 810 | else if ( size == 2 ) val2 = (int)*SHORTP(cp2, i); |
| 811 | else if ( size == 4 ) val2 = (int)*LONGP(cp2, i); |
| 812 | |
| 813 | if ( size == 1 ) *CHARP(ncp, i) = (signed char)(val1+val2); |
| 814 | else if ( size == 2 ) *SHORTP(ncp, i) = (short)(val1+val2); |
| 815 | else if ( size == 4 ) *LONGP(ncp, i) = (long)(val1+val2); |
| 816 | } |
| 817 | return rv; |
| 818 | } |
| 819 | |
| 820 | static object * |
| 821 | audioop_bias(self, args) |
| 822 | object *self; |
| 823 | object *args; |
| 824 | { |
| 825 | signed char *cp, *ncp; |
| 826 | int len, size, val; |
| 827 | object *rv; |
| 828 | int i; |
| 829 | int bias; |
| 830 | |
| 831 | if ( !getargs(args, "(s#ii)", |
| 832 | &cp, &len, &size , &bias) ) |
| 833 | return 0; |
| 834 | |
| 835 | if ( size != 1 && size != 2 && size != 4) { |
| 836 | err_setstr(AudioopError, "Size should be 1, 2 or 4"); |
| 837 | return 0; |
| 838 | } |
| 839 | |
| 840 | rv = newsizedstringobject(NULL, len); |
| 841 | if ( rv == 0 ) |
| 842 | return 0; |
| 843 | ncp = (signed char *)getstringvalue(rv); |
| 844 | |
| 845 | |
| 846 | for ( i=0; i < len; i += size ) { |
| 847 | if ( size == 1 ) val = (int)*CHARP(cp, i); |
| 848 | else if ( size == 2 ) val = (int)*SHORTP(cp, i); |
| 849 | else if ( size == 4 ) val = (int)*LONGP(cp, i); |
| 850 | |
| 851 | if ( size == 1 ) *CHARP(ncp, i) = (signed char)(val+bias); |
| 852 | else if ( size == 2 ) *SHORTP(ncp, i) = (short)(val+bias); |
| 853 | else if ( size == 4 ) *LONGP(ncp, i) = (long)(val+bias); |
| 854 | } |
| 855 | return rv; |
| 856 | } |
| 857 | |
| 858 | static object * |
Jack Jansen | 337b20e | 1993-02-23 13:39:57 +0000 | [diff] [blame] | 859 | audioop_reverse(self, args) |
| 860 | object *self; |
| 861 | object *args; |
| 862 | { |
| 863 | signed char *cp; |
| 864 | unsigned char *ncp; |
| 865 | int len, size, val; |
| 866 | object *rv; |
| 867 | int i, j; |
| 868 | |
| 869 | if ( !getargs(args, "(s#i)", |
| 870 | &cp, &len, &size) ) |
| 871 | return 0; |
| 872 | |
| 873 | if ( size != 1 && size != 2 && size != 4 ) { |
| 874 | err_setstr(AudioopError, "Size should be 1, 2 or 4"); |
| 875 | return 0; |
| 876 | } |
| 877 | |
| 878 | rv = newsizedstringobject(NULL, len); |
| 879 | if ( rv == 0 ) |
| 880 | return 0; |
| 881 | ncp = (unsigned char *)getstringvalue(rv); |
| 882 | |
| 883 | for ( i=0; i < len; i += size ) { |
| 884 | if ( size == 1 ) val = ((int)*CHARP(cp, i)) << 8; |
| 885 | else if ( size == 2 ) val = (int)*SHORTP(cp, i); |
| 886 | else if ( size == 4 ) val = ((int)*LONGP(cp, i)) >> 16; |
| 887 | |
| 888 | j = len - i - size; |
| 889 | |
| 890 | if ( size == 1 ) *CHARP(ncp, j) = (signed char)(val >> 8); |
| 891 | else if ( size == 2 ) *SHORTP(ncp, j) = (short)(val); |
