/*
 * Copyright (c) 2016, Alliance for Open Media. All rights reserved
 *
 * This source code is subject to the terms of the BSD 2 Clause License and
 * the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License
 * was not distributed with this source code in the LICENSE file, you can
 * obtain it at www.aomedia.org/license/software. If the Alliance for Open
 * Media Patent License 1.0 was not distributed with this source code in the
 * PATENTS file, you can obtain it at www.aomedia.org/license/patent.
 */

#include <math.h>

#include "./aom_dsp_rtcd.h"
#include "./av1_rtcd.h"
#include "aom_dsp/inv_txfm.h"
#include "aom_ports/mem.h"
#include "av1/common/av1_inv_txfm1d_cfg.h"
#include "av1/common/blockd.h"
#include "av1/common/enums.h"
#include "av1/common/idct.h"

int av1_get_tx_scale(const TX_SIZE tx_size) {
  if (txsize_sqr_up_map[tx_size] == TX_32X32) return 1;
#if CONFIG_TX64X64
  else if (txsize_sqr_up_map[tx_size] == TX_64X64)
    return 2;
#endif  // CONFIG_TX64X64
  else
    return 0;
}

// NOTE: The implementation of all inverses need to be aware of the fact
// that input and output could be the same buffer.

#if CONFIG_EXT_TX
static void iidtx4_c(const tran_low_t *input, tran_low_t *output) {
  int i;
  for (i = 0; i < 4; ++i)
    output[i] = (tran_low_t)dct_const_round_shift(input[i] * Sqrt2);
}

static void iidtx8_c(const tran_low_t *input, tran_low_t *output) {
  int i;
  for (i = 0; i < 8; ++i) output[i] = input[i] * 2;
}

static void iidtx16_c(const tran_low_t *input, tran_low_t *output) {
  int i;
  for (i = 0; i < 16; ++i)
    output[i] = (tran_low_t)dct_const_round_shift(input[i] * 2 * Sqrt2);
}

static void iidtx32_c(const tran_low_t *input, tran_low_t *output) {
  int i;
  for (i = 0; i < 32; ++i) output[i] = input[i] * 4;
}

#if CONFIG_TX64X64
static void iidtx64_c(const tran_low_t *input, tran_low_t *output) {
  int i;
  for (i = 0; i < 64; ++i)
    output[i] = (tran_low_t)dct_const_round_shift(input[i] * 4 * Sqrt2);
}
#endif  // CONFIG_TX64X64
#endif  // CONFIG_EXT_TX

// For use in lieu of ADST
static void ihalfright32_c(const tran_low_t *input, tran_low_t *output) {
  int i;
  tran_low_t inputhalf[16];
  // Multiply input by sqrt(2)
  for (i = 0; i < 16; ++i) {
    inputhalf[i] = (tran_low_t)dct_const_round_shift(input[i] * Sqrt2);
  }
  for (i = 0; i < 16; ++i) {
    output[i] = input[16 + i] * 4;
  }
  aom_idct16_c(inputhalf, output + 16);
  // Note overall scaling factor is 4 times orthogonal
}

#if CONFIG_TX64X64
static void idct64_col_c(const tran_low_t *input, tran_low_t *output) {
  int32_t in[64], out[64];
  int i;
  for (i = 0; i < 64; ++i) in[i] = (int32_t)input[i];
  av1_idct64_new(in, out, inv_cos_bit_col_dct_64, inv_stage_range_col_dct_64);
  for (i = 0; i < 64; ++i) output[i] = (tran_low_t)out[i];
}

static void idct64_row_c(const tran_low_t *input, tran_low_t *output) {
  int32_t in[64], out[64];
  int i;
  for (i = 0; i < 64; ++i) in[i] = (int32_t)input[i];
  av1_idct64_new(in, out, inv_cos_bit_row_dct_64, inv_stage_range_row_dct_64);
  for (i = 0; i < 64; ++i) output[i] = (tran_low_t)out[i];
}

// For use in lieu of ADST
static void ihalfright64_c(const tran_low_t *input, tran_low_t *output) {
  int i;
  tran_low_t inputhalf[32];
  // Multiply input by sqrt(2)
  for (i = 0; i < 32; ++i) {
    inputhalf[i] = (tran_low_t)dct_const_round_shift(input[i] * Sqrt2);
  }
  for (i = 0; i < 32; ++i) {
    output[i] = (tran_low_t)dct_const_round_shift(input[32 + i] * 4 * Sqrt2);
  }
  aom_idct32_c(inputhalf, output + 32);
  // Note overall scaling factor is 4 * sqrt(2)  times orthogonal
}
#endif  // CONFIG_TX64X64

// Inverse identity transform and add.
#if CONFIG_EXT_TX
static void inv_idtx_add_c(const tran_low_t *input, uint8_t *dest, int stride,
                           int bs, int tx_type) {
  int r, c;
  const int shift = bs < 32 ? 3 : (bs < 64 ? 2 : 1);
  if (tx_type == IDTX) {
    for (r = 0; r < bs; ++r) {
      for (c = 0; c < bs; ++c)
        dest[c] = clip_pixel_add(dest[c], input[c] >> shift);
      dest += stride;
      input += bs;
    }
  }
}
#endif  // CONFIG_EXT_TX

#define FLIPUD_PTR(dest, stride, size)       \
  do {                                       \
    (dest) = (dest) + ((size)-1) * (stride); \
    (stride) = -(stride);                    \
  } while (0)

