diff options
author | Andreas Huber <andih@google.com> | 2009-12-08 15:40:06 -0800 |
---|---|---|
committer | Andreas Huber <andih@google.com> | 2009-12-10 12:23:55 -0800 |
commit | 4f1efc098cb5791c3e9f483f2af84aef70d2d0a0 (patch) | |
tree | a2873e84aed3eecb1198f85954e24cddb1bdc380 /media/libstagefright/codecs/amrnb/common/src/az_lsp.cpp | |
parent | c54176addef15699a518b69cd6bbd40ffc95e72e (diff) | |
download | frameworks_av-4f1efc098cb5791c3e9f483f2af84aef70d2d0a0.zip frameworks_av-4f1efc098cb5791c3e9f483f2af84aef70d2d0a0.tar.gz frameworks_av-4f1efc098cb5791c3e9f483f2af84aef70d2d0a0.tar.bz2 |
Initial check in of AMR (NB and WB) decoders based on PV source code.
Diffstat (limited to 'media/libstagefright/codecs/amrnb/common/src/az_lsp.cpp')
-rw-r--r-- | media/libstagefright/codecs/amrnb/common/src/az_lsp.cpp | 740 |
1 files changed, 740 insertions, 0 deletions
diff --git a/media/libstagefright/codecs/amrnb/common/src/az_lsp.cpp b/media/libstagefright/codecs/amrnb/common/src/az_lsp.cpp new file mode 100644 index 0000000..bd99b30 --- /dev/null +++ b/media/libstagefright/codecs/amrnb/common/src/az_lsp.cpp @@ -0,0 +1,740 @@ +/* ------------------------------------------------------------------ + * Copyright (C) 1998-2009 PacketVideo + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either + * express or implied. + * See the License for the specific language governing permissions + * and limitations under the License. + * ------------------------------------------------------------------- + */ +/**************************************************************************************** +Portions of this file are derived from the following 3GPP standard: + + 3GPP TS 26.073 + ANSI-C code for the Adaptive Multi-Rate (AMR) speech codec + Available from http://www.3gpp.org + +(C) 2004, 3GPP Organizational Partners (ARIB, ATIS, CCSA, ETSI, TTA, TTC) +Permission to distribute, modify and use this file under the standard license +terms listed above has been obtained from the copyright holder. +****************************************************************************************/ +/* + + Pathname: ./audio/gsm-amr/c/src/az_lsp.c + Funtions: Chebps + Chebps_Wrapper + Az_lsp + +------------------------------------------------------------------------------ + REVISION HISTORY + + Description: Finished first pass of optimization. + + Description: Made changes based on review comments. + + Description: Made input to Chebps_Wrapper consistent with that of Chebps. + + Description: Replaced current Pseudo-code with the UMTS code version 3.2.0. + Updated coding template. + + Description: Replaced basic_op.h and oper_32b.h with the header files of the + math functions used by the file. + + Description: Made the following changes per comments from Phase 2/3 review: + 1. Used "-" operator instead of calling sub function in the + az_lsp() code. + 2. Copied detailed function description of az_lsp from the + header file. + 3. Modified local variable definition to one per line. + 4. Used NC in the definition of f1 and f2 arrays. + 5. Added curly brackets in the IF statement. + + Description: Changed function interface to pass in a pointer to overflow + flag into the function instead of using a global flag. Removed + inclusion of unneeded header files. + + Description: For Chebps() and Az_lsp() + 1. Eliminated unused include files. + 2. Replaced array addressing by pointers + 3. Eliminated math operations that unnecessary checked for + saturation. + 4. Eliminated not needed variables + 5. Eliminated if-else checks for saturation + 6. Deleted unused function cheps_wraper + + Description: Added casting to