| |
| /* 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; |
| |
| /* Passing a short** for an 's' argument is correct only |
| if the string contents is aligned for interpretation |
| as short[]. Due to the definition of PyStringObject, |
| this is currently (Python 2.6) the case. */ |
| if ( !PyArg_ParseTuple(args, "s#s#:findfit", |
| (char**)&cp1, &len1, (char**)&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]; |
| aj_lm1 = (double)cp1[j+len2-1]; |
| |
| sum_aij_2 = sum_aij_2 + aj_lm1*aj_lm1 - aj_m1*aj_m1; |
| sum_aij_ri = _sum2(cp1+j, cp2, len2); |
| |
| result = (sum_ri_2*sum_aij_2 - sum_aij_ri*sum_aij_ri) |
| / sum_aij_2; |
| |
| if ( result < best_result ) { |
| best_result = result; |
| best_j = j; |
| } |
| |
| } |
| |
| factor = _sum2(cp1+best_j, cp2, len2) / sum_ri_2; |
| |
| return Py_BuildValue("(if)", best_j, factor); |
| } |
| |
| /* |
| ** findfactor finds a factor f so that the energy in A-fB is minimal. |
| ** See the comment for findfit for details. |
| */ |
| static PyObject * |
| audioop_findfactor(PyObject *self, PyObject *args) |
| { |
| short *cp1, *cp2; |
| int len1, len2; |
| double sum_ri_2, sum_aij_ri, result; |
| |
| if ( !PyArg_ParseTuple(args, "s#s#:findfactor", |
| (char**)&cp1, &len1, (char**)&cp2, &len2) ) |
| return 0; |
| if ( len1 & 1 || len2 & 1 ) { |
| PyErr_SetString(AudioopError, "Strings should be even-sized"); |
| return 0; |
| } |
| if ( len1 != len2 ) { |
| PyErr_SetString(AudioopError, "Samples should be same size"); |
| return 0; |
| } |
| len2 >>= 1; |
| sum_ri_2 = _sum2(cp2, cp2, len2); |
| sum_aij_ri = _sum2(cp1, cp2, len2); |
| |
| result = sum_aij_ri / sum_ri_2; |
| |
| return PyFloat_FromDouble(result); |
| } |
| |
| /* |
| ** findmax returns the index of the n-sized segment of the input sample |
| ** that contains the most energy. |
| */ |
| static PyObject * |
| audioop_findmax(PyObject *self, PyObject *args) |
| { |
| short *cp1; |
| int len1, len2; |
| int j, best_j; |
| double aj_m1, aj_lm1; |
| double result, best_result; |
| |
| if ( !PyArg_ParseTuple(args, "s#i:findmax", |
| (char**)&cp1, &len1, &len2) ) |
| return 0; |
| if ( len1 & 1 ) { |
| PyErr_SetString(AudioopError, "Strings should be even-sized"); |
| return 0; |
| } |
| len1 >>= 1; |
| |
| if ( len2 < 0 || len1 < len2 ) { |
| PyErr_SetString(AudioopError, "Input sample should be longer"); |
| return 0; |
| } |
| |
| result = _sum2(cp1, cp1, len2); |
| |
| best_result = result; |
| best_j = 0; |
| j = 0; |
| |
| for ( j=1; j<=len1-len2; j++) { |
| aj_m1 = (double)cp1[j-1]; |
| aj_lm1 = (double)cp1[j+len2-1]; |
| |
| result = result + aj_lm1*aj_lm1 - aj_m1*aj_m1; |
| |
| if ( result > best_result ) { |
| best_result = result; |
| best_j = j; |
| } |
| |
| } |
| |
| return PyInt_FromLong(best_j); |
| } |
| |
| static PyObject * |
| audioop_avgpp(PyObject *self, PyObject *args) |
| { |
| signed char *cp; |
| int len, size, val = 0, prevval = 0, prevextremevalid = 0, |
| prevextreme = 0; |
| int i; |
| double avg = 0.0; |
| int diff, prevdiff, extremediff, nextreme = 0; |
| |
| if ( !PyArg_ParseTuple(args, "s#i:avgpp", &cp, &len, &size) ) |
| return 0; |
| if ( size != 1 && size != 2 && size != 4 ) { |
| PyErr_SetString(AudioopError, "Size should be 1, 2 or 4"); |
| return 0; |
| } |
| /* Compute first delta value ahead. Also automatically makes us |
| ** skip the first extreme value |
| */ |
| if ( size == 1 ) prevval = (int)*CHARP(cp, 0); |
| else if ( size == 2 ) prevval = (int)*SHORTP(cp, 0); |
| else if ( size == 4 ) prevval = (int)*LONGP(cp, 0); |
| if ( size == 1 ) val = (int)*CHARP(cp, size); |
| else if ( size == 2 ) val = (int)*SHORTP(cp, size); |
| else if ( size == 4 ) val = (int)*LONGP(cp, size); |
| prevdiff = val - prevval; |
| |
| for ( i=size; 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); |
| diff = val - prevval; |
| if ( diff*prevdiff < 0 ) { |
| /* Derivative changed sign. Compute difference to last |
| ** extreme value and remember. |
| */ |
| if ( prevextremevalid ) { |
