1 files changed, 89 insertions, 0 deletions
diff --git a/Drivers/CMSIS/DSP/DSP_Lib_TestSuite/RefLibs/src/TransformFunctions/dct4.c b/Drivers/CMSIS/DSP/DSP_Lib_TestSuite/RefLibs/src/TransformFunctions/dct4.c
new file mode 100644
index 0000000..9c1f207
--- /dev/null
+++ b/Drivers/CMSIS/DSP/DSP_Lib_TestSuite/RefLibs/src/TransformFunctions/dct4.c
@@ -0,0 +1,89 @@
+#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];
+	}
+}