| /* ------------------------------------------------------------------ |
| * 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/enc_lag3.c |
| Functions: |
| |
| Date: 01/28/2002 |
| |
| ------------------------------------------------------------------------------ |
| REVISION HISTORY |
| |
| Description: Replaced "int" and/or "char" with OSCL defined types. |
| |
| Description: |
| |
| ------------------------------------------------------------------------------ |
| */ |
| |
| /*---------------------------------------------------------------------------- |
| ; INCLUDES |
| ----------------------------------------------------------------------------*/ |
| #include "enc_lag3.h" |
| #include "typedef.h" |
| #include "basic_op.h" |
| #include "cnst.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 |
| ----------------------------------------------------------------------------*/ |
| |
| /* |
| ------------------------------------------------------------------------------ |
| FUNCTION NAME: enc_lag3 |
| ------------------------------------------------------------------------------ |
| INPUT AND OUTPUT DEFINITIONS |
| |
| Inputs: |
| T0 = Pitch delay of type Word16 |
| T0_frac = Fractional pitch delay of type Word16 |
| T0_prev = Integer pitch delay of last subframe of type Word16 |
| T0_min = minimum of search range of type Word16 |
| T0_max = maximum of search range of type Word16 |
| delta_flag = Flag for 1st (or 3rd) subframe of type Word16 |
| flag4 = Flag for encoding with 4 bits of type Word16 |
| pOverflow = pointer indicating overflow of type Flag |
| |
| Outputs: |
| pOverflow = 1 if there is an overflow else it is zero. |
| |
| Returns: |
| None |
| |
| Global Variables Used: |
| None |
| |
| Local Variables Needed: |
| None |
| |
| ------------------------------------------------------------------------------ |
| FUNCTION DESCRIPTION |
| |
| This function implements the encoding of fractional pitch lag with |
| 1/3 resolution. |
| |
| * FUNCTION: Enc_lag3 |
| * |
| * PURPOSE: Encoding of fractional pitch lag with 1/3 resolution. |
| * |
| * DESCRIPTION: |
| * First and third subframes: |
| * -------------------------- |
| * The pitch range is divided as follows: |
| * 19 1/3 to 84 2/3 resolution 1/3 |
| * 85 to 143 resolution 1 |
| * |
| * The period is encoded with 8 bits. |
| * For the range with fractions: |
| * index = (T-19)*3 + frac - 1; |
| * where T=[19..85] and frac=[-1,0,1] |
| * and for the integer only range |
| * index = (T - 85) + 197; where T=[86..143] |
| * |
| * Second and fourth subframes: |
| * ---------------------------- |
| * For the 2nd and 4th subframes a resolution of 1/3 is always used, |
| * and the search range is relative to the lag in previous subframe. |
| * If t0 is the lag in the previous subframe then |
| * t_min=t0-5 and t_max=t0+4 and the range is given by |
| * t_min - 2/3 to t_max + 2/3 |
| * |
| * The period in the 2nd (and 4th) subframe is encoded with 5 bits: |
| * index = (T-(t_min-1))*3 + frac - 1; |
| * where T=[t_min-1..t_max+1] |
| |
| ------------------------------------------------------------------------------ |
| REQUIREMENTS |
| |
| None |
| |
| ------------------------------------------------------------------------------ |
| REFERENCES |
| |
| enc_lag3.c, UMTS GSM AMR speech codec, R99 - Version 3.2.0, March 2, 2001 |
| |
| ------------------------------------------------------------------------------ |
| PSEUDO-CODE |
| |
| Word16 index, i, tmp_ind, uplag; |
| Word16 tmp_lag; |
| |
| if (delta_flag == 0) |
| { // if 1st or 3rd subframe |
| |
| // encode pitch delay (with fraction) |
| |
| if (sub (T0, 85) <= 0) |
| { |
| // index = T0*3 - 58 + T0_frac |
| i = add (add (T0, T0), T0); |
| index = add (sub (i, 58), T0_frac); |
| } |
| else |
| { |
| index = add (T0, 112); |
| } |
| } |
| else |
