/*

 *  Copyright (c) 2010 The WebM 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.

 */

#include <assert.h>

#include <math.h>

#include "./vp9_rtcd.h"

#include "./vpx_config.h"

#include "./vpx_dsp_rtcd.h"

#include "vp9/common/vp9_blockd.h"

#include "vp9/common/vp9_idct.h"

#include "vpx_dsp/fwd_txfm.h"

#include "vpx_ports/mem.h"

static void fdct4(const tran_low_t *input, tran_low_t *output) {

  tran_high_t step[4];

  tran_high_t temp1, temp2;

  step[0] = input[0] + input[3];

  step[1] = input[1] + input[2];

  step[2] = input[1] - input[2];

  step[3] = input[0] - input[3];

  temp1 = (step[0] + step[1]) * cospi_16_64;

  temp2 = (step[0] - step[1]) * cospi_16_64;

  output[0] = (tran_low_t)fdct_round_shift(temp1);

  output[2] = (tran_low_t)fdct_round_shift(temp2);

  temp1 = step[2] * cospi_24_64 + step[3] * cospi_8_64;

  temp2 = -step[2] * cospi_8_64 + step[3] * cospi_24_64;

  output[1] = (tran_low_t)fdct_round_shift(temp1);

  output[3] = (tran_low_t)fdct_round_shift(temp2);

}

static void fdct8(const tran_low_t *input, tran_low_t *output) {

  tran_high_t s0, s1, s2, s3, s4, s5, s6, s7;  // canbe16

  tran_high_t t0, t1, t2, t3;                  // needs32

  tran_high_t x0, x1, x2, x3;                  // canbe16

  // stage 1

  s0 = input[0] + input[7];

  s1 = input[1] + input[6];

  s2 = input[2] + input[5];

  s3 = input[3] + input[4];

  s4 = input[3] - input[4];

  s5 = input[2] - input[5];

  s6 = input[1] - input[6];

  s7 = input[0] - input[7];

  // fdct4(step, step);

  x0 = s0 + s3;

  x1 = s1 + s2;

  x2 = s1 - s2;

  x3 = s0 - s3;

  t0 = (x0 + x1) * cospi_16_64;

  t1 = (x0 - x1) * cospi_16_64;

  t2 = x2 * cospi_24_64 + x3 * cospi_8_64;

  t3 = -x2 * cospi_8_64 + x3 * cospi_24_64;

  output[0] = (tran_low_t)fdct_round_shift(t0);

  output[2] = (tran_low_t)fdct_round_shift(t2);

  output[4] = (tran_low_t)fdct_round_shift(t1);

  output[6] = (tran_low_t)fdct_round_shift(t3);

  // Stage 2

  t0 = (s6 - s5) * cospi_16_64;

  t1 = (s6 + s5) * cospi_16_64;

  t2 = (tran_low_t)fdct_round_shift(t0);

  t3 = (tran_low_t)fdct_round_shift(t1);

  // Stage 3

  x0 = s4 + t2;

  x1 = s4 - t2;

  x2 = s7 - t3;

  x3 = s7 + t3;

  // Stage 4

  t0 = x0 * cospi_28_64 + x3 * cospi_4_64;

  t1 = x1 * cospi_12_64 + x2 * cospi_20_64;

  t2 = x2 * cospi_12_64 + x1 * -cospi_20_64;

  t3 = x3 * cospi_28_64 + x0 * -cospi_4_64;

  output[1] = (tran_low_t)fdct_round_shift(t0);

  output[3] = (tran_low_t)fdct_round_shift(t2);

  output[5] = (tran_low_t)fdct_round_shift(t1);

  output[7] = (tran_low_t)fdct_round_shift(t3);

}

static void fdct16(const tran_low_t in[16], tran_low_t out[16]) {

  tran_high_t step1[8];      // canbe16

  tran_high_t step2[8];      // canbe16

  tran_high_t step3[8];      // canbe16

  tran_high_t input[8];      // canbe16

  tran_high_t temp1, temp2;  // needs32

  // step 1

  input[0] = in[0] + in[15];

  input[1] = in[1] + in[14];

  input[2] = in[2] + in[13];

  input[3] = in[3] + in[12];

  input[4] = in[4] + in[11];

  input[5] = in[5] + in[10];

  input[6] = in[6] + in[9];

  input[7] = in[7] + in[8];

  step1[0] = in[7] - in[8];

  step1[1] = in[6] - in[9];

  step1[2] = in[5] - in[10];

  step1[3] = in[4] - in[11];

  step1[4] = in[3] - in[12];

  step1[5] = in[2] - in[13];

  step1[6] = in[1] - in[14];

  step1[7] = in[0] - in[15];

