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Diffstat (limited to 'media/libstagefright/codecs/amrnb/dec/src/post_pro.cpp')
| -rw-r--r-- | media/libstagefright/codecs/amrnb/dec/src/post_pro.cpp | 395 |
1 files changed, 395 insertions, 0 deletions
diff --git a/media/libstagefright/codecs/amrnb/dec/src/post_pro.cpp b/media/libstagefright/codecs/amrnb/dec/src/post_pro.cpp new file mode 100644 index 0000000..ce31793 --- /dev/null +++ b/media/libstagefright/codecs/amrnb/dec/src/post_pro.cpp @@ -0,0 +1,395 @@ +/* ------------------------------------------------------------------ + * 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/post_pro.c + Functions: + Post_Process_reset + Post_Process + + Date: 04/03/2000 + +------------------------------------------------------------------------------ + REVISION HISTORY + + Description: Updated template used to PV coding template. First attempt at + optimizing C code. + + Description: Deleted variables listed in the Local Stores Needed/Modified + sections. Optimized the "else" portion of the first "if" + statement in Post_Process function. + + Description: Made grouping more explicit in the calculation of + signal[i] << 1 in the Post_Process function. + + Description: Added setting of Overflow flag in inlined code. + + Description: Synchronized file with UMTS version 3.2.0. Updated coding + template. Removed unnecessary include files. + + Description: Replaced basic_op.h with the header file of the math functions + used in the file. + + Description: Made the following changes per comments from Phase 2/3 review: + 1. Updated copyright year. + 2. Fixed typecasting issue with TI C compiler. + 3. Used short-hand notation for math operations, e.g., "+=", + in the code. + + Description: Removed the functions post_pro_init and post_pro_exit. + The post_pro related structure is no longer dynamically allocated. + + Description: Added pOverflow as a passed in variable as per changes needed + for the EPOC release. + + Description: Optimized file to reduce clock cycle usage. Updated copyright + year and removed unused files in Include section. + + Description: Replaced OSCL mem type functions and eliminated include + files that now are chosen by OSCL definitions + + Description: Replaced "int" and/or "char" with OSCL defined types. + + Description: Changed round function name to pv_round to avoid conflict with + round function in C standard library. + + Description: + +------------------------------------------------------------------------------ + MODULE DESCRIPTION + + This file contains the function that performs post-processing on the output + speech. Post-processing include filtering the output speech through a second + order high pass filter with cutoff frequency of 60 Hz, and up-scaling the + output speech by a factor of 2. In addition to the post-processing function + itself, a post-processing initialization function, post-processing reset + function, and post-processing exit function are also included in this file. + +------------------------------------------------------------------------------ +*/ + + +/*---------------------------------------------------------------------------- +; INCLUDES +----------------------------------------------------------------------------*/ +#include "post_pro.h" +#include "typedef.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 +; Function Prototype declaration +----------------------------------------------------------------------------*/ + +/*---------------------------------------------------------------------------- +; LOCAL VARIABLE DEFINITIONS +; Variable declaration - defined here and used outside this module +----------------------------------------------------------------------------*/ + +/* filter coefficients (fc = 60 Hz) */ +static const Word16 b[3] = {7699, -15398, 7699}; +static const Word16 a[3] = {8192, 15836, -7667}; + +/* +------------------------------------------------------------------------------ + FUNCTION NAME: Post_Process_reset +------------------------------------------------------------------------------ + INPUT AND OUTPUT DEFINITIONS + + Inputs: + state = pointer to a structure of type Post_ProcessState + + Outputs: + structure pointed to by state will have all its fields initialized + to zero + + Returns: + return_value = 0, if reset was successful; -1, otherwise (int) + + Global Variables Used: + None + + Local Variables Needed: + None + +------------------------------------------------------------------------------ + FUNCTION DESCRIPTION + + This function initializes state memory to zero. + +------------------------------------------------------------------------------ + REQUIREMENTS + + None + +------------------------------------------------------------------------------ + REFERENCES + + post_pro.c, UMTS GSM AMR speech codec, R99 - Version 3.2.0, March 2, 2001 + +------------------------------------------------------------------------------ + PSEUDO-CODE + +int Post_Process_reset (Post_ProcessState *state) +{ + if (state == (Post_ProcessState *) NULL){ + fprint(stderr, "Post_Process_reset: invalid parameter\n"); + return -1; + } + + state->y2_hi = 0; + state->y2_lo = 0; + state->y1_hi = 0; + state->y1_lo = 0; + state->x0 = 0; + state->x1 = 0; + + return 0; +} +------------------------------------------------------------------------------ + 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] + +------------------------------------------------------------------------------ +*/ + +Word16 Post_Process_reset(Post_ProcessState *state) +{ + if (state == (Post_ProcessState *) NULL) + { + /* fprint(stderr, "Post_Process_reset: invalid parameter\n"); */ + return(-1); + } + + state->y2_hi = 0; + state->y2_lo = 0; + state->y1_hi = 0; + state->y1_lo = 0; + state->x0 = 0; + state->x1 = 0; + + return(0); +} + +/****************************************************************************/ + +/* +------------------------------------------------------------------------------ + FUNCTION NAME: Post_Process +------------------------------------------------------------------------------ + INPUT AND OUTPUT DEFINITIONS + + Inputs: + st = pointer to a structure of type Post_ProcessState + signal = buffer containing the input signal (Word16) + lg = length of the input signal (Word16) + pOverflow = pointer to overflow indicator of type Flag + + Outputs: + structure pointed to by st contains new filter input and output values + signal buffer contains the HP filtered and up-scaled input signal + pOverflow points to 1 if overflow occurs in the math functions called + else it points to 0. + + Returns: + return_value = 0 (int) + + Global Variables Used: + a = buffer containing filter coefficients + b = buffer containing filter coefficients + + Local Variables Needed: + None + +------------------------------------------------------------------------------ + FUNCTION DESCRIPTION + + This function performs post-processing on the output speech signal. First, + the output speech goes through a second order high pass filter with a + cutoff frequency of 60 Hz. Then, the filtered output speech is multiplied + by a factor of 2. The algorithm implemented follows the following difference + equation: + + y[i] = b[0]*x[i]*2 + b[1]*x[i-1]*2 + b[2]*x[i-2]*2 + a[1]*y[i-1] + a[2]*y[i-2]; + +------------------------------------------------------------------------------ + REQUIREMENTS + + None + +------------------------------------------------------------------------------ + REFERENCES + + post_pro.c, UMTS GSM AMR speech codec, R99 - Version 3.2.0, March 2, 2001 + +------------------------------------------------------------------------------ + PSEUDO-CODE + +int Post_Process ( + Post_ProcessState *st, //i/o : post process state + Word16 signal[], //i/o : signal + Word16 lg //i : length of signal + ) +{ + Word16 i, x2; + Word32 L_tmp; + + for (i = 0; i < lg; i++) + { + x2 = st->x1; + st->x1 = st->x0; + st->x0 = signal[i]; + + // y[i] = b[0]*x[i]*2 + b[1]*x[i-1]*2 + b140[2]*x[i-2]/2 + // + a[1]*y[i-1] + a[2] * y[i-2]; + + L_tmp = Mpy_32_16 (st->y1_hi, st->y1_lo, a[1]); + L_tmp = L_add (L_tmp, Mpy_32_16 (st->y2_hi, st->y2_lo, a[2])); + L_tmp = L_mac (L_tmp, st->x0, b[0]); + L_tmp = L_mac (L_tmp, st->x1, b[1]); + L_tmp = L_mac (L_tmp, x2, b[2]); + L_tmp = L_shl (L_tmp, 2); + + //Multiplication by two of output speech with saturation. + signal[i] = pv_round(L_shl(L_tmp, 1)); + + st->y2_hi = st->y1_hi; + st->y2_lo = st->y1_lo; + L_Extract (L_tmp, &st->y1_hi, &st->y1_lo); + } + + return 0; +} + +------------------------------------------------------------------------------ + 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 Post_Process( + Post_ProcessState *st, /* i/o : post process state */ + Word16 signal[], /* i/o : signal */ + Word16 lg, /* i : length of signal */ + Flag *pOverflow +) +{ + Word16 i, x2; + Word32 L_tmp; + + Word16 *p_signal; + Word16 c_a1 = a[1]; + Word16 c_a2 = a[2]; + Word16 c_b0 = b[0]; + Word16 c_b1 = b[1]; + Word16 c_b2 = b[2]; + + p_signal = &signal[0]; + + for (i = 0; i < lg; i++) + { + x2 = st->x1; + st->x1 = st->x0; + st->x0 = *(p_signal); + + /* y[i] = b[0]*x[i]*2 + b[1]*x[i-1]*2 + b140[2]*x[i-2]/2 */ + /* + a[1]*y[i-1] + a[2] * y[i-2]; */ + + L_tmp = ((Word32) st->y1_hi) * c_a1; + L_tmp += (((Word32) st->y1_lo) * c_a1) >> 15; + L_tmp += ((Word32) st->y2_hi) * c_a2; + L_tmp += (((Word32) st->y2_lo) * c_a2) >> 15; + L_tmp += ((Word32) st->x0) * c_b0; + L_tmp += ((Word32) st->x1) * c_b1; + L_tmp += ((Word32) x2) * c_b2; + L_tmp <<= 3; + + + /* Multiplication by two of output speech with saturation. */ + + *(p_signal++) = pv_round(L_shl(L_tmp, 1, pOverflow), pOverflow); + + st->y2_hi = st->y1_hi; + st->y2_lo = st->y1_lo; + + st->y1_hi = (Word16)(L_tmp >> 16); + st->y1_lo = (Word16)((L_tmp >> 1) - ((Word32) st->y1_hi << 15)); + + } + + return; +} |