| 892 | else if ( size == 4 ) *LONGP(ncp, j) = (long)(val<<16); |
| 893 | } |
| 894 | return rv; |
| 895 | } |
| 896 | |
| 897 | static object * |
Jack Jansen | a90805f | 1993-02-17 14:29:28 +0000 | [diff] [blame] | 898 | audioop_lin2lin(self, args) |
| 899 | object *self; |
| 900 | object *args; |
| 901 | { |
| 902 | signed char *cp; |
| 903 | unsigned char *ncp; |
| 904 | int len, size, size2, val; |
| 905 | object *rv; |
| 906 | int i, j; |
| 907 | |
| 908 | if ( !getargs(args, "(s#ii)", |
| 909 | &cp, &len, &size, &size2) ) |
| 910 | return 0; |
| 911 | |
| 912 | if ( (size != 1 && size != 2 && size != 4) || |
| 913 | (size2 != 1 && size2 != 2 && size2 != 4)) { |
| 914 | err_setstr(AudioopError, "Size should be 1, 2 or 4"); |
| 915 | return 0; |
| 916 | } |
| 917 | |
| 918 | rv = newsizedstringobject(NULL, (len/size)*size2); |
| 919 | if ( rv == 0 ) |
| 920 | return 0; |
| 921 | ncp = (unsigned char *)getstringvalue(rv); |
| 922 | |
| 923 | for ( i=0, j=0; i < len; i += size, j += size2 ) { |
| 924 | if ( size == 1 ) val = ((int)*CHARP(cp, i)) << 8; |
| 925 | else if ( size == 2 ) val = (int)*SHORTP(cp, i); |
| 926 | else if ( size == 4 ) val = ((int)*LONGP(cp, i)) >> 16; |
| 927 | |
| 928 | if ( size2 == 1 ) *CHARP(ncp, j) = (signed char)(val >> 8); |
| 929 | else if ( size2 == 2 ) *SHORTP(ncp, j) = (short)(val); |
| 930 | else if ( size2 == 4 ) *LONGP(ncp, j) = (long)(val<<16); |
| 931 | } |
| 932 | return rv; |
| 933 | } |
| 934 | |
| 935 | static object * |
Guido van Rossum | b66efa0 | 1992-06-01 16:01:24 +0000 | [diff] [blame] | 936 | audioop_lin2ulaw(self, args) |
| 937 | object *self; |
| 938 | object *args; |
| 939 | { |
| 940 | signed char *cp; |
| 941 | unsigned char *ncp; |
| 942 | int len, size, val; |
| 943 | object *rv; |
| 944 | int i; |
| 945 | |
| 946 | if ( !getargs(args, "(s#i)", |
| 947 | &cp, &len, &size) ) |
| 948 | return 0; |
| 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 | |
| 955 | rv = newsizedstringobject(NULL, len/size); |
| 956 | if ( rv == 0 ) |
| 957 | return 0; |
| 958 | ncp = (unsigned char *)getstringvalue(rv); |
| 959 | |
| 960 | for ( i=0; i < len; i += size ) { |
| 961 | if ( size == 1 ) val = ((int)*CHARP(cp, i)) << 8; |
| 962 | else if ( size == 2 ) val = (int)*SHORTP(cp, i); |
| 963 | else if ( size == 4 ) val = ((int)*LONGP(cp, i)) >> 16; |
| 964 | |
| 965 | *ncp++ = st_linear_to_ulaw(val); |
| 966 | } |
| 967 | return rv; |
| 968 | } |
| 969 | |
| 970 | static object * |
| 971 | audioop_ulaw2lin(self, args) |
| 972 | object *self; |
| 973 | object *args; |
| 974 | { |
| 975 | unsigned char *cp; |
| 976 | unsigned char cval; |
| 977 | signed char *ncp; |
| 978 | int len, size, val; |
| 979 | object *rv; |