| extremediff = prevval - prevextreme; |
| if ( extremediff < 0 ) |
| extremediff = -extremediff; |
| avg += extremediff; |
| nextreme++; |
| } |
| prevextremevalid = 1; |
| prevextreme = prevval; |
| } |
| prevval = val; |
| if ( diff != 0 ) |
| prevdiff = diff; |
| } |
| if ( nextreme == 0 ) |
| val = 0; |
| else |
| val = (int)(avg / (double)nextreme); |
| return PyInt_FromLong(val); |
| } |
| |
| static PyObject * |
| audioop_maxpp(PyObject *self, PyObject *args) |
| { |
| signed char *cp; |
| int len, size, val = 0, prevval = 0, prevextremevalid = 0, |
| prevextreme = 0; |
| int i; |
| int max = 0; |
| int diff, prevdiff, extremediff; |
| |
| if ( !PyArg_ParseTuple(args, "s#i:maxpp", &cp, &len, &size) ) |
| return 0; |
| if ( size != 1 && size != 2 && size != 4 ) { |
| PyErr_SetString(AudioopError, "Size should be 1, 2 or 4"); |
| return 0; |
| } |
| /* Compute first delta value ahead. Also automatically makes us |
| ** skip the first extreme value |
| */ |
| if ( size == 1 ) prevval = (int)*CHARP(cp, 0); |
| else if ( size == 2 ) prevval = (int)*SHORTP(cp, 0); |
| else if ( size == 4 ) prevval = (int)*LONGP(cp, 0); |
| if ( size == 1 ) val = (int)*CHARP(cp, size); |
| else if ( size == 2 ) val = (int)*SHORTP(cp, size); |
| else if ( size == 4 ) val = (int)*LONGP(cp, size); |
| prevdiff = val - prevval; |
| |
| for ( i=size; 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); |
| diff = val - prevval; |
| if ( diff*prevdiff < 0 ) { |
| /* Derivative changed sign. Compute difference to |
| ** last extreme value and remember. |
| */ |
| if ( prevextremevalid ) { |
| extremediff = prevval - prevextreme; |
| if ( extremediff < 0 ) |
| extremediff = -extremediff; |
| if ( extremediff > max ) |
| max = extremediff; |
| } |
| prevextremevalid = 1; |
| prevextreme = prevval; |
| } |
| prevval = val; |
| if ( diff != 0 ) |
| prevdiff = diff; |
| } |
| return PyInt_FromLong(max); |
| } |
| |
| static PyObject * |
| audioop_cross(PyObject *self, PyObject *args) |
| { |
| signed char *cp; |
| int len, size, val = 0; |
| int i; |
| int prevval, ncross; |
| |
| if ( !PyArg_ParseTuple(args, "s#i:cross", &cp, &len, &size) ) |
| return 0; |
| if ( size != 1 && size != 2 && size != 4 ) { |
| PyErr_SetString(AudioopError, "Size should be 1, 2 or 4"); |
| return 0; |
| } |
| ncross = -1; |
| prevval = 17; /* Anything <> 0,1 */ |
| for ( i=0; i<len; i+= size) { |
| if ( size == 1 ) val = ((int)*CHARP(cp, i)) >> 7; |
| else if ( size == 2 ) val = ((int)*SHORTP(cp, i)) >> 15; |
| else if ( size == 4 ) val = ((int)*LONGP(cp, i)) >> 31; |
| val = val & 1; |
| if ( val != prevval ) ncross++; |
| prevval = val; |
| } |
| return PyInt_FromLong(ncross); |
| } |
| |
| static PyObject * |
| audioop_mul(PyObject *self, PyObject *args) |
| { |
| signed char *cp, *ncp; |
| int len, size, val = 0; |
| double factor, fval, maxval; |
| PyObject *rv; |
| int i; |
| |
| if ( !PyArg_ParseTuple(args, "s#id:mul", &cp, &len, &size, &factor ) ) |
| return 0; |
| |
| if ( size == 1 ) maxval = (double) 0x7f; |
| else if ( size == 2 ) maxval = (double) 0x7fff; |
| else if ( size == 4 ) maxval = (double) 0x7fffffff; |
| else { |
| PyErr_SetString(AudioopError, "Size should be 1, 2 or 4"); |
| return 0; |
| } |
| |
| rv = PyString_FromStringAndSize(NULL, len); |
| if ( rv == 0 ) |
| return 0; |
| ncp = (signed char *)PyString_AsString(rv); |
| |
| |
| 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); |
| fval = (double)val*factor; |
| if ( fval > maxval ) fval = maxval; |
| else if ( fval < -maxval ) fval = -maxval; |
| val = (int)fval; |
| if ( size == 1 ) *CHARP(ncp, i) = (signed char)val; |
| else if ( size == 2 ) *SHORTP(ncp, i) = (short)val; |
| else if ( size == 4 ) *LONGP(ncp, i) = (Py_Int32)val; |
| } |
| return rv; |
| } |
| |
| static PyObject * |
| audioop_tomono(PyObject *self, PyObject *args) |
| { |
| signed char *cp, *ncp; |
| int len, size, val1 = 0, val2 = 0; |
| double fac1, fac2, fval, maxval; |
| PyObject *rv; |
| int i; |
| |
