/* audioopmodule - Module to detect peak values in arrays */ #include "Python.h" #if SIZEOF_INT == 4typedef int Py_Int32;typedef unsigned int Py_UInt32;#else#if SIZEOF_LONG == 4typedef long Py_Int32;typedef unsigned long Py_UInt32;#else#error "No 4-byte integral type"#endif#endif typedef short PyInt16; #if defined(__CHAR_UNSIGNED__)#if defined(signed)/* This module currently does not work on systems where only unsigned characters are available. Take it out of Setup. Sorry. */#endif#endif /* Code shamelessly stolen from sox, 12.17.7, g711.c** (c) Craig Reese, Joe Campbell and Jeff Poskanzer 1989 */ /* From g711.c: * * December 30, 1994: * Functions linear2alaw, linear2ulaw have been updated to correctly * convert unquantized 16 bit values. * Tables for direct u- to A-law and A- to u-law conversions have been * corrected. * Borge Lindberg, Center for PersonKommunikation, Aalborg University. * bli@cpk.auc.dk * */#define BIAS 0x84 /* define the add-in bias for 16 bit samples */#define CLIP 32635#define SIGN_BIT (0x80) /* Sign bit for a A-law byte. */#define QUANT_MASK (0xf) /* Quantization field mask. */#define SEG_SHIFT (4) /* Left shift for segment number. */#define SEG_MASK (0x70) /* Segment field mask. */ static PyInt16 seg_aend[8] = {0x1F, 0x3F, 0x7F, 0xFF, 0x1FF, 0x3FF, 0x7FF, 0xFFF};static PyInt16 seg_uend[8] = {0x3F, 0x7F, 0xFF, 0x1FF, 0x3FF, 0x7FF, 0xFFF, 0x1FFF}; static PyInt16search(PyInt16 val, PyInt16 *table, int size){ int i; for (i = 0; i < size; i++) { if (val <= *table++) return (i); } return (size);}#define st_ulaw2linear16(uc) (_st_ulaw2linear16[uc])#define st_alaw2linear16(uc) (_st_alaw2linear16[uc]) static PyInt16 _st_ulaw2linear16[256] = { -32124, -31100, -30076, -29052, -28028, -27004, -25980, -24956, -23932, -22908, -21884, -20860, -19836, -18812, -17788, -16764, -15996, -15484, -14972, -14460, -13948, -13436, -12924, -12412, -11900, -11388, -10876, -10364, -9852, -9340, -8828, -8316, -7932, -7676, -7420, -7164, -6908, -6652, -6396, -6140, -5884, -5628, -5372, -5116, -4860, -4604, -4348, -4092, -3900, -3772, -3644, -3516, -3388, -3260, -3132, -3004, -2876, -2748, -2620, -2492, -2364, -2236, -2108, -1980, -1884, -1820, -1756, -1692, -1628, -1564, -1500, -1436, -1372, -1308, -1244, -1180, -1116, -1052, -988, -924, -876, -844, -812, -780, -748, -716, -684, -652, -620, -588, -556, -524, -492, -460, -428, -396, -372, -356, -340, -324, -308, -292, -276, -260, -244, -228, -212, -196, -180, -164, -148, -132, -120, -112, -104, -96, -88, -80, -72, -64, -56, -48, -40, -32, -24, -16, -8, 0, 32124, 31100, 30076, 29052, 28028, 27004, 25980, 24956, 23932, 22908, 21884, 20860, 19836, 18812, 17788, 16764, 15996, 15484, 14972, 14460, 13948, 13436, 12924, 12412, 11900, 11388, 10876, 10364, 9852, 9340, 8828, 8316, 7932, 7676, 7420, 7164, 6908, 6652, 6396, 6140, 5884, 5628, 5372, 5116, 4860, 4604, 4348, 4092, 3900, 3772, 3644, 3516, 3388, 3260, 3132, 3004, 2876, 2748, 2620, 2492, 2364, 2236, 2108, 1980, 1884, 1820, 1756, 1692, 1628, 1564, 1500, 1436, 1372, 1308, 1244, 1180, 1116, 1052, 988, 924, 876, 844, 812, 780, 748, 716, 684, 652, 620, 588, 556, 524, 492, 460, 428, 396, 372, 356, 340, 324, 308, 292, 276, 260, 244, 228, 212, 196, 180, 164, 148, 132, 120, 112, 104, 96, 88, 80, 72, 64, 56, 48, 40, 32, 24, 16, 8, 0}; /* * linear2ulaw() accepts a 14-bit signed integer and encodes it as u-law data * stored in a unsigned char. This function should only be called with * the data shifted such that it only contains information in the lower * 14-bits. * * In order to simplify the encoding process, the original linear magnitude * is biased by adding 