def Chebps_10(x: int, f: List[int], n: int) -> int: # Note: All computation are done in Q23. b2_h = 128 # b2 = 1.0 in Q23 DPF b2_l = 0 t0 = basic_op.L_mult(x, 256) # 2*x in Q23 t0 = basic_op.L_mac(t0, f[1], 4096) # + f[1] in Q23 b1_h, b1_l = oper_32b.L_Extract(t0) # b1 = 2*x + f[1] for i in range(2, n): t0 = oper_32b.Mpy_32_16(b1_h, b1_l, x) # t0 = 2.0*x*b1 t0 = basic_op.L_shl(t0, 1) t0 = basic_op.L_mac(t0, b2_h, -32768) # t0 = 2.0*x*b1 - b2 t0 = basic_op.L_msu(t0, b2_l, 1) t0 = basic_op.L_mac(t0, f[i], 4096) # t0 = 2.0*x*b1 - b2 + f[i] b0_h, b0_l = oper_32b.L_Extract(t0) # b0 = 2.0*x*b1 - b2 + f[i] b2_l = b1_l # b2 = b1 b2_h = b1_h b1_l = b0_l # b1 = b0 b1_h = b0_h t0 = oper_32b.Mpy_32_16(b1_h, b1_l, x) # t0 = x*b1 t0 = basic_op.L_mac(t0, b2_h, -32768) # t0 = x*b1 - b2 t0 = basic_op.L_msu(t0, b2_l, 1) t0 = basic_op.L_mac(t0, f[i], 2048) # t0 = x*b1 - b2 + f[i]/2 t0 = basic_op.L_shl(t0, 7) # Q23 to Q30 with saturation cheb = basic_op.extract_h(t0) return cheb
def Inv_sqrt(L_x) -> int: """ # (o) Q30 : output value (range: 0<=val<1) # (i) Q0 : input value (range: 0<=val<=7fffffff) """ if L_x <= 0: return basic_op.MAX_INT_30 exp = basic_op.norm_l(L_x) L_x = basic_op.L_shl(L_x, exp) # L_x is normalize exp = basic_op.sub(30, exp) if (exp & 1) == 0: # If exponent even -> shift right L_x = basic_op.L_shr(L_x, 1) exp = basic_op.shr(exp, 1) exp = basic_op.add(exp, 1) L_x = basic_op.L_shr(L_x, 9) i = basic_op.extract_h(L_x) # Extract b25-b31 L_x = basic_op.L_shr(L_x, 1) a = basic_op.extract_l(L_x) # Extract b10-b24 a = a & 0x7fff i = basic_op.sub(i, 16) L_y = basic_op.L_deposit_h(tab_ld8a.tabsqr[i]) # tabsqr[i] << 16 tmp = basic_op.sub(tab_ld8a.tabsqr[i], tab_ld8a.tabsqr[i + 1]) # tabsqr[i] - tabsqr[i+1]) L_y = basic_op.L_msu(L_y, tmp, a) # L_y -= tmp*a*2 L_y = basic_op.L_shr(L_y, exp) # denormalization return L_y
def Log2(L_x: int, exponent: int, fraction: int) -> Tuple[int, int]: """ # (i) Q0 : input value # (o) Q0 : Integer part of Log2. (range: 0<=val<=30) # (o) Q15: Fractional part of Log2. (range: 0<=val<1) """ if L_x <= 0: return (0, 0) exp = basic_op.norm_l(L_x) L_x = basic_op.L_shl(L_x, exp) # L_x is normalized exponent = basic_op.sub(30, exp) L_x = basic_op.L_shr(L_x, 9) i = basic_op.extract_h(L_x) # Extract b25-b31 L_x = basic_op.L_shr(L_x, 1) a = basic_op.extract_l(L_x) # Extract b10-b24 of fraction a = a & 0x7fff i = basic_op.sub(i, 32) L_y = basic_op.L_deposit_h(tab_ld8a.tablog[i]) # tablog[i] << 16 tmp = basic_op.sub(tab_ld8a.tablog[i], tab_ld8a.tablog[i + 1]) # tablog[i] - tablog[i+1] L_y = basic_op.L_msu(L_y, tmp, a) # L_y -= tmp*a*2 fraction = basic_op.extract_h(L_y) return (exponent, fraction)