eliminate warnings + + + Who: Date: + Description: + +------------------------------------------------------------------------------ + MODULE DESCRIPTION + + These modules compute the LSPs from the LP coefficients. + +------------------------------------------------------------------------------ +*/ + + +/*---------------------------------------------------------------------------- +; INCLUDES +----------------------------------------------------------------------------*/ +#include "az_lsp.h" +#include "cnst.h" +#include "basic_op.h" + +/*---------------------------------------------------------------------------- +; MACROS +; Define module specific macros here +----------------------------------------------------------------------------*/ + + +/*---------------------------------------------------------------------------- +; DEFINES +; Include all pre-processor statements here. Include conditional +; compile variables also. +----------------------------------------------------------------------------*/ +#define NC M/2 /* M = LPC order, NC = M/2 */ + +/*---------------------------------------------------------------------------- +; LOCAL FUNCTION DEFINITIONS +; Function Prototype declaration +----------------------------------------------------------------------------*/ + + +/*---------------------------------------------------------------------------- +; LOCAL VARIABLE DEFINITIONS +; Variable declaration - defined here and used outside this module +----------------------------------------------------------------------------*/ + +/* +------------------------------------------------------------------------------ + FUNCTION NAME: Chebps +------------------------------------------------------------------------------ + INPUT AND OUTPUT DEFINITIONS + + Inputs: + x = input value (Word16) + f = polynomial (Word16) + n = polynomial order (Word16) + + pOverflow = pointer to overflow (Flag) + + Outputs: + pOverflow -> 1 if the operations in the function resulted in saturation. + + Returns: + cheb = Chebyshev polynomial for the input value x.(Word16) + + Global Variables Used: + None. + + Local Variables Needed: + None. + +------------------------------------------------------------------------------ + FUNCTION DESCRIPTION + + This module evaluates the Chebyshev polynomial series. + - The polynomial order is n = m/2 = 5 + - The polynomial F(z) (F1(z) or F2(z)) is given by + F(w) = 2 exp(-j5w) C(x) + where + C(x) = T_n(x) + f(1)T_n-1(x) + ... +f(n-1)T_1(x) + f(n)/2 + and T_m(x) = cos(mw) is the mth order Chebyshev + polynomial ( x=cos(w) ) + - C(x) for the input x is returned. + +------------------------------------------------------------------------------ + REQUIREMENTS + + None. + +------------------------------------------------------------------------------ + REFERENCES + + az_lsp.c, UMTS GSM AMR speech codec, R99 - Version 3.2.0, March 2, 2001 + +------------------------------------------------------------------------------ + PSEUDO-CODE + +static Word16 Chebps (Word16 x, + Word16 f[], // (n) + Word16 n) +{ + Word16 i, cheb; + Word16 b0_h, b0_l, b1_h, b1_l, b2_h, b2_l; + Word32 t0; + +// The reference ETSI code uses a global flag for Overflow. However, in the +// actual implementation a pointer to Overflow flag is passed in as a +// parameter to the function. This pointer is passed into all the basic math +// functions invoked + + b2_h = 256; // b2 = 1.0 + b2_l = 0; + + t0 = L_mult (x, 512); // 2*x + t0 = L_mac (t0, f[1], 8192); // + f[1] + L_Extract (t0, &b1_h, &b1_l); // b1 = 2*x + f[1] + + for (i = 2; i < n; i++) + { + t0 = Mpy_32_16 (b1_h, b1_l, x); // t0 = 2.0*x*b1 + t0 = L_shl (t0, 1); + t0 = L_mac (t0, b2_h, (Word16) 0x8000); // t0 = 2.0*x*b1 - b2 + t0 = L_msu (t0, b2_l, 1); + t0 = L_mac (t0, f[i], 8192); // t0 = 2.0*x*b1 - b2 + f[i] + + L_Extract (t0, &b0_h, &b0_l); // 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 = Mpy_32_16 (b1_h, b1_l, x); // t0 = x*b1; + t0 = L_mac (t0, b2_h, (Word16) 0x8000); // t0 = x*b1 - b2 + t0 = L_msu (t0, b2_l, 1); + t0 = L_mac (t0, f[i], 4096); // t0 = x*b1 - b2 + f[i]/2 + + t0 = L_shl (t0, 6); + + cheb = extract_h (t0); + + return (cheb); +} + +------------------------------------------------------------------------------ + RESOURCES USED [optional] + + When the code is written for a specific target processor the + the resources used should be documented below. + + HEAP MEMORY USED: x bytes + + STACK MEMORY USED: x bytes + + CLOCK CYCLES: (cycle count equation for this function) + (variable + used to represent cycle count for each subroutine + called) + where: (cycle count variable) = cycle count for [subroutine + name] + +------------------------------------------------------------------------------ + CAUTION [optional] + [State any special notes, constraints or cautions for users of this function] + +------------------------------------------------------------------------------ +*/ + +static Word16 Chebps(Word16 x, + Word16 f[], /* (n) */ + Word16 n, + Flag *pOverflow) +{ + Word16 i; + Word16 cheb; + Word16 b1_h; + Word16 b1_l; + Word32 t0; + Word32 L_temp; + Word16 *p_f = &f[1]; + + OSCL_UNUSED_ARG(pOverflow); + + /* L_temp = 1.0 */ + + L_temp = 0x01000000L; + + t0 = ((Word32) x << 10) + ((Word32) * (p_f++) << 14); + + /* b1 = t0 = 2*x + f[1] */ + + b1_h = (Word16)(t0 >> 16); + b1_l = (Word16)((t0 >> 1) - (b1_h << 15)); + + + for (i = 2; i < n; i++) + { + /* t0 = 2.0*x*b1 */ + t0 = ((Word32) b1_h * x); + t0 += ((Word32) b1_l * x) >> 15; + t0 <<= 2; + + /* t0 = 2.0*x*b1 - b2 */ + t0 -= L_temp; + + /* t0 = 2.0*x*b1 - b2 + f[i] */ + t0 += (Word32) * (p_f++) << 14; + + L_temp = ((Word32) b1_h << 16) + ((Word32) b1_l << 1); + + /* b0 = 2.0*x*b1 - b2 + f[i]*/ + b1_h = (Word16)(t0 >> 16); + b1_l = (Word16)((t0 >> 1) - (b1_h << 15)); + + } + + /* t0 = x*b1; */ + t0 = ((Word32) b1_h * x); + t0 += ((Word32) b1_l * x) >> 15; + t0 <<= 1; + + + /* t0 = x*b1 - b2 */ + t0 -= L_temp; + + /* t0 = x*b1 - b2 + f[i]/2 */ + t0 += (Word32) * (p_f) << 13; + + + if ((UWord32)(t0 - 0xfe000000L) < 0x01ffffffL - 0xfe000000L) + { + cheb = (Word16)(t0 >> 10); + } + else + { + if (t0 > (Word32) 0x01ffffffL) + { + cheb = MAX_16; + + } + else + { + cheb = MIN_16; + } + } + + return (cheb); +} + + +/* +------------------------------------------------------------------------------ + FUNCTION NAME: Az_lsp +------------------------------------------------------------------------------ + INPUT AND OUTPUT DEFINITIONS FOR Az_lsp + + Inputs: + a = predictor coefficients (Word16) + lsp = line spectral pairs (Word16) + old_lsp = old line spectral pairs (Word16) + + pOverflow = pointer to overflow (Flag) + + Outputs: + pOverflow -> 1 if the operations in the function resulted in saturation. + + Returns: + None. + + Global Variables Used: + None. + + Local Variables Needed: + None. + +------------------------------------------------------------------------------ + FUNCTION DESCRIPTION + + This function computes the LSPs from the LP coefficients. + + The sum and difference filters are computed and divided by 1+z^{-1} and + 1-z^{-1}, respectively. + + f1[i] = a[i] + a[11-i] - f1[i-1] ; i=1,...,5 + f2[i] = a[i] - a[11-i] + f2[i-1] ; i=1,...,5 + + The roots of F1(z) and F2(z) are found using Chebyshev polynomial evaluation. + The polynomials are evaluated