| if ( !PyArg_ParseTuple(args, "s#idd:tomono", |
| &cp, &len, &size, &fac1, &fac2 ) ) |
| return 0; |
| |
| if ( size == 1 ) maxval = (double) 0x7f; |
| else if ( size == 2 ) maxval = (double) 0x7fff; |
| else if ( size == 4 ) maxval = (double) 0x7fffffff; |
| else { |
| PyErr_SetString(AudioopError, "Size should be 1, 2 or 4"); |
| return 0; |
| } |
| |
| rv = PyString_FromStringAndSize(NULL, len/2); |
| if ( rv == 0 ) |
| return 0; |
| ncp = (signed char *)PyString_AsString(rv); |
| |
| |
| for ( i=0; i < len; i += size*2 ) { |
| if ( size == 1 ) val1 = (int)*CHARP(cp, i); |
| else if ( size == 2 ) val1 = (int)*SHORTP(cp, i); |
| else if ( size == 4 ) val1 = (int)*LONGP(cp, i); |
| if ( size == 1 ) val2 = (int)*CHARP(cp, i+1); |
| else if ( size == 2 ) val2 = (int)*SHORTP(cp, i+2); |
| else if ( size == 4 ) val2 = (int)*LONGP(cp, i+4); |
| fval = (double)val1*fac1 + (double)val2*fac2; |
| if ( fval > maxval ) fval = maxval; |
| else if ( fval < -maxval ) fval = -maxval; |
| val1 = (int)fval; |
| if ( size == 1 ) *CHARP(ncp, i/2) = (signed char)val1; |
| else if ( size == 2 ) *SHORTP(ncp, i/2) = (short)val1; |
| else if ( size == 4 ) *LONGP(ncp, i/2)= (Py_Int32)val1; |
| } |
| return rv; |
| } |
| |
| static PyObject * |
| audioop_tostereo(PyObject *self, PyObject *args) |
| { |
| signed char *cp, *ncp; |
| int len, new_len, size, val1, val2, val = 0; |
| double fac1, fac2, fval, maxval; |
| PyObject *rv; |
| int i; |
| |
| if ( !PyArg_ParseTuple(args, "s#idd:tostereo", |
| &cp, &len, &size, &fac1, &fac2 ) ) |
| return 0; |
| |
| if ( size == 1 ) maxval = (double) 0x7f; |
| else if ( size == 2 ) maxval = (double) 0x7fff; |
| else if ( size == 4 ) maxval = (double) 0x7fffffff; |
| else { |
| PyErr_SetString(AudioopError, "Size should be 1, 2 or 4"); |
| return 0; |
| } |
| |
| new_len = len*2; |
| if (new_len < 0) { |
| PyErr_SetString(PyExc_MemoryError, |
| "not enough memory for output buffer"); |
| return 0; |
| } |
| |
| rv = PyString_FromStringAndSize(NULL, new_len); |
| if ( rv == 0 ) |
| return 0; |
| ncp = (signed char *)PyString_AsString(rv); |
| |
| |
| 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); |
| |
| fval = (double)val*fac1; |
| if ( fval > maxval ) fval = maxval; |
| else if ( fval < -maxval ) fval = -maxval; |
| val1 = (int)fval; |
| |
| fval = (double)val*fac2; |
| if ( fval > maxval ) fval = maxval; |
| else if ( fval < -maxval ) fval = -maxval; |
| val2 = (int)fval; |
| |
| if ( size == 1 ) *CHARP(ncp, i*2) = (signed char)val1; |
| else if ( size == 2 ) *SHORTP(ncp, i*2) = (short)val1; |
| else if ( size == 4 ) *LONGP(ncp, i*2) = (Py_Int32)val1; |
| |
| if ( size == 1 ) *CHARP(ncp, i*2+1) = (signed char)val2; |
| else if ( size == 2 ) *SHORTP(ncp, i*2+2) = (short)val2; |
| else if ( size == 4 ) *LONGP(ncp, i*2+4) = (Py_Int32)val2; |
| } |
| return rv; |
| } |
| |
| static PyObject * |
| audioop_add(PyObject *self, PyObject *args) |
| { |
| signed char *cp1, *cp2, *ncp; |
| int len1, len2, size, val1 = 0, val2 = 0, maxval, newval; |
| PyObject *rv; |
| int i; |
| |
| if ( !PyArg_ParseTuple(args, "s#s#i:add", |
| &cp1, &len1, &cp2, &len2, &size ) ) |
| return 0; |
| |
| if ( len1 != len2 ) { |
| PyErr_SetString(AudioopError, "Lengths should be the same"); |
| return 0; |
| } |
| |
| if ( size == 1 ) maxval = 0x7f; |
| else if ( size == 2 ) maxval = 0x7fff; |
| else if ( size == 4 ) maxval = 0x7fffffff; |
| else { |
| PyErr_SetString(AudioopError, "Size should be 1, 2 or 4"); |
| return 0; |
| } |
| |
| rv = PyString_FromStringAndSize(NULL, len1); |
| if ( rv == 0 ) |
| return 0; |
| ncp = (signed char *)PyString_AsString(rv); |
| |
| for ( i=0; i < len1; i += size ) { |
| if ( size == 1 ) val1 = (int)*CHARP(cp1, i); |
| else if ( size == 2 ) val1 = (int)*SHORTP(cp1, i); |
| else if ( size == 4 ) val1 = (int)*LONGP(cp1, i); |
| |
| if ( size == 1 ) val2 = (int)*CHARP(cp2, i); |
| else if ( size == 2 ) val2 = (int)*SHORTP(cp2, i); |
| else if ( size == 4 ) val2 = (int)*LONGP(cp2, i); |
| |
| newval = val1 + val2; |
