diff options
Diffstat (limited to 'media/libstagefright/codecs/amrwbenc/src/az_isp.c')
| -rw-r--r-- | media/libstagefright/codecs/amrwbenc/src/az_isp.c | 334 |
1 files changed, 167 insertions, 167 deletions
diff --git a/media/libstagefright/codecs/amrwbenc/src/az_isp.c b/media/libstagefright/codecs/amrwbenc/src/az_isp.c index 43db27a..d7074f0 100644 --- a/media/libstagefright/codecs/amrwbenc/src/az_isp.c +++ b/media/libstagefright/codecs/amrwbenc/src/az_isp.c @@ -58,138 +58,138 @@ static __inline Word16 Chebps2(Word16 x, Word16 f[], Word32 n); void Az_isp( - Word16 a[], /* (i) Q12 : predictor coefficients */ - Word16 isp[], /* (o) Q15 : Immittance spectral pairs */ - Word16 old_isp[] /* (i) : old isp[] (in case not found M roots) */ - ) + Word16 a[], /* (i) Q12 : predictor coefficients */ + Word16 isp[], /* (o) Q15 : Immittance spectral pairs */ + Word16 old_isp[] /* (i) : old isp[] (in case not found M roots) */ + ) { - Word32 i, j, nf, ip, order; - Word16 xlow, ylow, xhigh, yhigh, xmid, ymid, xint; - Word16 x, y, sign, exp; - Word16 *coef; - Word16 f1[NC + 1], f2[NC]; - Word32 t0; - /*-------------------------------------------------------------* - * find the sum and diff polynomials F1(z) and F2(z) * - * F1(z) = [A(z) + z^M A(z^-1)] * - * F2(z) = [A(z) - z^M A(z^-1)]/(1-z^-2) * - * * - * for (i=0; i<NC; i++) * - * { * - * f1[i] = a[i] + a[M-i]; * - * f2[i] = a[i] - a[M-i]; * - * } * - * f1[NC] = 2.0*a[NC]; * - * * - * for (i=2; i<NC; i++) Divide by (1-z^-2) * - * f2[i] += f2[i-2]; * - *-------------------------------------------------------------*/ - for (i = 0; i < NC; i++) - { - t0 = a[i] << 15; - f1[i] = vo_round(t0 + (a[M - i] << 15)); /* =(a[i]+a[M-i])/2 */ - f2[i] = vo_round(t0 - (a[M - i] << 15)); /* =(a[i]-a[M-i])/2 */ - } - f1[NC] = a[NC]; - for (i = 2; i < NC; i++) /* Divide by (1-z^-2) */ - f2[i] = add1(f2[i], f2[i - 2]); + Word32 i, j, nf, ip, order; + Word16 xlow, ylow, xhigh, yhigh, xmid, ymid, xint; + Word16 x, y, sign, exp; + Word16 *coef; + Word16 f1[NC + 1], f2[NC]; + Word32 t0; + /*-------------------------------------------------------------* + * find the sum and diff polynomials F1(z) and F2(z) * + * F1(z) = [A(z) + z^M A(z^-1)] * + * F2(z) = [A(z) - z^M A(z^-1)]/(1-z^-2) * + * * + * for (i=0; i<NC; i++) * + * { * + * f1[i] = a[i] + a[M-i]; * + * f2[i] = a[i] - a[M-i]; * + * } * + * f1[NC] = 2.0*a[NC]; * + * * + * for (i=2; i<NC; i++) Divide by (1-z^-2) * + * f2[i] += f2[i-2]; * + *-------------------------------------------------------------*/ + for (i = 0; i < NC; i++) + { + t0 = a[i] << 15; + f1[i] = vo_round(t0 + (a[M - i] << 15)); /* =(a[i]+a[M-i])/2 */ + f2[i] = vo_round(t0 - (a[M - i] << 15)); /* =(a[i]-a[M-i])/2 */ + } + f1[NC] = a[NC]; + for (i = 2; i < NC; i++) /* Divide by (1-z^-2) */ + f2[i] = add1(f2[i], f2[i - 2]); - /*---------------------------------------------------------------------* - * Find the ISPs (roots of F1(z) and F2(z) ) using the * - * Chebyshev polynomial evaluation. * - * The roots of F1(z) and F2(z) are alternatively searched. * - * We start by finding the first root of F1(z) then we switch * - * to F2(z) then back to F1(z) and so on until all roots are found. * - * * - * - Evaluate Chebyshev pol. at grid points and check for sign change.