| 980 | int i; |
| 981 | |
| 982 | if ( !getargs(args, "(s#i)", |
| 983 | &cp, &len, &size) ) |
| 984 | return 0; |
| 985 | |
| 986 | if ( size != 1 && size != 2 && size != 4) { |
| 987 | err_setstr(AudioopError, "Size should be 1, 2 or 4"); |
| 988 | return 0; |
| 989 | } |
| 990 | |
| 991 | rv = newsizedstringobject(NULL, len*size); |
| 992 | if ( rv == 0 ) |
| 993 | return 0; |
| 994 | ncp = (signed char *)getstringvalue(rv); |
| 995 | |
| 996 | for ( i=0; i < len*size; i += size ) { |
| 997 | cval = *cp++; |
| 998 | val = st_ulaw_to_linear(cval); |
| 999 | |
| 1000 | if ( size == 1 ) *CHARP(ncp, i) = (signed char)(val >> 8); |
| 1001 | else if ( size == 2 ) *SHORTP(ncp, i) = (short)(val); |
Guido van Rossum | aad5344 | 1992-06-05 15:11:56 +0000 | [diff] [blame] | 1002 | else if ( size == 4 ) *LONGP(ncp, i) = (long)(val<<16); |
Guido van Rossum | b66efa0 | 1992-06-01 16:01:24 +0000 | [diff] [blame] | 1003 | } |
| 1004 | return rv; |
| 1005 | } |
| 1006 | |
Guido van Rossum | 8e7a0f0 | 1992-06-23 15:23:57 +0000 | [diff] [blame] | 1007 | static object * |
Guido van Rossum | b64e635 | 1992-07-06 14:21:56 +0000 | [diff] [blame] | 1008 | audioop_lin2adpcm(self, args) |
| 1009 | object *self; |
| 1010 | object *args; |
| 1011 | { |
| 1012 | signed char *cp; |
| 1013 | signed char *ncp; |
Jack Jansen | d513f0b | 1993-01-08 14:40:53 +0000 | [diff] [blame] | 1014 | int len, size, val, step, valpred, delta, index, sign, vpdiff, diff; |
Guido van Rossum | b64e635 | 1992-07-06 14:21:56 +0000 | [diff] [blame] | 1015 | object *rv, *state, *str; |
| 1016 | int i, outputbuffer, bufferstep; |
| 1017 | |
| 1018 | if ( !getargs(args, "(s#iO)", |
| 1019 | &cp, &len, &size, &state) ) |
| 1020 | return 0; |
| 1021 | |
| 1022 | |
| 1023 | if ( size != 1 && size != 2 && size != 4) { |
| 1024 | err_setstr(AudioopError, "Size should be 1, 2 or 4"); |
| 1025 | return 0; |
| 1026 | } |
| 1027 | |
Jack Jansen | dd8a6ea | 1993-02-17 14:21:09 +0000 | [diff] [blame] | 1028 | str = newsizedstringobject(NULL, len/(size*2)); |
| 1029 | if ( str == 0 ) |
| 1030 | return 0; |
| 1031 | ncp = (signed char *)getstringvalue(str); |
| 1032 | |
Guido van Rossum | b64e635 | 1992-07-06 14:21:56 +0000 | [diff] [blame] | 1033 | /* Decode state, should have (value, step) */ |
| 1034 | if ( state == None ) { |
| 1035 | /* First time, it seems. Set defaults */ |
Jack Jansen | d513f0b | 1993-01-08 14:40:53 +0000 | [diff] [blame] | 1036 | valpred = 0; |
Guido van Rossum | b64e635 | 1992-07-06 14:21:56 +0000 | [diff] [blame] | 1037 | step = 7; |
| 1038 | index = 0; |
Jack Jansen | 55cea47 | 1993-02-10 13:21:59 +0000 | [diff] [blame] | 1039 | } else if ( !getargs(state, "(ii)", &valpred, &index) ) |
