/*
 *  Copyright (c) 2011 The WebRTC project authors. All Rights Reserved.
 *
 *  Use of this source code is governed by a BSD-style license
 *  that can be found in the LICENSE file in the root of the source
 *  tree. An additional intellectual property rights grant can be found
 *  in the file PATENTS.  All contributing project authors may
 *  be found in the AUTHORS file in the root of the source tree.
 */

/*
 * This file contains the resampling functions for 22 kHz.
 * The description header can be found in signal_processing_library.h
 *
 */

#include "common_audio/signal_processing/include/signal_processing_library.h"
#include "common_audio/signal_processing/resample_by_2_internal.h"

// Declaration of internally used functions
static void WebRtcSpl_32khzTo22khzIntToShort(const int32_t* In,
                                             int16_t* Out,
                                             int32_t K);

void WebRtcSpl_32khzTo22khzIntToInt(const int32_t* In, int32_t* Out, int32_t K);

// interpolation coefficients
static const int16_t kCoefficients32To22[5][9] = {
    {127, -712, 2359, -6333, 23456, 16775, -3695, 945, -154},
    {-39, 230, -830, 2785, 32366, -2324, 760, -218, 38},
    {117, -663, 2222, -6133, 26634, 13070, -3174, 831, -137},
    {-77, 457, -1677, 5958, 31175, -4136, 1405, -408, 71},
    {98, -560, 1900, -5406, 29240, 9423, -2480, 663, -110}};

//////////////////////
// 22 kHz -> 16 kHz //
//////////////////////

// number of subblocks; options: 1, 2, 4, 5, 10
#define SUB_BLOCKS_22_16 5

// 22 -> 16 resampler
void WebRtcSpl_Resample22khzTo16khz(const int16_t* in,
                                    int16_t* out,
                                    WebRtcSpl_State22khzTo16khz* state,
                                    int32_t* tmpmem) {
  int k;

  // process two blocks of 10/SUB_BLOCKS_22_16 ms (to reduce temp buffer size)
  for (k = 0; k < SUB_BLOCKS_22_16; k++) {
    ///// 22 --> 44 /////
    // int16_t  in[220/SUB_BLOCKS_22_16]
    // int32_t out[440/SUB_BLOCKS_22_16]
    /////
    WebRtcSpl_UpBy2ShortToInt(in, 220 / SUB_BLOCKS_22_16, tmpmem + 16,
                              state->S_22_44);

    ///// 44 --> 32 /////
    // int32_t  in[440/SUB_BLOCKS_22_16]
    // int32_t out[320/SUB_BLOCKS_22_16]
    /////
    // copy state to and from input array
    tmpmem[8] = state->S_44_32[0];
    tmpmem[9] = state->S_44_32[1];
    tmpmem[10] = state->S_44_32[2];
    tmpmem[11] = state->S_44_32[3];
    tmpmem[12] = state->S_44_32[4];
    tmpmem[13] = state->S_44_32[5];
    tmpmem[14] = state->S_44_32[6];
    tmpmem[15] = state->S_44_32[7];
    state->S_44_32[0] = tmpmem[440 / SUB_BLOCKS_22_16 + 8];
    state->S_44_32[1] = tmpmem[440 / SUB_BLOCKS_22_16 + 9];
    state->S_44_32[2] = tmpmem[440 / SUB_BLOCKS_22_16 + 10];
    state->S_44_32[3] = tmpmem[440 / SUB_BLOCKS_22_16 + 11];
    state->S_44_32[4] = tmpmem[440 / SUB_BLOCKS_22_16 + 12];
    state->S_44_32[5] = tmpmem[440 / SUB_BLOCKS_22_16 + 13];
    state->S_44_32[6] = tmpmem[440 / SUB_BLOCKS_22_16 + 14];
    state->S_44_32[7] = tmpmem[440 / SUB_BLOCKS_22_16 + 15];

    WebRtcSpl_Resample44khzTo32khz(tmpmem + 8, tmpmem, 40 / SUB_BLOCKS_22_16);

    ///// 32 --> 16 /////
    // int32_t  in[320/SUB_BLOCKS_22_16]
    // int32_t out[160/SUB_BLOCKS_22_16]
    /////
    WebRtcSpl_DownBy2IntToShort(tmpmem, 320 / SUB_BLOCKS_22_16, out,
                                state->S_32_16);

