dmlib: src/dmfft.c annotate

annotate src/dmfft.c @ 812:1e5cf1144f36

Move library source under src/ subdirectory.

author	Matti Hamalainen <ccr@tnsp.org>
date	Fri, 16 May 2014 03:22:39 +0300
parents	dmfft.c@95d9bd557a54
children	e06abfde6c39

rev	line source
749 44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	1 /*
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	2 * Realfftf
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	3 * Originally (C) Copyright 1993 Philib Van Baren
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	4 * Cleaned up and refactored to be re-entrant by
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	5 * Matti 'ccr' Hamalainen <ccr@tnsp.org>, 2013
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	6 *
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	7 * Note: Output is BIT-REVERSED! so you must use the BitReversed to
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	8 * get legible output, (i.e. Real_i = buffer[ BitReversed[i] ]
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	9 * Imag_i = buffer[ BitReversed[i]+1 ] )
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	10 * Input is in normal order.
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	11 */
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	12 #include "dmfft.h"
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	13 #include <math.h>
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	14
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	15
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	16 int dmInitializeFFT(DMFFTContext * ctx, const int fftlen)
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	17 {
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	18 int i;
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	19
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	20 if (ctx == NULL)
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	21 return DMERR_NULLPTR;
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	22
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	23 if (fftlen <= 16)
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	24 return DMERR_INVALID_ARGS;
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	25
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	26 // Allocate necessary tables
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	27 ctx->npoints = fftlen / 2;
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	28 ctx->sinTable = (DMFFTType ) dmMalloc(fftlen sizeof(DMFFTType));
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	29 if (ctx->sinTable == NULL)
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	30 return DMERR_MALLOC;
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	31
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	32 // Bitreversion buffer
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	33 ctx->breversed = (int ) dmMalloc(ctx->npoints sizeof(int));
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	34 if (ctx->breversed == NULL)
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	35 {
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	36 dmFree(ctx->sinTable);
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	37 return DMERR_MALLOC;
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	38 }
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	39
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	40 // Calculate data
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	41 for (i = 0; i < ctx->npoints; i++)
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	42 {
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	43 int mask, tmp;
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	44 for (tmp = 0, mask = ctx->npoints / 2; mask > 0; mask >>= 1)
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	45 {
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	46 tmp = (tmp >> 1) + ((i & mask) ? ctx->npoints : 0);
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	47 }
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	48
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	49 ctx->breversed[i] = tmp;
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	50 }
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	51
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	52 for (i = 0; i < ctx->npoints; i++)
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	53 {
751 817e792d9360 Use DM_PI instead of M_PI. Matti Hamalainen <ccr@tnsp.org> parents: 750 diff changeset	54 ctx->sinTable[ctx->breversed[i]] = -sin((2.0f * DM_PI * i) / fftlen);
749 44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	55 ctx->sinTable[ctx->breversed[i] + 1] =
751 817e792d9360 Use DM_PI instead of M_PI. Matti Hamalainen <ccr@tnsp.org> parents: 750 diff changeset	56 -cos((2.0f * DM_PI * i) / fftlen);
749 44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	57 }
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	58
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	59 return DMERR_OK;
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	60 }
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	61
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	62
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	63 void dmEndFFT(DMFFTContext * ctx)
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	64 {
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	65 if (ctx != NULL)
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	66 {
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	67 dmFree(ctx->breversed);
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	68 dmFree(ctx->sinTable);
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	69 memset(ctx, 0, sizeof(DMFFTContext));
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	70 }
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	71 }
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	72
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	73
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	74 int dmRealFFT(DMFFTContext * ctx, DMFFTType * buffer)
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	75 {
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	76 if (ctx == NULL \|\| buffer == NULL)
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	77 return DMERR_NULLPTR;
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	78
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	79 int rounds = ctx->npoints / 2;
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	80 DMFFTType endptr1 = buffer + ctx->npoints 2;
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	81
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	82 while (rounds > 0)
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	83 {
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	84 DMFFTType *sptr = ctx->sinTable;
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	85 DMFFTType *A = buffer,
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	86 B = buffer + rounds 2;
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	87
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	88 while (A < endptr1)
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	89 {
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	90 DMFFTType qsin = *sptr;
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	91 DMFFTType qcos = *(sptr + 1);
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	92 DMFFTType *endptr2 = B;
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	93
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	94 while (A < endptr2)
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	95 {
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	96 DMFFTType v1 = (B) qcos + ((B + 1)) qsin;
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	97 DMFFTType v2 = (B) qsin - ((B + 1)) qcos;
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	98 B = (A + v1) * 0.5;
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	99 (A++) = (B++) - v1;
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	100 B = (A - v2) * 0.5;
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	101 (A++) = (B++) + v2;
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	102 }
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	103 A = B;
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	104 B += rounds * 2;
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	105 sptr += 2;
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	106 }
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	107
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	108 rounds >>= 1;
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	109 }
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	110
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	111 /*
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	112 * Massage output to get the output for a real input sequence.
