cbsearch.cpp

实现3GPP的GSM中AMR语音的CODECS。

/* ------------------------------------------------------------------
 * Copyright (C) 2008 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/cbsearch.c
 Functions: D_plsf_3

     Date: 01/31/2002

------------------------------------------------------------------------------
 REVISION HISTORY

 Description:
 (1) Removed "count.h" and "basic_op.h" and replaced with individual include
     files (add.h, sub.h, etc.)
 (2) Added pOverflow parameter to code_10i40_35bits()

 Description:  Replaced "int" and/or "char" with OSCL defined types.

 Description:

 ------------------------------------------------------------------------------
 INPUT AND OUTPUT DEFINITIONS

 Inputs:
    x[] -- array of type Word16 -- target vector, Q0
    h[] -- array of type Word16 -- impulse response of weighted synthesis
                                   filter h[-L_subfr..-1] must be set to
                                   zero. Q12
    T0  -- Word16 -- Pitch lag
    pitch_sharp -- Word16 -- Last quantized pitch gain, Q14
    gain_pit --  Word16 gain_pit -- Pitch gain, Q14
    res2[] -- array of type Word16 -- Long term prediction residual, Q0
    mode -- enum Mode --  coder mode
    subNr -- Word16 -- subframe number

 Outputs:
    code[] -- array of type Word16 -- Innovative codebook, Q13
    y[] -- array of type Word16 -- filtered fixed codebook excitation
                                   Q12

    anap -- Double pointer to Word16 -- Signs of the pulses


    pOverflow -- pointer to Flag -- Flag set when overflow occurs

 Returns:
    Zero

 Global Variables Used:
    None

 Local Variables Needed:
    None

------------------------------------------------------------------------------
 FUNCTION DESCRIPTION

    Purpose          : Inovative codebook search (find index and gain)

------------------------------------------------------------------------------
 REQUIREMENTS



------------------------------------------------------------------------------
 REFERENCES

 cbsearch.c, UMTS GSM AMR speech codec, R99 - Version 3.2.0, March 2, 2001

------------------------------------------------------------------------------
 PSEUDO-CODE



------------------------------------------------------------------------------
 RESOURCES USED
   When the code is written for a specific target processor the
     the resources used should be documented below.

 STACK USAGE: [stack count for this module] + [variable to represent
          stack usage for each subroutine called]

     where: [stack usage variable] = stack usage for [subroutine
         name] (see [filename].ext)

 DATA MEMORY USED: x words

 PROGRAM MEMORY USED: x words

 CLOCK CYCLES: [cycle count equation for this module] + [variable
           used to represent cycle count for each subroutine
           called]

     where: [cycle count variable] = cycle count for [subroutine
        name] (see [filename].ext)

------------------------------------------------------------------------------
*/


/*----------------------------------------------------------------------------
; INCLUDES
----------------------------------------------------------------------------*/
#include "cbsearch.h"

#include "typedef.h"
#include "c2_9pf.h"
#include "c2_11pf.h"
#include "c3_14pf.h"
#include "c4_17pf.h"
#include "c8_31pf.h"
#include "c1035pf.h"
#include "mode.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 STORE/BUFFER/POINTER DEFINITIONS
; Variable declaration - defined here and used outside this module
----------------------------------------------------------------------------*/

/*----------------------------------------------------------------------------
; EXTERNAL FUNCTION REFERENCES
; Declare functions defined elsewhere and referenced in this module
----------------------------------------------------------------------------*/

/*----------------------------------------------------------------------------
; EXTERNAL GLOBAL STORE/BUFFER/POINTER REFERENCES
; Declare variables used in this module but defined elsewhere
----------------------------------------------------------------------------*/

/*----------------------------------------------------------------------------
; FUNCTION CODE
----------------------------------------------------------------------------*/

void cbsearch(Word16 x[],        /* i : target vector, Q0                     */
              Word16 h[],        /* i : impulse response of weighted synthesis*/
              /*     filter h[-L_subfr..-1] must be set to */
              /*     zero. Q12                             */
              Word16 T0,         /* i : Pitch lag                             */
              Word16 pitch_sharp,/* i : Last quantized pitch gain, Q14        */
              Word16 gain_pit,   /* i : Pitch gain, Q14                       */
              Word16 res2[],     /* i : Long term prediction residual, Q0     */
              Word16 code[],     /* o : Innovative codebook, Q13              */
              Word16 y[],        /* o : filtered fixed codebook excitation    */
              /*     Q12                                   */
              Word16 **anap,     /* o : Signs of the pulses                   */
              enum Mode mode,    /* i : coder mode                            */
              Word16 subNr,      /* i : subframe number                       */
              Flag  *pOverflow)  /* o : Flag set when overflow occurs         */
{
    Word16 index;
    Word16 i;
    Word16 temp;
    Word16 pit_sharpTmp;