    // move input/output pointers 10/SUB_BLOCKS_22_16 ms seconds ahead
    in += 220 / SUB_BLOCKS_22_16;
    out += 160 / SUB_BLOCKS_22_16;
  }
}

// initialize state of 22 -> 16 resampler
void WebRtcSpl_ResetResample22khzTo16khz(WebRtcSpl_State22khzTo16khz* state) {
  int k;
  for (k = 0; k < 8; k++) {
    state->S_22_44[k] = 0;
    state->S_44_32[k] = 0;
    state->S_32_16[k] = 0;
  }
}

//////////////////////
// 16 kHz -> 22 kHz //
//////////////////////

// number of subblocks; options: 1, 2, 4, 5, 10
#define SUB_BLOCKS_16_22 4

// 16 -> 22 resampler
void WebRtcSpl_Resample16khzTo22khz(const int16_t* in,
                                    int16_t* out,
                                    WebRtcSpl_State16khzTo22khz* state,
                                    int32_t* tmpmem) {
  int k;

  // process two blocks of 10/SUB_BLOCKS_16_22 ms (to reduce temp buffer size)
  for (k = 0; k < SUB_BLOCKS_16_22; k++) {
    ///// 16 --> 32 /////
    // int16_t  in[160/SUB_BLOCKS_16_22]
    // int32_t out[320/SUB_BLOCKS_16_22]
    /////
    WebRtcSpl_UpBy2ShortToInt(in, 160 / SUB_BLOCKS_16_22, tmpmem + 8,
                              state->S_16_32);

    ///// 32 --> 22 /////
    // int32_t  in[320/SUB_BLOCKS_16_22]
    // int32_t out[220/SUB_BLOCKS_16_22]
    /////
    // copy state to and from input array
    tmpmem[0] = state->S_32_22[0];
    tmpmem[1] = state->S_32_22[1];
    tmpmem[2] = state->S_32_22[2];
    tmpmem[3] = state->S_32_22[3];
    tmpmem[4] = state->S_32_22[4];
    tmpmem[5] = state->S_32_22[5];
    tmpmem[6] = state->S_32_22[6];
    tmpmem[7] = state->S_32_22[7];
    state->S_32_22[0] = tmpmem[320 / SUB_BLOCKS_16_22];
    state->S_32_22[1] = tmpmem[320 / SUB_BLOCKS_16_22 + 1];
    state->S_32_22[2] = tmpmem[320 / SUB_BLOCKS_16_22 + 2];
    state->S_32_22[3] = tmpmem[320 / SUB_BLOCKS_16_22 + 3];
    state->S_32_22[4] = tmpmem[320 / SUB_BLOCKS_16_22 + 4];
    state->S_32_22[5] = tmpmem[320 / SUB_BLOCKS_16_22 + 5];
    state->S_32_22[6] = tmpmem[320 / SUB_BLOCKS_16_22 + 6];
    state->S_32_22[7] = tmpmem[320 / SUB_BLOCKS_16_22 + 7];

    WebRtcSpl_32khzTo22khzIntToShort(tmpmem, out, 20 / SUB_BLOCKS_16_22);

    // move input/output pointers 10/SUB_BLOCKS_16_22 ms seconds ahead
    in += 160 / SUB_BLOCKS_16_22;
    out += 220 / SUB_BLOCKS_16_22;
  }
}

// initialize state of 16 -> 22 resampler
void WebRtcSpl_ResetResample16khzTo22khz(WebRtcSpl_State16khzTo22khz* state) {
  int k;
  for (k = 0; k < 8; k++) {
    state->S_16_32[k] = 0;
    state->S_32_22[k] = 0;
  }
}

//////////////////////
// 22 kHz ->  8 kHz //
//////////////////////

// number of subblocks; options: 1, 2, 5, 10
#define SUB_BLOCKS_22_8 2

// 22 -> 8 resampler
void WebRtcSpl_Resample22khzTo8khz(const int16_t* in,
                                   int16_t* out,
                                   WebRtcSpl_State22khzTo8khz* state,
                                   int32_t* tmpmem) {
  int k;

  // process two blocks of 10/SUB_BLOCKS_22_8 ms (to reduce temp buffer size)
  for (k = 0; k < SUB_BLOCKS_22_8; k++) {
    ///// 22 --> 22 lowpass /////
    // int16_t  in[220/SUB_BLOCKS_22_8]
    // int32_t out[220/SUB_BLOCKS_22_8]
    /////
    WebRtcSpl_LPBy2ShortToInt(in, 220 / SUB_BLOCKS_22_8, tmpmem + 16,
                              state->S_22_22);