Guido van Rossum | b64e635 | 1992-07-06 14:21:56 +0000 | [diff] [blame] | 1040 | return 0; |
| 1041 | |
Jack Jansen | 55cea47 | 1993-02-10 13:21:59 +0000 | [diff] [blame] | 1042 | step = stepsizeTable[index]; |
Guido van Rossum | b64e635 | 1992-07-06 14:21:56 +0000 | [diff] [blame] | 1043 | bufferstep = 1; |
| 1044 | |
| 1045 | for ( i=0; i < len; i += size ) { |
| 1046 | if ( size == 1 ) val = ((int)*CHARP(cp, i)) << 8; |
| 1047 | else if ( size == 2 ) val = (int)*SHORTP(cp, i); |
| 1048 | else if ( size == 4 ) val = ((int)*LONGP(cp, i)) >> 16; |
| 1049 | |
| 1050 | /* Step 1 - compute difference with previous value */ |
Jack Jansen | d513f0b | 1993-01-08 14:40:53 +0000 | [diff] [blame] | 1051 | diff = val - valpred; |
| 1052 | sign = (diff < 0) ? 8 : 0; |
| 1053 | if ( sign ) diff = (-diff); |
Guido van Rossum | b64e635 | 1992-07-06 14:21:56 +0000 | [diff] [blame] | 1054 | |
| 1055 | /* Step 2 - Divide and clamp */ |
Jack Jansen | d513f0b | 1993-01-08 14:40:53 +0000 | [diff] [blame] | 1056 | /* Note: |
| 1057 | ** This code *approximately* computes: |
| 1058 | ** delta = diff*4/step; |
| 1059 | ** vpdiff = (delta+0.5)*step/4; |
| 1060 | ** but in shift step bits are dropped. The net result of this is |
| 1061 | ** that even if you have fast mul/div hardware you cannot put it to |
| 1062 | ** good use since the fixup would be too expensive. |
| 1063 | */ |
| 1064 | delta = 0; |
| 1065 | vpdiff = (step >> 3); |
| 1066 | |
| 1067 | if ( diff >= step ) { |
| 1068 | delta = 4; |
| 1069 | diff -= step; |
| 1070 | vpdiff += step; |
| 1071 | } |
| 1072 | step >>= 1; |
| 1073 | if ( diff >= step ) { |
| 1074 | delta |= 2; |
| 1075 | diff -= step; |
| 1076 | vpdiff += step; |
| 1077 | } |
| 1078 | step >>= 1; |
| 1079 | if ( diff >= step ) { |
| 1080 | delta |= 1; |
| 1081 | vpdiff += step; |
| 1082 | } |
| 1083 | |
Guido van Rossum | b64e635 | 1992-07-06 14:21:56 +0000 | [diff] [blame] | 1084 | /* Step 3 - Update previous value */ |
| 1085 | if ( sign ) |
Jack Jansen | d513f0b | 1993-01-08 14:40:53 +0000 | [diff] [blame] | 1086 | valpred -= vpdiff; |
Guido van Rossum | b64e635 | 1992-07-06 14:21:56 +0000 | [diff] [blame] | 1087 | else |
Jack Jansen | d513f0b | 1993-01-08 14:40:53 +0000 | [diff] [blame] | 1088 | valpred += vpdiff; |
Guido van Rossum | b64e635 | 1992-07-06 14:21:56 +0000 | [diff] [blame] | 1089 | |
| 1090 | /* Step 4 - Clamp previous value to 16 bits */ |
Jack Jansen | d513f0b | 1993-01-08 14:40:53 +0000 | [diff] [blame] | 1091 | if ( valpred > 32767 ) |
| 1092 | valpred = 32767; |
| 1093 | else if ( valpred < -32768 ) |
| 1094 | valpred = -32768; |
Guido van Rossum | b64e635 | 1992-07-06 14:21:56 +0000 | [diff] [blame] | 1095 | |
| 1096 | /* Step 5 - Assemble value, update index and step values */ |
