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changed alloc functions to allow for initialization of user-supplied buffer

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This commit is contained in:
Mark Borgerding
2003-12-14 03:02:30 +00:00
parent ab32979a47
commit 559c14b49b
11 changed files with 135 additions and 112 deletions
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81
kiss_fft.c
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@ -18,19 +18,6 @@ THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
fixed or floating point complex numbers. It also delares the kf_ internal functions.
*/
kiss_fft_cpx kf_cexp(double phase) /* returns e ** (j*phase) */
{
kiss_fft_cpx x;
#ifdef FIXED_POINT
x.r = (kiss_fft_scalar) ( 32767*cos(phase) );
x.i = (kiss_fft_scalar) ( 32767*sin(phase) );
#else
x.r = cos(phase);
x.i = sin(phase);
#endif
return x;
}
static void kf_bfly2(
kiss_fft_cpx * Fout,
int fstride,
@ -276,16 +263,6 @@ void kf_work(
}
}
int kf_allocsize(int nfft)
{
int allocsize = sizeof(kiss_fft_state)
+ sizeof(kiss_fft_cpx)*nfft /* twiddle factors*/
+ sizeof(kiss_fft_cpx)*nfft /* tmpbuf*/
+ sizeof(int)*nfft /* factors*/
+ sizeof(kiss_fft_cpx)*nfft; /* scratch*/
return allocsize;
}
/* facbuf is populated by p1,m1,p2,m2, ...
where
p[i] * m[i] = m[i-1]
@ -312,27 +289,6 @@ void kf_factor(int n,int * facbuf)
} while (n > 1);
}
void kf_init_state(kiss_fft_state * st,int nfft,int inverse_fft)
{
int i;
st->nfft=nfft;
st->inverse = inverse_fft;
st->twiddles = (kiss_fft_cpx*)(st+1); /* just beyond struct*/
st->tmpbuf = (kiss_fft_cpx*)(st->twiddles + nfft);/* just after twiddles*/
st->scratch = (kiss_fft_cpx*)(st->tmpbuf + nfft);
st->factors = (int*)(st->scratch + nfft);
for (i=0;i<nfft;++i) {
const double pi=3.14159265358979323846264338327;
double phase = ( -2*pi /nfft ) * i;
if (st->inverse)
phase *= -1;
st->twiddles[i] = kf_cexp( phase );
}
kf_factor(nfft,st->factors);
}
/*
* void * kiss_fft_alloc(int nfft,int inverse_fft)
*
@ -341,14 +297,41 @@ void kf_init_state(kiss_fft_state * st,int nfft,int inverse_fft)
* The return value is a contiguous block of memory, allocated with malloc. As such,
* It can be freed with free(), rather than a kiss_fft-specific function.
* */
void * kiss_fft_alloc(int nfft,int inverse_fft)
void * kiss_fft_alloc(int nfft,int inverse_fft,void * mem,size_t * lenmem )
{
kiss_fft_state * st=NULL;
size_t memneeded = sizeof(kiss_fft_state)
+ sizeof(kiss_fft_cpx)*nfft /* twiddle factors*/
+ sizeof(kiss_fft_cpx)*nfft /* tmpbuf*/
+ sizeof(int)*nfft /* factors*/
+ sizeof(kiss_fft_cpx)*nfft; /* scratch*/
st = ( kiss_fft_state *)malloc( kf_allocsize(nfft) );
if (!st)
return NULL;
kf_init_state( st ,nfft,inverse_fft );
if ( lenmem==NULL ) {
st = ( kiss_fft_state *)malloc( memneeded );
}else{
if (*lenmem >= memneeded)
st = ( kiss_fft_state *)mem;
*lenmem = memneeded;
}
if (st){
int i;
st->nfft=nfft;
st->inverse = inverse_fft;
st->twiddles = (kiss_fft_cpx*)(st+1); /* just beyond struct*/
st->tmpbuf = (kiss_fft_cpx*)(st->twiddles + nfft);/* just after twiddles*/
st->scratch = (kiss_fft_cpx*)(st->tmpbuf + nfft);
st->factors = (int*)(st->scratch + nfft);
for (i=0;i<nfft;++i) {
const double pi=3.14159265358979323846264338327;
double phase = ( -2*pi /nfft ) * i;
if (st->inverse)
phase *= -1;
st->twiddles[i] = kf_cexp( phase );
}
kf_factor(nfft,st->factors);
}
return st;
}