    ///// 22 --> 16 /////
    // int32_t  in[220/SUB_BLOCKS_22_8]
    // int32_t out[160/SUB_BLOCKS_22_8]
    /////
    // copy state to and from input array
    tmpmem[8] = state->S_22_16[0];
    tmpmem[9] = state->S_22_16[1];
    tmpmem[10] = state->S_22_16[2];
    tmpmem[11] = state->S_22_16[3];
    tmpmem[12] = state->S_22_16[4];
    tmpmem[13] = state->S_22_16[5];
    tmpmem[14] = state->S_22_16[6];
    tmpmem[15] = state->S_22_16[7];
    state->S_22_16[0] = tmpmem[220 / SUB_BLOCKS_22_8 + 8];
    state->S_22_16[1] = tmpmem[220 / SUB_BLOCKS_22_8 + 9];
    state->S_22_16[2] = tmpmem[220 / SUB_BLOCKS_22_8 + 10];
    state->S_22_16[3] = tmpmem[220 / SUB_BLOCKS_22_8 + 11];
    state->S_22_16[4] = tmpmem[220 / SUB_BLOCKS_22_8 + 12];
    state->S_22_16[5] = tmpmem[220 / SUB_BLOCKS_22_8 + 13];
    state->S_22_16[6] = tmpmem[220 / SUB_BLOCKS_22_8 + 14];
    state->S_22_16[7] = tmpmem[220 / SUB_BLOCKS_22_8 + 15];

    WebRtcSpl_Resample44khzTo32khz(tmpmem + 8, tmpmem, 20 / SUB_BLOCKS_22_8);

    ///// 16 --> 8 /////
    // int32_t in[160/SUB_BLOCKS_22_8]
    // int32_t out[80/SUB_BLOCKS_22_8]
    /////
    WebRtcSpl_DownBy2IntToShort(tmpmem, 160 / SUB_BLOCKS_22_8, out,
                                state->S_16_8);

    // move input/output pointers 10/SUB_BLOCKS_22_8 ms seconds ahead
    in += 220 / SUB_BLOCKS_22_8;
    out += 80 / SUB_BLOCKS_22_8;
  }
}

// initialize state of 22 -> 8 resampler
void WebRtcSpl_ResetResample22khzTo8khz(WebRtcSpl_State22khzTo8khz* state) {
  int k;
  for (k = 0; k < 8; k++) {
    state->S_22_22[k] = 0;
    state->S_22_22[k + 8] = 0;
    state->S_22_16[k] = 0;
    state->S_16_8[k] = 0;
  }
}

//////////////////////
//  8 kHz -> 22 kHz //
//////////////////////

// number of subblocks; options: 1, 2, 5, 10
#define SUB_BLOCKS_8_22 2

// 8 -> 22 resampler
void WebRtcSpl_Resample8khzTo22khz(const int16_t* in,
                                   int16_t* out,
                                   WebRtcSpl_State8khzTo22khz* state,
                                   int32_t* tmpmem) {
  int k;

  // process two blocks of 10/SUB_BLOCKS_8_22 ms (to reduce temp buffer size)
  for (k = 0; k < SUB_BLOCKS_8_22; k++) {
    ///// 8 --> 16 /////
    // int16_t  in[80/SUB_BLOCKS_8_22]
    // int32_t out[160/SUB_BLOCKS_8_22]
    /////
    WebRtcSpl_UpBy2ShortToInt(in, 80 / SUB_BLOCKS_8_22, tmpmem + 18,
                              state->S_8_16);

    ///// 16 --> 11 /////
    // int32_t  in[160/SUB_BLOCKS_8_22]
    // int32_t out[110/SUB_BLOCKS_8_22]
    /////
    // copy state to and from input array
    tmpmem[10] = state->S_16_11[0];
    tmpmem[11] = state->S_16_11[1];
    tmpmem[12] = state->S_16_11[2];
    tmpmem[13] = state->S_16_11[3];
    tmpmem[14] = state->S_16_11[4];
    tmpmem[15] = state->S_16_11[5];
    tmpmem[16] = state->S_16_11[6];
    tmpmem[17] = state->S_16_11[7];
    state->S_16_11[0] = tmpmem[160 / SUB_BLOCKS_8_22 + 10];
    state->S_16_11[1] = tmpmem[160 / SUB_BLOCKS_8_22 + 11];
    state->S_16_11[2] = tmpmem[160 / SUB_BLOCKS_8_22 + 12];
    state->S_16_11[3] = tmpmem[160 / SUB_BLOCKS_8_22 + 13];
    state->S_16_11[4] = tmpmem[160 / SUB_BLOCKS_8_22 + 14];
    state->S_16_11[5] = tmpmem[160 / SUB_BLOCKS_8_22 + 15];
    state->S_16_11[6] = tmpmem[160 / SUB_BLOCKS_8_22 + 16];
    state->S_16_11[7] = tmpmem[160 / SUB_BLOCKS_8_22 + 17];