| { // if second or fourth subframe |
| if (flag4 == 0) { |
| |
| // 'normal' encoding: either with 5 or 6 bit resolution |
| |
| // index = 3*(T0 - T0_min) + 2 + T0_frac |
| i = sub (T0, T0_min); |
| i = add (add (i, i), i); |
| index = add (add (i, 2), T0_frac); |
| } |
| else { |
| |
| // encoding with 4 bit resolution |
| |
| tmp_lag = T0_prev; |
| |
| if ( sub( sub(tmp_lag, T0_min), 5) > 0) |
| tmp_lag = add (T0_min, 5); |
| if ( sub( sub(T0_max, tmp_lag), 4) > 0) |
| tmp_lag = sub (T0_max, 4); |
| |
| uplag = add (add (add (T0, T0), T0), T0_frac); |
| |
| i = sub (tmp_lag, 2); |
| tmp_ind = add (add (i, i), i); |
| |
| if (sub (tmp_ind, uplag) >= 0) { |
| index = add (sub (T0, tmp_lag), 5); |
| } |
| else { |
| |
| i = add (tmp_lag, 1); |
| i = add (add (i, i), i); |
| |
| if (sub (i, uplag) > 0) { |
| |
| index = add ( sub (uplag, tmp_ind), 3); |
| } |
| else { |
| |
| index = add (sub (T0, tmp_lag), 11); |
| } |
| } |
| |
| } // end if (encoding with 4 bit resolution) |
| } // end if (second of fourth subframe) |
| |
| return index; |
| } |
| |
| ------------------------------------------------------------------------------ |
| 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 Enc_lag3( /* o : Return index of encoding */ |
| Word16 T0, /* i : Pitch delay */ |
| Word16 T0_frac, /* i : Fractional pitch delay */ |
| Word16 T0_prev, /* i : Integer pitch delay of last subframe */ |
| Word16 T0_min, /* i : minimum of search range */ |
| Word16 T0_max, /* i : maximum of search range */ |
| Word16 delta_flag, /* i : Flag for 1st (or 3rd) subframe */ |
| Word16 flag4, /* i : Flag for encoding with 4 bits */ |
| Flag *pOverflow |
| ) |
| { |
| Word16 index, i, tmp_ind, uplag; |
| Word16 tmp_lag; |
| Word16 temp1; |
| Word16 temp2; |
| |
| |
| |
| if (delta_flag == 0) |
| { /* if 1st or 3rd subframe */ |
| |
| /* encode pitch delay (with fraction) */ |
| temp1 = sub(T0, 85, pOverflow); |
| if (temp1 <= 0) |
| { |
| /* index = T0*3 - 58 + T0_frac */ |
| temp2 = add(T0, T0, pOverflow); |
| i = add(temp2, T0, pOverflow); |
| temp2 = sub(i, 58, pOverflow); |
| index = add(temp2, T0_frac, pOverflow); |
| } |
| else |
| { |
| index = add(T0, 112, pOverflow); |
| } |
| } |
| else |
| { /* if second or fourth subframe */ |
| if (flag4 == 0) |
| { |
| |
| /* 'normal' encoding: either with 5 or 6 bit resolution */ |
| |
| /* index = 3*(T0 - T0_min) + 2 + T0_frac */ |
| i = sub(T0, T0_min, pOverflow); |
| temp2 = add(i, i, pOverflow); |
| i = add(temp2, i, pOverflow); |
| temp2 = add(i, 2, pOverflow); |
| index = add(temp2, T0_frac, pOverflow); |
| } |
| else |
| { |
| |
| /* encoding with 4 bit resolution */ |
| |
| tmp_lag = T0_prev; |
| temp1 = sub(tmp_lag, T0_min, pOverflow); |
| temp2 = sub(temp1, 5, pOverflow); |
| if (temp2 > 0) |
| tmp_lag = add(T0_min, 5, pOverflow); |
| temp1 = sub(T0_max, tmp_lag, pOverflow); |
| temp2 = sub(temp1, 4, pOverflow); |
| if (temp2 > 0) |
| tmp_lag = sub(T0_max, 4, pOverflow); |
| |
| temp1 = add(T0, T0, pOverflow); |
| temp2 = add(temp1, T0, pOverflow); |
| uplag = add(temp2, T0_frac, pOverflow); |
| |
| i = sub(tmp_lag, 2, pOverflow); |
| temp1 = add(i, i, pOverflow); |
| tmp_ind = add(temp1, i, pOverflow); |
| |
| temp1 = sub(tmp_ind, uplag, pOverflow); |
| if (temp1 >= 0) |
| { |
| temp1 = sub(T0, tmp_lag, pOverflow); |
| index = add(temp1, 5, pOverflow); |
| } |
| else |
| { |
| |
| i = add(tmp_lag, 1, pOverflow); |
| temp1 = add(i, i, pOverflow); |
| i = add(temp1, i, pOverflow); |
| |
| if (sub(i, uplag, pOverflow) > 0) |
| { |
| temp1 = sub(uplag, tmp_ind, pOverflow); |
| index = add(temp1, 3, pOverflow); |
| } |
| else |
| { |
| temp1 = sub(T0, tmp_lag, pOverflow); |
| index = add(temp1, 11, pOverflow); |
| } |
| } |
| |
| } /* end if (encoding with 4 bit resolution) */ |
| } /* end if (second of fourth subframe) */ |
| |
| return index; |
| } |
| |
| |
| |