#if CONFIG_EXT_TX
static void maybe_flip_strides(uint8_t **dst, int *dstride, tran_low_t **src,
                               int *sstride, int tx_type, int sizey,
                               int sizex) {
  // Note that the transpose of src will be added to dst. In order to LR
  // flip the addends (in dst coordinates), we UD flip the src. To UD flip
  // the addends, we UD flip the dst.
  switch (tx_type) {
    case DCT_DCT:
    case ADST_DCT:
    case DCT_ADST:
    case ADST_ADST:
    case IDTX:
    case V_DCT:
    case H_DCT:
    case V_ADST:
    case H_ADST: break;
    case FLIPADST_DCT:
    case FLIPADST_ADST:
    case V_FLIPADST:
      // flip UD
      FLIPUD_PTR(*dst, *dstride, sizey);
      break;
    case DCT_FLIPADST:
    case ADST_FLIPADST:
    case H_FLIPADST:
      // flip LR
      FLIPUD_PTR(*src, *sstride, sizex);
      break;
    case FLIPADST_FLIPADST:
      // flip UD
      FLIPUD_PTR(*dst, *dstride, sizey);
      // flip LR
      FLIPUD_PTR(*src, *sstride, sizex);
      break;
    default: assert(0); break;
  }
}
#endif  // CONFIG_EXT_TX

#if CONFIG_HIGHBITDEPTH
#if CONFIG_EXT_TX && CONFIG_TX64X64
static void highbd_inv_idtx_add_c(const tran_low_t *input, uint8_t *dest8,
                                  int stride, int bs, int tx_type, int bd) {
  int r, c;
  const int shift = bs < 32 ? 3 : 2;
  uint16_t *dest = CONVERT_TO_SHORTPTR(dest8);

  if (tx_type == IDTX) {
    for (r = 0; r < bs; ++r) {
      for (c = 0; c < bs; ++c)
        dest[c] = highbd_clip_pixel_add(dest[c], input[c] >> shift, bd);
      dest += stride;
      input += bs;
    }
  }
}
#endif  // CONFIG_EXT_TX && CONFIG_TX64X64
#endif  // CONFIG_HIGHBITDEPTH

void av1_iht4x4_16_add_c(const tran_low_t *input, uint8_t *dest, int stride,
                         int tx_type) {
  static const transform_2d IHT_4[] = {
    { aom_idct4_c, aom_idct4_c },    // DCT_DCT  = 0
    { aom_iadst4_c, aom_idct4_c },   // ADST_DCT = 1
    { aom_idct4_c, aom_iadst4_c },   // DCT_ADST = 2
    { aom_iadst4_c, aom_iadst4_c },  // ADST_ADST = 3
#if CONFIG_EXT_TX
    { aom_iadst4_c, aom_idct4_c },   // FLIPADST_DCT
    { aom_idct4_c, aom_iadst4_c },   // DCT_FLIPADST
    { aom_iadst4_c, aom_iadst4_c },  // FLIPADST_FLIPADST
    { aom_iadst4_c, aom_iadst4_c },  // ADST_FLIPADST
    { aom_iadst4_c, aom_iadst4_c },  // FLIPADST_ADST
    { iidtx4_c, iidtx4_c },          // IDTX
    { aom_idct4_c, iidtx4_c },       // V_DCT
    { iidtx4_c, aom_idct4_c },       // H_DCT
    { aom_iadst4_c, iidtx4_c },      // V_ADST
    { iidtx4_c, aom_iadst4_c },      // H_ADST
    { aom_iadst4_c, iidtx4_c },      // V_FLIPADST
    { iidtx4_c, aom_iadst4_c },      // H_FLIPADST
#endif                               // CONFIG_EXT_TX
  };

  int i, j;
  tran_low_t tmp[4][4];
  tran_low_t out[4][4];
  tran_low_t *outp = &out[0][0];
  int outstride = 4;

  // inverse transform row vectors
  for (i = 0; i < 4; ++i) {
    IHT_4[tx_type].rows(input, out[i]);
    input += 4;
  }

  // transpose
  for (i = 0; i < 4; i++) {
    for (j = 0; j < 4; j++) {
      tmp[j][i] = out[i][j];
    }
  }

  // inverse transform column vectors
  for (i = 0; i < 4; ++i) {
    IHT_4[tx_type].cols(tmp[i], out[i]);
  }

#if CONFIG_EXT_TX
  maybe_flip_strides(&dest, &stride, &outp, &outstride, tx_type, 4, 4);
#endif

  // Sum with the destination
  for (i = 0; i < 4; ++i) {
    for (j = 0; j < 4; ++j) {
      int d = i * stride + j;
      int s = j * outstride + i;
      dest[d] = clip_pixel_add(dest[d], ROUND_POWER_OF_TWO(outp[s], 4));
    }
  }
}

void av1_iht4x8_32_add_c(const tran_low_t *input, uint8_t *dest, int stride,
                         int tx_type) {
  static const transform_2d IHT_4x8[] = {
    { aom_idct8_c, aom_idct4_c },    // DCT_DCT
    { aom_iadst8_c, aom_idct4_c },   // ADST_DCT
    { aom_idct8_c, aom_iadst4_c },   // DCT_ADST
    { aom_iadst8_c, aom_iadst4_c },  // ADST_ADST
#if CONFIG_EXT_TX
    { aom_iadst8_c, aom_idct4_c },   // FLIPADST_DCT
    { aom_idct8_c, aom_iadst4_c },   // DCT_FLIPADST
    { aom_iadst8_c, aom_iadst4_c },  // FLIPADST_FLIPADST
    { aom_iadst8_c, aom_iadst4_c },  // ADST_FLIPADST
    { aom_iadst8_c, aom_iadst4_c },  // FLIPADST_ADST
    { iidtx8_c, iidtx4_c },          // IDTX
    { aom_idct8_c, iidtx4_c },       // V_DCT
    { iidtx8_c, aom_idct4_c },       // H_DCT
    { aom_iadst8_c, iidtx4_c },      // V_ADST
    { iidtx8_c, aom_iadst4_c },      // H_ADST
    { aom_iadst8_c, iidtx4_c },      // V_FLIPADST
    { iidtx8_c, aom_iadst4_c },      // H_FLIPADST
#endif
  };

  const int n = 4;
  const int n2 = 8;
  int i, j;
  tran_low_t out[4][8], tmp[4][8], outtmp[4];
  tran_low_t *outp = &out[0][0];
  int outstride = n2;