  // fdct8(step, step);

  {

    tran_high_t s0, s1, s2, s3, s4, s5, s6, s7;  // canbe16

    tran_high_t t0, t1, t2, t3;                  // needs32

    tran_high_t x0, x1, x2, x3;                  // canbe16

    // stage 1

    s0 = input[0] + input[7];

    s1 = input[1] + input[6];

    s2 = input[2] + input[5];

    s3 = input[3] + input[4];

    s4 = input[3] - input[4];

    s5 = input[2] - input[5];

    s6 = input[1] - input[6];

    s7 = input[0] - input[7];

    // fdct4(step, step);

    x0 = s0 + s3;

    x1 = s1 + s2;

    x2 = s1 - s2;

    x3 = s0 - s3;

    t0 = (x0 + x1) * cospi_16_64;

    t1 = (x0 - x1) * cospi_16_64;

    t2 = x3 * cospi_8_64 + x2 * cospi_24_64;

    t3 = x3 * cospi_24_64 - x2 * cospi_8_64;

    out[0] = (tran_low_t)fdct_round_shift(t0);

    out[4] = (tran_low_t)fdct_round_shift(t2);

    out[8] = (tran_low_t)fdct_round_shift(t1);

    out[12] = (tran_low_t)fdct_round_shift(t3);

    // Stage 2

    t0 = (s6 - s5) * cospi_16_64;

    t1 = (s6 + s5) * cospi_16_64;

    t2 = fdct_round_shift(t0);

    t3 = fdct_round_shift(t1);

    // Stage 3

    x0 = s4 + t2;

    x1 = s4 - t2;

    x2 = s7 - t3;

    x3 = s7 + t3;

    // Stage 4

    t0 = x0 * cospi_28_64 + x3 * cospi_4_64;

    t1 = x1 * cospi_12_64 + x2 * cospi_20_64;

    t2 = x2 * cospi_12_64 + x1 * -cospi_20_64;

    t3 = x3 * cospi_28_64 + x0 * -cospi_4_64;

    out[2] = (tran_low_t)fdct_round_shift(t0);

    out[6] = (tran_low_t)fdct_round_shift(t2);

    out[10] = (tran_low_t)fdct_round_shift(t1);

    out[14] = (tran_low_t)fdct_round_shift(t3);

  }

  // step 2

  temp1 = (step1[5] - step1[2]) * cospi_16_64;

  temp2 = (step1[4] - step1[3]) * cospi_16_64;

  step2[2] = fdct_round_shift(temp1);

  step2[3] = fdct_round_shift(temp2);

  temp1 = (step1[4] + step1[3]) * cospi_16_64;

  temp2 = (step1[5] + step1[2]) * cospi_16_64;

  step2[4] = fdct_round_shift(temp1);

  step2[5] = fdct_round_shift(temp2);

  // step 3

  step3[0] = step1[0] + step2[3];

  step3[1] = step1[1] + step2[2];

  step3[2] = step1[1] - step2[2];

  step3[3] = step1[0] - step2[3];

  step3[4] = step1[7] - step2[4];

  step3[5] = step1[6] - step2[5];

  step3[6] = step1[6] + step2[5];

  step3[7] = step1[7] + step2[4];

  // step 4

  temp1 = step3[1] * -cospi_8_64 + step3[6] * cospi_24_64;

  temp2 = step3[2] * cospi_24_64 + step3[5] * cospi_8_64;

  step2[1] = fdct_round_shift(temp1);

  step2[2] = fdct_round_shift(temp2);

  temp1 = step3[2] * cospi_8_64 - step3[5] * cospi_24_64;

  temp2 = step3[1] * cospi_24_64 + step3[6] * cospi_8_64;

  step2[5] = fdct_round_shift(temp1);

  step2[6] = fdct_round_shift(temp2);

