sbc: removed mapping from V to U

test/sbc/sbc_decoder.py

@@ -156,7 +156,6 @@ def sbc_frame_synthesis_v1(frame, ch, blk, proto_table):
     L2 = 2*L
 
     S = np.zeros(M)
-    U = np.zeros(L)
     W = np.zeros(L)
     frame.X = np.zeros(M)
     
@@ -171,16 +170,10 @@ def sbc_frame_synthesis_v1(frame, ch, blk, proto_table):
         V[ch][k] = 0
         for i in range(M):
             V[ch][k] += N[k][i] * S[i]
-    
-    for i in range(5):
-        for j in range(M):
-            U[i*M2+j] = V[ch][i*2*M2+j]
-            U[(i*2+1)*M+j] = V[ch][(i*4+3)*M+j]
 
     for i in range(L):
         D = proto_table[i] * (-M)
-        W[i] = U[i]*D
-
+        W[i] = D * VSGN(i,M2) * V[ch][remap_V(i)]
     
     offset = blk*M
     for j in range(M):

test/sbc/sbc_synthesis_v1.py

@@ -9,6 +9,8 @@ from sbc import *
 matrix_R = np.zeros(shape = (16,8))
 matrix_C2 = np.zeros(shape = (8,8))
 matrix_N = np.zeros(shape = (16,16))
+V_SGN = [1,1,1,1, 0, -1,-1,-1,-1, 1,1,1,1,1,1,1]
+V_remap = np.zeros(80)
 
 def sbc_init_synthesis_v1(M):
     global matrix_R, matrix_C2, matrix_N
@@ -16,10 +18,13 @@ def sbc_init_synthesis_v1(M):
         print("SBC V1 init failed, 4-subband version not implemented yet")
     M2 = M << 1
     Mh = M >> 1
-    
+    L  = 10 * M
+    L2 = L << 1
+
     matrix_R = np.zeros(shape = (M2,M))
     matrix_C2 = np.zeros(shape = (M,M))
     matrix_N = np.zeros(shape = (M2,M2))
+    V_remap  = np.zeros(L)
 
     R_c1 = 12 
     
@@ -35,6 +40,21 @@ def sbc_init_synthesis_v1(M):
     
     matrix_N = np.dot(matrix_R, matrix_C2)
 
+    for i in range(L):
+        offset = i%M2
+        if offset >= M:
+            offset += M2
+        V_remap[i] = L2/5 * (i/M2) + offset
+
+
+
+def VSGN(i,M2):
+    return V_SGN[i%M2]
+
+def remap_V(i):
+    global V_remap
+    return V_remap[i]
+
 def sbc_frame_synthesis_v1_4subbands(frame, ch, blk):
     print "sbc_frame_synthesis_v1_4subbands(frame, ch, blk) not implemented yet"
     exit(1)