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cmProc5.h/c : Added cmGoldCode.

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This commit is contained in:
kevin 2015-07-03 12:36:54 -04:00
parent 032d359a90
commit b1ff1dfb07
2 changed files with 289 additions and 0 deletions
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220
cmProc5.c
View File

@ -16,7 +16,11 @@
#include "cmProcObj.h" #include "cmProcObj.h"
#include "cmProcTemplate.h" #include "cmProcTemplate.h"
#include "cmMath.h" #include "cmMath.h"
#include "cmFile.h"
#include "cmTime.h"
#include "cmMidi.h"
#include "cmProc.h" #include "cmProc.h"
#include "cmProc2.h"
#include "cmProc5.h" #include "cmProc5.h"
#include "cmVectOps.h" #include "cmVectOps.h"
@ -123,3 +127,219 @@ cmRC_t cmGoertzelExec( cmGoertzel* p, const cmSample_t* inpV, unsigned procSmpCn
} }
//=======================================================================================================================
double _cmGoldSigSinc( double t, double T )
{
double x = t/T;
return x == 0 ? 1.0 : sin(M_PI*x)/(M_PI*x);
}
void _cmGoldSigRaisedCos( cmSample_t* yV, int yN, double sPc, double beta )
{
int i;
for(i=0; i<yN; ++i)
{
double t = i - yN/2;
double den = 1 - (4*(beta*beta)*(t*t) / (sPc*sPc));
double a;
if(fabs(den) < 0.00001 )
a = 1;
else
a = cos(M_PI * beta * t/ sPc ) / den;
yV[i] = _cmGoldSigSinc(t,sPc) * a;
}
}
void _cmGoldSigConv( cmGoldSig_t* p, unsigned chIdx )
{
int i;
int sPc = p->a.samplesPerChip;
int osf = p->a.rcosOSFact;
// for each bit in the spreading-code
for(i=0; i<p->mlsN; ++i)
{
int j = (i*sPc) + sPc/2; // index into bbV[] of center of impulse response
int k = j - (sPc*osf)/2; // index into bbV[] of start of impulse response
int h;
// for each sample in the impulse response
for(h=0; h<p->rcosN; ++h,++k)
{
while( k<0 )
k += p->sigN;
while( k>=p->sigN )
k -= p->sigN;
p->ch[chIdx].bbV[k] += p->ch[chIdx].pnV[i] * p->rcosV[h];
}
}
}
void _cmGoldSigModulate( cmGoldSig_t* p, unsigned chIdx )
{
unsigned i;
double rps = 2.0 * M_PI * p->a.carrierHz / p->a.srate;
cmSample_t* yV = p->ch[chIdx].mdV;
cmSample_t* bbV = p->ch[chIdx].bbV;
for(i=0; i<p->sigN; ++i)
yV[ i ] = bbV[i]*cos(rps*i) + bbV[i]*sin(rps*i);
// apply a half Hann envelope to the onset/offset of the id signal
if( p->a.envMs > 0 )
{
unsigned wndMs = p->a.envMs * 2;
unsigned wndN = wndMs * p->a.srate / 1000;
wndN += wndN % 2 ? 0 : 1; // force the window length to be odd
unsigned wNo2 = wndN/2 + 1;
cmSample_t wndV[ wndN ];
cmVOS_Hann(wndV,wndN);
cmVOS_MultVV(yV,wNo2,wndV);
cmVOS_MultVV(yV + p->sigN - wNo2, wNo2, wndV + wNo2 - 1);
}
}
cmGoldSig_t* cmGoldSigAlloc( cmCtx* ctx, cmGoldSig_t* p, const cmGoldSigArg_t* a )
{
cmGoldSig_t* op = cmObjAlloc(cmGoldSig_t,ctx,p);
if( a != NULL )
if( cmGoldSigInit(op,a) != cmOkRC )
cmGoldSigFree(&op);
return op;
}
cmRC_t cmGoldSigFree( cmGoldSig_t** pp )
{
cmRC_t rc = cmOkRC;
if( pp == NULL || *pp == NULL )
return rc;