| /* truncate in case of overflow */ |
| if (newval > maxval) newval = maxval; |
| else if (newval < -maxval) newval = -maxval; |
| else if (size == 4 && (newval^val1) < 0 && (newval^val2) < 0) |
| newval = val1 > 0 ? maxval : - maxval; |
| |
| if ( size == 1 ) *CHARP(ncp, i) = (signed char)newval; |
| else if ( size == 2 ) *SHORTP(ncp, i) = (short)newval; |
| else if ( size == 4 ) *LONGP(ncp, i) = (Py_Int32)newval; |
| } |
| return rv; |
| } |
| |
| static PyObject * |
| audioop_bias(PyObject *self, PyObject *args) |
| { |
| signed char *cp, *ncp; |
| int len, size, val = 0; |
| PyObject *rv; |
| int i; |
| int bias; |
| |
| if ( !PyArg_ParseTuple(args, "s#ii:bias", |
| &cp, &len, &size , &bias) ) |
| return 0; |
| |
| if ( size != 1 && size != 2 && size != 4) { |
| PyErr_SetString(AudioopError, "Size should be 1, 2 or 4"); |
| return 0; |
| } |
| |
| rv = PyString_FromStringAndSize(NULL, len); |
| if ( rv == 0 ) |
| return 0; |
| ncp = (signed char *)PyString_AsString(rv); |
| |
| |
| 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 ( size == 1 ) *CHARP(ncp, i) = (signed char)(val+bias); |
| else if ( size == 2 ) *SHORTP(ncp, i) = (short)(val+bias); |
| else if ( size == 4 ) *LONGP(ncp, i) = (Py_Int32)(val+bias); |
| } |
| return rv; |
| } |
| |
| static PyObject * |
| audioop_reverse(PyObject *self, PyObject *args) |
| { |
| signed char *cp; |
| unsigned char *ncp; |
| int len, size, val = 0; |
| PyObject *rv; |
| int i, j; |
| |
| if ( !PyArg_ParseTuple(args, "s#i:reverse", |
| &cp, &len, &size) ) |
| return 0; |
| |
| if ( size != 1 && size != 2 && size != 4 ) { |
| PyErr_SetString(AudioopError, "Size should be 1, 2 or 4"); |
| return 0; |
| } |
| |
| rv = PyString_FromStringAndSize(NULL, len); |
| if ( rv == 0 ) |
| return 0; |
| ncp = (unsigned char *)PyString_AsString(rv); |
| |
| for ( i=0; i < len; i += size ) { |
| if ( size == 1 ) val = ((int)*CHARP(cp, i)) << 8; |
| else if ( size == 2 ) val = (int)*SHORTP(cp, i); |
| else if ( size == 4 ) val = ((int)*LONGP(cp, i)) >> 16; |
| |
| j = len - i - size; |
| |
| if ( size == 1 ) *CHARP(ncp, j) = (signed char)(val >> 8); |
| else if ( size == 2 ) *SHORTP(ncp, j) = (short)(val); |
| else if ( size == 4 ) *LONGP(ncp, j) = (Py_Int32)(val<<16); |
| } |
| return rv; |
| } |
| |
| static PyObject * |
| audioop_lin2lin(PyObject *self, PyObject *args) |
| { |
| signed char *cp; |
| unsigned char *ncp; |
| int len, new_len, size, size2, val = 0; |
| PyObject *rv; |
| int i, j; |
| |
| if ( !PyArg_ParseTuple(args, "s#ii:lin2lin", |
| &cp, &len, &size, &size2) ) |
| return 0; |
| |
| if ( (size != 1 && size != 2 && size != 4) || |
| (size2 != 1 && size2 != 2 && size2 != 4)) { |
| PyErr_SetString(AudioopError, "Size should be 1, 2 or 4"); |
| return 0; |
| } |
| |
| new_len = (len/size)*size2; |
| if (new_len < 0) { |
| PyErr_SetString(PyExc_MemoryError, |
| "not enough memory for output buffer"); |
| return 0; |
| } |
| rv = PyString_FromStringAndSize(NULL, new_len); |
| if ( rv == 0 ) |
| return 0; |
| ncp = (unsigned char *)PyString_AsString(rv); |
| |
| for ( i=0, j=0; i < len; i += size, j += size2 ) { |
| if ( size == 1 ) val = ((int)*CHARP(cp, i)) << 8; |
| else if ( size == 2 ) val = (int)*SHORTP(cp, i); |
| else if ( size == 4 ) val = ((int)*LONGP(cp, i)) >> 16; |
| |
| if ( size2 == 1 ) *CHARP(ncp, j) = (signed char)(val >> 8); |
| else if ( size2 == 2 ) *SHORTP(ncp, j) = (short)(val); |
| else if ( size2 == 4 ) *LONGP(ncp, j) = (Py_Int32)(val<<16); |
| } |
| return rv; |
| } |
| |
| static int |
| gcd(int a, int b) |
| { |
| while (b > 0) { |
| int tmp = a % b; |
| a = b; |
| b = tmp; |
| } |
| return a; |
| } |
| |
| static PyObject * |
| audioop_ratecv(PyObject *self, PyObject *args) |
| { |
| char *cp, *ncp; |
| int len, size, nchannels, inrate, outrate, weightA, weightB; |
| int chan, d, *prev_i, *cur_i, cur_o; |
| PyObject *state, *samps, *str, *rv = NULL; |
| int bytes_per_frame; |
| size_t alloc_size; |
| |
| weightA = 1; |
| weightB = 0; |