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	113 */
772 59df354b99cc Add some utility functions in the FFT module. Matti Hamalainen <ccr@tnsp.org> parents: 751 diff changeset	114 const int *br1 = ctx->breversed + 1;
59df354b99cc Add some utility functions in the FFT module. Matti Hamalainen <ccr@tnsp.org> parents: 751 diff changeset	115 const int *br2 = ctx->breversed + ctx->npoints - 1;
749 44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	116
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	117 while (br1 <= br2)
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	118 {
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	119 const DMFFTType vsin = ctx->sinTable[*br1];
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	120 const DMFFTType vcos = ctx->sinTable[*br1 + 1];
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	121 DMFFTType A = buffer + br1,
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	122 B = buffer + br2,
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	123 HRplus, HRminus,
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	124 HIplus, HIminus,
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	125 tmp1, tmp2;
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	126
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	127 HRminus = A - B;
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	128 HRplus = HRminus + (B 2);
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	129
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	130 HIminus = (A + 1) - (B + 1);
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	131 HIplus = HIminus + ((B + 1) 2);
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	132
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	133 tmp1 = (vsin * HRminus) - (vcos * HIplus);
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	134 tmp2 = (vcos * HRminus) + (vsin * HIplus);
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	135
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	136 A = (HRplus + tmp1) 0.5f;
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	137 B = A - tmp1;
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	138
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	139 (A + 1) = (HIminus + tmp2) 0.5f;
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	140 (B + 1) = ((A + 1)) - HIminus;
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	141
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	142 br1++;
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	143 br2--;
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	144 }
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	145
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	146 // Handle DC bin separately
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	147 buffer[0] += buffer[1];
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	148 buffer[1] = 0;
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	149
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	150 return DMERR_OK;
44138892c784 Add FFT routines. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	151 }
750 e6d807ce715b Add two more functions for converting FFT data to frequency and time Matti Hamalainen <ccr@tnsp.org> parents: 749 diff changeset	152
e6d807ce715b Add two more functions for converting FFT data to frequency and time Matti Hamalainen <ccr@tnsp.org> parents: 749 diff changeset	153
772 59df354b99cc Add some utility functions in the FFT module. Matti Hamalainen <ccr@tnsp.org> parents: 751 diff changeset	154 int dmConvertFFTtoFreqDomain(DMFFTContext ctx, DMFFTType buffer,
59df354b99cc Add some utility functions in the FFT module. Matti Hamalainen <ccr@tnsp.org> parents: 751 diff changeset	155 DMFFTType real, DMFFTType imag)
750 e6d807ce715b Add two more functions for converting FFT data to frequency and time Matti Hamalainen <ccr@tnsp.org> parents: 749 diff changeset	156 {