    /* For MR74, the pre and post CB pitch sharpening is included in the
     * codebook search routine, while for MR122 is it not.
     */

    if ((mode == MR475) || (mode == MR515))
    {
        /* MR475, MR515 */
        *(*anap)++ =
            code_2i40_9bits(
                subNr,
                x,
                h,
                T0,
                pitch_sharp,
                code,
                y,
                &index,
                pOverflow);

        *(*anap)++ = index;    /* sign index */
    }
    else if (mode == MR59)
    {   /* MR59 */
        *(*anap)++ =
            code_2i40_11bits(
                x,
                h,
                T0,
                pitch_sharp,
                code,
                y,
                &index,
                pOverflow);

        *(*anap)++ = index;    /* sign index */
    }
    else if (mode == MR67)
    {   /* MR67 */
        *(*anap)++ =
            code_3i40_14bits(
                x,
                h,
                T0,
                pitch_sharp,
                code,
                y,
                &index,
                pOverflow);

        *(*anap)++ = index;    /* sign index */
    }
    else if ((mode == MR74) || (mode == MR795))
    {   /* MR74, MR795 */
        *(*anap)++ =
            code_4i40_17bits(
                x,
                h,
                T0,
                pitch_sharp,
                code,
                y,
                &index,
                pOverflow);

        *(*anap)++ = index;    /* sign index */
    }
    else if (mode == MR102)
    {   /* MR102 */
        /*-------------------------------------------------------------*
         * - include pitch contribution into impulse resp. h1[]        *
         *-------------------------------------------------------------*/
        /* pit_sharpTmp = pit_sharp;                     */
        /* if (pit_sharpTmp > 1.0) pit_sharpTmp = 1.0;   */

        pit_sharpTmp =
            shl(
                pitch_sharp,
                1,
                pOverflow);

        for (i = T0; i < L_SUBFR; i++)
        {
            temp =
                mult(
                    h[i - T0],
                    pit_sharpTmp,
                    pOverflow);

            h[i] =
                add(
                    h[i],
                    temp,
                    pOverflow);
        }

        /*--------------------------------------------------------------*
         * - Innovative codebook search (find index and gain)           *
         *--------------------------------------------------------------*/
        code_8i40_31bits(
            x,
            res2,
            h,
            code,
            y,
            *anap,
            pOverflow);

        *anap += 7;

        /*-------------------------------------------------------*
         * - Add the pitch contribution to code[].               *
         *-------------------------------------------------------*/
        for (i = T0; i < L_SUBFR; i++)
        {
            temp =
                mult(
                    code[i - T0],
                    pit_sharpTmp,
                    pOverflow);

            code[i] =
                add(
                    code[i],
                    temp,
                    pOverflow);
        }
    }
    else
    {  /* MR122 */
        /*-------------------------------------------------------------*
         * - include pitch contribution into impulse resp. h1[]        *
         *-------------------------------------------------------------*/

        /* pit_sharpTmp = gain_pit;                      */
        /* if (pit_sharpTmp > 1.0) pit_sharpTmp = 1.0;   */

        pit_sharpTmp = shl(gain_pit, 1, pOverflow);

        for (i = T0; i < L_SUBFR; i++)
        {
            temp = ((Word32)h[i - T0] * pit_sharpTmp) >> 15;
            /*
                     mult(
                            h[i - T0],
                            ,
                            pOverflow);
            */
            h[i] =
                add(
                    h[i],
                    temp,
                    pOverflow);
        }
        /*--------------------------------------------------------------*
         * - Innovative codebook search (find index and gain)           *
         *--------------------------------------------------------------*/

        code_10i40_35bits(
            x,
            res2,
            h,
            code,
            y,
            *anap,
            pOverflow);

        *anap += 10;

        /*-------------------------------------------------------*
         * - Add the pitch contribution to code[].               *
         *-------------------------------------------------------*/
        for (i = T0; i < L_SUBFR; i++)
        {
            temp =
                mult(
                    code[i - T0],
                    pit_sharpTmp,
                    pOverflow);

            code[i] =
                add(
                    code[i],
                    temp,
                    pOverflow);
        }
    }

}