| if (!PyArg_ParseTuple(args, "s#iiiiO|ii:ratecv", &cp, &len, &size, |
| &nchannels, &inrate, &outrate, &state, |
| &weightA, &weightB)) |
| return NULL; |
| if (size != 1 && size != 2 && size != 4) { |
| PyErr_SetString(AudioopError, "Size should be 1, 2 or 4"); |
| return NULL; |
| } |
| if (nchannels < 1) { |
| PyErr_SetString(AudioopError, "# of channels should be >= 1"); |
| return NULL; |
| } |
| bytes_per_frame = size * nchannels; |
| if (bytes_per_frame / nchannels != size) { |
| /* This overflow test is rigorously correct because |
| both multiplicands are >= 1. Use the argument names |
| from the docs for the error msg. */ |
| PyErr_SetString(PyExc_OverflowError, |
| "width * nchannels too big for a C int"); |
| return NULL; |
| } |
| if (weightA < 1 || weightB < 0) { |
| PyErr_SetString(AudioopError, |
| "weightA should be >= 1, weightB should be >= 0"); |
| return NULL; |
| } |
| if (len % bytes_per_frame != 0) { |
| PyErr_SetString(AudioopError, "not a whole number of frames"); |
| return NULL; |
| } |
| if (inrate <= 0 || outrate <= 0) { |
| PyErr_SetString(AudioopError, "sampling rate not > 0"); |
| return NULL; |
| } |
| /* divide inrate and outrate by their greatest common divisor */ |
| d = gcd(inrate, outrate); |
| inrate /= d; |
| outrate /= d; |
| |
| alloc_size = sizeof(int) * (unsigned)nchannels; |
| if (alloc_size < nchannels) { |
| PyErr_SetString(PyExc_MemoryError, |
| "not enough memory for output buffer"); |
| return 0; |
| } |
| prev_i = (int *) malloc(alloc_size); |
| cur_i = (int *) malloc(alloc_size); |
| if (prev_i == NULL || cur_i == NULL) { |
| (void) PyErr_NoMemory(); |
| goto exit; |
| } |
| |
| len /= bytes_per_frame; /* # of frames */ |
| |
| if (state == Py_None) { |
| d = -outrate; |
| for (chan = 0; chan < nchannels; chan++) |
| prev_i[chan] = cur_i[chan] = 0; |
| } |
| else { |
| if (!PyArg_ParseTuple(state, |
| "iO!;audioop.ratecv: illegal state argument", |
| &d, &PyTuple_Type, &samps)) |
| goto exit; |
| if (PyTuple_Size(samps) != nchannels) { |
| PyErr_SetString(AudioopError, |
| "illegal state argument"); |
| goto exit; |
| } |
| for (chan = 0; chan < nchannels; chan++) { |
| if (!PyArg_ParseTuple(PyTuple_GetItem(samps, chan), |
| "ii:ratecv", &prev_i[chan], |
| &cur_i[chan])) |
| goto exit; |
| } |
| } |
| |
| /* str <- Space for the output buffer. */ |
| { |
| /* There are len input frames, so we need (mathematically) |
| ceiling(len*outrate/inrate) output frames, and each frame |
| requires bytes_per_frame bytes. Computing this |
| without spurious overflow is the challenge; we can |
| settle for a reasonable upper bound, though. */ |
| int ceiling; /* the number of output frames */ |
| int nbytes; /* the number of output bytes needed */ |
| int q = len / inrate; |
| /* Now len = q * inrate + r exactly (with r = len % inrate), |
| and this is less than q * inrate + inrate = (q+1)*inrate. |
| So a reasonable upper bound on len*outrate/inrate is |
| ((q+1)*inrate)*outrate/inrate = |
| (q+1)*outrate. |
| */ |
| ceiling = (q+1) * outrate; |
| nbytes = ceiling * bytes_per_frame; |
| /* See whether anything overflowed; if not, get the space. */ |
| if (q+1 < 0 || |
| ceiling / outrate != q+1 || |
| nbytes / bytes_per_frame != ceiling) |
| str = NULL; |
| else |
| str = PyString_FromStringAndSize(NULL, nbytes); |
| |
| if (str == NULL) { |
| PyErr_SetString(PyExc_MemoryError, |
| "not enough memory for output buffer"); |
| goto exit; |
| } |
| } |
| ncp = PyString_AsString(str); |
| |
| for (;;) { |
| while (d < 0) { |
| if (len == 0) { |
| samps = PyTuple_New(nchannels); |
| if (samps == NULL) |
| goto exit; |
| for (chan = 0; chan < nchannels; chan++) |
| PyTuple_SetItem(samps, chan, |
| Py_BuildValue("(ii)", |
| prev_i[chan], |
| cur_i[chan])); |
| if (PyErr_Occurred()) |
| goto exit; |
| /* We have checked before that the length |
| * of the string fits into int. */ |
| len = (int)(ncp - PyString_AsString(str)); |
| if (len == 0) { |
| /*don't want to resize to zero length*/ |
| rv = PyString_FromStringAndSize("", 0); |
