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Diffstat (limited to 'media/libstagefright/codecs/amrnb/enc/src/g_code.cpp')
| -rw-r--r-- | media/libstagefright/codecs/amrnb/enc/src/g_code.cpp | 322 |
1 files changed, 322 insertions, 0 deletions
diff --git a/media/libstagefright/codecs/amrnb/enc/src/g_code.cpp b/media/libstagefright/codecs/amrnb/enc/src/g_code.cpp new file mode 100644 index 0000000..f937cb7 --- /dev/null +++ b/media/libstagefright/codecs/amrnb/enc/src/g_code.cpp @@ -0,0 +1,322 @@ +/* ------------------------------------------------------------------ + * 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. +****************************************************************************************/ +/* +------------------------------------------------------------------------------ + + + + Filename: /audio/gsm_amr/c/src/g_code.c + + Date: 01/31/2002 + +------------------------------------------------------------------------------ + REVISION HISTORY + + Description: The return of L_mult was being stored in a Word16 before it was + being operated on (extract_h). Data loss happened here. + + Description: + 1. Eliminated unused include files. + 2. Replaced array addressing by pointers + 3. Eliminated math operations that unnecessary checked for + saturation, in some cases this by shifting before adding and + in other cases by evaluating the operands + 4. Unrolled loops to speed up processing + 5. Eliminated calls to shifts left and right functions by adding + if-else statements that do the same faster. + + Description: Added casting to eliminate warnings + + Description: Replaced "int" and/or "char" with OSCL defined types. + + Description: 1. Using inlines from fxp_arithmetic.h + 2. Removing a compiler warning. + + Description: Replacing fxp_arithmetic.h with basic_op.h. + + Description: + +------------------------------------------------------------------------------ +*/ + +/*---------------------------------------------------------------------------- +; INCLUDES +----------------------------------------------------------------------------*/ +#include "g_code.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.] +----------------------------------------------------------------------------*/ + +/*---------------------------------------------------------------------------- +; LOCAL FUNCTION DEFINITIONS +; [List function prototypes here] +----------------------------------------------------------------------------*/ + +/*---------------------------------------------------------------------------- +; LOCAL VARIABLE DEFINITIONS +; [Variable declaration - defined here and used outside this module] +----------------------------------------------------------------------------*/ + +/* +------------------------------------------------------------------------------ + FUNCTION NAME: G_code +------------------------------------------------------------------------------ + INPUT AND OUTPUT DEFINITIONS + + Inputs: + xn2[] = target vector (Word16) + y2[] = filtered innovation vector + pOverflow = pointer to overflow (Flag) + + Outputs: + pOverflow -> 1 if the innovative gain calculation resulted in overflow + + Returns: + gain = Gain of Innovation code (Word16) + + Global Variables Used: + None + + Local Variables Needed: + None + +------------------------------------------------------------------------------ + FUNCTION DESCRIPTION + + This function computes the innovative codebook gain. + + The innovative codebook gain is given by + g = <x[], y[]> / <y[], y[]> + + where x[] is the target vector, y[] is the filtered innovative codevector, + and <> denotes dot product. + +------------------------------------------------------------------------------ + REQUIREMENTS + + None + +------------------------------------------------------------------------------ + REFERENCES + + [1] g_code.c, UMTS GSM AMR speech codec, R99 - Version 3.2.0, March 2, 2001 + +------------------------------------------------------------------------------ + PSEUDO-CODE + +Word16 G_code ( // out : Gain of innovation code + Word16 xn2[], // in : target vector + Word16 y2[] // in : filtered innovation vector +) +{ + Word16 i; + Word16 xy, yy, exp_xy, exp_yy, gain; + Word16 scal_y2[L_SUBFR]; + Word32 s; + +// The original ETSI implementation uses a global overflow flag. However in +// actual implementation a pointer to Overflow flag is passed into the +// function for access by the low level math functions. + + // Scale down Y[] by 2 to avoid overflow + + for (i = 0; i < L_SUBFR; i++) + { + scal_y2[i] = shr (y2[i], 1); + } + + // Compute scalar product <X[],Y[]> + + s = 1L; // Avoid case of all zeros + for (i = 0; i < L_SUBFR; i++) + { + s = L_mac (s, xn2[i], scal_y2[i]); + } + exp_xy = norm_l (s); + xy = extract_h (L_shl (s, exp_xy)); + + // If (xy < 0) gain = 0 + + if (xy <= 0) + return ((Word16) 0); + + // Compute scalar product <Y[],Y[]> + + s = 0L; + for (i = 0; i < L_SUBFR; i++) + { + s = L_mac (s, scal_y2[i], scal_y2[i]); + } + exp_yy = norm_l (s); + yy = extract_h (L_shl (s, exp_yy)); + + // compute gain = xy/yy + + xy = shr (xy, 1); // Be sure xy < yy + gain = div_s (xy, yy); + + // Denormalization of division + i = add (exp_xy, 5); // 15-1+9-18 = 5 + i = sub (i, exp_yy); + + gain = shl (shr (gain, i), 1); // Q0 -> Q1/ + + return (gain); +} + + +------------------------------------------------------------------------------ + 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] + +------------------------------------------------------------------------------ +*/ + +/*---------------------------------------------------------------------------- +; FUNCTION CODE +----------------------------------------------------------------------------*/ +Word16 G_code( /* o : Gain of innovation code */ + Word16 xn2[], /* i : target vector */ + Word16 y2[], /* i : filtered innovation vector */ + Flag *pOverflow /* i/o : overflow flag */ +) +{ + Word16 i; + Word16 xy, yy, exp_xy, exp_yy, gain; + Word32 s; + + Word16 *p_xn2 = xn2; + Word16 *p_y2 = y2; + Word16 temp; + Word32 temp2; + + OSCL_UNUSED_ARG(pOverflow); + + /* Compute scalar product <X[],Y[]> */ + s = 0; + + for (i = (L_SUBFR >> 2); i != 0 ; i--) + { + temp2 = (Word32)(*(p_y2++) >> 1); + s = amrnb_fxp_mac_16_by_16bb((Word32) * (p_xn2++), temp2, s); + temp2 = (Word32)(*(p_y2++) >> 1); + s = amrnb_fxp_mac_16_by_16bb((Word32) * (p_xn2++), temp2, s); + temp2 = (Word32)(*(p_y2++) >> 1); + s = amrnb_fxp_mac_16_by_16bb((Word32) * (p_xn2++), temp2, s); + temp2 = (Word32)(*(p_y2++) >> 1); + s = amrnb_fxp_mac_16_by_16bb((Word32) * (p_xn2++), temp2, s); + } + s <<= 1; + exp_xy = norm_l(s + 1); /* Avoid case of all zeros, add 1 */ + + if (exp_xy < 17) /* extra right shift to be sure xy < yy */ + { + xy = (Word16)(s >> (17 - exp_xy)); + } + else + { + xy = (Word16)(s << (exp_xy - 17)); + } + + /* If (xy < 0) gain = 0 */ + + if (xy <= 0) + { + return ((Word16) 0); + } + + /* Compute scalar product <Y[],Y[]> */ + + s = 0L; + p_y2 = y2; + + for (i = (L_SUBFR >> 1); i != 0 ; i--) + { + temp = *(p_y2++) >> 1; + s += ((Word32) temp * temp) >> 2; + temp = *(p_y2++) >> 1; + s += ((Word32) temp * temp) >> 2; + } + s <<= 3; + exp_yy = norm_l(s); + + if (exp_yy < 16) + { + yy = (Word16)(s >> (16 - exp_yy)); + } + else + { + yy = (Word16)(s << (exp_yy - 16)); + } + + gain = div_s(xy, yy); + + /* Denormalization of division */ + i = exp_xy + 5; /* 15-1+9-18 = 5 */ + i -= exp_yy; + + // gain = shl (shr (gain, i), 1); /* Q0 -> Q1 */ + + if (i > 1) + { + gain >>= i - 1; + } + else + { + gain <<= 1 - i; + } + + + return (gain); +} |