  // step 5

  step1[0] = step3[0] + step2[1];

  step1[1] = step3[0] - step2[1];

  step1[2] = step3[3] + step2[2];

  step1[3] = step3[3] - step2[2];

  step1[4] = step3[4] - step2[5];

  step1[5] = step3[4] + step2[5];

  step1[6] = step3[7] - step2[6];

  step1[7] = step3[7] + step2[6];

  // step 6

  temp1 = step1[0] * cospi_30_64 + step1[7] * cospi_2_64;

  temp2 = step1[1] * cospi_14_64 + step1[6] * cospi_18_64;

  out[1] = (tran_low_t)fdct_round_shift(temp1);

  out[9] = (tran_low_t)fdct_round_shift(temp2);

  temp1 = step1[2] * cospi_22_64 + step1[5] * cospi_10_64;

  temp2 = step1[3] * cospi_6_64 + step1[4] * cospi_26_64;

  out[5] = (tran_low_t)fdct_round_shift(temp1);

  out[13] = (tran_low_t)fdct_round_shift(temp2);

  temp1 = step1[3] * -cospi_26_64 + step1[4] * cospi_6_64;

  temp2 = step1[2] * -cospi_10_64 + step1[5] * cospi_22_64;

  out[3] = (tran_low_t)fdct_round_shift(temp1);

  out[11] = (tran_low_t)fdct_round_shift(temp2);

  temp1 = step1[1] * -cospi_18_64 + step1[6] * cospi_14_64;

  temp2 = step1[0] * -cospi_2_64 + step1[7] * cospi_30_64;

  out[7] = (tran_low_t)fdct_round_shift(temp1);

  out[15] = (tran_low_t)fdct_round_shift(temp2);

}

static void fadst4(const tran_low_t *input, tran_low_t *output) {

  tran_high_t x0, x1, x2, x3;

  tran_high_t s0, s1, s2, s3, s4, s5, s6, s7;

  x0 = input[0];

  x1 = input[1];

  x2 = input[2];

  x3 = input[3];

  if (!(x0 | x1 | x2 | x3)) {

    output[0] = output[1] = output[2] = output[3] = 0;

    return;

  }

  s0 = sinpi_1_9 * x0;

  s1 = sinpi_4_9 * x0;

  s2 = sinpi_2_9 * x1;

  s3 = sinpi_1_9 * x1;

  s4 = sinpi_3_9 * x2;

  s5 = sinpi_4_9 * x3;

  s6 = sinpi_2_9 * x3;

  s7 = x0 + x1 - x3;

  x0 = s0 + s2 + s5;

  x1 = sinpi_3_9 * s7;

  x2 = s1 - s3 + s6;

  x3 = s4;

  s0 = x0 + x3;

  s1 = x1;

  s2 = x2 - x3;

  s3 = x2 - x0 + x3;

  // 1-D transform scaling factor is sqrt(2).

  output[0] = (tran_low_t)fdct_round_shift(s0);

  output[1] = (tran_low_t)fdct_round_shift(s1);

  output[2] = (tran_low_t)fdct_round_shift(s2);

  output[3] = (tran_low_t)fdct_round_shift(s3);

}

static void fadst8(const tran_low_t *input, tran_low_t *output) {

  tran_high_t s0, s1, s2, s3, s4, s5, s6, s7;

  tran_high_t x0 = input[7];

  tran_high_t x1 = input[0];

  tran_high_t x2 = input[5];

  tran_high_t x3 = input[2];

  tran_high_t x4 = input[3];

  tran_high_t x5 = input[4];

  tran_high_t x6 = input[1];

  tran_high_t x7 = input[6];