* - * - If sign change track the root by subdividing the interval * - * 2 times and ckecking sign change. * - *---------------------------------------------------------------------*/ - nf = 0; /* number of found frequencies */ - ip = 0; /* indicator for f1 or f2 */ - coef = f1; - order = NC; - xlow = vogrid[0]; - ylow = Chebps2(xlow, coef, order); - j = 0; - while ((nf < M - 1) && (j < GRID_POINTS)) - { - j ++; - xhigh = xlow; - yhigh = ylow; - xlow = vogrid[j]; - ylow = Chebps2(xlow, coef, order); - if ((ylow * yhigh) <= (Word32) 0) - { - /* divide 2 times the interval */ - for (i = 0; i < 2; i++) - { - xmid = (xlow >> 1) + (xhigh >> 1); /* xmid = (xlow + xhigh)/2 */ - ymid = Chebps2(xmid, coef, order); - if ((ylow * ymid) <= (Word32) 0) - { - yhigh = ymid; - xhigh = xmid; - } else - { - ylow = ymid; - xlow = xmid; - } - } - /*-------------------------------------------------------------* - * Linear interpolation * - * xint = xlow - ylow*(xhigh-xlow)/(yhigh-ylow); * - *-------------------------------------------------------------*/ - x = xhigh - xlow; - y = yhigh - ylow; - if (y == 0) - { - xint = xlow; - } else - { - sign = y; - y = abs_s(y); - exp = norm_s(y); - y = y << exp; - y = div_s((Word16) 16383, y); - t0 = x * y; - t0 = (t0 >> (19 - exp)); - y = vo_extract_l(t0); /* y= (xhigh-xlow)/(yhigh-ylow) in Q11 */ - if (sign < 0) - y = -y; - t0 = ylow * y; /* result in Q26 */ - t0 = (t0 >> 10); /* result in Q15 */ - xint = vo_sub(xlow, vo_extract_l(t0)); /* xint = xlow - ylow*y */ - } - isp[nf] = xint; - xlow = xint; - nf++; - if (ip == 0) - { - ip = 1; - coef = f2; - order = NC - 1; - } else - { - ip = 0; - coef = f1; - order = NC; - } - ylow = Chebps2(xlow, coef, order); - } - } - /* Check if M-1 roots found */ - if(nf < M - 1) - { - for (i = 0; i < M; i++) - { - isp[i] = old_isp[i]; - } - } else - { - isp[M - 1] = a[M] << 3; /* From Q12 to Q15 with saturation */ - } - return; + /*---------------------------------------------------------------------* + * Find the ISPs (roots of F1(z) and F2(z) ) using the * + * Chebyshev polynomial evaluation. * + * The roots of F1(z) and F2(z) are alternatively searched. * + * We start by finding the first root of F1(z) then we switch * + * to F2(z) then back to F1(z) and so on until all roots are found. * + * * + * - Evaluate Chebyshev pol. at grid points and check for sign change.* + * - If sign change track the root by subdividing the interval * + * 2 times and ckecking sign change. * + *---------------------------------------------------------------------*/ + nf = 0; /* number of found frequencies */ + ip = 0; /* indicator for f1 or f2 */ + coef = f1; + order = NC; + xlow = vogrid[0]; + ylow = Chebps2(xlow, coef, order); + j = 0; + while ((nf < M - 1) && (j < GRID_POINTS)) + { + j ++; + xhigh = xlow; + yhigh = ylow; + xlow = vogrid[j]; + ylow = Chebps2(xlow, coef, order); + if ((ylow * yhigh) <= (Word32) 0) + { + /* divide 2 times the interval */ + for (i = 0; i < 2; i++) + { + xmid = (xlow >> 1) + (xhigh >> 1); /* xmid = (xlow + xhigh)/2 */ + ymid = Chebps2(xmid, coef, order); + if ((ylow * ymid) <= (Word32) 0) + { + yhigh = ymid; + xhigh = xmid; + } else + { + ylow = ymid; + xlow = xmid; + } + } + /*-------------------------------------------------------------* + * Linear