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Commit c633c62d authored by Jakub Pawlowski's avatar Jakub Pawlowski
Browse files

Use FFT for LC3 

Bug: 150670922
Change-Id: I51a37d7dd7354d60668fc8a589da3e41470efba8
parent 0f308be5

system/embdrv/lc3/Android.bp

+2 −0
Original line number Diff line number Diff line
@@ -18,6 +18,7 @@ cc_library_static { 
    defaults: ["fluoride_defaults"],

    srcs: [

        "Common/*.cpp",

        "Common/fft/*.c",

        "Common/Tables/*.cpp",

        "Encoder/*.cpp",

        "Decoder/*.cpp",
@@ -46,6 +47,7 @@ cc_library_static { 
    export_include_dirs: [

        "Api",

        "Common",

        "Common/fft",

        "Common/Tables",

        "TestSupport",

    ],

system/embdrv/lc3/Common/DctIV.cpp

+32 −2
Original line number Diff line number Diff line
@@ -64,8 +64,7 @@ 
 * really wanted to make sure, that no other code or build impact is generated

 * by the options in this file.

 */

//TODO: pick a FFT implementation library

//#define USE_KISSFFT

#define USE_OWN_FFT



#if defined USE_FFTW || defined USE_FFTW_FOR_FFT

#include <fftw3.h>
@@ -116,6 +115,8 @@ class KissfftConfig { 
  kissfft<double>* fft;

};



#elif defined USE_OWN_FFT

#include "fft.h"

#endif



DctIVDbl::DctIVDbl(uint16_t NF_)
@@ -134,6 +135,8 @@ DctIVDbl::DctIVDbl(uint16_t NF_) 
#elif defined USE_KISSFFT

  dctIVconfig = new KissfftConfig(NF / 2);



#elif defined USE_OWN_FFT

// setup is not needed

#endif



  for (uint16_t n = 0; n < NF; n++) {
@@ -155,6 +158,8 @@ DctIVDbl::~DctIVDbl() { 
    delete kissfftConfig;

  }



#elif defined USE_OWN_FFT

// cleanup is not needed

#endif

  if (nullptr != in) {

    delete[] in;
@@ -232,6 +237,31 @@ void DctIVDbl::run() { 
    out[NF - 2 * n - 1] = -complexOut.imag() * 2;

  }



#elif defined USE_OWN_FFT



  fft_complex inbuf[NF / 2];

  fft_complex outbuf[NF / 2];



  // assume NF being 4 times an integer

  for (uint16_t n = 1; n < NF / 2; n += 2) {

    double buffer;

    buffer = in[n];

    in[n] = in[NF - n];

    in[NF - n] = buffer;

  }



  for (uint16_t n = 0; n < NF / 2; n++) {

    inbuf[n].re = in[2 * n];

    inbuf[n].im = in[2 * n + 1];

  }



  fft_complex* actal_output = fft(false, inbuf, NF / 2, inbuf, outbuf);



  for (uint16_t n = 0; n < NF / 2; n++) {

    out[2 * n] = actal_output[n].re;

    out[NF - 2 * n - 1] = actal_output[n].im;

  }



#else

  DctIVDirectDbl(NF, in, out);

#endif