  // inverse transform row vectors and transpose
  for (i = 0; i < n2; ++i) {
    IHT_4x8[tx_type].rows(input, outtmp);
    for (j = 0; j < n; ++j)
      tmp[j][i] = (tran_low_t)dct_const_round_shift(outtmp[j] * Sqrt2);
    input += n;
  }

  // inverse transform column vectors
  for (i = 0; i < n; ++i) {
    IHT_4x8[tx_type].cols(tmp[i], out[i]);
  }

#if CONFIG_EXT_TX
  maybe_flip_strides(&dest, &stride, &outp, &outstride, tx_type, n2, n);
#endif

  // Sum with the destination
  for (i = 0; i < n2; ++i) {
    for (j = 0; j < n; ++j) {
      int d = i * stride + j;
      int s = j * outstride + i;
      dest[d] = clip_pixel_add(dest[d], ROUND_POWER_OF_TWO(outp[s], 5));
    }
  }
}

void av1_iht8x4_32_add_c(const tran_low_t *input, uint8_t *dest, int stride,
                         int tx_type) {
  static const transform_2d IHT_8x4[] = {
    { aom_idct4_c, aom_idct8_c },    // DCT_DCT
    { aom_iadst4_c, aom_idct8_c },   // ADST_DCT
    { aom_idct4_c, aom_iadst8_c },   // DCT_ADST
    { aom_iadst4_c, aom_iadst8_c },  // ADST_ADST
#if CONFIG_EXT_TX
    { aom_iadst4_c, aom_idct8_c },   // FLIPADST_DCT
    { aom_idct4_c, aom_iadst8_c },   // DCT_FLIPADST
    { aom_iadst4_c, aom_iadst8_c },  // FLIPADST_FLIPADST
    { aom_iadst4_c, aom_iadst8_c },  // ADST_FLIPADST
    { aom_iadst4_c, aom_iadst8_c },  // FLIPADST_ADST
    { iidtx4_c, iidtx8_c },          // IDTX
    { aom_idct4_c, iidtx8_c },       // V_DCT
    { iidtx4_c, aom_idct8_c },       // H_DCT
    { aom_iadst4_c, iidtx8_c },      // V_ADST
    { iidtx4_c, aom_iadst8_c },      // H_ADST
    { aom_iadst4_c, iidtx8_c },      // V_FLIPADST
    { iidtx4_c, aom_iadst8_c },      // H_FLIPADST
#endif
  };
  const int n = 4;
  const int n2 = 8;

  int i, j;
  tran_low_t out[8][4], tmp[8][4], outtmp[8];
  tran_low_t *outp = &out[0][0];
  int outstride = n;

  // inverse transform row vectors and transpose
  for (i = 0; i < n; ++i) {
    IHT_8x4[tx_type].rows(input, outtmp);
    for (j = 0; j < n2; ++j)
      tmp[j][i] = (tran_low_t)dct_const_round_shift(outtmp[j] * Sqrt2);
    input += n2;
  }

  // inverse transform column vectors
  for (i = 0; i < n2; ++i) {
    IHT_8x4[tx_type].cols(tmp[i], out[i]);
  }

#if CONFIG_EXT_TX
  maybe_flip_strides(&dest, &stride, &outp, &outstride, tx_type, n, n2);
#endif

  // Sum with the destination
  for (i = 0; i < n; ++i) {
    for (j = 0; j < n2; ++j) {
      int d = i * stride + j;
      int s = j * outstride + i;
      dest[d] = clip_pixel_add(dest[d], ROUND_POWER_OF_TWO(outp[s], 5));
    }
  }
}

void av1_iht4x16_64_add_c(const tran_low_t *input, uint8_t *dest, int stride,
                          int tx_type) {
  static const transform_2d IHT_4x16[] = {
    { aom_idct16_c, aom_idct4_c },    // DCT_DCT
    { aom_iadst16_c, aom_idct4_c },   // ADST_DCT
    { aom_idct16_c, aom_iadst4_c },   // DCT_ADST
    { aom_iadst16_c, aom_iadst4_c },  // ADST_ADST
#if CONFIG_EXT_TX
    { aom_iadst16_c, aom_idct4_c },   // FLIPADST_DCT
    { aom_idct16_c, aom_iadst4_c },   // DCT_FLIPADST
    { aom_iadst16_c, aom_iadst4_c },  // FLIPADST_FLIPADST
    { aom_iadst16_c, aom_iadst4_c },  // ADST_FLIPADST
    { aom_iadst16_c, aom_iadst4_c },  // FLIPADST_ADST
    { iidtx16_c, iidtx4_c },          // IDTX
    { aom_idct16_c, iidtx4_c },       // V_DCT
    { iidtx16_c, aom_idct4_c },       // H_DCT
    { aom_iadst16_c, iidtx4_c },      // V_ADST
    { iidtx16_c, aom_iadst4_c },      // H_ADST
    { aom_iadst16_c, iidtx4_c },      // V_FLIPADST
    { iidtx16_c, aom_iadst4_c },      // H_FLIPADST
#endif
  };

  const int n = 4;
  const int n4 = 16;
  int i, j;
  tran_low_t out[4][16], tmp[4][16], outtmp[4];
  tran_low_t *outp = &out[0][0];
  int outstride = n4;

  // inverse transform row vectors and transpose
  for (i = 0; i < n4; ++i) {
    IHT_4x16[tx_type].rows(input, outtmp);
    for (j = 0; j < n; ++j) tmp[j][i] = outtmp[j];
    input += n;
  }

  // inverse transform column vectors
  for (i = 0; i < n; ++i) IHT_4x16[tx_type].cols(tmp[i], out[i]);

#if CONFIG_EXT_TX
  maybe_flip_strides(&dest, &stride, &outp, &outstride, tx_type, n4, n);
#endif