| Py_DECREF(str); |
| str = rv; |
| } else if (_PyString_Resize(&str, len) < 0) |
| goto exit; |
| rv = Py_BuildValue("(O(iO))", str, d, samps); |
| Py_DECREF(samps); |
| Py_DECREF(str); |
| goto exit; /* return rv */ |
| } |
| for (chan = 0; chan < nchannels; chan++) { |
| prev_i[chan] = cur_i[chan]; |
| if (size == 1) |
| cur_i[chan] = ((int)*CHARP(cp, 0)) << 8; |
| else if (size == 2) |
| cur_i[chan] = (int)*SHORTP(cp, 0); |
| else if (size == 4) |
| cur_i[chan] = ((int)*LONGP(cp, 0)) >> 16; |
| cp += size; |
| /* implements a simple digital filter */ |
| cur_i[chan] = |
| (weightA * cur_i[chan] + |
| weightB * prev_i[chan]) / |
| (weightA + weightB); |
| } |
| len--; |
| d += outrate; |
| } |
| while (d >= 0) { |
| for (chan = 0; chan < nchannels; chan++) { |
| cur_o = (prev_i[chan] * d + |
| cur_i[chan] * (outrate - d)) / |
| outrate; |
| if (size == 1) |
| *CHARP(ncp, 0) = (signed char)(cur_o >> 8); |
| else if (size == 2) |
| *SHORTP(ncp, 0) = (short)(cur_o); |
| else if (size == 4) |
| *LONGP(ncp, 0) = (Py_Int32)(cur_o<<16); |
| ncp += size; |
| } |
| d -= inrate; |
| } |
| } |
| exit: |
| if (prev_i != NULL) |
| free(prev_i); |
| if (cur_i != NULL) |
| free(cur_i); |
| return rv; |
| } |
| |
| static PyObject * |
| audioop_lin2ulaw(PyObject *self, PyObject *args) |
| { |
| signed char *cp; |
| unsigned char *ncp; |
| int len, size, val = 0; |
| PyObject *rv; |
| int i; |
| |
| if ( !PyArg_ParseTuple(args, "s#i:lin2ulaw", |
| &cp, &len, &size) ) |
| return 0 ; |
| |
| if ( size != 1 && size != 2 && size != 4) { |
| PyErr_SetString(AudioopError, "Size should be 1, 2 or 4"); |
| return 0; |
| } |
| |
| rv = PyString_FromStringAndSize(NULL, len/size); |
| if ( rv == 0 ) |
| return 0; |
| ncp = (unsigned char *)PyString_AsString(rv); |
| |
| for ( i=0; i < len; i += size ) { |
| if ( size == 1 ) val = ((int)*CHARP(cp, i)) << 8; |
| else if ( size == 2 ) val = (int)*SHORTP(cp, i); |
| else if ( size == 4 ) val = ((int)*LONGP(cp, i)) >> 16; |
| |
| *ncp++ = st_14linear2ulaw(val); |
| } |
| return rv; |
| } |
| |
| static PyObject * |
| audioop_ulaw2lin(PyObject *self, PyObject *args) |
| { |
| unsigned char *cp; |
| unsigned char cval; |
| signed char *ncp; |
| int len, new_len, size, val; |
| PyObject *rv; |
| int i; |
| |
| if ( !PyArg_ParseTuple(args, "s#i:ulaw2lin", |
| &cp, &len, &size) ) |
| return 0; |
| |
| if ( size != 1 && size != 2 && size != 4) { |
| PyErr_SetString(AudioopError, "Size should be 1, 2 or 4"); |
| return 0; |
| } |
| |
| new_len = len*size; |
| if (new_len < 0) { |
| PyErr_SetString(PyExc_MemoryError, |
| "not enough memory for output buffer"); |
| return 0; |
| } |
| rv = PyString_FromStringAndSize(NULL, new_len); |
| if ( rv == 0 ) |
| return 0; |
| ncp = (signed char *)PyString_AsString(rv); |
| |
| for ( i=0; i < new_len; i += size ) { |
| cval = *cp++; |
| val = st_ulaw2linear16(cval); |
| |
| if ( size == 1 ) *CHARP(ncp, i) = (signed char)(val >> 8); |
| else if ( size == 2 ) *SHORTP(ncp, i) = (short)(val); |
| else if ( size == 4 ) *LONGP(ncp, i) = (Py_Int32)(val<<16); |
| } |
| return rv; |
| } |
| |
| static PyObject * |
| audioop_lin2alaw(PyObject *self, PyObject *args) |
| { |
| signed char *cp; |
| unsigned char *ncp; |
| int len, size, val = 0; |
| PyObject *rv; |
| int i; |
| |
| if ( !PyArg_ParseTuple(args, "s#i:lin2alaw", |
| &cp, &len, &size) ) |
| return 0; |
| |
| if ( size != 1 && size != 2 && size != 4) { |
| PyErr_SetString(AudioopError, "Size should be 1, 2 or 4"); |
| return 0; |
| } |
| |
| rv = PyString_FromStringAndSize(NULL, len/size); |
| if ( rv == 0 ) |
| return 0; |
| ncp = (unsigned char *)PyString_AsString(rv); |
| |
| for ( i=0; i < len; i += size ) { |
| if ( size == 1 ) val = ((int)*CHARP(cp, i)) << 8; |
| else if ( size == 2 ) val = (int)*SHORTP(cp, i); |
| else if ( size == 4 ) val = ((int)*LONGP(cp, i)) >> 16; |
| |
| *ncp++ = st_linear2alaw(val); |
| } |
| return rv; |
| } |
| |
| static PyObject * |
| audioop_alaw2lin(PyObject *self, PyObject *args) |