e6d807ce715b Add two more functions for converting FFT data to frequency and time Matti Hamalainen <ccr@tnsp.org> parents: 749 diff changeset	157 int i;
e6d807ce715b Add two more functions for converting FFT data to frequency and time Matti Hamalainen <ccr@tnsp.org> parents: 749 diff changeset	158 if (ctx == NULL \|\| buffer == NULL \|\| real == NULL \|\| imag == NULL)
e6d807ce715b Add two more functions for converting FFT data to frequency and time Matti Hamalainen <ccr@tnsp.org> parents: 749 diff changeset	159 return DMERR_NULLPTR;
e6d807ce715b Add two more functions for converting FFT data to frequency and time Matti Hamalainen <ccr@tnsp.org> parents: 749 diff changeset	160
e6d807ce715b Add two more functions for converting FFT data to frequency and time Matti Hamalainen <ccr@tnsp.org> parents: 749 diff changeset	161 // Convert from bitreversed form to normal frequency domain
772 59df354b99cc Add some utility functions in the FFT module. Matti Hamalainen <ccr@tnsp.org> parents: 751 diff changeset	162 const int *breversed = ctx->breversed;
59df354b99cc Add some utility functions in the FFT module. Matti Hamalainen <ccr@tnsp.org> parents: 751 diff changeset	163
750 e6d807ce715b Add two more functions for converting FFT data to frequency and time Matti Hamalainen <ccr@tnsp.org> parents: 749 diff changeset	164 for (i = 1; i < ctx->npoints; i++)
e6d807ce715b Add two more functions for converting FFT data to frequency and time Matti Hamalainen <ccr@tnsp.org> parents: 749 diff changeset	165 {
772 59df354b99cc Add some utility functions in the FFT module. Matti Hamalainen <ccr@tnsp.org> parents: 751 diff changeset	166 real[i] = buffer[breversed[i] ];
59df354b99cc Add some utility functions in the FFT module. Matti Hamalainen <ccr@tnsp.org> parents: 751 diff changeset	167 imag[i] = buffer[breversed[i]+1];
750 e6d807ce715b Add two more functions for converting FFT data to frequency and time Matti Hamalainen <ccr@tnsp.org> parents: 749 diff changeset	168 }
e6d807ce715b Add two more functions for converting FFT data to frequency and time Matti Hamalainen <ccr@tnsp.org> parents: 749 diff changeset	169
e6d807ce715b Add two more functions for converting FFT data to frequency and time Matti Hamalainen <ccr@tnsp.org> parents: 749 diff changeset	170 // Make the ends meet
e6d807ce715b Add two more functions for converting FFT data to frequency and time Matti Hamalainen <ccr@tnsp.org> parents: 749 diff changeset	171 real[0] = buffer[0];
e6d807ce715b Add two more functions for converting FFT data to frequency and time Matti Hamalainen <ccr@tnsp.org> parents: 749 diff changeset	172 imag[0] = 0;
e6d807ce715b Add two more functions for converting FFT data to frequency and time Matti Hamalainen <ccr@tnsp.org> parents: 749 diff changeset	173 real[ctx->npoints] = buffer[1];
e6d807ce715b Add two more functions for converting FFT data to frequency and time Matti Hamalainen <ccr@tnsp.org> parents: 749 diff changeset	174 imag[ctx->npoints] = 0;
e6d807ce715b Add two more functions for converting FFT data to frequency and time Matti Hamalainen <ccr@tnsp.org> parents: 749 diff changeset	175
e6d807ce715b Add two more functions for converting FFT data to frequency and time Matti Hamalainen <ccr@tnsp.org> parents: 749 diff changeset	176 return DMERR_OK;
e6d807ce715b Add two more functions for converting FFT data to frequency and time Matti Hamalainen <ccr@tnsp.org> parents: 749 diff changeset	177 }
e6d807ce715b Add two more functions for converting FFT data to frequency and time Matti Hamalainen <ccr@tnsp.org> parents: 749 diff changeset	178
e6d807ce715b Add two more functions for converting FFT data to frequency and time Matti Hamalainen <ccr@tnsp.org> parents: 749 diff changeset	179
772 59df354b99cc Add some utility functions in the FFT module. Matti Hamalainen <ccr@tnsp.org> parents: 751 diff changeset	180 #define DM_PW(a, b, c) sqrt(a * a + b * b) * c
