sbc: calculate cos in advance, prepare for DCT

test/sbc/sbc_synthesis_v1.py

@@ -0,0 +1,64 @@
+#!/usr/bin/env python
+import numpy as np
+import wave
+import struct
+import sys
+import time
+from sbc import *
+
+matrix_R = np.zeros(shape = (16,8))
+matrix_C2 = np.zeros(shape = (8,8))
+matrix_N = np.zeros(shape = (16,16))
+
+def sbc_init_synthesis_v1(M):
+    global matrix_R, matrix_C2, matrix_N
+    if M == 4:
+        print("SBC V1 init failed, 4-subband version not implemented yet")
+    M2 = M << 1
+    Mh = M >> 1
+    
+    matrix_R = np.zeros(shape = (M2,M))
+    matrix_C2 = np.zeros(shape = (M,M))
+    matrix_N = np.zeros(shape = (M2,M2))
+
+    R_c1 = 12 
+    
+    for k in range(Mh):
+        matrix_R[k][k+Mh] = 1
+
+    for k in range(Mh+1,M2):
+        matrix_R[k][abs(R_c1-k)] = -1
+
+    for k in range(M):
+        for i in range(M):
+            matrix_C2[k][i] = np.cos((i+0.5)*k*np.pi/M)
+    
+    matrix_N = np.dot(matrix_R, matrix_C2)
+
+def sbc_frame_synthesis_v1_4subbands(frame, ch, blk):
+    print "sbc_frame_synthesis_v1_4subbands(frame, ch, blk) not implemented yet"
+    exit(1)
+
+def sbc_frame_synthesis_v1_8subbands(frame, ch, blk):
+    print "sbc_frame_synthesis_v1_8subbands(frame, ch, blk) not implemented yet"
+    exit(1)
+
+def matrix_R():
+    global matrix_R
+    return matrix_R
+
+def matrix_C2():
+    global matrix_C2
+    return matrix_C2
+
+def matrix_N():
+    global matrix_N
+    return matrix_N
+
+def R(k,i):
+    global matrix_R
+    return matrix_R[k][i]
+
+def C2(k,i):
+    global matrix_C2
+    return matrix_C2[k][i]