/*
  * copyright (c) 2008 Michael Niedermayer <michaelni@gmx.at>

  * Copyright (C) 2016 foo86

  *
  * This file is part of FFmpeg.
  *
  * FFmpeg is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either
  * version 2.1 of the License, or (at your option) any later version.
  *
  * FFmpeg is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Lesser General Public License for more details.
  *
  * You should have received a copy of the GNU Lesser General Public
  * License along with FFmpeg; if not, write to the Free Software
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 

 #include "fft.h"

 #include "dcadct.h"
 #include "dcamath.h"

 #include "synth_filter.h"
 

 static void synth_filter_float(FFTContext *imdct,

                                float *synth_buf_ptr, int *synth_buf_offset,
                                float synth_buf2[32], const float window[512],
                                float out[32], const float in[32], float scale)

 {

     float *synth_buf = synth_buf_ptr + *synth_buf_offset;

     int i, j;
 

     imdct->imdct_half(imdct, synth_buf, in);

     for (i = 0; i < 16; i++) {
         float a = synth_buf2[i     ];
         float b = synth_buf2[i + 16];
         float c = 0;
         float d = 0;
         for (j = 0; j < 512 - *synth_buf_offset; j += 64) {
             a += window[i + j     ] * (-synth_buf[15 - i + j      ]);
             b += window[i + j + 16] * ( synth_buf[     i + j      ]);
             c += window[i + j + 32] * ( synth_buf[16 + i + j      ]);
             d += window[i + j + 48] * ( synth_buf[31 - i + j      ]);

         }

         for (     ; j < 512; j += 64) {
             a += window[i + j     ] * (-synth_buf[15 - i + j - 512]);
             b += window[i + j + 16] * ( synth_buf[     i + j - 512]);
             c += window[i + j + 32] * ( synth_buf[16 + i + j - 512]);
             d += window[i + j + 48] * ( synth_buf[31 - i + j - 512]);

         }

         out[i     ] = a * scale;
         out[i + 16] = b * scale;

         synth_buf2[i     ] = c;
         synth_buf2[i + 16] = d;

     }

 
     *synth_buf_offset = (*synth_buf_offset - 32) & 511;

 }

 static void synth_filter_float_64(FFTContext *imdct,
                                   float *synth_buf_ptr, int *synth_buf_offset,
                                   float synth_buf2[64], const float window[1024],
                                   float out[64], const float in[64], float scale)
 {
     float *synth_buf = synth_buf_ptr + *synth_buf_offset;
     int i, j;
 
     imdct->imdct_half(imdct, synth_buf, in);
 
     for (i = 0; i < 32; i++) {
         float a = synth_buf2[i     ];
         float b = synth_buf2[i + 32];
         float c = 0;
         float d = 0;
         for (j = 0; j < 1024 - *synth_buf_offset; j += 128) {
             a += window[i + j     ] * (-synth_buf[31 - i + j       ]);
             b += window[i + j + 32] * ( synth_buf[     i + j       ]);
             c += window[i + j + 64] * ( synth_buf[32 + i + j       ]);
             d += window[i + j + 96] * ( synth_buf[63 - i + j       ]);
         }
         for (     ; j < 1024; j += 128) {
             a += window[i + j     ] * (-synth_buf[31 - i + j - 1024]);
             b += window[i + j + 32] * ( synth_buf[     i + j - 1024]);
             c += window[i + j + 64] * ( synth_buf[32 + i + j - 1024]);
             d += window[i + j + 96] * ( synth_buf[63 - i + j - 1024]);
         }
         out[i     ] = a * scale;
         out[i + 32] = b * scale;
         synth_buf2[i     ] = c;
         synth_buf2[i + 32] = d;
     }
 