| { |
| unsigned char *cp; |
| unsigned char cval; |
| signed char *ncp; |
| int len, new_len, size, val; |
| PyObject *rv; |
| int i; |
| |
| if ( !PyArg_ParseTuple(args, "s#i:alaw2lin", |
| &cp, &len, &size) ) |
| return 0; |
| |
| if ( size != 1 && size != 2 && size != 4) { |
| PyErr_SetString(AudioopError, "Size should be 1, 2 or 4"); |
| return 0; |
| } |
| |
| new_len = len*size; |
| if (new_len < 0) { |
| PyErr_SetString(PyExc_MemoryError, |
| "not enough memory for output buffer"); |
| return 0; |
| } |
| rv = PyString_FromStringAndSize(NULL, new_len); |
| if ( rv == 0 ) |
| return 0; |
| ncp = (signed char *)PyString_AsString(rv); |
| |
| for ( i=0; i < new_len; i += size ) { |
| cval = *cp++; |
| val = st_alaw2linear16(cval); |
| |
| if ( size == 1 ) *CHARP(ncp, i) = (signed char)(val >> 8); |
| else if ( size == 2 ) *SHORTP(ncp, i) = (short)(val); |
| else if ( size == 4 ) *LONGP(ncp, i) = (Py_Int32)(val<<16); |
| } |
| return rv; |
| } |
| |
| static PyObject * |
| audioop_lin2adpcm(PyObject *self, PyObject *args) |
| { |
| signed char *cp; |
| signed char *ncp; |
| int len, size, val = 0, step, valpred, delta, |
| index, sign, vpdiff, diff; |
| PyObject *rv, *state, *str; |
| int i, outputbuffer = 0, bufferstep; |
| |
| if ( !PyArg_ParseTuple(args, "s#iO:lin2adpcm", |
| &cp, &len, &size, &state) ) |
| return 0; |
| |
| |
| if ( size != 1 && size != 2 && size != 4) { |
| PyErr_SetString(AudioopError, "Size should be 1, 2 or 4"); |
| return 0; |
| } |
| |
| str = PyString_FromStringAndSize(NULL, len/(size*2)); |
| if ( str == 0 ) |
| return 0; |
| ncp = (signed char *)PyString_AsString(str); |
| |
| /* Decode state, should have (value, step) */ |
| if ( state == Py_None ) { |
| /* First time, it seems. Set defaults */ |
| valpred = 0; |
| step = 7; |
| index = 0; |
| } else if ( !PyArg_ParseTuple(state, "ii", &valpred, &index) ) |
| return 0; |
| |
| step = stepsizeTable[index]; |
| bufferstep = 1; |
| |
| for ( i=0; i < len; i += size ) { |
| if ( size == 1 ) val = ((int)*CHARP(cp, i)) << 8; |
| else if ( size == 2 ) val = (int)*SHORTP(cp, i); |
| else if ( size == 4 ) val = ((int)*LONGP(cp, i)) >> 16; |
| |
| /* Step 1 - compute difference with previous value */ |
| diff = val - valpred; |
| sign = (diff < 0) ? 8 : 0; |
| if ( sign ) diff = (-diff); |
| |
| /* Step 2 - Divide and clamp */ |
| /* Note: |
| ** This code *approximately* computes: |
| ** delta = diff*4/step; |
| ** vpdiff = (delta+0.5)*step/4; |
| ** but in shift step bits are dropped. The net result of this |
| ** is that even if you have fast mul/div hardware you cannot |
| ** put it to good use since the fixup would be too expensive. |
| */ |
| delta = 0; |
| vpdiff = (step >> 3); |
| |
| if ( diff >= step ) { |
| delta = 4; |
| diff -= step; |
| vpdiff += step; |
| } |
| step >>= 1; |
| if ( diff >= step ) { |
| delta |= 2; |
| diff -= step; |
| vpdiff += step; |
| } |
| step >>= 1; |
| if ( diff >= step ) { |
| delta |= 1; |
| vpdiff += step; |
| } |
| |
| /* Step 3 - Update previous value */ |
| if ( sign ) |
| valpred -= vpdiff; |
| else |
| valpred += vpdiff; |
| |
| /* Step 4 - Clamp previous value to 16 bits */ |
| if ( valpred > 32767 ) |
| valpred = 32767; |
| else if ( valpred < -32768 ) |
| valpred = -32768; |
| |
| /* Step 5 - Assemble value, update index and step values */ |
| delta |= sign; |
| |
| index += indexTable[delta]; |
| if ( index < 0 ) index = 0; |
| if ( index > 88 ) index = 88; |
| step = stepsizeTable[index]; |
| |
| /* Step 6 - Output value */ |
| if ( bufferstep ) { |
| outputbuffer = (delta << 4) & 0xf0; |
| } else { |
| *ncp++ = (delta & 0x0f) | outputbuffer; |
| } |
| bufferstep = !bufferstep; |
| } |
| rv = Py_BuildValue("(O(ii))", str, valpred, index); |
| Py_DECREF(str); |
| return rv; |
| } |
| |
| static PyObject * |
| audioop_adpcm2lin(PyObject *self, PyObject *args) |
| { |
| signed char *cp; |
| signed char *ncp; |
| int len, new_len, size, valpred, step, delta, index, sign, vpdiff; |
| PyObject *rv, *str, *state; |