  // stage 1

  s0 = cospi_2_64 * x0 + cospi_30_64 * x1;

  s1 = cospi_30_64 * x0 - cospi_2_64 * x1;

  s2 = cospi_10_64 * x2 + cospi_22_64 * x3;

  s3 = cospi_22_64 * x2 - cospi_10_64 * x3;

  s4 = cospi_18_64 * x4 + cospi_14_64 * x5;

  s5 = cospi_14_64 * x4 - cospi_18_64 * x5;

  s6 = cospi_26_64 * x6 + cospi_6_64 * x7;

  s7 = cospi_6_64 * x6 - cospi_26_64 * x7;

  x0 = fdct_round_shift(s0 + s4);

  x1 = fdct_round_shift(s1 + s5);

  x2 = fdct_round_shift(s2 + s6);

  x3 = fdct_round_shift(s3 + s7);

  x4 = fdct_round_shift(s0 - s4);

  x5 = fdct_round_shift(s1 - s5);

  x6 = fdct_round_shift(s2 - s6);

  x7 = fdct_round_shift(s3 - s7);

  // stage 2

  s0 = x0;

  s1 = x1;

  s2 = x2;

  s3 = x3;

  s4 = cospi_8_64 * x4 + cospi_24_64 * x5;

  s5 = cospi_24_64 * x4 - cospi_8_64 * x5;

  s6 = -cospi_24_64 * x6 + cospi_8_64 * x7;

  s7 = cospi_8_64 * x6 + cospi_24_64 * x7;

  x0 = s0 + s2;

  x1 = s1 + s3;

  x2 = s0 - s2;

  x3 = s1 - s3;

  x4 = fdct_round_shift(s4 + s6);

  x5 = fdct_round_shift(s5 + s7);

  x6 = fdct_round_shift(s4 - s6);

  x7 = fdct_round_shift(s5 - s7);

  // stage 3

  s2 = cospi_16_64 * (x2 + x3);

  s3 = cospi_16_64 * (x2 - x3);

  s6 = cospi_16_64 * (x6 + x7);

  s7 = cospi_16_64 * (x6 - x7);

  x2 = fdct_round_shift(s2);

  x3 = fdct_round_shift(s3);

  x6 = fdct_round_shift(s6);

  x7 = fdct_round_shift(s7);

  output[0] = (tran_low_t)x0;

  output[1] = (tran_low_t)-x4;

  output[2] = (tran_low_t)x6;

  output[3] = (tran_low_t)-x2;

  output[4] = (tran_low_t)x3;

  output[5] = (tran_low_t)-x7;

  output[6] = (tran_low_t)x5;

  output[7] = (tran_low_t)-x1;

}

static void fadst16(const tran_low_t *input, tran_low_t *output) {

  tran_high_t s0, s1, s2, s3, s4, s5, s6, s7, s8;

  tran_high_t s9, s10, s11, s12, s13, s14, s15;

  tran_high_t x0 = input[15];

  tran_high_t x1 = input[0];

  tran_high_t x2 = input[13];

  tran_high_t x3 = input[2];

  tran_high_t x4 = input[11];

  tran_high_t x5 = input[4];

  tran_high_t x6 = input[9];

  tran_high_t x7 = input[6];

  tran_high_t x8 = input[7];

  tran_high_t x9 = input[8];

  tran_high_t x10 = input[5];

  tran_high_t x11 = input[10];

  tran_high_t x12 = input[3];

  tran_high_t x13 = input[12];

  tran_high_t x14 = input[1];

  tran_high_t x15 = input[14];

  // stage 1

  s0 = x0 * cospi_1_64 + x1 * cospi_31_64;

  s1 = x0 * cospi_31_64 - x1 * cospi_1_64;

  s2 = x2 * cospi_5_64 + x3 * cospi_27_64;

  s3 = x2 * cospi_27_64 - x3 * cospi_5_64;

  s4 = x4 * cospi_9_64 + x5 * cospi_23_64;

  s5 = x4 * cospi_23_64 - x5 * cospi_9_64;

  s6 = x6 * cospi_13_64 + x7 * cospi_19_64;

  s7 = x6 * cospi_19_64 - x7 * cospi_13_64;

  s8 = x8 * cospi_17_64 + x9 * cospi_15_64;

  s9 = x8 * cospi_15_64 - x9 * cospi_17_64;

  s10 = x10 * cospi_21_64 + x11 * cospi_11_64;

  s11 = x10 * cospi_11_64 - x11 * cospi_21_64;

  s12 = x12 * cospi_25_64 + x13 * cospi_7_64;

  s13 = x12 * cospi_7_64 - x13 * cospi_25_64;