def Syn_filt(a: List[int], x: List[int], y: List[int], lg: int, mem: List[int], update: int) -> None: """ # (i) Q12 : a[m+1] prediction coefficients (m=10) # (i) : input signal # (o) : output signal # (i) : size of filtering # (i/o) : memory associated with this filtering. # (i) : 0=no update, 1=update of memory. """ #Word16 i, j #Word32 s #Word16 tmp[100] # This is usually done by memory allocation (lg+M) #Word16 *yy tmp = [0] * 100 # Copy mem[] to yy[] (yy points to tmp) for i in range(0, ld8a.M): tmp[i] = mem[i] # Do the filtering. for i in range(0, lg): s = basic_op.L_mult(x[i], a[0]) for j in range(1, ld8a.M + 1): # this negative index needs tested s = basic_op.L_msu(s, a[j], tmp[-j]) s = basic_op.L_shl(s, 3) tmp[i] = basic_op.round(s) for i in range (0, lg): y[i] = tmp[i+M] # Update of memory if update==1 if update != 0: for i in range(0, ld8a.M): mem[i] = y[lg-M+i]
def Pow2(exponent: int, fraction: int) -> int: """ # (o) Q0 : result (range: 0<=val<=0x7fffffff) # (i) Q0 : Integer part. (range: 0<=val<=30) # (i) Q15 : Fractional part. (range: 0.0<=val<1.0) """ L_x = basic_op.L_mult(fraction, 32) # L_x = fraction<<6 i = basic_op.extract_h(L_x) # Extract b10-b15 of fraction L_x = basic_op.L_shr(L_x, 1) a = basic_op.extract_l(L_x) # Extract b0-b9 of fraction a = a & 0x7fff L_x = basic_op.L_deposit_h(tab_ld8a.tabpow[i]) # tabpow[i] << 16 tmp = basic_op.sub(tab_ld8a.tabpow[i], tab_ld8a.tabpow[i + 1]) # tabpow[i] - tabpow[i+1] L_x = basic_op.L_msu(L_x, tmp, a) # L_x -= tmp*a*2 exp = basic_op.sub(30, exponent) L_x = basic_op.L_shr_r(L_x, exp) return L_x
def Az_lsp(a: List[int], lsp: List[int], old_lsp: List[int]) -> None: """ # (i) Q12 : predictor coefficients # (o) Q15 : line spectral pairs # (i) : old lsp[] (in case not found 10 roots) """ #Word16 i, j, nf, ip #Word16 xlow, ylow, xhigh, yhigh, xmid, ymid, xint #Word16 x, y, sign, exp #Word16 *coef #Word16 f1[M / 2 + 1], f2[M / 2 + 1] #Word32 t0, L_temp #Flag ovf_coef #Word16 (*pChebps)(Word16 x, Word16 f[], Word16 n) f1 = [0] * ((ld8a.M / 2) + 1) f2 = [0] * ((ld8a.M / 2) + 1) ######### # find the sum and diff. pol. F1(z) and F2(z) # F1(z) <--- F1(z)/(1+z**-1) & F2(z) <--- F2(z)/(1-z**-1) # # f1[0] = 1.0 # f2[0] = 1.0 # # for (i = 0 i< NC i++) # { # f1[i+1] = a[i+1] + a[M-i] - f1[i] # f2[i+1] = a[i+1] - a[M-i] + f2[i] # } ######## ovf_coef = 0 pChebps = 'Chebps_11' f1[0] = 2048 # f1[0] = 1.0 is in Q11 f2[0] = 2048 # f2[0] = 1.0 is in Q11 for i in range(0, ld8a.NC): basic_op.setOverflow(0) t0 = basic_op.L_mult(a[i + 1], 16384) # x = (a[i+1] + a[M-i]) >> 1 t0 = basic_op.L_mac(t0, a[M - i], 16384) # -> From Q12 to Q11 x = basic_op.extract_h(t0) if basic_op.getOverflow() != 0: ovf_coef = 1 basic_op.setOverflow(0) f1[i + 1] = basic_op.sub(x, f1[i]) # f1[i+1] = a[i+1] + a[M-i] - f1[i] if basic_op.getOverflow() != 0: ovf_coef = 1 basic_op.setOverflow(0) t0 = basic_op.L_mult(a[i + 1], 16384) # x = (a[i+1] - a[M-i]) >> 