    WebRtcSpl_32khzTo22khzIntToInt(tmpmem + 10, tmpmem, 10 / SUB_BLOCKS_8_22);

    ///// 11 --> 22 /////
    // int32_t  in[110/SUB_BLOCKS_8_22]
    // int16_t out[220/SUB_BLOCKS_8_22]
    /////
    WebRtcSpl_UpBy2IntToShort(tmpmem, 110 / SUB_BLOCKS_8_22, out,
                              state->S_11_22);

    // move input/output pointers 10/SUB_BLOCKS_8_22 ms seconds ahead
    in += 80 / SUB_BLOCKS_8_22;
    out += 220 / SUB_BLOCKS_8_22;
  }
}

// initialize state of 8 -> 22 resampler
void WebRtcSpl_ResetResample8khzTo22khz(WebRtcSpl_State8khzTo22khz* state) {
  int k;
  for (k = 0; k < 8; k++) {
    state->S_8_16[k] = 0;
    state->S_16_11[k] = 0;
    state->S_11_22[k] = 0;
  }
}

// compute two inner-products and store them to output array
static void WebRtcSpl_DotProdIntToInt(const int32_t* in1,
                                      const int32_t* in2,
                                      const int16_t* coef_ptr,
                                      int32_t* out1,
                                      int32_t* out2) {
  int32_t tmp1 = 16384;
  int32_t tmp2 = 16384;
  int16_t coef;

  coef = coef_ptr[0];
  tmp1 += coef * in1[0];
  tmp2 += coef * in2[-0];

  coef = coef_ptr[1];
  tmp1 += coef * in1[1];
  tmp2 += coef * in2[-1];

  coef = coef_ptr[2];
  tmp1 += coef * in1[2];
  tmp2 += coef * in2[-2];

  coef = coef_ptr[3];
  tmp1 += coef * in1[3];
  tmp2 += coef * in2[-3];

  coef = coef_ptr[4];
  tmp1 += coef * in1[4];
  tmp2 += coef * in2[-4];

  coef = coef_ptr[5];
  tmp1 += coef * in1[5];
  tmp2 += coef * in2[-5];

  coef = coef_ptr[6];
  tmp1 += coef * in1[6];
  tmp2 += coef * in2[-6];

  coef = coef_ptr[7];
  tmp1 += coef * in1[7];
  tmp2 += coef * in2[-7];

  coef = coef_ptr[8];
  *out1 = tmp1 + coef * in1[8];
  *out2 = tmp2 + coef * in2[-8];
}

// compute two inner-products and store them to output array
static void WebRtcSpl_DotProdIntToShort(const int32_t* in1,
                                        const int32_t* in2,
                                        const int16_t* coef_ptr,
                                        int16_t* out1,
                                        int16_t* out2) {
  int32_t tmp1 = 16384;
  int32_t tmp2 = 16384;
  int16_t coef;

  coef = coef_ptr[0];
  tmp1 += coef * in1[0];
  tmp2 += coef * in2[-0];

  coef = coef_ptr[1];
  tmp1 += coef * in1[1];
  tmp2 += coef * in2[-1];

  coef = coef_ptr[2];
  tmp1 += coef * in1[2];
  tmp2 += coef * in2[-2];

  coef = coef_ptr[3];
  tmp1 += coef * in1[3];
  tmp2 += coef * in2[-3];

  coef = coef_ptr[4];
  tmp1 += coef * in1[4];
  tmp2 += coef * in2[-4];

  coef = coef_ptr[5];
  tmp1 += coef * in1[5];
  tmp2 += coef * in2[-5];

  coef = coef_ptr[6];
  tmp1 += coef * in1[6];
  tmp2 += coef * in2[-6];

  coef = coef_ptr[7];
  tmp1 += coef * in1[7];
  tmp2 += coef * in2[-7];

  coef = coef_ptr[8];
  tmp1 += coef * in1[8];
  tmp2 += coef * in2[-8];