33 which shifts the encoding range from (0 - 8158) to * (33 - 8191). The result can be seen in the following encoding table: * * Biased Linear Input Code Compressed Code * ------------------------ --------------- * 00000001wxyza 000wxyz * 0000001wxyzab 001wxyz * 000001wxyzabc 010wxyz * 00001wxyzabcd 011wxyz * 0001wxyzabcde 100wxyz * 001wxyzabcdef 101wxyz * 01wxyzabcdefg 110wxyz * 1wxyzabcdefgh 111wxyz * * Each biased linear code has a leading 1 which identifies the segment * number. The value of the segment number is equal to 7 minus the number * of leading 0's. The quantization interval is directly available as the * four bits wxyz. * The trailing bits (a - h) are ignored. * * Ordinarily the complement of the resulting code word is used for * transmission, and so the code word is complemented before it is returned. * * For further information see John C. Bellamy's Digital Telephony, 1982, * John Wiley & Sons, pps 98-111 and 472-476. */static unsigned charst_14linear2ulaw(PyInt16 pcm_val) /* 2's complement (14-bit range) */{ PyInt16 mask; PyInt16 seg; unsigned char uval; /* The original sox code does this in the calling function, not here */ pcm_val = pcm_val >> 2; /* u-law inverts all bits */ /* Get the sign and the magnitude of the value. */ if (pcm_val < 0) { pcm_val = -pcm_val; mask = 0x7F; } else { mask = 0xFF; } if ( pcm_val > CLIP ) pcm_val = CLIP; /* clip the magnitude */ pcm_val += (BIAS >> 2); /* Convert the scaled magnitude to segment number. */ seg = search(pcm_val, seg_uend, 8); /* * Combine the sign, segment, quantization bits; * and complement the code word. */ if (seg >= 8) /* out of range, return maximum value. */ return (unsigned char) (0x7F ^ mask); else { uval = (unsigned char) (seg << 4) | ((pcm_val >> (seg + 1)) & 0xF); return (uval ^ mask); } } static PyInt16 _st_alaw2linear16[256] = { -5504, -5248, -6016, -5760, -4480, -4224, -4992, -4736, -7552, -7296, -8064, -7808, -6528, -6272, -7040, -6784, -2752, -2624, -3008, -2880, -2240, -2112, -2496, -2368, -3776, -3648, -4032, -3904, -3264, -3136, -3520, -3392, -22016, -20992, -24064, -23040, -17920, -16896, -19968, -18944, -30208, -29184, -32256, -31232, -26112, -25088, -28160, -27136, -11008, -10496, -12032, -11520, -8960, -8448, -9984, -9472, -15104, -14592, -16128, -15616, -13056, -12544, -14080, -13568, -344, -328, -376, -360, -280, -264, -312, -296, -472, -456, -504, -488, -408, -392, -440, -424, -88, -72, -120, -104, -24, -8, -56, -40, -216, -200, -248, -232, -152, -136, -184, -168, -1376, -1312, -1504, -1440, -1120, -1056, -1248, -1184, -1888, -1824, -2016, -1952, -1632, -1568, -1760, -1696, -688, -656, -752, -720, -560, -528, -624, -592, -944, -912, -1008, -976, -816, -784, -880, -848, 5504, 5248, 6016, 5760, 4480, 4224, 4992, 4736, 7552, 7296, 8064, 7808, 6528, 6272, 7040, 6784, 2752, 2624, 3008, 2880, 2240, 2112, 2496, 2368, 3776, 3648, 4032, 3904, 3264, 3136, 3520, 3392, 22016, 20992, 24064, 23040, 17920, 16896, 19968, 18944, 30208, 29184, 32256, 31232, 26112, 25088, 28160, 27136, 11008, 10496, 12032, 11520, 8960, 8448, 9984, 9472, 15104, 14592, 16128, 15616, 13056, 12544, 14080, 13568, 344, 328, 376, 360, 280, 264, 312, 296, 472, 456, 504, 488, 408, 392, 440, 424, 88, 72, 120, 104, 24, 8, 56, 40, 216, 200, 248, 232, 152, 136, 184, 168, 1376, 1312, 1504, 1440, 1120, 1056, 1248, 1184, 1888, 1824, 2016, 1952, 1632, 1568, 1760, 1696, 688, 656, 752, 720, 560, 528, 624, 592, 944, 912, 1008, 976, 816, 784, 880, 848}; /* * linear2alaw() accepts an 13-bit signed integer and encodes it as A-law data * stored in a unsigned char. This function should only be called with * the data shifted such that it only contains information in the lower * 13-bits. * * Linear Input Code Compressed Code * ------------------------ --------------- * 0000000wxyza 000wxyz * 0000001wxyza 001wxyz * 000001wxyzab 010wxyz * 00001wxyzabc 011wxyz * 0001wxyzabcd 100wxyz * 001wxyzabcde 101wxyz * 01wxyzabcdef 110wxyz * 1wxyzabcdefg 111wxyz * * For further information see John C. Bellamy's Digital Telephony, 1982, * John Wiley & Sons, pps 98-111 and 472-476. */static unsigned charst_linear2alaw(PyInt16 pcm_val) /* 2's complement (13-bit range) */{ PyInt16 mask; short seg; unsigned char aval; /* The original sox code does this in the calling function, not here */ pcm_val = pcm_val >> 3; /* A-law using even bit inversion */ if (pcm_val >= 0) { mask = 0xD5; /* sign (7th) bit = 1 */ } else { mask = 0x55; /* sign bit = 0 */ pcm_val = -pcm_val - 1; } /* Convert the scaled magnitude to segment number. */ seg = search(pcm_val, seg_aend, 8); /* Combine the sign, segment, and quantization bits. */ if (seg >= 8) /* out of range, return maximum value. */ return (unsigned char) (0x7F ^ mask); else { aval = (unsigned char) seg << SEG_SHIFT; if (seg < 2) aval |= (pcm_val >> 1) & QUANT_MASK; else aval |= (pcm_val >> seg) & QUANT_MASK; return (aval ^ mask); }}/* End of code taken from sox */ /* Intel ADPCM step variation table */static int indexTable[16] = { -1, -1, -1, -1, 2, 4, 6, 8, -1, -1, -1, -1, 2, 4, 6, 8,}; static int stepsizeTable[89] = { 7, 8, 9, 10, 11, 12, 13, 14, 16, 17, 19, 21, 23, 25, 28, 31, 34, 37, 41, 45, 50, 55, 60, 66, 73, 80, 88, 97, 107, 118, 130, 143, 157, 173, 190, 209, 230, 253, 279, 307, 337, 371, 408, 449, 494, 544, 598, 658, 724, 796, 876, 963, 1060, 1166, 1282, 1411, 1552, 1707, 1878, 2066, 2272, 2499, 2749, 3024, 3327, 3660, 4026, 4428, 4871, 5358, 5894, 6484, 7132, 7845, 8630, 9493, 10442, 11487, 12635, 13899, 15289, 16818, 18500, 20350, 22385, 24623, 27086, 29794, 32767}; #define CHARP(cp, i) ((signed char *)(cp+i))#define SHORTP(cp, i) ((short *)(cp+i))#define LONGP(cp, i) ((Py_Int32 *)(cp+i)) static PyObject *AudioopError; static PyObject *audioop_getsample(PyObject *self, PyObject *args){ signed char *cp; int len, size, val = 0; int i; if ( !PyArg_ParseTuple(args, "s#ii:getsample", &cp, &len, &size, &i) ) return 0; if ( size != 1 && size != 2 && size != 4 ) { PyErr_SetString(AudioopError, "Size should be 1, 2 or 4"); return 0; } if ( i < 0 || i >= len/size ) { PyErr_SetString(AudioopError, "Index out of range"); return 0; } if ( size == 1 ) val = (int)*CHARP(cp, i); else if ( size == 2 ) val = (int)*SHORTP(cp, i*2); else if ( size == 4 ) val = (int)*LONGP(cp, i*4); return PyInt_FromLong(val);} static PyObject *audioop_max(PyObject *self, PyObject *args){ signed char *cp; int len, size, val = 0; int i; int max = 0; if ( !PyArg_ParseTuple(args, "s#i:max", &cp, &len, &size) ) return 0; if ( size != 1 && size != 2 && size != 4 ) { PyErr_SetString(AudioopError, "Size should be 1, 2 or 4"); return 0; } for ( i=0; i<len; i+= size) { if ( size == 1 ) val = (int)*CHARP(cp, i); else if ( size == 2 ) val = (int)*SHORTP(cp, i); else if ( size == 4 ) val = (int)*LONGP(cp, i); if ( val < 0 ) val = (-val); if ( val > max ) max = val; } return PyInt_FromLong(max);} static PyObject *audioop_minmax(PyObject *self, PyObject *args){ signed char *cp; int len, size, val = 0; int i; int min = 0x7fffffff, max = -0x7fffffff; if (!PyArg_ParseTuple(args, "s#i:minmax", &cp, &len, &size)) return NULL; if (size != 1 && size != 2 && size != 4) { PyErr_SetString(AudioopError, "Size should be 1, 2 or 4"); return NULL; } for (i = 0; i < len; i += size) { if (size == 1) val = (int) *CHARP(cp, i); else if (size == 2) val = (int) *SHORTP(cp, i); else if (size == 4) val = (int) *LONGP(cp, i); if (val > max) max = val; if (val < min) min = val; } return Py_BuildValue("(ii)", min, max);} static PyObject *audioop_avg(PyObject *self, PyObject *args){ signed char *cp; int len, size, val = 0; int i; double avg = 0.0; if ( !PyArg_ParseTuple(args, "s#i:avg", &cp, &len, &size) ) return 0; if ( size != 1 && size != 2 && size != 4 ) { PyErr_SetString(AudioopError, "Size should be 1, 2 or 4"); return 0; } for ( i=0; i<len; i+= size) { if ( size == 1 ) val = (int)*CHARP(cp, i); else if ( size == 2 ) val = (int)*SHORTP(cp, i); else if ( size == 4 ) val = (int)*LONGP(cp, i); avg += val; } if ( len == 0 ) val = 0; else val = (int)(avg / (double)(len/size)); return PyInt_FromLong(val);} static PyObject *audioop_rms(PyObject *self, PyObject *args){ signed char *cp; int len, size, val = 0; int i; double sum_squares = 0.0; if ( !PyArg_ParseTuple(args, "s#i:rms", &cp, &len, &size) ) return 0; if ( size != 1 && size != 2 && size != 4 ) { PyErr_SetString(AudioopError, "Size should be 1, 2 or 4"); return 0; } for ( i=0; i<len; i+= size) { if ( size == 1 ) val = (int)*CHARP(cp, i); else if ( size == 2 ) val = (int)*SHORTP(cp, i); else if ( size == 4 ) val = (int)*LONGP(cp, i); sum_squares += (double)val*(double)val; } if ( len == 0 ) val = 0; else val = (int)sqrt(sum_squares / (double)(len/size)); return PyInt_FromLong(val);} static double _sum2(short *a, short *b, int len){ int i; double sum = 0.0; for( i=0; i<len; i++) { sum = sum + (double)a[i]*(double)b[i]; } return sum;} /*** Findfit tries to locate a sample within another sample. Its main use** is in echo-cancellation (to find the feedback of the output signal in** the input signal).** The method used is as follows:**** let R be the reference signal (length n) and A the input signal (length N)** with N > n, and let all sums be over i from 0 to n-1.**** Now, for each j in {0..N-n} we compute a factor fj so that -fj*R matches A** as good as possible, i.e. sum( (A[j+i]+fj*R[i])^2 ) is minimal. This** equation gives fj = sum( A[j+i]R[i] ) / sum(R[i]^2).**** Next, we compute the relative distance between the original signal and** the modified signal and minimize that over j:** vj = sum( (A[j+i]-fj*R[i])^2 ) / sum( A[j+i]^2 ) =>** vj = ( sum(A[j+i]^2)*sum(R[i]^2) - sum(A[j+i]R[i])^2 ) / sum( A[j+i]^2 )**** In the code variables correspond as follows:** cp1 A** cp2 R** len1 N** len2 n** aj_m1 A[j-1]** aj_lm1 A[j+n-1]** sum_ri_2 sum(R[i]^2)** sum_aij_2 sum(A[i+j]^2)** sum_aij_ri sum(A[i+j]R[i])**** sum_ri is calculated once, sum_aij_2 is updated each step and sum_aij_ri** is completely recalculated each step.*/static PyObject *audioop_findfit(PyObject *self, PyObject *args){ short *cp1, *cp2; int len1, len2; int j, best_j; double aj_m1, aj_lm1; double sum_ri_2, sum_aij_2, sum_aij_ri, result, best_result, factor; if ( !PyArg_ParseTuple(args, "s#s#:findfit", &cp1, &len1, &cp2, &len2) ) return 0; if ( len1 & 1 || len2 & 1 ) { PyErr_SetString(AudioopError, "Strings should be even-sized"); return 0; } len1 >>= 1; len2 >>= 1; if ( len1 < len2 ) { PyErr_SetString(AudioopError, "First sample should be longer"); return 0; } sum_ri_2 = _sum2(cp2, cp2, len2); sum_aij_2 = _sum2(cp1, cp1, len2); sum_aij_ri = _sum2(cp1, cp2, len2); result = (sum_ri_2*sum_aij_2 - sum_aij_ri*sum_aij_ri) / sum_aij_2; best_result = result; best_j = 0; j = 0; for ( j=1; j<=len1-len2; j++) { aj_m1 = (double)cp1[j-1];Lines 1–500 of 1612. 