media/libstagefright/codecs/aacdec/dst8.cpp

/* ------------------------------------------------------------------
 * 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.
 * -------------------------------------------------------------------
 */
/*

 Filename: dst8.c

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


 Who:                                   Date: MM/DD/YYYY
 Description:

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

    Int32 x             32-bit integer input length 8


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

    Implement discrete sine transform of lenght 8

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


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

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

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


/*----------------------------------------------------------------------------
; INCLUDES
----------------------------------------------------------------------------*/

#ifdef AAC_PLUS


#include "dst8.h"

#include "fxp_mul32.h"


/*----------------------------------------------------------------------------
; MACROS
; Define module specific macros here
----------------------------------------------------------------------------*/


/*----------------------------------------------------------------------------
; DEFINES
; Include all pre-processor statements here. Include conditional
; compile variables also.
----------------------------------------------------------------------------*/

#define Qfmt15(x)   (Int16)(x*((Int32)1<<15) + (x>=0?0.5F:-0.5F))

/*----------------------------------------------------------------------------
; 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
----------------------------------------------------------------------------*/


#define R_SHIFT     29
#define Qfmt(x)   (Int32)(x*((Int32)1<<R_SHIFT) + (x>=0?0.5F:-0.5F))

#define Qfmt31(x)   (Int32)(x*0x7FFFFFFF + (x>=0?0.5F:-0.5F))


void dst_8(Int32 vec[])
{

    Int32 temp1;
    Int32 temp2;
    Int32 temp3;
    Int32 temp4;
    Int32 temp5;
    Int32 temp6;
    Int32 temp7;
    Int32 tmp_a;
    Int32 tmp_aa;
    Int32 tmp_b;
    Int32 tmp_bb;
    Int32 tmp_c;
    Int32 tmp_cc;
    Int32 tmp_d;
    Int32 tmp_dd;

    temp1 = fxp_mul32_by_16(vec[1], Qfmt15(0.50979557910416F));         /* (1/(2*cos(  phi)));*/
    temp2 = fxp_mul32_by_16(vec[2], Qfmt15(0.54119610014620F));         /* (1/(2*cos(2*phi)));*/
    temp3 = fxp_mul32_by_16(vec[3], Qfmt15(0.60134488693505F));         /* (1/(2*cos(3*phi)));*/
    temp5 = fxp_mul32_by_16(vec[5], Qfmt15(0.89997622313642F));         /* (1/(2*cos(5*phi)));*/
    temp6 = fxp_mul32_by_16(vec[6] << 1, Qfmt15(0.65328148243819F));        /* (1/(2*cos(6*phi)));*/
    temp7 = vec[7] + fxp_mul32_Q31(vec[7], Qfmt31(0.56291544774152F));          /* (1/(2*cos(7*phi)));*/

    /*  even  */
    tmp_a = fxp_mul32_Q31((temp2 + temp6) << 1, Qfmt31(0.70710678118655F));
    tmp_b = (temp2 - temp6) + tmp_a;

    temp4 = fxp_mul32_by_16(vec[4], Qfmt15(0.70710678118655F));
    vec[0] =   tmp_a + temp4;
    vec[1] =   tmp_b + temp4;
    vec[2] =   tmp_b - temp4;
    vec[3] =   tmp_a - temp4;


    /* odd */

    tmp_a  = fxp_mul32_by_16((temp1 + temp7) << 1, Qfmt15(0.54119610014620F));  /* (1/(2*cos(2*phi)));  */
    tmp_aa = (temp1 - temp7);
    tmp_bb = (temp5 - temp3);
    temp5  = fxp_mul32_Q29((temp5 + temp3), Qfmt(1.30656296487638F));   /* (1/(2*cos(6*phi)));  */


    tmp_c  = fxp_mul32_by_16((tmp_a + temp5) << 1, Qfmt15(0.70710678118655F));
    tmp_cc =  tmp_a - temp5;

    tmp_d  = fxp_mac32_by_16((tmp_aa - tmp_bb) << 1, Qfmt15(0.70710678118655F), tmp_c);
    tmp_dd = (tmp_aa + tmp_bb);

    tmp_dd +=  tmp_c;
    tmp_a   =  tmp_d  + tmp_cc;
    vec[5]  =  tmp_a  - vec[2];
    vec[2] +=  tmp_a;

    temp5   =  tmp_dd + tmp_cc;

    vec[4]  =  temp5  - vec[3];
    vec[3] +=  temp5;
    vec[7]  =  tmp_c  - vec[0];
    vec[0] +=  tmp_c;
    vec[6]  =  tmp_d  - vec[1];
    vec[1] +=  tmp_d;

}


#endif