  // Sum with the destination
  for (i = 0; i < n4; ++i) {
    for (j = 0; j < n; ++j) {
      int d = i * stride + j;
      int s = j * outstride + i;
      dest[d] = clip_pixel_add(dest[d], ROUND_POWER_OF_TWO(outp[s], 5));
    }
  }
}

void av1_iht16x4_64_add_c(const tran_low_t *input, uint8_t *dest, int stride,
                          int tx_type) {
  static const transform_2d IHT_16x4[] = {
    { aom_idct4_c, aom_idct16_c },    // DCT_DCT
    { aom_iadst4_c, aom_idct16_c },   // ADST_DCT
    { aom_idct4_c, aom_iadst16_c },   // DCT_ADST
    { aom_iadst4_c, aom_iadst16_c },  // ADST_ADST
#if CONFIG_EXT_TX
    { aom_iadst4_c, aom_idct16_c },   // FLIPADST_DCT
    { aom_idct4_c, aom_iadst16_c },   // DCT_FLIPADST
    { aom_iadst4_c, aom_iadst16_c },  // FLIPADST_FLIPADST
    { aom_iadst4_c, aom_iadst16_c },  // ADST_FLIPADST
    { aom_iadst4_c, aom_iadst16_c },  // FLIPADST_ADST
    { iidtx4_c, iidtx16_c },          // IDTX
    { aom_idct4_c, iidtx16_c },       // V_DCT
    { iidtx4_c, aom_idct16_c },       // H_DCT
    { aom_iadst4_c, iidtx16_c },      // V_ADST
    { iidtx4_c, aom_iadst16_c },      // H_ADST
    { aom_iadst4_c, iidtx16_c },      // V_FLIPADST
    { iidtx4_c, aom_iadst16_c },      // H_FLIPADST
#endif
  };
  const int n = 4;
  const int n4 = 16;

  int i, j;
  tran_low_t out[16][4], tmp[16][4], outtmp[16];
  tran_low_t *outp = &out[0][0];
  int outstride = n;

  // inverse transform row vectors and transpose
  for (i = 0; i < n; ++i) {
    IHT_16x4[tx_type].rows(input, outtmp);
    for (j = 0; j < n4; ++j) tmp[j][i] = outtmp[j];
    input += n4;
  }

  // inverse transform column vectors
  for (i = 0; i < n4; ++i) IHT_16x4[tx_type].cols(tmp[i], out[i]);

#if CONFIG_EXT_TX
  maybe_flip_strides(&dest, &stride, &outp, &outstride, tx_type, n, n4);
#endif

  // Sum with the destination
  for (i = 0; i < n; ++i) {
    for (j = 0; j < n4; ++j) {
      int d = i * stride + j;
      int s = j * outstride + i;
      dest[d] = clip_pixel_add(dest[d], ROUND_POWER_OF_TWO(outp[s], 5));
    }
  }
}

void av1_iht8x16_128_add_c(const tran_low_t *input, uint8_t *dest, int stride,
                           int tx_type) {
  static const transform_2d IHT_8x16[] = {
    { aom_idct16_c, aom_idct8_c },    // DCT_DCT
    { aom_iadst16_c, aom_idct8_c },   // ADST_DCT
    { aom_idct16_c, aom_iadst8_c },   // DCT_ADST
    { aom_iadst16_c, aom_iadst8_c },  // ADST_ADST
#if CONFIG_EXT_TX
    { aom_iadst16_c, aom_idct8_c },   // FLIPADST_DCT
    { aom_idct16_c, aom_iadst8_c },   // DCT_FLIPADST
    { aom_iadst16_c, aom_iadst8_c },  // FLIPADST_FLIPADST
    { aom_iadst16_c, aom_iadst8_c },  // ADST_FLIPADST
    { aom_iadst16_c, aom_iadst8_c },  // FLIPADST_ADST
    { iidtx16_c, iidtx8_c },          // IDTX
    { aom_idct16_c, iidtx8_c },       // V_DCT
    { iidtx16_c, aom_idct8_c },       // H_DCT
    { aom_iadst16_c, iidtx8_c },      // V_ADST
    { iidtx16_c, aom_iadst8_c },      // H_ADST
    { aom_iadst16_c, iidtx8_c },      // V_FLIPADST
    { iidtx16_c, aom_iadst8_c },      // H_FLIPADST
#endif
  };

  const int n = 8;
  const int n2 = 16;
  int i, j;
  tran_low_t out[8][16], tmp[8][16], outtmp[8];
  tran_low_t *outp = &out[0][0];
  int outstride = n2;

  // inverse transform row vectors and transpose
  for (i = 0; i < n2; ++i) {
    IHT_8x16[tx_type].rows(input, outtmp);
    for (j = 0; j < n; ++j)
      tmp[j][i] = (tran_low_t)dct_const_round_shift(outtmp[j] * Sqrt2);
    input += n;
  }

  // inverse transform column vectors
  for (i = 0; i < n; ++i) {
    IHT_8x16[tx_type].cols(tmp[i], out[i]);
  }

#if CONFIG_EXT_TX
  maybe_flip_strides(&dest, &stride, &outp, &outstride, tx_type, n2, n);
#endif

  // Sum with the destination
  for (i = 0; i < n2; ++i) {
    for (j = 0; j < n; ++j) {
      int d = i * stride + j;
      int s = j * outstride + i;
      dest[d] = clip_pixel_add(dest[d], ROUND_POWER_OF_TWO(outp[s], 6));
    }
  }
}

void av1_iht16x8_128_add_c(const tran_low_t *input, uint8_t *dest, int stride,
                           int tx_type) {
  static const transform_2d IHT_16x8[] = {
    { aom_idct8_c, aom_idct16_c },    // DCT_DCT
    { aom_iadst8_c, aom_idct16_c },   // ADST_DCT
    { aom_idct8_c, aom_iadst16_c },   // DCT_ADST
    { aom_iadst8_c, aom_iadst16_c },  // ADST_ADST
#if CONFIG_EXT_TX
    { aom_iadst8_c, aom_idct16_c },   // FLIPADST_DCT
    { aom_idct8_c, aom_iadst16_c },   // DCT_FLIPADST
    { aom_iadst8_c, aom_iadst16_c },  // FLIPADST_FLIPADST
    { aom_iadst8_c, aom_iadst16_c },  // ADST_FLIPADST
    { aom_iadst8_c, aom_iadst16_c },  // FLIPADST_ADST
    { iidtx8_c, iidtx16_c },          // IDTX
    { aom_idct8_c, iidtx16_c },       // V_DCT
    { iidtx8_c, aom_idct16_c },       // H_DCT
    { aom_iadst8_c, iidtx16_c },      // V_ADST
    { iidtx8_c, aom_iadst16_c },      // H_ADST
    { aom_iadst8_c, iidtx16_c },      // V_FLIPADST
    { iidtx8_c, aom_iadst16_c },      // H_FLIPADST
#endif
  };
  const int n = 8;
  const int n2 = 16;

  int i, j;
  tran_low_t out[16][8], tmp[16][8], outtmp[16];
  tran_low_t *outp = &out[0][0];
  int outstride = n;