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/* audioopmodule - Module to detect peak values in arrays */ #include "Python.h" #if SIZEOF_INT == 4 typedef int Py_Int32; typedef unsigned int Py_UInt32; #else #if SIZEOF_LONG == 4 typedef long Py_Int32; typedef unsigned long Py_UInt32; #else #error "No 4-byte integral type" #endif #endif typedef short PyInt16; #if defined(__CHAR_UNSIGNED__) #if defined(signed) /* This module currently does not work on systems where only unsigned characters are available. Take it out of Setup. Sorry. */ #endif #endif /* Code shamelessly stolen from sox, 12.17.7, g711.c ** (c) Craig Reese, Joe Campbell and Jeff Poskanzer 1989 */ /* From g711.c: * * December 30, 1994: * Functions linear2alaw, linear2ulaw have been updated to correctly * convert unquantized 16 bit values. * Tables for direct u- to A-law and A- to u-law conversions have been * corrected. * Borge Lindberg, Center for PersonKommunikation, Aalborg University. * bli@cpk.auc.dk * */ #define BIAS 0x84 /* define the add-in bias for 16 bit samples */ #define CLIP 32635 #define SIGN_BIT (0x80) /* Sign bit for a A-law byte. */ #define QUANT_MASK (0xf) /* Quantization field mask. */ #define SEG_SHIFT (4) /* Left shift for segment number. */ #define SEG_MASK (0x70) /* Segment field mask. */ static PyInt16 seg_aend[8] = {0x1F, 0x3F, 0x7F, 0xFF, 0x1FF, 0x3FF, 0x7FF, 0xFFF}; static PyInt16 seg_uend[8] = {0x3F, 0x7F, 0xFF, 0x1FF, 0x3FF, 0x7FF, 0xFFF, 0x1FFF}; static PyInt16 search(PyInt16 val, PyInt16 *table, int size) { int i; for (i = 0; i < size; i++) { if (val <= *table++) return (i); } return (size); } #define st_ulaw2linear16(uc) (_st_ulaw2linear16[uc]) #define st_alaw2linear16(uc) (_st_alaw2linear16[uc]) static PyInt16 _st_ulaw2linear16[256] = { -32124, -31100, -30076, -29052, -28028, -27004, -25980, -24956, -23932, -22908, -21884, -20860, -19836, -18812, -17788, -16764, -15996, -15484, -14972, -14460, -13948, -13436, -12924, -12412, -11900, -11388, -10876, -10364, -9852, -9340, -8828, -8316, -7932, -7676, -7420, -7164, -6908, -6652, -6396, -6140, -5884, -5628, -5372, -5116, -4860, -4604, -4348, -4092, -3900, -3772, -3644, -3516, -3388, -3260, -3132, -3004, -2876, -2748, -2620, -2492, -2364, -2236, -2108, -1980, -1884, -1820, -1756, -1692, -1628, -1564, -1500, -1436, -1372, -1308, -1244, -1180, -1116, -1052, -988, -924, -876, -844, -812, -780, -748, -716, -684, -652, -620, -588, -556, -524, -492, -460, -428, -396, -372, -356, -340, -324, -308, -292, -276, -260, -244, -228, -212, -196, -180, -164, -148, -132, -120, -112, -104, -96, -88, -80, -72, -64, -56, -48, -40, -32, -24, -16, -8, 0, 32124, 31100, 30076, 29052, 28028, 27004, 25980, 24956, 23932, 22908, 21884, 20860, 19836, 18812, 17788, 16764, 15996, 15484, 14972, 14460, 13948, 13436, 12924, 12412, 11900, 11388, 10876, 10364, 9852, 9340, 8828, 8316, 7932, 7676, 7420, 7164, 6908, 6652, 6396, 6140, 5884, 5628, 5372, 5116, 4860, 4604, 4348, 4092, 3900, 3772, 3644, 3516, 3388, 3260, 3132, 3004, 2876, 2748, 2620, 2492, 2364, 2236, 2108, 1980, 1884, 1820, 1756, 1692, 1628, 1564, 1500, 1436, 1372, 1308, 1244, 1180, 1116, 1052, 988, 924, 876, 844, 812, 780, 748, 716, 684, 652, 620, 588, 556, 524, 492, 460, 428, 396, 372, 356, 340, 324, 308, 292, 276, 260, 244, 228, 212, 196, 180, 164, 148, 132, 120, 112, 104, 96, 88, 80, 72, 64, 56, 48, 40, 32, 24, 16, 8, 0 }; /* * linear2ulaw() accepts a 14-bit signed integer and encodes it as u-law data * stored in a unsigned char. This function should only be called with * the data shifted such that it only contains information in the lower * 14-bits. * * In order to simplify the encoding process, the original linear magnitude * is biased by adding 33 which shifts the encoding range from (0 - 8158) to * (33 - 8191). The result can be seen in the following encoding table: * * Biased Linear Input Code Compressed Code * ------------------------ --------------- * 00000001wxyza 000wxyz * 0000001wxyzab 001wxyz * 000001wxyzabc 010wxyz * 00001wxyzabcd 011wxyz * 0001wxyzabcde 100wxyz * 001wxyzabcdef 101wxyz * 01wxyzabcdefg 110wxyz * 1wxyzabcdefgh 111wxyz * * Each biased linear code has a leading 1 which identifies the segment * number. The value of the segment number is equal to 7 minus the number * of leading 0's. The quantization interval is directly available as the * four bits wxyz. * The trailing bits (a - h) are ignored. * * Ordinarily the complement of the resulting code word is used for * transmission, and so the code word is complemented before it is returned. * * For further information see John C. Bellamy's Digital Telephony, 1982, * John Wiley & Sons, pps 98-111 and 472-476. */ static unsigned char st_14linear2ulaw(PyInt16 pcm_val) /* 2's complement (14-bit range) */ { PyInt16 mask; PyInt16 seg; unsigned char uval; /* The original sox code does this in the calling function, not here */ pcm_val = pcm_val >> 2; /* u-law inverts all bits */ /* Get the sign and the magnitude of the value. */ if (pcm_val < 0) { pcm_val = -pcm_val; mask = 0x7F; } else { mask = 0xFF; } if ( pcm_val > CLIP ) pcm_val = CLIP; /* clip the magnitude */ pcm_val += (BIAS >> 2); /* Convert the scaled magnitude to segment number. */ seg = search(pcm_val, seg_uend, 8); /* * Combine the sign, segment, quantization bits; * and complement the code word. */ if (seg >= 8) /* out of range, return maximum value. */ return (unsigned char) (0x7F ^ mask); else { uval = (unsigned char) (seg << 4) | ((pcm_val >> (seg + 1)) & 0xF); return (uval ^ mask); } } static PyInt16 _st_alaw2linear16[256] = { -5504, -5248, -6016, -5760, -4480, -4224, -4992, -4736, -7552, -7296, -8064, -7808, -6528, -6272, -7040, -6784, -2752, -2624, -3008, -2880, -2240, -2112, -2496, -2368, -3776, -3648, -4032, -3904, -3264, -3136, -3520, -3392, -22016, -20992, -24064, -23040, -17920, -16896, -19968, -18944, -30208, -29184, -32256, -31232, -26112, -25088, -28160, -27136, -11008, -10496, -12032, -11520, -8960, -8448, -9984, -9472, -15104, -14592, -16128, -15616, -13056, -12544, -14080, -13568, -344, -328, -376, -360, -280, -264, -312, -296, -472, -456, -504, -488, -408, -392, -440, -424, -88, -72, -120, -104, -24, -8, -56, -40, -216, -200, -248, -232, -152, -136, -184, -168, -1376, -1312, -1504, -1440, -1120, -1056, -1248, -1184, -1888, -1824, -2016, -1952, -1632, -1568, -1760, -1696, -688, -656, -752, -720, -560, -528, -624, -592, -944, -912, -1008, -976, -816, -784, -880, -848, 5504, 5248, 6016, 5760, 4480, 4224, 4992, 4736, 7552, 7296, 8064, 7808, 6528, 6272, 7040, 6784, 2752, 2624, 3008, 2880, 2240, 2112, 2496, 2368, 3776, 3648, 4032, 3904, 3264, 3136, 3520, 3392, 22016, 20992, 24064, 23040, 17920, 16896, 19968, 18944, 30208, 29184, 32256, 31232, 26112, 25088, 28160, 27136, 11008, 10496, 12032, 11520, 8960, 8448, 9984, 9472, 15104, 14592, 16128, 15616, 13056, 12544, 14080, 13568, 344, 328, 376, 360, 280, 264, 312, 296, 472, 456, 504, 488, 408, 392, 440, 424, 88, 72, 120, 104, 24, 8, 56, 40, 216, 200, 248, 232, 152, 136, 184, 168, 1376, 1312, 1504, 1440, 1120, 1056, 1248, 1184, 1888, 1824, 2016, 1952, 1632, 1568, 1760, 1696, 688, 656, 752, 720, 560, 528, 624, 592, 944, 912, 1008, 976, 816, 784, 880, 848 }; /* * linear2alaw() accepts an 13-bit signed integer and encodes it as A-law data * stored in a unsigned char. This function