59df354b99cc Add some utility functions in the FFT module. Matti Hamalainen <ccr@tnsp.org> parents: 751 diff changeset	181
59df354b99cc Add some utility functions in the FFT module. Matti Hamalainen <ccr@tnsp.org> parents: 751 diff changeset	182
59df354b99cc Add some utility functions in the FFT module. Matti Hamalainen <ccr@tnsp.org> parents: 751 diff changeset	183 int dmConvertFFTtoFreqAndPower(DMFFTContext ctx, DMFFTType buffer,
59df354b99cc Add some utility functions in the FFT module. Matti Hamalainen <ccr@tnsp.org> parents: 751 diff changeset	184 DMFFTType real, DMFFTType imag, DMFFTType *power, const DMFFTType scale)
59df354b99cc Add some utility functions in the FFT module. Matti Hamalainen <ccr@tnsp.org> parents: 751 diff changeset	185 {
59df354b99cc Add some utility functions in the FFT module. Matti Hamalainen <ccr@tnsp.org> parents: 751 diff changeset	186 int i;
59df354b99cc Add some utility functions in the FFT module. Matti Hamalainen <ccr@tnsp.org> parents: 751 diff changeset	187 if (ctx == NULL \|\| buffer == NULL \|\| real == NULL \|\| imag == NULL \|\| power == NULL)
59df354b99cc Add some utility functions in the FFT module. Matti Hamalainen <ccr@tnsp.org> parents: 751 diff changeset	188 return DMERR_NULLPTR;
59df354b99cc Add some utility functions in the FFT module. Matti Hamalainen <ccr@tnsp.org> parents: 751 diff changeset	189
59df354b99cc Add some utility functions in the FFT module. Matti Hamalainen <ccr@tnsp.org> parents: 751 diff changeset	190 // Convert from bitreversed form to normal frequency domain
59df354b99cc Add some utility functions in the FFT module. Matti Hamalainen <ccr@tnsp.org> parents: 751 diff changeset	191 const int *breversed = ctx->breversed;
59df354b99cc Add some utility functions in the FFT module. Matti Hamalainen <ccr@tnsp.org> parents: 751 diff changeset	192
59df354b99cc Add some utility functions in the FFT module. Matti Hamalainen <ccr@tnsp.org> parents: 751 diff changeset	193 for (i = 1; i < ctx->npoints; i++)
59df354b99cc Add some utility functions in the FFT module. Matti Hamalainen <ccr@tnsp.org> parents: 751 diff changeset	194 {
59df354b99cc Add some utility functions in the FFT module. Matti Hamalainen <ccr@tnsp.org> parents: 751 diff changeset	195 DMFFTType fre = real[i] = buffer[breversed[i] ],
59df354b99cc Add some utility functions in the FFT module. Matti Hamalainen <ccr@tnsp.org> parents: 751 diff changeset	196 fim = imag[i] = buffer[breversed[i]+1];
59df354b99cc Add some utility functions in the FFT module. Matti Hamalainen <ccr@tnsp.org> parents: 751 diff changeset	197
59df354b99cc Add some utility functions in the FFT module. Matti Hamalainen <ccr@tnsp.org> parents: 751 diff changeset	198 power[i] = DM_PW(fre, fim, scale);
59df354b99cc Add some utility functions in the FFT module. Matti Hamalainen <ccr@tnsp.org> parents: 751 diff changeset	199 }
59df354b99cc Add some utility functions in the FFT module. Matti Hamalainen <ccr@tnsp.org> parents: 751 diff changeset	200
59df354b99cc Add some utility functions in the FFT module. Matti Hamalainen <ccr@tnsp.org> parents: 751 diff changeset	201 // Make the ends meet
59df354b99cc Add some utility functions in the FFT module. Matti Hamalainen <ccr@tnsp.org> parents: 751 diff changeset	202 real[0] = buffer[0];
59df354b99cc Add some utility functions in the FFT module. Matti Hamalainen <ccr@tnsp.org> parents: 751 diff changeset	203 imag[0] = 0;
59df354b99cc Add some utility functions in the FFT module. Matti Hamalainen <ccr@tnsp.org> parents: 751 diff changeset	204 power[0] = DM_PW(buffer[0], 0, scale);
59df354b99cc Add some utility functions in the FFT module. Matti Hamalainen <ccr@tnsp.org> parents: 751 diff changeset	205
59df354b99cc Add some utility functions in the FFT module. Matti Hamalainen <ccr@tnsp.org> parents: 751 diff changeset	206 real[ctx->npoints] = buffer[1];