  // inverse transform row vectors and transpose
  for (i = 0; i < n; ++i) {
    IHT_16x8[tx_type].rows(input, outtmp);
    for (j = 0; j < n2; ++j)
      tmp[j][i] = (tran_low_t)dct_const_round_shift(outtmp[j] * Sqrt2);
    input += n2;
  }

  // inverse transform column vectors
  for (i = 0; i < n2; ++i) {
    IHT_16x8[tx_type].cols(tmp[i], out[i]);
  }

#if CONFIG_EXT_TX
  maybe_flip_strides(&dest, &stride, &outp, &outstride, tx_type, n, n2);
#endif

  // Sum with the destination
  for (i = 0; i < n; ++i) {
    for (j = 0; j < n2; ++j) {
      int d = i * stride + j;
      int s = j * outstride + i;
      dest[d] = clip_pixel_add(dest[d], ROUND_POWER_OF_TWO(outp[s], 6));
    }
  }
}

void av1_iht8x32_256_add_c(const tran_low_t *input, uint8_t *dest, int stride,
                           int tx_type) {
  static const transform_2d IHT_8x32[] = {
    { aom_idct32_c, aom_idct8_c },     // DCT_DCT
    { ihalfright32_c, aom_idct8_c },   // ADST_DCT
    { aom_idct32_c, aom_iadst8_c },    // DCT_ADST
    { ihalfright32_c, aom_iadst8_c },  // ADST_ADST
#if CONFIG_EXT_TX
    { ihalfright32_c, aom_idct8_c },   // FLIPADST_DCT
    { aom_idct32_c, aom_iadst8_c },    // DCT_FLIPADST
    { ihalfright32_c, aom_iadst8_c },  // FLIPADST_FLIPADST
    { ihalfright32_c, aom_iadst8_c },  // ADST_FLIPADST
    { ihalfright32_c, aom_iadst8_c },  // FLIPADST_ADST
    { iidtx32_c, iidtx8_c },           // IDTX
    { aom_idct32_c, iidtx8_c },        // V_DCT
    { iidtx32_c, aom_idct8_c },        // H_DCT
    { ihalfright32_c, iidtx8_c },      // V_ADST
    { iidtx32_c, aom_iadst8_c },       // H_ADST
    { ihalfright32_c, iidtx8_c },      // V_FLIPADST
    { iidtx32_c, aom_iadst8_c },       // H_FLIPADST
#endif
  };

  const int n = 8;
  const int n4 = 32;
  int i, j;
  tran_low_t out[8][32], tmp[8][32], outtmp[8];
  tran_low_t *outp = &out[0][0];
  int outstride = n4;

  // inverse transform row vectors and transpose
  for (i = 0; i < n4; ++i) {
    IHT_8x32[tx_type].rows(input, outtmp);
    for (j = 0; j < n; ++j) tmp[j][i] = outtmp[j];
    input += n;
  }

  // inverse transform column vectors
  for (i = 0; i < n; ++i) IHT_8x32[tx_type].cols(tmp[i], out[i]);

#if CONFIG_EXT_TX
  maybe_flip_strides(&dest, &stride, &outp, &outstride, tx_type, n4, n);
#endif

  // Sum with the destination
  for (i = 0; i < n4; ++i) {
    for (j = 0; j < n; ++j) {
      int d = i * stride + j;
      int s = j * outstride + i;
      dest[d] = clip_pixel_add(dest[d], ROUND_POWER_OF_TWO(outp[s], 6));
    }
  }
}

void av1_iht32x8_256_add_c(const tran_low_t *input, uint8_t *dest, int stride,
                           int tx_type) {
  static const transform_2d IHT_32x8[] = {
    { aom_idct8_c, aom_idct32_c },     // DCT_DCT
    { aom_iadst8_c, aom_idct32_c },    // ADST_DCT
    { aom_idct8_c, ihalfright32_c },   // DCT_ADST
    { aom_iadst8_c, ihalfright32_c },  // ADST_ADST
#if CONFIG_EXT_TX
    { aom_iadst8_c, aom_idct32_c },    // FLIPADST_DCT
    { aom_idct8_c, ihalfright32_c },   // DCT_FLIPADST
    { aom_iadst8_c, ihalfright32_c },  // FLIPADST_FLIPADST
    { aom_iadst8_c, ihalfright32_c },  // ADST_FLIPADST
    { aom_iadst8_c, ihalfright32_c },  // FLIPADST_ADST
    { iidtx8_c, iidtx32_c },           // IDTX
    { aom_idct8_c, iidtx32_c },        // V_DCT
    { iidtx8_c, aom_idct32_c },        // H_DCT
    { aom_iadst8_c, iidtx32_c },       // V_ADST
    { iidtx8_c, ihalfright32_c },      // H_ADST
    { aom_iadst8_c, iidtx32_c },       // V_FLIPADST
    { iidtx8_c, ihalfright32_c },      // H_FLIPADST
#endif
  };
  const int n = 8;
  const int n4 = 32;

  int i, j;
  tran_low_t out[32][8], tmp[32][8], outtmp[32];
  tran_low_t *outp = &out[0][0];
  int outstride = n;