should only be called with * the data shifted such that it only contains information in the lower * 13-bits. * * Linear Input Code Compressed Code * ------------------------ --------------- * 0000000wxyza 000wxyz * 0000001wxyza 001wxyz * 000001wxyzab 010wxyz * 00001wxyzabc 011wxyz * 0001wxyzabcd 100wxyz * 001wxyzabcde 101wxyz * 01wxyzabcdef 110wxyz * 1wxyzabcdefg 111wxyz * * For further information see John C. Bellamy's Digital Telephony, 1982, * John Wiley & Sons, pps 98-111 and 472-476. */ static unsigned char st_linear2alaw(PyInt16 pcm_val) /* 2's complement (13-bit range) */ { PyInt16 mask; short seg; unsigned char aval; /* The original sox code does this in the calling function, not here */ pcm_val = pcm_val >> 3; /* A-law using even bit inversion */ if (pcm_val >= 0) { mask = 0xD5; /* sign (7th) bit = 1 */ } else { mask = 0x55; /* sign bit = 0 */ pcm_val = -pcm_val - 1; } /* Convert the scaled magnitude to segment number. */ seg = search(pcm_val, seg_aend, 8); /* Combine the sign, segment, and quantization bits. */ if (seg >= 8) /* out of range, return maximum value. */ return (unsigned char) (0x7F ^ mask); else { aval = (unsigned char) seg << SEG_SHIFT; if (seg < 2) aval |= (pcm_val >> 1) & QUANT_MASK; else aval |= (pcm_val >> seg) & QUANT_MASK; return (aval ^ mask); } } /* End of code taken from sox */ /* Intel ADPCM step variation table */ static int indexTable[16] = { -1, -1, -1, -1, 2, 4, 6, 8, -1, -1, -1, -1, 2, 4, 6, 8, }; static int stepsizeTable[89] = { 7, 8, 9, 10, 11, 12, 13, 14, 16, 17, 19, 21, 23, 25, 28, 31, 34, 37, 41, 45, 50, 55, 60, 66, 73, 80, 88, 97, 107, 118, 130, 143, 157, 173, 190, 209, 230, 253, 279, 307, 337, 371, 408, 449, 494, 544, 598, 658, 724, 796, 876, 963, 1060, 1166, 1282, 1411, 1552, 1707, 1878, 2066, 2272, 2499, 2749, 3024, 3327, 3660, 4026, 4428, 4871, 5358, 5894, 6484, 7132, 7845, 8630, 9493, 10442, 11487, 12635, 13899, 15289, 16818, 18500, 20350, 22385, 24623, 27086, 29794, 32767 }; #define CHARP(cp, i) ((signed char *)(cp+i)) #define SHORTP(cp, i) ((short *)(cp+i)) #define LONGP(cp, i) ((Py_Int32 *)(cp+i)) static PyObject *AudioopError; static PyObject * audioop_getsample(PyObject *self, PyObject *args) { signed char *cp; int len, size, val = 0; int i; if ( !PyArg_ParseTuple(args, "s#ii:getsample", &cp, &len, &size, &i) ) return 0; if ( size != 1 && size != 2 && size != 4 ) { PyErr_SetString(AudioopError, "Size should be 1, 2 or 4"); return 0; } if ( i < 0 || i >= len/size ) { PyErr_SetString(AudioopError, "Index out of range"); return 0; } if ( size == 1 ) val = (int)*CHARP(cp, i); else if ( size == 2 ) val = (int)*SHORTP(cp, i*2); else if ( size == 4 ) val = (int)*LONGP(cp, i*4); return PyInt_FromLong(val); } static PyObject * audioop_max(PyObject *self, PyObject *args) { signed char *cp; int len, size, val = 0; int i; int max = 0; if ( !PyArg_ParseTuple(args, "s#i:max", &cp, &len, &size) ) return 0; if ( size != 1 && size != 2 && size != 4 ) { PyErr_SetString(AudioopError, "Size should be 1, 2 or 4"); return 0; } for ( i=0; i<len; i+= size) { if ( size == 1 ) val = (int)*CHARP(cp, i); else if ( size == 2 ) val = (int)*SHORTP(cp, i); else if ( size == 4 ) val = (int)*LONGP(cp, i); if ( val < 0 ) val = (-val); if ( val > max ) max = val; } return PyInt_FromLong(max); } static PyObject * audioop_minmax(PyObject *self, PyObject *args) { signed char *cp; int len, size, val = 0; int i; int min = 0x7fffffff, max = -0x7fffffff; if (!PyArg_ParseTuple(args, "s#i:minmax", &cp, &len, &size)) return NULL; if (size != 1 && size != 2 && size != 4) { PyErr_SetString(AudioopError, "Size should be 1, 2 or 4"); return