59df354b99cc Add some utility functions in the FFT module. Matti Hamalainen <ccr@tnsp.org> parents: 751 diff changeset	207 imag[ctx->npoints] = 0;
59df354b99cc Add some utility functions in the FFT module. Matti Hamalainen <ccr@tnsp.org> parents: 751 diff changeset	208 power[ctx->npoints] = DM_PW(buffer[1], 0, scale);
59df354b99cc Add some utility functions in the FFT module. Matti Hamalainen <ccr@tnsp.org> parents: 751 diff changeset	209
59df354b99cc Add some utility functions in the FFT module. Matti Hamalainen <ccr@tnsp.org> parents: 751 diff changeset	210 return DMERR_OK;
59df354b99cc Add some utility functions in the FFT module. Matti Hamalainen <ccr@tnsp.org> parents: 751 diff changeset	211 }
59df354b99cc Add some utility functions in the FFT module. Matti Hamalainen <ccr@tnsp.org> parents: 751 diff changeset	212
59df354b99cc Add some utility functions in the FFT module. Matti Hamalainen <ccr@tnsp.org> parents: 751 diff changeset	213
59df354b99cc Add some utility functions in the FFT module. Matti Hamalainen <ccr@tnsp.org> parents: 751 diff changeset	214 int dmConvertFFTtoPowerAndSum(DMFFTContext ctx, DMFFTType buffer,
59df354b99cc Add some utility functions in the FFT module. Matti Hamalainen <ccr@tnsp.org> parents: 751 diff changeset	215 DMFFTType power, const DMFFTType pscale, DMFFTType sum, const DMFFTType sscale)
59df354b99cc Add some utility functions in the FFT module. Matti Hamalainen <ccr@tnsp.org> parents: 751 diff changeset	216 {
59df354b99cc Add some utility functions in the FFT module. Matti Hamalainen <ccr@tnsp.org> parents: 751 diff changeset	217 int i;
59df354b99cc Add some utility functions in the FFT module. Matti Hamalainen <ccr@tnsp.org> parents: 751 diff changeset	218 if (ctx == NULL \|\| buffer == NULL \|\| power == NULL \|\| sum == NULL)
59df354b99cc Add some utility functions in the FFT module. Matti Hamalainen <ccr@tnsp.org> parents: 751 diff changeset	219 return DMERR_NULLPTR;
59df354b99cc Add some utility functions in the FFT module. Matti Hamalainen <ccr@tnsp.org> parents: 751 diff changeset	220
59df354b99cc Add some utility functions in the FFT module. Matti Hamalainen <ccr@tnsp.org> parents: 751 diff changeset	221 // Convert from bitreversed form to normal frequency domain
59df354b99cc Add some utility functions in the FFT module. Matti Hamalainen <ccr@tnsp.org> parents: 751 diff changeset	222 const int *breversed = ctx->breversed;
59df354b99cc Add some utility functions in the FFT module. Matti Hamalainen <ccr@tnsp.org> parents: 751 diff changeset	223 DMFFTType psum = 0;
59df354b99cc Add some utility functions in the FFT module. Matti Hamalainen <ccr@tnsp.org> parents: 751 diff changeset	224
59df354b99cc Add some utility functions in the FFT module. Matti Hamalainen <ccr@tnsp.org> parents: 751 diff changeset	225 for (i = 1; i < ctx->npoints; i++)
59df354b99cc Add some utility functions in the FFT module. Matti Hamalainen <ccr@tnsp.org> parents: 751 diff changeset	226 {
59df354b99cc Add some utility functions in the FFT module. Matti Hamalainen <ccr@tnsp.org> parents: 751 diff changeset	227 DMFFTType fre = buffer[breversed[i] ],
59df354b99cc Add some utility functions in the FFT module. Matti Hamalainen <ccr@tnsp.org> parents: 751 diff changeset	228 fim = buffer[breversed[i]+1],
59df354b99cc Add some utility functions in the FFT module. Matti Hamalainen <ccr@tnsp.org> parents: 751 diff changeset	229 fpw = sqrt(fre * fre + fim * fim);
59df354b99cc Add some utility functions in the FFT module. Matti Hamalainen <ccr@tnsp.org> parents: 751 diff changeset	230
59df354b99cc Add some utility functions in the FFT module. Matti Hamalainen <ccr@tnsp.org> parents: 751 diff changeset	231 power[i] = fpw * pscale;
59df354b99cc Add some utility functions in the FFT module. Matti Hamalainen <ccr@tnsp.org> parents: 751 diff changeset	232 psum += fpw * sscale;
59df354b99cc Add some utility functions in the FFT module. Matti Hamalainen <ccr@tnsp.org> parents: 751 diff changeset	233 }