at 60 points regularly spaced in the + frequency domain. The sign change interval is subdivided 4 times to better + track the root. The LSPs are found in the cosine domain [1,-1]. + + If less than 10 roots are found, the LSPs from the past frame are used. + +------------------------------------------------------------------------------ + REQUIREMENTS + + None. + +------------------------------------------------------------------------------ + REFERENCES + + az_lsp.c, UMTS GSM AMR speech codec, R99 - Version 3.2.0, March 2, 2001 + +------------------------------------------------------------------------------ + PSEUDO-CODE + +void Az_lsp ( + Word16 a[], // (i) : predictor coefficients (MP1) + Word16 lsp[], // (o) : line spectral pairs (M) + Word16 old_lsp[] // (i) : old lsp[] (in case not found 10 roots) (M) +) +{ + 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; + + *-------------------------------------------------------------* + * 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] ; * + * } * + *-------------------------------------------------------------* + + f1[0] = 1024; // f1[0] = 1.0 + f2[0] = 1024; // f2[0] = 1.0 + +// The reference ETSI code uses a global flag for Overflow. However, in the +// actual implementation a pointer to Overflow flag is passed in as a +// parameter to the function. This pointer is passed into all the basic math +// functions invoked + + for (i = 0; i < NC; i++) + { + t0 = L_mult (a[i + 1], 8192); // x = (a[i+1] + a[M-i]) >> 2 + t0 = L_mac (t0, a[M - i], 8192); + x = extract_h (t0); + // f1[i+1] = a[i+1] + a[M-i] - f1[i] + f1[i + 1] = sub (x, f1[i]); + + t0 = L_mult (a[i + 1], 8192); // x = (a[i+1] - a[M-i]) >> 2 + t0 = L_msu (t0, a[M - i], 8192); + x = extract_h (t0); + // f2[i+1] = a[i+1] - a[M-i] + f2[i] + f2[i + 1] = add (x, f2[i]); + } + + *-------------------------------------------------------------* + * find the LSPs using the Chebychev pol. evaluation * + *-------------------------------------------------------------* + + nf = 0; // number of found frequencies + ip = 0; // indicator for f1 or f2 + + coef = f1; + + xlow = grid[0]; + ylow = Chebps (xlow, coef, NC); + + j = 0; + // while ( (nf < M) && (j < grid_points) ) + while ((sub (nf, M) < 0) && (sub (j, grid_points) < 0)) + { + j++; + xhigh = xlow; + yhigh = ylow; + xlow = grid[j]; + ylow = Chebps (xlow, coef, NC); + + if (L_mult (ylow, yhigh) <= (Word32) 0L) + { + + // divide 4 times the interval + + for (i = 0; i < 4; i++) + { + // xmid = (xlow + xhigh)/2 + xmid = add (shr (xlow, 1), shr (xhigh, 1)); + ymid = Chebps (xmid, coef, NC); + + if (L_mult (ylow, ymid) <= (Word32) 0L) + { + yhigh = ymid; + xhigh = xmid; + } + else + { + ylow = ymid; + xlow = xmid; + } + } + + *-------------------------------------------------------------* + * Linear interpolation * + * xint = xlow - ylow*(xhigh-xlow)/(yhigh-ylow); * + *-------------------------------------------------------------* + + x = sub (xhigh, xlow); + y = sub (yhigh, ylow); + + if (y == 0) + { + xint = xlow; + } + else + { + sign = y; + y = abs_s (y); + exp = norm_s (y); + y = shl (y, exp); + y = div_s ((Word16) 16383, y); + t0 = L_mult (x, y); + t0 = L_shr (t0, sub (20, exp)); + y = extract_l (t0); // y= (xhigh-xlow)/(yhigh-ylow) + + if (sign < 0) + y = negate (y); + + t0 = L_mult (ylow, y); + t0 = L_shr (t0, 11); + xint = sub (xlow, extract_l (t0)); // xint = xlow - ylow*y + } + + lsp[nf] = xint; + xlow = xint; + nf++; + + if (ip == 0) + { + ip = 1; + coef = f2; + } + else + { + ip = 0; + coef = f1; + } + ylow = Chebps (xlow, coef, NC); + + } + } + + // Check if M roots found + + if (sub (nf, M) < 0) + { + for (i = 0; i < M; i++) + { + lsp[i] = old_lsp[i]; + } + + } + return; +} + +------------------------------------------------------------------------------ + RESOURCES USED [optional] + + When the code is written for a specific target processor the + the resources used should be documented below. + + HEAP MEMORY USED: x bytes + + STACK MEMORY USED: x bytes + + CLOCK CYCLES: (cycle count equation for this function) + (variable + used to represent cycle count for each subroutine + called) + where: (cycle count variable) = cycle count for [subroutine + name] + +------------------------------------------------------------------------------ + CAUTION [optional] + [State any special notes, constraints or cautions for users of this function] + +------------------------------------------------------------------------------ +*/ + +void Az_lsp( + Word16 a[], /* (i) : predictor coefficients (MP1) */ + Word16 lsp[], /* (o) : line spectral pairs (M) */ + Word16 old_lsp[], /* (i) : old lsp[] (in case not found 10 roots) (M) */ + Flag *pOverflow /* (i/o): overflow flag */ +) +{ + register Word16 i; + register Word16 j; + register Word16 nf; + register Word16 ip; + Word16 xlow; + Word16 ylow; + Word16 xhigh; + Word16 yhigh; + Word16 xmid; + Word16 ymid; + Word16 xint; + Word16 x; + Word16 y; + Word16 sign; + Word16 exp; + Word16 *coef; + Word16 f1[NC + 1]; + Word16 f2[NC + 1]; + Word32 L_temp1; + Word32 L_temp2; + Word16 *p_f1 = f1; + Word16 *p_f2 = f2; + + /*-------------------------------------------------------------* + * 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] ; * + * } * + *-------------------------------------------------------------*/ + + *p_f1 = 1024; /* f1[0] = 1.0 */ + *p_f2 = 1024; /* f2[0] = 1.0 */ + + for (i = 0; i < NC; i++) + { + L_temp1 = (Word32) * (a + i + 1); + L_temp2 = (Word32) * (a + M - i); + /* x = (a[i+1] + a[M-i]) >> 2 */ + x = (Word16)((L_temp1 + L_temp2) >> 2); + /* y = (a[i+1] - a[M-i]) >> 2 */ + y = (Word16)((L_temp1 - L_temp2) >> 2); + /* f1[i+1] = a[i+1] + a[M-i] - f1[i] */ + x -= *(p_f1++); + *(p_f1) = x; + /* f2[i+1] = a[i+1] - a[M-i] + f2[i] */ + y += *(p_f2++); + *(p_f2) = y; + } + + /*-------------------------------------------------------------* + * find the LSPs using the Chebychev pol. evaluation * + *-------------------------------------------------------------*/ + + nf = 0; /* number of found frequencies */ + ip = 0; /* indicator for f1 or f2 */ + + coef = f1; + + xlow = *(grid); + ylow = Chebps(xlow, coef, NC, pOverflow); + + j = 0; + + while ((nf < M) && (j < grid_points)) + { + j++; + xhigh = xlow; + yhigh = ylow; + xlow = *(grid + j); + ylow = Chebps(xlow, coef, NC, pOverflow); + + if (((Word32)ylow*yhigh) <= 0) + { + /* divide 4 times the interval */ + for (i = 4; i != 0; i--) + { + /* xmid = (xlow + xhigh)/2 */ + x = xlow >> 1; + y = xhigh >> 1; + xmid = x + y; + + ymid = Chebps(xmid, coef, NC, pOverflow); + + if (((Word32)ylow*ymid) <= 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 <<= exp; + y = div_s((Word16) 16383, y); + + y = ((Word32)x * y) >> (19 - exp); + + if (sign < 0) + { + y = -y; + } + + /* xint = xlow - ylow*y */ + xint = xlow - (((Word32) ylow * y) >> 10); + } + + *(lsp + nf) = xint; + xlow = xint; + nf++; + + if (ip == 0) + { + ip = 1; + coef = f2; + } + else + { + ip = 0; + coef = f1; + } + + ylow = Chebps(xlow, coef, NC, pOverflow); + + } + } + + /* Check if M roots found */ + + if (nf < M) + { + for (i = NC; i != 0 ; i--) + { + *lsp++ = *old_lsp++; + *lsp++ = *old_lsp++; + } + } + +} + +Word16 Chebps_Wrapper(Word16 x, + Word16 f[], /* (n) */ + Word16 n, + Flag *pOverflow) +{ + return Chebps(x, f, n, pOverflow); +} + |