  s14 = x14 * cospi_29_64 + x15 * cospi_3_64;

  s15 = x14 * cospi_3_64 - x15 * cospi_29_64;

  x0 = fdct_round_shift(s0 + s8);

  x1 = fdct_round_shift(s1 + s9);

  x2 = fdct_round_shift(s2 + s10);

  x3 = fdct_round_shift(s3 + s11);

  x4 = fdct_round_shift(s4 + s12);

  x5 = fdct_round_shift(s5 + s13);

  x6 = fdct_round_shift(s6 + s14);

  x7 = fdct_round_shift(s7 + s15);

  x8 = fdct_round_shift(s0 - s8);

  x9 = fdct_round_shift(s1 - s9);

  x10 = fdct_round_shift(s2 - s10);

  x11 = fdct_round_shift(s3 - s11);

  x12 = fdct_round_shift(s4 - s12);

  x13 = fdct_round_shift(s5 - s13);

  x14 = fdct_round_shift(s6 - s14);

  x15 = fdct_round_shift(s7 - s15);

  // stage 2

  s0 = x0;

  s1 = x1;

  s2 = x2;

  s3 = x3;

  s4 = x4;

  s5 = x5;

  s6 = x6;

  s7 = x7;

  s8 = x8 * cospi_4_64 + x9 * cospi_28_64;

  s9 = x8 * cospi_28_64 - x9 * cospi_4_64;

  s10 = x10 * cospi_20_64 + x11 * cospi_12_64;

  s11 = x10 * cospi_12_64 - x11 * cospi_20_64;

  s12 = -x12 * cospi_28_64 + x13 * cospi_4_64;

  s13 = x12 * cospi_4_64 + x13 * cospi_28_64;

  s14 = -x14 * cospi_12_64 + x15 * cospi_20_64;

  s15 = x14 * cospi_20_64 + x15 * cospi_12_64;

  x0 = s0 + s4;

  x1 = s1 + s5;

  x2 = s2 + s6;

  x3 = s3 + s7;

  x4 = s0 - s4;

  x5 = s1 - s5;

  x6 = s2 - s6;

  x7 = s3 - s7;

  x8 = fdct_round_shift(s8 + s12);

  x9 = fdct_round_shift(s9 + s13);

  x10 = fdct_round_shift(s10 + s14);

  x11 = fdct_round_shift(s11 + s15);

  x12 = fdct_round_shift(s8 - s12);

  x13 = fdct_round_shift(s9 - s13);

  x14 = fdct_round_shift(s10 - s14);

  x15 = fdct_round_shift(s11 - s15);

  // stage 3

  s0 = x0;

  s1 = x1;

  s2 = x2;

  s3 = x3;

  s4 = x4 * cospi_8_64 + x5 * cospi_24_64;

  s5 = x4 * cospi_24_64 - x5 * cospi_8_64;

  s6 = -x6 * cospi_24_64 + x7 * cospi_8_64;

  s7 = x6 * cospi_8_64 + x7 * cospi_24_64;

  s8 = x8;

  s9 = x9;

  s10 = x10;

  s11 = x11;

  s12 = x12 * cospi_8_64 + x13 * cospi_24_64;

  s13 = x12 * cospi_24_64 - x13 * cospi_8_64;

  s14 = -x14 * cospi_24_64 + x15 * cospi_8_64;

  s15 = x14 * cospi_8_64 + x15 * cospi_24_64;

  x0 = s0 + s2;

  x1 = s1 + s3;

  x2 = s0 - s2;

  x3 = s1 - s3;

  x4 = fdct_round_shift(s4 + s6);

  x5 = fdct_round_shift(s5 + s7);

  x6 = fdct_round_shift(s4 - s6);

  x7 = fdct_round_shift(s5 - s7);

  x8 = s8 + s10;

  x9 = s9 + s11;

  x10 = s8 - s10;

  x11 = s9 - s11;

  x12 = fdct_round_shift(s12 + s14);

  x13 = fdct_round_shift(s13 + s15);

  x14 = fdct_round_shift(s12 - s14);

  x15 = fdct_round_shift(s13 - s15);

