DCT with factor 5 introduced

lib_dsp/api/dsp_dct.h

@@ -21,6 +21,17 @@
  */
 void dsp_dct_forward48(int32_t output[48], int32_t input[48]);
 
+/** This function performs a 40 point DCT
+ *
+ *  The first output is the DC value, subsequent values are the values for
+ *  the basis vectors of half a cosine, a whole cosine, 1.5 cosine, 2
+ *  consines, etc.
+ *
+ *  \param  input           input values to the DCT
+ *  \param  output          DCT values.
+ */
+void dsp_dct_forward40(int32_t output[40], int32_t input[40]);
+
 /** This function performs a 32 point DCT
  *
  *  The first output is the DC value, subsequent values are the values for
@@ -43,6 +54,17 @@ void dsp_dct_forward32(int32_t output[32], int32_t input[32]);
  */
 void dsp_dct_forward24(int32_t output[24], int32_t input[24]);
 
+/** This function performs a 20 point DCT
+ *
+ *  The first output is the DC value, subsequent values are the values for
+ *  the basis vectors of half a cosine, a whole cosine, 1.5 cosine, 2
+ *  consines, etc.
+ *
+ *  \param  input           input values to the DCT
+ *  \param  output          DCT values.
+ */
+void dsp_dct_forward20(int32_t output[20], int32_t input[20]);
+
 /** This function performs a 16 point DCT
  *
  *  The first output is the DC value, subsequent values are the values for
@@ -65,6 +87,17 @@ void dsp_dct_forward16(int32_t output[16], int32_t input[16]);
  */
 void dsp_dct_forward12(int32_t output[12], int32_t input[12]);
 
+/** This function performs a 10 point DCT
+ *
+ *  The first output is the DC value, subsequent values are the values for
+ *  the basis vectors of half a cosine, a whole cosine, 1.5 cosine, 2
+ *  consines, etc.
+ *
+ *  \param  input           input values to the DCT
+ *  \param  output          DCT values.
+ */
+void dsp_dct_forward10(int32_t output[10], int32_t input[10]);
+
 /** This function performs a 8 point DCT
  *
  *  The first output is the DC value, subsequent values are the values for

lib_dsp/src/dsp_dct.xc

@@ -111,6 +111,50 @@ static const int32_t costable48[24] = {
     70263695,
 };
 
+static const int32_t costable10[5] = {
+    2121044560,
+    1913421940,
+    1518500249,
+    974937174,
+    335940455,
+};
+
+static const int32_t costable20[10] = {
+    2140863672,
+    2088148503,
+    1984016188,
+    1831030810,
+    1632959376,
+    1394679064,
+    1122057123,
+    821806413,
+    501320101,
+    168489625,
+};
+
+static const int32_t costable40[20] = {
+    2145828015,
+    2132598272,
+    2106220351,
+    2066856882,
+    2014750552,
+    1950222615,
+    1873670908,
+    1785567396,
+    1686455267,
+    1576945581,
+    1457713501,
+    1329494132,
+    1193077990,
+    1049306126,
+    899064940,
+    743280720,
+    582913927,
+    418953276,
+    252409639,
+    84309812,
+};
+
 static inline int32_t mulcos(int32_t x, int32_t cos) {
     long long r = cos * (long long) x;
     return r >> 31;
@@ -139,6 +183,14 @@ void dsp_dct_forward##N(int32_t output[N], int32_t input[N]) { \
     } \
 }
 
+void dsp_dct_forward5(int32_t output[5], int32_t input[5]) {
+    output[0] = input[0] + input[1] + input[2] + input[3] + input[4];
+    output[1] = mulcos(input[0] - input[4], 2042378317) + mulcos(input[1] - input[3], 1262259218);
+    output[2] = mulcos(input[0] + input[4], 1737350766) + mulcos(input[1] + input[3], -663608941) - input[2];
+    output[3] = mulcos(input[0] - input[4], 1262259218) + mulcos(input[1] - input[3], -2042378316);
+    output[4] = mulcos(input[0] + input[4], 663608942) + mulcos(input[1] + input[3], -1737350765) + input[2];
+}
+
 void dsp_dct_forward4(int32_t output[4], int32_t input[4]) {
     int32_t i03 = input[0] + input[3];
     int32_t i12 = input[1] + input[2];
@@ -171,10 +223,13 @@ void dsp_dct_forward1(int32_t output[1], int32_t input[1]) {
 
 DCT(6,3)
 DCT(8,4)
+DCT(10,5)
 DCT(12,6)
 DCT(16,8)
+DCT(20,10)
 DCT(24,12)
 DCT(32,16)
+DCT(40,20)
 DCT(48,24)
 
 #ifdef INCLUDE_REFERENCE_DCT