  // scale down, round and saturate
  tmp1 >>= 15;
  if (tmp1 > (int32_t)0x00007FFF)
    tmp1 = 0x00007FFF;
  if (tmp1 < (int32_t)0xFFFF8000)
    tmp1 = 0xFFFF8000;
  tmp2 >>= 15;
  if (tmp2 > (int32_t)0x00007FFF)
    tmp2 = 0x00007FFF;
  if (tmp2 < (int32_t)0xFFFF8000)
    tmp2 = 0xFFFF8000;
  *out1 = (int16_t)tmp1;
  *out2 = (int16_t)tmp2;
}

//   Resampling ratio: 11/16
// input:  int32_t (normalized, not saturated) :: size 16 * K
// output: int32_t (shifted 15 positions to the left, + offset 16384) :: size 11
// * K
//      K: Number of blocks

void WebRtcSpl_32khzTo22khzIntToInt(const int32_t* In,
                                    int32_t* Out,
                                    int32_t K) {
  /////////////////////////////////////////////////////////////
  // Filter operation:
  //
  // Perform resampling (16 input samples -> 11 output samples);
  // process in sub blocks of size 16 samples.
  int32_t m;

  for (m = 0; m < K; m++) {
    // first output sample
    Out[0] = ((int32_t)In[3] << 15) + (1 << 14);

    // sum and accumulate filter coefficients and input samples
    WebRtcSpl_DotProdIntToInt(&In[0], &In[22], kCoefficients32To22[0], &Out[1],
                              &Out[10]);

    // sum and accumulate filter coefficients and input samples
    WebRtcSpl_DotProdIntToInt(&In[2], &In[20], kCoefficients32To22[1], &Out[2],
                              &Out[9]);

    // sum and accumulate filter coefficients and input samples
    WebRtcSpl_DotProdIntToInt(&In[3], &In[19], kCoefficients32To22[2], &Out[3],
                              &Out[8]);

    // sum and accumulate filter coefficients and input samples
    WebRtcSpl_DotProdIntToInt(&In[5], &In[17], kCoefficients32To22[3], &Out[4],
                              &Out[7]);

    // sum and accumulate filter coefficients and input samples
    WebRtcSpl_DotProdIntToInt(&In[6], &In[16], kCoefficients32To22[4], &Out[5],
                              &Out[6]);

    // update pointers
    In += 16;
    Out += 11;
  }
}

//   Resampling ratio: 11/16
// input:  int32_t (normalized, not saturated) :: size 16 * K
// output: int16_t (saturated) :: size 11 * K
//      K: Number of blocks

void WebRtcSpl_32khzTo22khzIntToShort(const int32_t* In,
                                      int16_t* Out,
                                      int32_t K) {
  /////////////////////////////////////////////////////////////
  // Filter operation:
  //
  // Perform resampling (16 input samples -> 11 output samples);
  // process in sub blocks of size 16 samples.
  int32_t tmp;
  int32_t m;

  for (m = 0; m < K; m++) {
    // first output sample
    tmp = In[3];
    if (tmp > (int32_t)0x00007FFF)
      tmp = 0x00007FFF;
    if (tmp < (int32_t)0xFFFF8000)
      tmp = 0xFFFF8000;
    Out[0] = (int16_t)tmp;

    // sum and accumulate filter coefficients and input samples
    WebRtcSpl_DotProdIntToShort(&In[0], &In[22], kCoefficients32To22[0],
                                &Out[1], &Out[10]);

    // sum and accumulate filter coefficients and input samples
    WebRtcSpl_DotProdIntToShort(&In[2], &In[20], kCoefficients32To22[1],
                                &Out[2], &Out[9]);

    // sum and accumulate filter coefficients and input samples
    WebRtcSpl_DotProdIntToShort(&In[3], &In[19], kCoefficients32To22[2],
                                &Out[3], &Out[8]);

    // sum and accumulate filter coefficients and input samples
    WebRtcSpl_DotProdIntToShort(&In[5], &In[17], kCoefficients32To22[3],
                                &Out[4], &Out[7]);

    // sum and accumulate filter coefficients and input samples
    WebRtcSpl_DotProdIntToShort(&In[6], &In[16], kCoefficients32To22[4],
                                &Out[5], &Out[6]);

    // update pointers
    In += 16;
    Out += 11;
  }
}