  // stage 4

  s2 = (-cospi_16_64) * (x2 + x3);

  s3 = cospi_16_64 * (x2 - x3);

  s6 = cospi_16_64 * (x6 + x7);

  s7 = cospi_16_64 * (-x6 + x7);

  s10 = cospi_16_64 * (x10 + x11);

  s11 = cospi_16_64 * (-x10 + x11);

  s14 = (-cospi_16_64) * (x14 + x15);

  s15 = cospi_16_64 * (x14 - x15);

  x2 = fdct_round_shift(s2);

  x3 = fdct_round_shift(s3);

  x6 = fdct_round_shift(s6);

  x7 = fdct_round_shift(s7);

  x10 = fdct_round_shift(s10);

  x11 = fdct_round_shift(s11);

  x14 = fdct_round_shift(s14);

  x15 = fdct_round_shift(s15);

  output[0] = (tran_low_t)x0;

  output[1] = (tran_low_t)-x8;

  output[2] = (tran_low_t)x12;

  output[3] = (tran_low_t)-x4;

  output[4] = (tran_low_t)x6;

  output[5] = (tran_low_t)x14;

  output[6] = (tran_low_t)x10;

  output[7] = (tran_low_t)x2;

  output[8] = (tran_low_t)x3;

  output[9] = (tran_low_t)x11;

  output[10] = (tran_low_t)x15;

  output[11] = (tran_low_t)x7;

  output[12] = (tran_low_t)x5;

  output[13] = (tran_low_t)-x13;

  output[14] = (tran_low_t)x9;

  output[15] = (tran_low_t)-x1;

}

static const transform_2d FHT_4[] = {

  { fdct4, fdct4 },   // DCT_DCT  = 0

  { fadst4, fdct4 },  // ADST_DCT = 1

  { fdct4, fadst4 },  // DCT_ADST = 2

  { fadst4, fadst4 }  // ADST_ADST = 3

};

static const transform_2d FHT_8[] = {

  { fdct8, fdct8 },   // DCT_DCT  = 0

  { fadst8, fdct8 },  // ADST_DCT = 1

  { fdct8, fadst8 },  // DCT_ADST = 2

  { fadst8, fadst8 }  // ADST_ADST = 3

};

static const transform_2d FHT_16[] = {

  { fdct16, fdct16 },   // DCT_DCT  = 0

  { fadst16, fdct16 },  // ADST_DCT = 1

  { fdct16, fadst16 },  // DCT_ADST = 2

  { fadst16, fadst16 }  // ADST_ADST = 3

};

void vp9_fht4x4_c(const int16_t *input, tran_low_t *output, int stride,

                  int tx_type) {

  if (tx_type == DCT_DCT) {

    vpx_fdct4x4_c(input, output, stride);

  } else {

    tran_low_t out[4 * 4];

    int i, j;

    tran_low_t temp_in[4], temp_out[4];

    const transform_2d ht = FHT_4[tx_type];

    // Columns

    for (i = 0; i < 4; ++i) {

      for (j = 0; j < 4; ++j) temp_in[j] = input[j * stride + i] * 16;

      if (i == 0 && temp_in[0]) temp_in[0] += 1;

      ht.cols(temp_in, temp_out);

      for (j = 0; j < 4; ++j) out[j * 4 + i] = temp_out[j];

    }

    // Rows

    for (i = 0; i < 4; ++i) {

      for (j = 0; j < 4; ++j) temp_in[j] = out[j + i * 4];

      ht.rows(temp_in, temp_out);

      for (j = 0; j < 4; ++j) output[j + i * 4] = (temp_out[j] + 1) >> 2;

    }

  }

}

void vp9_fht8x8_c(const int16_t *input, tran_low_t *output, int stride,

                  int tx_type) {

  if (tx_type == DCT_DCT) {

    vpx_fdct8x8_c(input, output, stride);

  } else {

    tran_low_t out[64];

    int i, j;

    tran_low_t temp_in[8], temp_out[8];

    const transform_2d ht = FHT_8[tx_type];

    // Columns

    for (i = 0; i < 8; ++i) {

      for (j = 0; j < 8; ++j) temp_in[j] = input[j * stride + i] * 4;

      ht.cols(temp_in, temp_out);

      for (j = 0; j < 8; ++j) out[j * 8 + i] = temp_out[j];