cmGoldSig_t* p = *pp;
if((rc = cmGoldSigFinal(p)) != cmOkRC )
return rc;
unsigned i;
for(i=0; i<p->a.chN; ++i)
{
cmMemFree(p->ch[i].bbV);
cmMemFree(p->ch[i].mdV);
}
cmMemFree(p->ch);
cmMemFree(p->rcosV);
cmMemFree(p->pnM);
cmMemFree(p);
*pp = NULL;
return rc;
}
cmRC_t cmGoldSigInit( cmGoldSig_t* p, const cmGoldSigArg_t* a )
{
cmRC_t rc = cmOkRC;
unsigned i;
p->a = *a; // store arg recd
p->ch = cmMemResizeZ(cmGoldSigCh_t,p->ch,a->chN); // alloc channel array
p->mlsN = (1 << a->lfsrN) - 1; // calc spreading code length
p->rcosN = a->samplesPerChip * a->rcosOSFact; // calc rcos imp. resp. length
p->rcosN += (p->rcosN % 2)==0; // force rcos imp. length odd
p->rcosV = cmMemResizeZ(cmSample_t,p->rcosV,p->rcosN); // alloc rcos imp. resp. vector
p->pnM = cmMemResizeZ(int,p->pnM,p->mlsN*a->chN); // alloc spreading-code mtx
p->sigN = p->mlsN * a->samplesPerChip; // calc audio signal length
// generate spreading codes
if( cmGenGoldCodes(a->lfsrN, a->mlsCoeff0, a->mlsCoeff1, a->chN, p->pnM, p->mlsN ) == false )
{
rc = cmCtxRtCondition(&p->obj,cmSubSysFailRC,"Unable to generate sufficient balanced Gold codes.");
goto errLabel;
}
// generate the rcos impulse response
_cmGoldSigRaisedCos(p->rcosV,p->rcosN,a->samplesPerChip,a->rcosBeta);
// for each channel
for(i=0; i<a->chN; ++i)
{
// Note: if (i*p->mlsN) is set to 0 in the following line then all channels
// will use the same spreading code.
p->ch[i].pnV = p->pnM + (i*p->mlsN); // get ch. spreading code
p->ch[i].bbV = cmMemResizeZ(cmSample_t,p->ch[i].bbV,p->sigN); // alloc baseband signal vector
p->ch[i].mdV = cmMemResizeZ(cmSample_t,p->ch[i].mdV,p->sigN); // alloc output audio vector
// Convolve spreading code with rcos impulse reponse to form baseband signal.
_cmGoldSigConv(p, i );
// Modulate baseband signal to carrier frq. and apply attack/decay envelope.
_cmGoldSigModulate(p, i );
}
errLabel:
if((rc = cmErrLastRC(&p->obj.err)) != cmOkRC )
cmGoldSigFree(&p);
return rc;
}
cmRC_t cmGoldSigFinal( cmGoldSig_t* p )
{ return cmOkRC; }
cmRC_t cmGoldSigWrite( cmCtx* ctx, cmGoldSig_t* p, const char* fn )
{
cmVectArray_t* vap = NULL;
unsigned i;
vap = cmVectArrayAlloc(ctx,kSampleVaFl);
for(i=0; i<p->a.chN; ++i)
{
cmVectArrayAppendS(vap,p->ch[i].bbV,p->sigN);
cmVectArrayAppendS(vap,p->ch[i].mdV,p->sigN);
}
cmVectArrayWrite(vap,fn);
cmVectArrayFree(&vap);
return cmOkRC;
}
cmRC_t cmGoldSigGen( cmGoldSig_t* p, unsigned chIdx, unsigned prefixN, unsigned dsN, unsigned *bsiV, unsigned bsiN, double noiseGain, cmSample_t** yVRef, unsigned* yNRef )
{
unsigned yN = prefixN + bsiN * (p->sigN + dsN);
cmSample_t* yV = cmMemAllocZ(cmSample_t,yN);
unsigned i;
cmVOS_Random(yV, yN, -noiseGain, noiseGain );
for(i=0; i<bsiN; ++i)
{
bsiV[i] = prefixN + i*(p->sigN + dsN);
cmVOS_AddVV(yV + bsiV[i], p->sigN, p->ch[chIdx].mdV );
}
if( yVRef != NULL )
*yVRef = yV;
if( yNRef != NULL )
*yNRef = yN;
return cmOkRC;
}

69
cmProc5.h