| 1097 | delta |= sign; |
| 1098 | |
| 1099 | index += indexTable[delta]; |
| 1100 | if ( index < 0 ) index = 0; |
| 1101 | if ( index > 88 ) index = 88; |
| 1102 | step = stepsizeTable[index]; |
| 1103 | |
Jack Jansen | d513f0b | 1993-01-08 14:40:53 +0000 | [diff] [blame] | 1104 | /* Step 6 - Output value */ |
Guido van Rossum | b64e635 | 1992-07-06 14:21:56 +0000 | [diff] [blame] | 1105 | if ( bufferstep ) { |
Jack Jansen | d513f0b | 1993-01-08 14:40:53 +0000 | [diff] [blame] | 1106 | outputbuffer = (delta << 4) & 0xf0; |
Guido van Rossum | b64e635 | 1992-07-06 14:21:56 +0000 | [diff] [blame] | 1107 | } else { |
Jack Jansen | d513f0b | 1993-01-08 14:40:53 +0000 | [diff] [blame] | 1108 | *ncp++ = (delta & 0x0f) | outputbuffer; |
Guido van Rossum | b64e635 | 1992-07-06 14:21:56 +0000 | [diff] [blame] | 1109 | } |
| 1110 | bufferstep = !bufferstep; |
| 1111 | } |
Jack Jansen | 55cea47 | 1993-02-10 13:21:59 +0000 | [diff] [blame] | 1112 | rv = mkvalue("(O(ii))", str, valpred, index); |
Guido van Rossum | b64e635 | 1992-07-06 14:21:56 +0000 | [diff] [blame] | 1113 | DECREF(str); |
| 1114 | return rv; |
| 1115 | } |
| 1116 | |
| 1117 | static object * |
| 1118 | audioop_adpcm2lin(self, args) |
| 1119 | object *self; |
| 1120 | object *args; |
| 1121 | { |
| 1122 | signed char *cp; |
| 1123 | signed char *ncp; |
Guido van Rossum | 3bbc62e | 1995-01-02 19:30:30 +0000 | [diff] [blame] | 1124 | int len, size, valpred, step, delta, index, sign, vpdiff; |
Guido van Rossum | b64e635 | 1992-07-06 14:21:56 +0000 | [diff] [blame] | 1125 | object *rv, *str, *state; |
| 1126 | int i, inputbuffer, bufferstep; |
| 1127 | |
| 1128 | if ( !getargs(args, "(s#iO)", |
| 1129 | &cp, &len, &size, &state) ) |
| 1130 | return 0; |
| 1131 | |
| 1132 | if ( size != 1 && size != 2 && size != 4) { |
| 1133 | err_setstr(AudioopError, "Size should be 1, 2 or 4"); |
| 1134 | return 0; |
| 1135 | } |
| 1136 | |
| 1137 | /* Decode state, should have (value, step) */ |
| 1138 | if ( state == None ) { |
| 1139 | /* First time, it seems. Set defaults */ |
Jack Jansen | d513f0b | 1993-01-08 14:40:53 +0000 | [diff] [blame] | 1140 | valpred = 0; |
Guido van Rossum | b64e635 | 1992-07-06 14:21:56 +0000 | [diff] [blame] | 1141 | step = 7; |
| 1142 | index = 0; |
Jack Jansen | 55cea47 | 1993-02-10 13:21:59 +0000 | [diff] [blame] | 1143 | } else if ( !getargs(state, "(ii)", &valpred, &index) ) |
Guido van Rossum | b64e635 | 1992-07-06 14:21:56 +0000 | [diff] [blame] | 1144 | return 0; |
| 1145 | |
| 1146 | str = newsizedstringobject(NULL, len*size*2); |
| 1147 | if ( str == 0 ) |
| 1148 | return 0; |
| 1149 | ncp = (signed char *)getstringvalue(str); |
| 1150 | |