    }

    // Rows

    for (i = 0; i < 8; ++i) {

      for (j = 0; j < 8; ++j) temp_in[j] = out[j + i * 8];

      ht.rows(temp_in, temp_out);

      for (j = 0; j < 8; ++j)

        output[j + i * 8] = (temp_out[j] + (temp_out[j] < 0)) >> 1;

    }

  }

}

/* 4-point reversible, orthonormal Walsh-Hadamard in 3.5 adds, 0.5 shifts per

   pixel. */

void vp9_fwht4x4_c(const int16_t *input, tran_low_t *output, int stride) {

  int i;

  tran_high_t a1, b1, c1, d1, e1;

  const int16_t *ip_pass0 = input;

  const tran_low_t *ip = NULL;

  tran_low_t *op = output;

  for (i = 0; i < 4; i++) {

    a1 = ip_pass0[0 * stride];

    b1 = ip_pass0[1 * stride];

    c1 = ip_pass0[2 * stride];

    d1 = ip_pass0[3 * stride];

    a1 += b1;

    d1 = d1 - c1;

    e1 = (a1 - d1) >> 1;

    b1 = e1 - b1;

    c1 = e1 - c1;

    a1 -= c1;

    d1 += b1;

    op[0] = (tran_low_t)a1;

    op[4] = (tran_low_t)c1;

    op[8] = (tran_low_t)d1;

    op[12] = (tran_low_t)b1;

    ip_pass0++;

    op++;

  }

  ip = output;

  op = output;

  for (i = 0; i < 4; i++) {

    a1 = ip[0];

    b1 = ip[1];

    c1 = ip[2];

    d1 = ip[3];

    a1 += b1;

    d1 -= c1;

    e1 = (a1 - d1) >> 1;

    b1 = e1 - b1;

    c1 = e1 - c1;

    a1 -= c1;

    d1 += b1;

    op[0] = (tran_low_t)(a1 * UNIT_QUANT_FACTOR);

    op[1] = (tran_low_t)(c1 * UNIT_QUANT_FACTOR);

    op[2] = (tran_low_t)(d1 * UNIT_QUANT_FACTOR);

    op[3] = (tran_low_t)(b1 * UNIT_QUANT_FACTOR);

    ip += 4;

    op += 4;

  }

}

void vp9_fht16x16_c(const int16_t *input, tran_low_t *output, int stride,

                    int tx_type) {

  if (tx_type == DCT_DCT) {

    vpx_fdct16x16_c(input, output, stride);

  } else {

    tran_low_t out[256];

    int i, j;

    tran_low_t temp_in[16], temp_out[16];

    const transform_2d ht = FHT_16[tx_type];

    // Columns

    for (i = 0; i < 16; ++i) {

      for (j = 0; j < 16; ++j) temp_in[j] = input[j * stride + i] * 4;

      ht.cols(temp_in, temp_out);

      for (j = 0; j < 16; ++j)

        out[j * 16 + i] = (temp_out[j] + 1 + (temp_out[j] < 0)) >> 2;

    }

    // Rows

    for (i = 0; i < 16; ++i) {

      for (j = 0; j < 16; ++j) temp_in[j] = out[j + i * 16];

      ht.rows(temp_in, temp_out);

      for (j = 0; j < 16; ++j) output[j + i * 16] = temp_out[j];

    }

  }

}

#if CONFIG_VP9_HIGHBITDEPTH

void vp9_highbd_fht4x4_c(const int16_t *input, tran_low_t *output, int stride,

                         int tx_type) {

  vp9_fht4x4_c(input, output, stride, tx_type);

}

void vp9_highbd_fht8x8_c(const int16_t *input, tran_low_t *output, int stride,

                         int tx_type) {

  vp9_fht8x8_c(input, output, stride, tx_type);

}

void vp9_highbd_fwht4x4_c(const int16_t *input, tran_low_t *output,

                          int stride) {

  vp9_fwht4x4_c(input, output, stride);

}

void vp9_highbd_fht16x16_c(const int16_t *input, tran_low_t *output, int stride,

                           int tx_type) {

  vp9_fht16x16_c(input, output, stride, tx_type);

}

#endif  // CONFIG_VP9_HIGHBITDEPTH