wirtz
/
OpenAudio_ArduinoLibrary
mirror of https://github.com/chipaudette/OpenAudio_ArduinoLibrary.git
1
0
Fork 0
Code Issues Releases Wiki Activity

Removed nonsense register modifier

Browse Source
master
boblark 2 months ago
parent 8f091dad1e
commit 5113b5394b
1 changed files with 49 additions and 48 deletions
Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL
Show Stats Download Patch File Download Diff File
  1. 97
      utility/BTNRH_rfft.cpp

97
utility/BTNRH_rfft.cpp
Unescape View File

@ -18,18 +18,19 @@ namespace BTNRH_FFT {
ilog2(int n) ilog2(int n)
{ {
int m; int m;
for (m = 1; m < 32; m++) for (m = 1; m < 32; m++)
if (n == (1 << m)) if (n == (1 << m))
return (m); return (m);
return (-1); return (-1);
} }
static __inline int static __inline int
bitrev(int ii, int m) bitrev(int ii, int m)
{ {
register int jj; // Was: register int jj; RSL 9 Oct 2024
int jj;
jj = ii & 1; jj = ii & 1;
--m; --m;
while (--m > 0) { while (--m > 0) {
@ -39,26 +40,26 @@ namespace BTNRH_FFT {
} }
return (jj); return (jj);
} }
static __inline void static __inline void
rad2(int ii, float *x0, float *x1) rad2(int ii, float *x0, float *x1)
{ {
int k; int k;
float t; float t;
for (k = 0; k < ii; k++) { for (k = 0; k < ii; k++) {
t = x0[k] + x1[k]; t = x0[k] + x1[k];
x1[k] = x0[k] - x1[k]; x1[k] = x0[k] - x1[k];
x0[k] = t; x0[k] = t;
} }
} }
static __inline void static __inline void
reorder1(int m, float *x) reorder1(int m, float *x)
{ {
int j, k, kl, n; int j, k, kl, n;
float t; float t;
k = 4; k = 4;
kl = 2; kl = 2;
n = 1 << m; n = 1 << m;
@ -75,13 +76,13 @@ namespace BTNRH_FFT {
} }
} }
} }
static __inline void static __inline void
reorder2(int m, float *x) reorder2(int m, float *x)
{ {
int ji, ij, n; int ji, ij, n;
float t; float t;
n = 1 << m; n = 1 << m;
for (ij = 0; ij <= (n - 2); ij += 2) { for (ij = 0; ij <= (n - 2); ij += 2) {
ji = bitrev(ij >> 1, m) << 1; ji = bitrev(ij >> 1, m) << 1;
@ -95,11 +96,11 @@ namespace BTNRH_FFT {
} }
} }
} }
/***********************************************************/ /***********************************************************/
// rcfft // rcfft
static void static void
rcrad4(int ii, int nn, rcrad4(int ii, int nn,
float *x0, float *x1, float *x2, float *x3, float *x0, float *x1, float *x2, float *x3,
@ -109,7 +110,7 @@ namespace BTNRH_FFT {
float c1, c2, c3, s1, s2, s3, pr, pi, r1, r5; float c1, c2, c3, s1, s2, s3, pr, pi, r1, r5;
float t0, t1, t2, t3, t4, t5, t6, t7; float t0, t1, t2, t3, t4, t5, t6, t7;
int i0, i4, j, j0, ji, jl, jr, jlast, k, k0, kl, m, n, ni; int i0, i4, j, j0, ji, jl, jr, jlast, k, k0, kl, m, n, ni;
n = nn / 4; n = nn / 4;
for (m = 1; (1 << m) < n; m++) for (m = 1; (1 << m) < n; m++)
continue; continue;
@ -186,19 +187,19 @@ namespace BTNRH_FFT {
} }
} }
} }
//----------------------------------------------------------- //-----------------------------------------------------------
static int static int
rcfft2(float *x, int m) rcfft2(float *x, int m)
{ {
int ii, nn, m2, it, n; int ii, nn, m2, it, n;
n = 1 << m;; n = 1 << m;;
m2 = m / 2; m2 = m / 2;
// radix 2 // radix 2
if (m <= m2 * 2) { if (m <= m2 * 2) {
nn = 1; nn = 1;
} else { } else {