59df354b99cc Add some utility functions in the FFT module. Matti Hamalainen <ccr@tnsp.org> parents: 751 diff changeset	234
59df354b99cc Add some utility functions in the FFT module. Matti Hamalainen <ccr@tnsp.org> parents: 751 diff changeset	235 // Make the ends meet
59df354b99cc Add some utility functions in the FFT module. Matti Hamalainen <ccr@tnsp.org> parents: 751 diff changeset	236 power[0] = DM_PW(buffer[0], 0, pscale);
59df354b99cc Add some utility functions in the FFT module. Matti Hamalainen <ccr@tnsp.org> parents: 751 diff changeset	237 power[ctx->npoints] = DM_PW(buffer[1], 0, pscale);
59df354b99cc Add some utility functions in the FFT module. Matti Hamalainen <ccr@tnsp.org> parents: 751 diff changeset	238
773 95d9bd557a54 Return the power sum variable in the FFT conversion. Matti Hamalainen <ccr@tnsp.org> parents: 772 diff changeset	239 *sum = psum;
95d9bd557a54 Return the power sum variable in the FFT conversion. Matti Hamalainen <ccr@tnsp.org> parents: 772 diff changeset	240
772 59df354b99cc Add some utility functions in the FFT module. Matti Hamalainen <ccr@tnsp.org> parents: 751 diff changeset	241 return DMERR_OK;
59df354b99cc Add some utility functions in the FFT module. Matti Hamalainen <ccr@tnsp.org> parents: 751 diff changeset	242 }
59df354b99cc Add some utility functions in the FFT module. Matti Hamalainen <ccr@tnsp.org> parents: 751 diff changeset	243
59df354b99cc Add some utility functions in the FFT module. Matti Hamalainen <ccr@tnsp.org> parents: 751 diff changeset	244
750 e6d807ce715b Add two more functions for converting FFT data to frequency and time Matti Hamalainen <ccr@tnsp.org> parents: 749 diff changeset	245 int dmConvertFFTtoTimeDomain(DMFFTContext ctx, DMFFTType buffer, DMFFTType *tdom)
e6d807ce715b Add two more functions for converting FFT data to frequency and time Matti Hamalainen <ccr@tnsp.org> parents: 749 diff changeset	246 {
772 59df354b99cc Add some utility functions in the FFT module. Matti Hamalainen <ccr@tnsp.org> parents: 751 diff changeset	247 int i, n;
750 e6d807ce715b Add two more functions for converting FFT data to frequency and time Matti Hamalainen <ccr@tnsp.org> parents: 749 diff changeset	248 if (ctx == NULL \|\| buffer == NULL \|\| tdom == NULL)
e6d807ce715b Add two more functions for converting FFT data to frequency and time Matti Hamalainen <ccr@tnsp.org> parents: 749 diff changeset	249 return DMERR_NULLPTR;
e6d807ce715b Add two more functions for converting FFT data to frequency and time Matti Hamalainen <ccr@tnsp.org> parents: 749 diff changeset	250
772 59df354b99cc Add some utility functions in the FFT module. Matti Hamalainen <ccr@tnsp.org> parents: 751 diff changeset	251 for (n = i = 0; i < ctx->npoints; i++, n += 2)
750 e6d807ce715b Add two more functions for converting FFT data to frequency and time Matti Hamalainen <ccr@tnsp.org> parents: 749 diff changeset	252 {
772 59df354b99cc Add some utility functions in the FFT module. Matti Hamalainen <ccr@tnsp.org> parents: 751 diff changeset	253 tdom[n ] = buffer[ctx->breversed[i] ];
59df354b99cc Add some utility functions in the FFT module. Matti Hamalainen <ccr@tnsp.org> parents: 751 diff changeset	254 tdom[n+1] = buffer[ctx->breversed[i]+1];
750 e6d807ce715b Add two more functions for converting FFT data to frequency and time Matti Hamalainen <ccr@tnsp.org> parents: 749 diff changeset	255 }
e6d807ce715b Add two more functions for converting FFT data to frequency and time Matti Hamalainen <ccr@tnsp.org> parents: 749 diff changeset	256
e6d807ce715b Add two more functions for converting FFT data to frequency and time Matti Hamalainen <ccr@tnsp.org> parents: 749 diff changeset	257 return DMERR_OK;
e6d807ce715b Add two more functions for converting FFT data to frequency and time Matti Hamalainen <ccr@tnsp.org> parents: 749 diff changeset	258 }

Mercurial > hg > dmlib

annotate src/dmfft.c @ 812:1e5cf1144f36