NULL; } for (i = 0; i < len; i += size) { if (size == 1) val = (int) *CHARP(cp, i); else if (size == 2) val = (int) *SHORTP(cp, i); else if (size == 4) val = (int) *LONGP(cp, i); if (val > max) max = val; if (val < min) min = val; } return Py_BuildValue("(ii)", min, max); } static PyObject * audioop_avg(PyObject *self, PyObject *args) { signed char *cp; int len, size, val = 0; int i; double avg = 0.0; if ( !PyArg_ParseTuple(args, "s#i:avg", &cp, &len, &size) ) return 0; if ( size != 1 && size != 2 && size != 4 ) { PyErr_SetString(AudioopError, "Size should be 1, 2 or 4"); return 0; } for ( i=0; i<len; i+= size) { if ( size == 1 ) val = (int)*CHARP(cp, i); else if ( size == 2 ) val = (int)*SHORTP(cp, i); else if ( size == 4 ) val = (int)*LONGP(cp, i); avg += val; } if ( len == 0 ) val = 0; else val = (int)(avg / (double)(len/size)); return PyInt_FromLong(val); } static PyObject * audioop_rms(PyObject *self, PyObject *args) { signed char *cp; int len, size, val = 0; int i; double sum_squares = 0.0; if ( !PyArg_ParseTuple(args, "s#i:rms", &cp, &len, &size) ) return 0; if ( size != 1 && size != 2 && size != 4 ) { PyErr_SetString(AudioopError, "Size should be 1, 2 or 4"); return 0; } for ( i=0; i<len; i+= size) { if ( size == 1 ) val = (int)*CHARP(cp, i); else if ( size == 2 ) val = (int)*SHORTP(cp, i); else if ( size == 4 ) val = (int)*LONGP(cp, i); sum_squares += (double)val*(double)val; } if ( len == 0 ) val = 0; else val = (int)sqrt(sum_squares / (double)(len/size)); return PyInt_FromLong(val); } static double _sum2(short *a, short *b, int len) { int i; double sum = 0.0; for( i=0; i<len; i++) { sum = sum + (double)a[i]*(double)b[i]; } return sum; } /* ** Findfit tries to locate a sample within another sample. Its main use ** is in echo-cancellation (to find the feedback of the output signal in ** the input signal). ** The method used is as follows: ** ** let R be the reference signal (length n) and A the input signal (length N) ** with N > n, and let all sums be over i from 0 to n-1. ** ** Now, for each j in {0..N-n} we compute a factor fj so that -fj*R matches A ** as good as possible, i.e. sum( (A[j+i]+fj*R[i])^2 ) is minimal. This ** equation gives fj = sum( A[j+i]R[i] ) / sum(R[i]^2). ** ** Next, we compute the relative distance between the original signal and ** the modified signal and minimize that over j: ** vj = sum( (A[j+i]-fj*R[i])^2 ) / sum( A[j+i]^2 ) => ** vj = ( sum(A[j+i]^2)*sum(R[i]^2) - sum(A[j+i]R[i])^2 ) / sum( A[j+i]^2 ) ** ** In the code variables correspond as follows: ** cp1 A ** cp2 R ** len1 N ** len2 n ** aj_m1 A[j-1] ** aj_lm1 A[j+n-1] ** sum_ri_2 sum(R[i]^2) ** sum_aij_2 sum(A[i+j]^2) ** sum_aij_ri sum(A[i+j]R[i]) ** ** sum_ri is calculated once, sum_aij_2 is updated each step and sum_aij_ri ** is completely recalculated each step. */ static PyObject * audioop_findfit(PyObject *self, PyObject *args) { short *cp1, *cp2; int len1, len2; int j, best_j; double aj_m1, aj_lm1; double sum_ri_2, sum_aij_2, sum_aij_ri, result, best_result, factor; if ( !PyArg_ParseTuple(args, "s#s#:findfit", &cp1, &len1, &cp2, &len2) ) return 0; if ( len1 & 1 || len2 & 1 ) { PyErr_SetString(AudioopError, "Strings should be even-sized"); return 0; } len1 >>= 1; len2 >>= 1; if ( len1 < len2 ) { PyErr_SetString(AudioopError, "First sample should be longer"); return 0; } sum_ri_2 = _sum2(cp2, cp2, len2); sum_aij_2 = _sum2(cp1, cp1, len2); sum_aij_ri = _sum2(cp1, cp2, len2); result = (sum_ri_2*sum_aij_2 - sum_aij_ri*sum_aij_ri) / sum_aij_2; best_result = result; best_j = 0; j = 0; for ( j=1; j<=len1-len2; j++) { aj_m1 = (double)cp1[j-1];