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#include "ref.h"
void ref_dct4_f32(
const arm_dct4_instance_f32 * S,
float32_t * pState,
float32_t * pInlineBuffer)
{
uint32_t n,k;
float32_t sum;
float32_t pi_by_N = 3.14159265358979f / (float32_t)S->N;
float32_t tmp;
float32_t normalize = sqrtf(2.0f / (float32_t)S->N);
for(k=0;k<S->N;k++)
{
sum=0.0f;
tmp = ((float32_t)k + 0.5f)*pi_by_N;
for(n=0;n<S->N;n++)
{
sum += pInlineBuffer[n] * cosf(tmp * ((float32_t)n + 0.5f));
}
scratchArray[k] = normalize * sum;
}
for(k=0;k<S->N;k++)
{
pInlineBuffer[k] = scratchArray[k];
}
}
void ref_dct4_q31(
const arm_dct4_instance_q31 * S,
q31_t * pState,
q31_t * pInlineBuffer)
{
arm_dct4_instance_f32 SS;
float32_t *fSrc = (float32_t*)pInlineBuffer;
uint32_t i;
SS.N = S->N;
for(i=0;i<S->N;i++)
{
//read the q31 data, cast to float, scale down for float
fSrc[i] = (float32_t)pInlineBuffer[i] / 2147483648.0f;
}
ref_dct4_f32(&SS,(float32_t*)0,fSrc);
for(i=0;i<S->N;i++)
{
fSrc[i] = fSrc[i] * 2147483648.0f / (float32_t)S->N ;
fSrc[i] += (fSrc[i] > 0) ? 0.5f : -0.5f;
pInlineBuffer[i] = (q31_t)fSrc[i];
}
}
void ref_dct4_q15(
const arm_dct4_instance_q15 * S,
q15_t * pState,
q15_t * pInlineBuffer)
{
arm_dct4_instance_f32 SS;
float32_t *fSrc = (float32_t*)pInlineBuffer;
uint32_t i;
SS.N = S->N;
for(i=0;i<S->N;i++)
{
//read the q15 data, cast to float, scale down for float, place in temporary buffer
scratchArray[i] = (float32_t)pInlineBuffer[i] / 32768.0f;
}
for(i=0;i<S->N;i++)
{
//copy from temp buffer to final buffer
fSrc[i] = scratchArray[i];
}
ref_dct4_f32(&SS,(float32_t*)0,fSrc);
for(i=0;i<S->N;i++)
{
fSrc[i] = fSrc[i] * 32768.0f / (float32_t)S->N;
fSrc[i] += (fSrc[i] > 0) ? 0.5f : -0.5f;
pInlineBuffer[i] = (q15_t)fSrc[i];
}
}
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