  // inverse transform row vectors and transpose
  for (i = 0; i < n; ++i) {
    IHT_32x8[tx_type].rows(input, outtmp);
    for (j = 0; j < n4; ++j) tmp[j][i] = outtmp[j];
    input += n4;
  }

  // inverse transform column vectors
  for (i = 0; i < n4; ++i) IHT_32x8[tx_type].cols(tmp[i], out[i]);

#if CONFIG_EXT_TX
  maybe_flip_strides(&dest, &stride, &outp, &outstride, tx_type, n, n4);
#endif

  // Sum with the destination
  for (i = 0; i < n; ++i) {
    for (j = 0; j < n4; ++j) {
      int d = i * stride + j;
      int s = j * outstride + i;
      dest[d] = clip_pixel_add(dest[d], ROUND_POWER_OF_TWO(outp[s], 6));
    }
  }
}

void av1_iht16x32_512_add_c(const tran_low_t *input, uint8_t *dest, int stride,
                            int tx_type) {
  static const transform_2d IHT_16x32[] = {
    { aom_idct32_c, aom_idct16_c },     // DCT_DCT
    { ihalfright32_c, aom_idct16_c },   // ADST_DCT
    { aom_idct32_c, aom_iadst16_c },    // DCT_ADST
    { ihalfright32_c, aom_iadst16_c },  // ADST_ADST
#if CONFIG_EXT_TX
    { ihalfright32_c, aom_idct16_c },   // FLIPADST_DCT
    { aom_idct32_c, aom_iadst16_c },    // DCT_FLIPADST
    { ihalfright32_c, aom_iadst16_c },  // FLIPADST_FLIPADST
    { ihalfright32_c, aom_iadst16_c },  // ADST_FLIPADST
    { ihalfright32_c, aom_iadst16_c },  // FLIPADST_ADST
    { iidtx32_c, iidtx16_c },           // IDTX
    { aom_idct32_c, iidtx16_c },        // V_DCT
    { iidtx32_c, aom_idct16_c },        // H_DCT
    { ihalfright32_c, iidtx16_c },      // V_ADST
    { iidtx32_c, aom_iadst16_c },       // H_ADST
    { ihalfright32_c, iidtx16_c },      // V_FLIPADST
    { iidtx32_c, aom_iadst16_c },       // H_FLIPADST
#endif
  };

  const int n = 16;
  const int n2 = 32;
  int i, j;
  tran_low_t out[16][32], tmp[16][32], outtmp[16];
  tran_low_t *outp = &out[0][0];
  int outstride = n2;

  // inverse transform row vectors and transpose
  for (i = 0; i < n2; ++i) {
    IHT_16x32[tx_type].rows(input, outtmp);
    for (j = 0; j < n; ++j)
      tmp[j][i] = (tran_low_t)dct_const_round_shift(outtmp[j] * Sqrt2);
    input += n;
  }

  // inverse transform column vectors
  for (i = 0; i < n; ++i) {
    IHT_16x32[tx_type].cols(tmp[i], out[i]);
  }

#if CONFIG_EXT_TX
  maybe_flip_strides(&dest, &stride, &outp, &outstride, tx_type, n2, n);
#endif

  // Sum with the destination
  for (i = 0; i < n2; ++i) {
    for (j = 0; j < n; ++j) {
      int d = i * stride + j;
      int s = j * outstride + i;
      dest[d] = clip_pixel_add(dest[d], ROUND_POWER_OF_TWO(outp[s], 6));
    }
  }
}

void av1_iht32x16_512_add_c(const tran_low_t *input, uint8_t *dest, int stride,
                            int tx_type) {
  static const transform_2d IHT_32x16[] = {
    { aom_idct16_c, aom_idct32_c },     // DCT_DCT
    { aom_iadst16_c, aom_idct32_c },    // ADST_DCT
    { aom_idct16_c, ihalfright32_c },   // DCT_ADST
    { aom_iadst16_c, ihalfright32_c },  // ADST_ADST
#if CONFIG_EXT_TX
    { aom_iadst16_c, aom_idct32_c },    // FLIPADST_DCT
    { aom_idct16_c, ihalfright32_c },   // DCT_FLIPADST
    { aom_iadst16_c, ihalfright32_c },  // FLIPADST_FLIPADST
    { aom_iadst16_c, ihalfright32_c },  // ADST_FLIPADST
    { aom_iadst16_c, ihalfright32_c },  // FLIPADST_ADST
    { iidtx16_c, iidtx32_c },           // IDTX
    { aom_idct16_c, iidtx32_c },        // V_DCT
    { iidtx16_c, aom_idct32_c },        // H_DCT
    { aom_iadst16_c, iidtx32_c },       // V_ADST
    { iidtx16_c, ihalfright32_c },      // H_ADST
    { aom_iadst16_c, iidtx32_c },       // V_FLIPADST
    { iidtx16_c, ihalfright32_c },      // H_FLIPADST
#endif
  };
  const int n = 16;
  const int n2 = 32;

  int i, j;
  tran_low_t out[32][16], tmp[32][16], outtmp[32];
  tran_low_t *outp = &out[0][0];
  int outstride = n;

  // inverse transform row vectors and transpose
  for (i = 0; i < n; ++i) {
    IHT_32x16[tx_type].rows(input, outtmp);
    for (j = 0; j < n2; ++j)
      tmp[j][i] = (tran_low_t)dct_const_round_shift(outtmp[j] * Sqrt2);
    input += n2;
  }

  // inverse transform column vectors
  for (i = 0; i < n2; ++i) {
    IHT_32x16[tx_type].cols(tmp[i], out[i]);
  }

#if CONFIG_EXT_TX
  maybe_flip_strides(&dest, &stride, &outp, &outstride, tx_type, n, n2);
#endif