interpolation * + * xint = xlow - ylow*(xhigh-xlow)/(yhigh-ylow); * + *-------------------------------------------------------------*/ + x = xhigh - xlow; + y = yhigh - ylow; + if (y == 0) + { + xint = xlow; + } else + { + sign = y; + y = abs_s(y); + exp = norm_s(y); + y = y << exp; + y = div_s((Word16) 16383, y); + t0 = x * y; + t0 = (t0 >> (19 - exp)); + y = vo_extract_l(t0); /* y= (xhigh-xlow)/(yhigh-ylow) in Q11 */ + if (sign < 0) + y = -y; + t0 = ylow * y; /* result in Q26 */ + t0 = (t0 >> 10); /* result in Q15 */ + xint = vo_sub(xlow, vo_extract_l(t0)); /* xint = xlow - ylow*y */ + } + isp[nf] = xint; + xlow = xint; + nf++; + if (ip == 0) + { + ip = 1; + coef = f2; + order = NC - 1; + } else + { + ip = 0; + coef = f1; + order = NC; + } + ylow = Chebps2(xlow, coef, order); + } + } + /* Check if M-1 roots found */ + if(nf < M - 1) + { + for (i = 0; i < M; i++) + { + isp[i] = old_isp[i]; + } + } else + { + isp[M - 1] = a[M] << 3; /* From Q12 to Q15 with saturation */ + } + return; } /*--------------------------------------------------------------* @@ -213,55 +213,55 @@ void Az_isp( static __inline Word16 Chebps2(Word16 x, Word16 f[], Word32 n) { - Word32 i, cheb; - Word16 b0_h, b0_l, b1_h, b1_l, b2_h, b2_l; - Word32 t0; + Word32 i, cheb; + Word16 b0_h, b0_l, b1_h, b1_l, b2_h, b2_l; + Word32 t0; - /* Note: All computation are done in Q24. */ + /* Note: All computation are done in Q24. */ - t0 = f[0] << 13; - b2_h = t0 >> 16; - b2_l = (t0 & 0xffff)>>1; + t0 = f[0] << 13; + b2_h = t0 >> 16; + b2_l = (t0 & 0xffff)>>1; - t0 = ((b2_h * x)<<1) + (((b2_l * x)>>15)<<1); - t0 <<= 1; - t0 += (f[1] << 13); /* + f[1] in Q24 */ + t0 = ((b2_h * x)<<1) + (((b2_l * x)>>15)<<1); + t0 <<= 1; + t0 += (f[1] << 13); /* + f[1] in Q24 */ - b1_h = t0 >> 16; - b1_l = (t0 & 0xffff) >> 1; + b1_h = t0 >> 16; + b1_l = (t0 & 0xffff) >> 1; - for (i = 2; i < n; i++) - { - t0 = ((b1_h * x)<<1) + (((b1_l * x)>>15)<<1); + for (i = 2; i < n; i++) + { + t0 = ((b1_h * x)<<1) + (((b1_l * x)>>15)<<1); - t0 += (b2_h * (-16384))<<1; - t0 += (f[i] << 12); - t0 <<= 1; - t0 -= (b2_l << 1); /* t0 = 2.0*x*b1 - b2 + f[i]; */ + t0 += (b2_h * (-16384))<<1; + t0 += (f[i] << 12); + t0 <<= 1; + t0 -= (b2_l << 1); /* t0 = 2.0*x*b1 - b2 + f[i]; */ - b0_h = t0 >> 16; - b0_l = (t0 & 0xffff) >> 1; + b0_h = t0 >> 16; + b0_l = (t0 & 0xffff) >> 1; - b2_l = b1_l; /* b2 = b1; */ - b2_h = b1_h; - b1_l = b0_l; /* b1 = b0; */ - b1_h = b0_h; - } + b2_l = b1_l; /* b2 = b1; */ + b2_h = b1_h; + b1_l = b0_l; /* b1 = b0; */ + b1_h = b0_h; + } - t0 = ((b1_h * x)<<1) + (((b1_l * x)>>15)<<1); - t0 += (b2_h * (-32768))<<1; /* t0 = x*b1 - b2 */ - t0 -= (b2_l << 1); - t0 += (f[n] << 12); /* t0 = x*b1 - b2 + f[i]/2 */ + t0 = ((b1_h * x)<<1) + (((b1_l * x)>>15)<<1); + t0 += (b2_h * (-32768))<<1; /* t0 = x*b1 - b2 */ + t0 -= (b2_l << 1); + t0 += (f[n] << 12); /* t0 = x*b1 - b2 + f[i]/2 */ - t0 = L_shl2(t0, 6); /* Q24 to Q30 with saturation */ + t0 = L_shl2(t0, 6); /* Q24 to Q30 with saturation */ - cheb = extract_h(t0); /* Result in Q14 */ + cheb = extract_h(t0); /* Result in Q14 */ - if (cheb == -32768) - { - cheb = -32767; /* to avoid saturation in Az_isp */ - } - return (cheb); + if (cheb == -32768) + { + cheb = -32767; /* to avoid saturation in Az_isp */ + } + return (cheb); } |