@ -206,9 +207,9 @@ namespace BTNRH_FFT {
ii = n / nn; ii = n / nn;
rad2(ii, x, x + ii); rad2(ii, x, x + ii);
} }
// radix 4 // radix 4
if (m2 != 0) { if (m2 != 0) {
for (it = 0; it < m2; it++) { for (it = 0; it < m2; it++) {
nn = nn * 4; nn = nn * 4;
@ -217,9 +218,9 @@ namespace BTNRH_FFT {
x, x + ii, x + 2 * ii, x + 3 * ii); x, x + ii, x + 2 * ii, x + 3 * ii);
} }
} }
// re-order // re-order
reorder1(m, x); reorder1(m, x);
reorder2(m, x); reorder2(m, x);
for (it = 3; it < n; it += 2) for (it = 3; it < n; it += 2)
@ -227,14 +228,14 @@ namespace BTNRH_FFT {
x[n] = x[1]; x[n] = x[1];
x[1] = 0.0; x[1] = 0.0;
x[n + 1] = 0.0; x[n + 1] = 0.0;
return (0); return (0);
} }
/***********************************************************/ /***********************************************************/
// rcfft // rcfft
static void static void
crrad4(int jj, int nn, crrad4(int jj, int nn,
float *x0, float *x1, float *x2, float *x3, float *x0, float *x1, float *x2, float *x3,
@ -244,7 +245,7 @@ namespace BTNRH_FFT {
float c1, c2, c3, s1, s2, s3; float c1, c2, c3, s1, s2, s3;
float t0, t1, t2, t3, t4, t5, t6, t7; float t0, t1, t2, t3, t4, t5, t6, t7;
int ii, j, j0, ji, jr, jl, jlast, j4, k, k0, kl, m, n, ni; int ii, j, j0, ji, jr, jl, jlast, j4, k, k0, kl, m, n, ni;
tpiovn = 2 * M_PI / nn; tpiovn = 2 * M_PI / nn;
ji = 3; ji = 3;
jl = 2; jl = 2;
@ -317,27 +318,27 @@ namespace BTNRH_FFT {
} }
} }
} }
//----------------------------------------------------------- //-----------------------------------------------------------
static int static int
crfft2(float *x, int m) crfft2(float *x, int m)
{ {
int n, i, it, nn, jj, m2; int n, i, it, nn, jj, m2;
n = 1 << m; n = 1 << m;
x[1] = x[n]; x[1] = x[n];
m2 = m / 2; m2 = m / 2;
// re-order // re-order
for (i = 3; i < n; i += 2) for (i = 3; i < n; i += 2)
x[i] = -x[i]; x[i] = -x[i];
reorder2(m, x); reorder2(m, x);
reorder1(m, x); reorder1(m, x);
// radix 4 // radix 4
if (m2 != 0) { if (m2 != 0) {
nn = 4 * n; nn = 4 * n;
for (it = 0; it < m2; it++) { for (it = 0; it < m2; it++) {
@ -347,39 +348,39 @@ namespace BTNRH_FFT {
x, x + jj, x + 2 * jj, x + 3 * jj); x, x + jj, x + 2 * jj, x + 3 * jj);
} }
} }
// radix 2 // radix 2
if (m > m2 * 2) { if (m > m2 * 2) {
jj = n / 2; jj = n / 2;
rad2(jj, x, x + jj); rad2(jj, x, x + jj);
} }
return (0); return (0);
} }
/***********************************************************/ /***********************************************************/
// real-to-complex FFT // real-to-complex FFT
//FUNC(void) //FUNC(void)
void cha_fft_rc(float *x, int n) void cha_fft_rc(float *x, int n)
{ {
int m; int m;
// assume n is a power of two // assume n is a power of two
m = ilog2(n); m = ilog2(n);
rcfft2(x, m); rcfft2(x, m);
} }
// complex-to-real inverse FFT // complex-to-real inverse FFT
//FUNC(void) //FUNC(void)
void cha_fft_cr(float *x, int n) void cha_fft_cr(float *x, int n)
{ {
int i, m; int i, m;
// assume n is a power of two // assume n is a power of two
m = ilog2(n); m = ilog2(n);
crfft2(x, m); crfft2(x, m);
// scale inverse by 1/n // scale inverse by 1/n
@ -390,4 +391,4 @@ namespace BTNRH_FFT {
}; };
//endif //endif

Write Preview
Loading…
Cancel
Save