Jack Jansen | 55cea47 | 1993-02-10 13:21:59 +0000 | [diff] [blame] | 1151 | step = stepsizeTable[index]; |
Guido van Rossum | b64e635 | 1992-07-06 14:21:56 +0000 | [diff] [blame] | 1152 | bufferstep = 0; |
| 1153 | |
| 1154 | for ( i=0; i < len*size*2; i += size ) { |
| 1155 | /* Step 1 - get the delta value and compute next index */ |
| 1156 | if ( bufferstep ) { |
| 1157 | delta = inputbuffer & 0xf; |
| 1158 | } else { |
| 1159 | inputbuffer = *cp++; |
| 1160 | delta = (inputbuffer >> 4) & 0xf; |
| 1161 | } |
| 1162 | |
| 1163 | bufferstep = !bufferstep; |
| 1164 | |
Jack Jansen | d513f0b | 1993-01-08 14:40:53 +0000 | [diff] [blame] | 1165 | /* Step 2 - Find new index value (for later) */ |
Guido van Rossum | b64e635 | 1992-07-06 14:21:56 +0000 | [diff] [blame] | 1166 | index += indexTable[delta]; |
| 1167 | if ( index < 0 ) index = 0; |
| 1168 | if ( index > 88 ) index = 88; |
| 1169 | |
Jack Jansen | d513f0b | 1993-01-08 14:40:53 +0000 | [diff] [blame] | 1170 | /* Step 3 - Separate sign and magnitude */ |
Guido van Rossum | b64e635 | 1992-07-06 14:21:56 +0000 | [diff] [blame] | 1171 | sign = delta & 8; |
| 1172 | delta = delta & 7; |
| 1173 | |
Jack Jansen | d513f0b | 1993-01-08 14:40:53 +0000 | [diff] [blame] | 1174 | /* Step 4 - Compute difference and new predicted value */ |
| 1175 | /* |
| 1176 | ** Computes 'vpdiff = (delta+0.5)*step/4', but see comment |
| 1177 | ** in adpcm_coder. |
| 1178 | */ |
| 1179 | vpdiff = step >> 3; |
| 1180 | if ( delta & 4 ) vpdiff += step; |
| 1181 | if ( delta & 2 ) vpdiff += step>>1; |
| 1182 | if ( delta & 1 ) vpdiff += step>>2; |
| 1183 | |
Guido van Rossum | b64e635 | 1992-07-06 14:21:56 +0000 | [diff] [blame] | 1184 | if ( sign ) |
Jack Jansen | d513f0b | 1993-01-08 14:40:53 +0000 | [diff] [blame] | 1185 | valpred -= vpdiff; |
Guido van Rossum | b64e635 | 1992-07-06 14:21:56 +0000 | [diff] [blame] | 1186 | else |
Jack Jansen | d513f0b | 1993-01-08 14:40:53 +0000 | [diff] [blame] | 1187 | valpred += vpdiff; |
Guido van Rossum | b64e635 | 1992-07-06 14:21:56 +0000 | [diff] [blame] | 1188 | |
Jack Jansen | d513f0b | 1993-01-08 14:40:53 +0000 | [diff] [blame] | 1189 | /* Step 5 - clamp output value */ |
| 1190 | if ( valpred > 32767 ) |
| 1191 | valpred = 32767; |
| 1192 | else if ( valpred < -32768 ) |
| 1193 | valpred = -32768; |
Guido van Rossum | b64e635 | 1992-07-06 14:21:56 +0000 | [diff] [blame] | 1194 | |
Jack Jansen | d513f0b | 1993-01-08 14:40:53 +0000 | [diff] [blame] | 1195 | /* Step 6 - Update step value */ |
Guido van Rossum | b64e635 | 1992-07-06 14:21:56 +0000 | [diff] [blame] | 1196 | step = stepsizeTable[index]; |
| 1197 | |
| 1198 | /* Step 6 - Output value */ |
Jack Jansen | d513f0b | 1993-01-08 14:40:53 +0000 | [diff] [blame] | 1199 | if ( size == 1 ) *CHARP(ncp, i) = (signed char)(valpred >> 8); |
