env_calc_arm.cpp - Android社区 - https://www.androidos.net.cn/

/* -----------------------------------------------------------------------------------------------------------
Software License for The Fraunhofer FDK AAC Codec Library for Android

1.    INTRODUCTION
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the MPEG Advanced Audio Coding ("AAC") encoding and decoding scheme for digital audio.
This FDK AAC Codec software is intended to be used on a wide variety of Android devices.

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Commercially-licensed AAC software libraries, including floating-point versions with enhanced sound quality,
are also available from Fraunhofer. Users are encouraged to check the Fraunhofer website for additional
applications information and documentation.

2.    COPYRIGHT LICENSE

Redistribution and use in source and binary forms, with or without modification, are permitted without
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This FDK AAC Codec software is provided by Fraunhofer on behalf of the copyright holders and contributors
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5.    CONTACT INFORMATION

Fraunhofer Institute for Integrated Circuits IIS
Attention: Audio and Multimedia Departments - FDK AAC LL
Am Wolfsmantel 33
91058 Erlangen, Germany

www.iis.fraunhofer.de/amm
amm-info@iis.fraunhofer.de
----------------------------------------------------------------------------------------------------------- */

/********************************  Fraunhofer IIS  ***************************

Author(s):   Arthur Tritthart
   Description: (ARM optimised) SBR domain coding

******************************************************************************/
#ifndef INCLUSION_GUARD_CALC_ENV_ARM
#define INCLUSION_GUARD_CALC_ENV_ARM

/*!
  \brief   Compute maximal value of a complex array (re/im) of a given width
           Negative values are temporarily logically or'ed with 0xFFFFFFFF
           instead of negating the value, if the sign bit is set.
  \param   maxVal  Preset maximal value
  \param   reTmp   real input signal
  \param   imTmp   imaginary input signal
  \return  new maximal value
*/

#ifdef FUNCTION_FDK_get_maxval
__asm FIXP_DBL FDK_get_maxval (FIXP_DBL maxVal, FIXP_DBL *reTmp, FIXP_DBL *imTmp, int width )
{

/* Register map:
     r0    maxVal
     r1    reTmp
     r2    imTmp
     r3    width
     r4    real
     r5    imag
  */
    PUSH    {r4-r5}

MOVS    r3, r3, ASR #1
    ADC     r3, r3, #0
    BCS     FDK_get_maxval_loop_2nd_part
    BEQ     FDK_get_maxval_loop_end

FDK_get_maxval_loop
    LDR     r4, [r1], #4
    LDR     r5, [r2], #4
    EOR     r4, r4, r4, ASR #31
    EOR     r5, r5, r5, ASR #31
    ORR     r0, r0, r4
    ORR     r0, r0, r5

FDK_get_maxval_loop_2nd_part
    LDR     r4, [r1], #4
    LDR     r5, [r2], #4
    EOR     r4, r4, r4, ASR #31
    EOR     r5, r5, r5, ASR #31
    ORR     r0, r0, r4
    ORR     r0, r0, r5

SUBS    r3, r3, #1
    BNE     FDK_get_maxval_loop

FDK_get_maxval_loop_end
    POP     {r4-r5}
    BX      lr
}
#endif /* FUNCTION_FDK_get_maxval */

#endif /* INCLUSION_GUARD_CALC_ENV_ARM */

C++程序 | 149行 | 6.19 KB

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