| int i, inputbuffer = 0, bufferstep; |
| |
| if ( !PyArg_ParseTuple(args, "s#iO:adpcm2lin", |
| &cp, &len, &size, &state) ) |
| return 0; |
| |
| if ( size != 1 && size != 2 && size != 4) { |
| PyErr_SetString(AudioopError, "Size should be 1, 2 or 4"); |
| return 0; |
| } |
| |
| /* Decode state, should have (value, step) */ |
| if ( state == Py_None ) { |
| /* First time, it seems. Set defaults */ |
| valpred = 0; |
| step = 7; |
| index = 0; |
| } else if ( !PyArg_ParseTuple(state, "ii", &valpred, &index) ) |
| return 0; |
| |
| new_len = len*size*2; |
| if (new_len < 0) { |
| PyErr_SetString(PyExc_MemoryError, |
| "not enough memory for output buffer"); |
| return 0; |
| } |
| str = PyString_FromStringAndSize(NULL, new_len); |
| if ( str == 0 ) |
| return 0; |
| ncp = (signed char *)PyString_AsString(str); |
| |
| step = stepsizeTable[index]; |
| bufferstep = 0; |
| |
| for ( i=0; i < new_len; i += size ) { |
| /* Step 1 - get the delta value and compute next index */ |
| if ( bufferstep ) { |
| delta = inputbuffer & 0xf; |
| } else { |
| inputbuffer = *cp++; |
| delta = (inputbuffer >> 4) & 0xf; |
| } |
| |
| bufferstep = !bufferstep; |
| |
| /* Step 2 - Find new index value (for later) */ |
| index += indexTable[delta]; |
| if ( index < 0 ) index = 0; |
| if ( index > 88 ) index = 88; |
| |
| /* Step 3 - Separate sign and magnitude */ |
| sign = delta & 8; |
| delta = delta & 7; |
| |
| /* Step 4 - Compute difference and new predicted value */ |
| /* |
| ** Computes 'vpdiff = (delta+0.5)*step/4', but see comment |
| ** in adpcm_coder. |
| */ |
| vpdiff = step >> 3; |
| if ( delta & 4 ) vpdiff += step; |
| if ( delta & 2 ) vpdiff += step>>1; |
| if ( delta & 1 ) vpdiff += step>>2; |
| |
| if ( sign ) |
| valpred -= vpdiff; |
| else |
| valpred += vpdiff; |
| |
| /* Step 5 - clamp output value */ |
| if ( valpred > 32767 ) |
| valpred = 32767; |
| else if ( valpred < -32768 ) |
| valpred = -32768; |
| |
| /* Step 6 - Update step value */ |
| step = stepsizeTable[index]; |
| |
| /* Step 6 - Output value */ |
| if ( size == 1 ) *CHARP(ncp, i) = (signed char)(valpred >> 8); |
| else if ( size == 2 ) *SHORTP(ncp, i) = (short)(valpred); |
| else if ( size == 4 ) *LONGP(ncp, i) = (Py_Int32)(valpred<<16); |
| } |
| |
| rv = Py_BuildValue("(O(ii))", str, valpred, index); |
| Py_DECREF(str); |
| return rv; |
| } |
| |
| static PyMethodDef audioop_methods[] = { |
| { "max", audioop_max, METH_VARARGS }, |
| { "minmax", audioop_minmax, METH_VARARGS }, |
| { "avg", audioop_avg, METH_VARARGS }, |
| { "maxpp", audioop_maxpp, METH_VARARGS }, |
| { "avgpp", audioop_avgpp, METH_VARARGS }, |
| { "rms", audioop_rms, METH_VARARGS }, |
| { "findfit", audioop_findfit, METH_VARARGS }, |
| { "findmax", audioop_findmax, METH_VARARGS }, |
| { "findfactor", audioop_findfactor, METH_VARARGS }, |
| { "cross", audioop_cross, METH_VARARGS }, |
| { "mul", audioop_mul, METH_VARARGS }, |
| { "add", audioop_add, METH_VARARGS }, |
| { "bias", audioop_bias, METH_VARARGS }, |
| { "ulaw2lin", audioop_ulaw2lin, METH_VARARGS }, |
| { "lin2ulaw", audioop_lin2ulaw, METH_VARARGS }, |
| { "alaw2lin", audioop_alaw2lin, METH_VARARGS }, |
| { "lin2alaw", audioop_lin2alaw, METH_VARARGS }, |
| { "lin2lin", audioop_lin2lin, METH_VARARGS }, |
| { "adpcm2lin", audioop_adpcm2lin, METH_VARARGS }, |
| { "lin2adpcm", audioop_lin2adpcm, METH_VARARGS }, |
| { "tomono", audioop_tomono, METH_VARARGS }, |
| { "tostereo", audioop_tostereo, METH_VARARGS }, |
| { "getsample", audioop_getsample, METH_VARARGS }, |
| { "reverse", audioop_reverse, METH_VARARGS }, |
| { "ratecv", audioop_ratecv, METH_VARARGS }, |
| { 0, 0 } |
| }; |
| |
| PyMODINIT_FUNC |
| initaudioop(void) |
| { |
| PyObject *m, *d; |
| m = Py_InitModule("audioop", audioop_methods); |
| if (m == NULL) |
| return; |
| d = PyModule_GetDict(m); |
| if (d == NULL) |
| return; |
| AudioopError = PyErr_NewException("audioop.error", NULL, NULL); |
| if (AudioopError != NULL) |
| PyDict_SetItemString(d,"error",AudioopError); |
| } |