| 1200 | else if ( size == 2 ) *SHORTP(ncp, i) = (short)(valpred); |
| 1201 | else if ( size == 4 ) *LONGP(ncp, i) = (long)(valpred<<16); |
Guido van Rossum | b64e635 | 1992-07-06 14:21:56 +0000 | [diff] [blame] | 1202 | } |
| 1203 | |
Jack Jansen | 55cea47 | 1993-02-10 13:21:59 +0000 | [diff] [blame] | 1204 | rv = mkvalue("(O(ii))", str, valpred, index); |
Guido van Rossum | b64e635 | 1992-07-06 14:21:56 +0000 | [diff] [blame] | 1205 | DECREF(str); |
| 1206 | return rv; |
| 1207 | } |
| 1208 | |
Guido van Rossum | b66efa0 | 1992-06-01 16:01:24 +0000 | [diff] [blame] | 1209 | static struct methodlist audioop_methods[] = { |
| 1210 | { "max", audioop_max }, |
Sjoerd Mullender | a142613 | 1994-09-06 16:19:33 +0000 | [diff] [blame] | 1211 | { "minmax", audioop_minmax }, |
Guido van Rossum | b66efa0 | 1992-06-01 16:01:24 +0000 | [diff] [blame] | 1212 | { "avg", audioop_avg }, |
Jack Jansen | e1b4d7c | 1992-08-24 14:36:31 +0000 | [diff] [blame] | 1213 | { "maxpp", audioop_maxpp }, |
| 1214 | { "avgpp", audioop_avgpp }, |
| 1215 | { "rms", audioop_rms }, |
Jack Jansen | a90805f | 1993-02-17 14:29:28 +0000 | [diff] [blame] | 1216 | { "findfit", audioop_findfit }, |
| 1217 | { "findmax", audioop_findmax }, |
| 1218 | { "findfactor", audioop_findfactor }, |
Guido van Rossum | b66efa0 | 1992-06-01 16:01:24 +0000 | [diff] [blame] | 1219 | { "cross", audioop_cross }, |
| 1220 | { "mul", audioop_mul }, |
| 1221 | { "add", audioop_add }, |
| 1222 | { "bias", audioop_bias }, |
| 1223 | { "ulaw2lin", audioop_ulaw2lin }, |
| 1224 | { "lin2ulaw", audioop_lin2ulaw }, |
Jack Jansen | a90805f | 1993-02-17 14:29:28 +0000 | [diff] [blame] | 1225 | { "lin2lin", audioop_lin2lin }, |
Guido van Rossum | 8e7a0f0 | 1992-06-23 15:23:57 +0000 | [diff] [blame] | 1226 | { "adpcm2lin", audioop_adpcm2lin }, |
| 1227 | { "lin2adpcm", audioop_lin2adpcm }, |
Guido van Rossum | b66efa0 | 1992-06-01 16:01:24 +0000 | [diff] [blame] | 1228 | { "tomono", audioop_tomono }, |
| 1229 | { "tostereo", audioop_tostereo }, |
| 1230 | { "getsample", audioop_getsample }, |
Jack Jansen | 337b20e | 1993-02-23 13:39:57 +0000 | [diff] [blame] | 1231 | { "reverse", audioop_reverse }, |
Guido van Rossum | b66efa0 | 1992-06-01 16:01:24 +0000 | [diff] [blame] | 1232 | { 0, 0 } |
| 1233 | }; |
| 1234 | |
| 1235 | |
| 1236 | void |
| 1237 | initaudioop() |
| 1238 | { |
| 1239 | object *m, *d; |
| 1240 | m = initmodule("audioop", audioop_methods); |
| 1241 | d = getmoduledict(m); |
| 1242 | AudioopError = newstringobject("audioop.error"); |
| 1243 | if ( AudioopError == NULL || dictinsert(d,"error",AudioopError) ) |
| 1244 | fatal("can't define audioop.error"); |
| 1245 | } |