--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/symbian-qemu-0.9.1-12/python-2.6.1/Modules/audioop.c Fri Jul 31 15:01:17 2009 +0100
@@ -0,0 +1,1655 @@
+
+/* 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);
+}