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@ -39,7 +39,76 @@ extern "C" {
cmRC_t cmGoertzelExec( cmGoertzel* p, const cmSample_t* in, unsigned procSmpCnt, double* outV, unsigned chCnt ); cmRC_t cmGoertzelExec( cmGoertzel* p, const cmSample_t* in, unsigned procSmpCnt, double* outV, unsigned chCnt );
//=======================================================================================================================
// Gold Code Signal Generator
//
typedef struct
{
unsigned chN; // count of channels (each channel has a unique id)
double srate; // system sample rate (samples/second)
unsigned lfsrN; // linear feedback shift register (LFSR) length used to form Gold codes
unsigned mlsCoeff0; // LFSR coeff. 0
unsigned mlsCoeff1; // LFSR coeff. 1
unsigned samplesPerChip; // samples per spreading code bit
double rcosBeta; // raised cosine impulse response beta coeff.
unsigned rcosOSFact; // raised cosine impulse response oversample factor
double carrierHz; // carrier frequency
double envMs; // attack/decay envelope duration
} cmGoldSigArg_t;
typedef struct
{
int* pnV; // pnV[ mlsN ] spread code (aliased from pnM[:,i])
cmSample_t* bbV; // bbV[ sigN ] baseband signal at audio rate
cmSample_t* mdV; // mdV[ sigN ] modulated signal at audio rate
} cmGoldSigCh_t;
typedef struct
{
cmObj obj; //
cmGoldSigArg_t a; // argument record
cmGoldSigCh_t* ch; // ch[ chN ] channel array
int* pnM; // pnM[mlsN,chN] (aliased to ch[].pnV)
cmSample_t* rcosV; // rcosV[rcosN] raised cosine impulse response
unsigned rcosN; // length of raised cosine impulse response
unsigned mlsN; // length of Gold codes (Maximum length sequence length)
unsigned sigN; // length of channel signals bbV[] and mdV[]
} cmGoldSig_t;
cmGoldSig_t* cmGoldSigAlloc( cmCtx* ctx, cmGoldSig_t* p, const cmGoldSigArg_t* a );
cmRC_t cmGoldSigFree( cmGoldSig_t** pp );
cmRC_t cmGoldSigInit( cmGoldSig_t* p, const cmGoldSigArg_t* a );
cmRC_t cmGoldSigFinal( cmGoldSig_t* p );
cmRC_t cmGoldSigWrite( cmCtx* ctx, cmGoldSig_t* p, const char* fn );
// Generate a signal consisting of underlying white noise with
// bsiN repeated copies of the id signal associated with
// channel 'chIdx'. Each discrete id signal copy is separated by 'dsN' samples.
// The signal will be prefixed with 'prefixN' samples of silence (noise).
// On return sets 'yVRef' to point to the generated signal and 'yNRef'
// to the count of samples in 'yVRef'.
// On error sets yVRef to NULL and yNRef to zero.
// The vector returned in 'yVRef' should be freed via atMemFree().
// On return sets bsiV[bsiN] to the onset sample index of each id signal copy.
// The background noise signal is limited to the range -noiseGain to noiseGain.
cmRC_t cmGoldSigGen(
cmGoldSig_t* p,
unsigned chIdx,
unsigned prefixN,
unsigned dsN,
unsigned *bsiV,
unsigned bsiN,
double noiseGain,
cmSample_t** yVRef,
unsigned* yNRef );
cmRC_t cmGoldSigTest( cmCtx* ctx );
#ifdef __cplusplus #ifdef __cplusplus
} }
#endif #endif