  // Sum with the destination
  for (i = 0; i < n; ++i) {
    for (j = 0; j < n2; ++j) {
      int d = i * stride + j;
      int s = j * outstride + i;
      dest[d] = clip_pixel_add(dest[d], ROUND_POWER_OF_TWO(outp[s], 6));
    }
  }
}

void av1_iht8x8_64_add_c(const tran_low_t *input, uint8_t *dest, int stride,
                         int tx_type) {
  static const transform_2d IHT_8[] = {
    { aom_idct8_c, aom_idct8_c },    // DCT_DCT  = 0
    { aom_iadst8_c, aom_idct8_c },   // ADST_DCT = 1
    { aom_idct8_c, aom_iadst8_c },   // DCT_ADST = 2
    { aom_iadst8_c, aom_iadst8_c },  // ADST_ADST = 3
#if CONFIG_EXT_TX
    { aom_iadst8_c, aom_idct8_c },   // FLIPADST_DCT
    { aom_idct8_c, aom_iadst8_c },   // DCT_FLIPADST
    { aom_iadst8_c, aom_iadst8_c },  // FLIPADST_FLIPADST
    { aom_iadst8_c, aom_iadst8_c },  // ADST_FLIPADST
    { aom_iadst8_c, aom_iadst8_c },  // FLIPADST_ADST
    { iidtx8_c, iidtx8_c },          // IDTX
    { aom_idct8_c, iidtx8_c },       // V_DCT
    { iidtx8_c, aom_idct8_c },       // H_DCT
    { aom_iadst8_c, iidtx8_c },      // V_ADST
    { iidtx8_c, aom_iadst8_c },      // H_ADST
    { aom_iadst8_c, iidtx8_c },      // V_FLIPADST
    { iidtx8_c, aom_iadst8_c },      // H_FLIPADST
#endif                               // CONFIG_EXT_TX
  };

  int i, j;
  tran_low_t tmp[8][8];
  tran_low_t out[8][8];
  tran_low_t *outp = &out[0][0];
  int outstride = 8;

  // inverse transform row vectors
  for (i = 0; i < 8; ++i) {
    IHT_8[tx_type].rows(input, out[i]);
    input += 8;
  }

  // transpose
  for (i = 0; i < 8; i++) {
    for (j = 0; j < 8; j++) {
      tmp[j][i] = out[i][j];
    }
  }

  // inverse transform column vectors
  for (i = 0; i < 8; ++i) {
    IHT_8[tx_type].cols(tmp[i], out[i]);
  }

#if CONFIG_EXT_TX
  maybe_flip_strides(&dest, &stride, &outp, &outstride, tx_type, 8, 8);
#endif

  // Sum with the destination
  for (i = 0; i < 8; ++i) {
    for (j = 0; j < 8; ++j) {
      int d = i * stride + j;
      int s = j * outstride + i;
      dest[d] = clip_pixel_add(dest[d], ROUND_POWER_OF_TWO(outp[s], 5));
    }
  }
}

void av1_iht16x16_256_add_c(const tran_low_t *input, uint8_t *dest, int stride,
                            int tx_type) {
  static const transform_2d IHT_16[] = {
    { aom_idct16_c, aom_idct16_c },    // DCT_DCT  = 0
    { aom_iadst16_c, aom_idct16_c },   // ADST_DCT = 1
    { aom_idct16_c, aom_iadst16_c },   // DCT_ADST = 2
    { aom_iadst16_c, aom_iadst16_c },  // ADST_ADST = 3
#if CONFIG_EXT_TX
    { aom_iadst16_c, aom_idct16_c },   // FLIPADST_DCT
    { aom_idct16_c, aom_iadst16_c },   // DCT_FLIPADST
    { aom_iadst16_c, aom_iadst16_c },  // FLIPADST_FLIPADST
    { aom_iadst16_c, aom_iadst16_c },  // ADST_FLIPADST
    { aom_iadst16_c, aom_iadst16_c },  // FLIPADST_ADST
    { iidtx16_c, iidtx16_c },          // IDTX
    { aom_idct16_c, iidtx16_c },       // V_DCT
    { iidtx16_c, aom_idct16_c },       // H_DCT
    { aom_iadst16_c, iidtx16_c },      // V_ADST
    { iidtx16_c, aom_iadst16_c },      // H_ADST
    { aom_iadst16_c, iidtx16_c },      // V_FLIPADST
    { iidtx16_c, aom_iadst16_c },      // H_FLIPADST
#endif                                 // CONFIG_EXT_TX
  };

  int i, j;
  tran_low_t tmp[16][16];
  tran_low_t out[16][16];
  tran_low_t *outp = &out[0][0];
  int outstride = 16;

  // inverse transform row vectors
  for (i = 0; i < 16; ++i) {
    IHT_16[tx_type].rows(input, out[i]);
    input += 16;
  }

  // transpose
  for (i = 0; i < 16; i++) {
    for (j = 0; j < 16; j++) {
      tmp[j][i] = out[i][j];
    }
  }

  // inverse transform column vectors
  for (i = 0; i < 16; ++i) {
    IHT_16[tx_type].cols(tmp[i], out[i]);
  }

#if CONFIG_EXT_TX
  maybe_flip_strides(&dest, &stride, &outp, &outstride, tx_type, 16, 16);
#endif

  // Sum with the destination
  for (i = 0; i < 16; ++i) {
    for (j = 0; j < 16; ++j) {
      int d = i * stride + j;
      int s = j * outstride + i;
      dest[d] = clip_pixel_add(dest[d], ROUND_POWER_OF_TWO(outp[s], 6));
    }
  }
}