1 t0 = basic_op.L_msu(t0, a[M - i], 16384) # -> From Q12 to Q11 x = basic_op.extract_h(t0) if basic_op.getOverflow() != 0: ovf_coef = 1 basic_op.setOverflow(0) f2[i + 1] = basic_op.add(x, f2[i]) # f2[i+1] = a[i+1] - a[M-i] + f2[i] if basic_op.getOverflow() != 0: ovf_coef = 1 if ovf_coef == 1: #printf("===== OVF ovf_coef =====\n") pChebps = 'Chebps_10' f1[0] = 1024 # f1[0] = 1.0 is in Q10 f2[0] = 1024 # f2[0] = 1.0 is in Q10 for i in range(0, ld8a.NC): t0 = basic_op.L_mult(a[i + 1], 8192) # x = (a[i+1] + a[M-i]) >> 1 t0 = basic_op.L_mac(t0, a[M - i], 8192) # -> From Q11 to Q10 x = basic_op.extract_h(t0) f1[i + 1] = basic_op.sub(x, f1[i]) # f1[i+1] = a[i+1] + a[M-i] - f1[i] t0 = basic_op.L_mult(a[i + 1], 8192) # x = (a[i+1] - a[M-i]) >> 1 t0 = basic_op.L_msu(t0, a[M - i], 8192) # -> From Q11 to Q10 x = basic_op.extract_h(t0) f2[i + 1] = basic_op.add(x, f2[i]) # f2[i+1] = a[i+1] - a[M-i] + f2[i] ######## # find the LSPs using the Chebichev pol. evaluation ######## nf = 0 # number of found frequencies ip = 0 # indicator for f1 or f2 coef = f1 # Alias for f1 or f2 xlow = grid[0] if pChebps == 'Chebps_11': ylow = Chebps_11(xlow, coef, NC) else: ylow = Chebps_10(xlow, coef, NC) j = 0 while nf < ld81.M and j < ld8a.GRID_POINTS: j = basic_op.add(j, 1) xhigh = xlow yhigh = ylow xlow = grid[j] if pChebps == 'Chebps_11': ylow = Chebps_11(xlow, coef, ld8a.NC) else: ylow = Chebps_10(xlow, coef, ld8a.NC) L_temp = basic_op.L_mult(ylow, yhigh) if L_temp <= 0: # divide 2 times the interval for i in range(0, 2): xmid = basic_op.add(basic_op.shr(xlow, 1), basic_op.shr(xhigh, 1)) # xmid = (xlow + xhigh)/2 if pChebps == 'Chebps_11': ymid = Chebps_11(xmid, coef, ld8a.NC) else: ymid = Chebps_10(xmid, coef, ld8a.NC) L_temp = basic_op.L_mult(ylow, ymid) if L_temp <= 0: yhigh = ymid xhigh = xmid else: ylow = ymid xlow = xmid ######## # Linear interpolation # xint = xlow - ylow*(xhigh-xlow)/(yhigh-ylow) ######## x = basic_op.sub(xhigh, xlow) y = basic_op.sub(yhigh, ylow) if y == 0: xint = xlow else: sign = y y = basic_op.abs_s(y) exp = basic_op.norm_s(y) y = basic_op.shl(y, exp) y = basic_op.div_s(16383, y) t0 = basic_op.L_mult(x, y) t0 = basic_op.L_shr(t0, basic_op.sub(20, exp)) y = basic_op.extract_l(t0) # y= (xhigh-xlow)/(yhigh-ylow) in Q11 if sign < 0: y = basic_op.negate(y) t0 = basic_op.L_mult(ylow, y) # result in Q26 t0 = basic_op.L_shr(t0, 11) # result in Q15 xint = basic_op.sub(xlow, basic_op.extract_l(t0)) # xint = xlow - ylow*y lsp[nf] = xint xlow = xint nf = basic_op.add(nf, 1) if ip == 0: ip = 1 coef = f2 else: ip = 0 coef = f1 if pChebps == 'Chebps_11': ylow = Chebps_11(xlow, coef, ld8a.NC) else: ylow = Chebps_10(xlow, coef, ld8a.NC) # Check if M roots found if basic_op.sub(nf, ld8a.M) < 0: for i in range (0, ld8a.M): lsp[i] = old_lsp[i]