     *synth_buf_offset = (*synth_buf_offset - 64) & 1023;
 }
 
 static void synth_filter_fixed(DCADCTContext *imdct,
                                int32_t *synth_buf_ptr, int *synth_buf_offset,
                                int32_t synth_buf2[32], const int32_t window[512],
                                int32_t out[32], const int32_t in[32])
 {
     int32_t *synth_buf = synth_buf_ptr + *synth_buf_offset;
     int i, j;
 
     imdct->imdct_half[0](synth_buf, in);
 
     for (i = 0; i < 16; i++) {
         int64_t a = synth_buf2[i     ] * (INT64_C(1) << 21);
         int64_t b = synth_buf2[i + 16] * (INT64_C(1) << 21);
         int64_t c = 0;
         int64_t d = 0;
         for (j = 0; j < 512 - *synth_buf_offset; j += 64) {
             a += (int64_t)window[i + j     ] * synth_buf[     i + j      ];
             b += (int64_t)window[i + j + 16] * synth_buf[15 - i + j      ];
             c += (int64_t)window[i + j + 32] * synth_buf[16 + i + j      ];
             d += (int64_t)window[i + j + 48] * synth_buf[31 - i + j      ];
         }
         for (     ; j < 512; j += 64) {
             a += (int64_t)window[i + j     ] * synth_buf[     i + j - 512];
             b += (int64_t)window[i + j + 16] * synth_buf[15 - i + j - 512];
             c += (int64_t)window[i + j + 32] * synth_buf[16 + i + j - 512];
             d += (int64_t)window[i + j + 48] * synth_buf[31 - i + j - 512];
         }
         out[i     ] = clip23(norm21(a));
         out[i + 16] = clip23(norm21(b));
         synth_buf2[i     ] = norm21(c);
         synth_buf2[i + 16] = norm21(d);
     }
 
     *synth_buf_offset = (*synth_buf_offset - 32) & 511;
 }
 
 static void synth_filter_fixed_64(DCADCTContext *imdct,
                                   int32_t *synth_buf_ptr, int *synth_buf_offset,
                                   int32_t synth_buf2[64], const int32_t window[1024],
                                   int32_t out[64], const int32_t in[64])
 {
     int32_t *synth_buf = synth_buf_ptr + *synth_buf_offset;
     int i, j;
 
     imdct->imdct_half[1](synth_buf, in);
 
     for (i = 0; i < 32; i++) {
         int64_t a = synth_buf2[i     ] * (INT64_C(1) << 20);
         int64_t b = synth_buf2[i + 32] * (INT64_C(1) << 20);
         int64_t c = 0;
         int64_t d = 0;
         for (j = 0; j < 1024 - *synth_buf_offset; j += 128) {
             a += (int64_t)window[i + j     ] * synth_buf[     i + j       ];
             b += (int64_t)window[i + j + 32] * synth_buf[31 - i + j       ];
             c += (int64_t)window[i + j + 64] * synth_buf[32 + i + j       ];
             d += (int64_t)window[i + j + 96] * synth_buf[63 - i + j       ];
         }
         for (     ; j < 1024; j += 128) {
             a += (int64_t)window[i + j     ] * synth_buf[     i + j - 1024];
             b += (int64_t)window[i + j + 32] * synth_buf[31 - i + j - 1024];
             c += (int64_t)window[i + j + 64] * synth_buf[32 + i + j - 1024];
             d += (int64_t)window[i + j + 96] * synth_buf[63 - i + j - 1024];
         }
         out[i     ] = clip23(norm20(a));
         out[i + 32] = clip23(norm20(b));
         synth_buf2[i     ] = norm20(c);
         synth_buf2[i + 32] = norm20(d);
     }
 
     *synth_buf_offset = (*synth_buf_offset - 64) & 1023;
 }
 

 av_cold void ff_synth_filter_init(SynthFilterContext *c)
 {

     c->synth_filter_float    = synth_filter_float;
     c->synth_filter_float_64 = synth_filter_float_64;
     c->synth_filter_fixed    = synth_filter_fixed;
     c->synth_filter_fixed_64 = synth_filter_fixed_64;

     if (ARCH_AARCH64)
         ff_synth_filter_init_aarch64(c);
     if (ARCH_ARM)
         ff_synth_filter_init_arm(c);
     if (ARCH_X86)
         ff_synth_filter_init_x86(c);

 }