#if CONFIG_EXT_TX
void av1_iht32x32_1024_add_c(const tran_low_t *input, uint8_t *dest, int stride,
                             int tx_type) {
  static const transform_2d IHT_32[] = {
    { aom_idct32_c, aom_idct32_c },      // DCT_DCT
    { ihalfright32_c, aom_idct32_c },    // ADST_DCT
    { aom_idct32_c, ihalfright32_c },    // DCT_ADST
    { ihalfright32_c, ihalfright32_c },  // ADST_ADST
    { ihalfright32_c, aom_idct32_c },    // FLIPADST_DCT
    { aom_idct32_c, ihalfright32_c },    // DCT_FLIPADST
    { ihalfright32_c, ihalfright32_c },  // FLIPADST_FLIPADST
    { ihalfright32_c, ihalfright32_c },  // ADST_FLIPADST
    { ihalfright32_c, ihalfright32_c },  // FLIPADST_ADST
    { iidtx32_c, iidtx32_c },            // IDTX
    { aom_idct32_c, iidtx32_c },         // V_DCT
    { iidtx32_c, aom_idct32_c },         // H_DCT
    { ihalfright32_c, iidtx32_c },       // V_ADST
    { iidtx32_c, ihalfright32_c },       // H_ADST
    { ihalfright32_c, iidtx32_c },       // V_FLIPADST
    { iidtx32_c, ihalfright32_c },       // H_FLIPADST
  };

  int i, j;
  tran_low_t tmp[32][32];
  tran_low_t out[32][32];
  tran_low_t *outp = &out[0][0];
  int outstride = 32;

  // inverse transform row vectors
  for (i = 0; i < 32; ++i) {
    IHT_32[tx_type].rows(input, out[i]);
    input += 32;
  }

  // transpose
  for (i = 0; i < 32; i++) {
    for (j = 0; j < 32; j++) {
      tmp[j][i] = out[i][j];
    }
  }

  // inverse transform column vectors
  for (i = 0; i < 32; ++i) {
    IHT_32[tx_type].cols(tmp[i], out[i]);
  }

  maybe_flip_strides(&dest, &stride, &outp, &outstride, tx_type, 32, 32);

  // Sum with the destination
  for (i = 0; i < 32; ++i) {
    for (j = 0; j < 32; ++j) {
      int d = i * stride + j;
      int s = j * outstride + i;
      dest[d] = clip_pixel_add(dest[d], ROUND_POWER_OF_TWO(outp[s], 6));
    }
  }
}
#endif  // CONFIG_EXT_TX

#if CONFIG_TX64X64
void av1_iht64x64_4096_add_c(const tran_low_t *input, uint8_t *dest, int stride,
                             int tx_type) {
  static const transform_2d IHT_64[] = {
    { idct64_col_c, idct64_row_c },      // DCT_DCT
    { ihalfright64_c, idct64_row_c },    // ADST_DCT
    { idct64_col_c, ihalfright64_c },    // DCT_ADST
    { ihalfright64_c, ihalfright64_c },  // ADST_ADST
#if CONFIG_EXT_TX
    { ihalfright64_c, idct64_row_c },    // FLIPADST_DCT
    { idct64_col_c, ihalfright64_c },    // DCT_FLIPADST
    { ihalfright64_c, ihalfright64_c },  // FLIPADST_FLIPADST
    { ihalfright64_c, ihalfright64_c },  // ADST_FLIPADST
    { ihalfright64_c, ihalfright64_c },  // FLIPADST_ADST
    { iidtx64_c, iidtx64_c },            // IDTX
    { idct64_col_c, iidtx64_c },         // V_DCT
    { iidtx64_c, idct64_row_c },         // H_DCT
    { ihalfright64_c, iidtx64_c },       // V_ADST
    { iidtx64_c, ihalfright64_c },       // H_ADST
    { ihalfright64_c, iidtx64_c },       // V_FLIPADST
    { iidtx64_c, ihalfright64_c },       // H_FLIPADST
#endif                                   // CONFIG_EXT_TX
  };

  int i, j;
  tran_low_t tmp[64][64];
  tran_low_t out[64][64];
  tran_low_t *outp = &out[0][0];
  int outstride = 64;

  // inverse transform row vectors
  for (i = 0; i < 64; ++i) {
    IHT_64[tx_type].rows(input, out[i]);
    for (j = 0; j < 64; ++j) out[i][j] = ROUND_POWER_OF_TWO(out[i][j], 1);
    input += 64;
  }

  // transpose
  for (i = 0; i < 64; i++) {
    for (j = 0; j < 64; j++) {
      tmp[j][i] = out[i][j];
    }
  }

  // inverse transform column vectors
  for (i = 0; i < 64; ++i) {
    IHT_64[tx_type].cols(tmp[i], out[i]);
  }

#if CONFIG_EXT_TX
  maybe_flip_strides(&dest, &stride, &outp, &outstride, tx_type, 64, 64);
#endif  // CONFIG_EXT_TX

  // Sum with the destination
  for (i = 0; i < 64; ++i) {
    for (j = 0; j < 64; ++j) {
      int d = i * stride + j;
      int s = j * outstride + i;
      dest[d] = clip_pixel_add(dest[d], ROUND_POWER_OF_TWO(outp[s], 5));
    }
  }
}
#endif  // CONFIG_TX64X64

// idct
void av1_idct4x4_add(const tran_low_t *input, uint8_t *dest, int stride,
                     int eob) {
  if (eob > 1)
    aom_idct4x4_16_add(input, dest, stride);
  else
    aom_idct4x4_1_add(input, dest, stride);
}

void av1_iwht4x4_add(const tran_low_t *input, uint8_t *dest, int stride,
                     int eob) {
  if (eob > 1)
    aom_iwht4x4_16_add(input, dest, stride);
  else
    aom_iwht4x4_1_add(input, dest, stride);
}

static void idct8x8_add(const tran_low_t *input, uint8_t *dest, int stride,
                        const INV_TXFM_PARAM *param) {
// If dc is 1, then input[0] is the reconstructed value, do not need
// dequantization. Also, when dc is 1, dc is counted in eobs, namely eobs >=1.

// The calculation can be simplified if there are not many non-zero dct
// coefficients. Use eobs to decide what to do.
// TODO(yunqingwang): "eobs = 1" case is also handled in av1_short_idct8x8_c.
// Combine that with code here.
#if CONFIG_ADAPT_SCAN
  const int16_t half = param->eob_threshold[0];
#else
  const int16_t half = 12;
#endif

  const int eob = param->eob;
  if (eob == 1)
    // DC only DCT coefficient
    aom_idct8x8_1_add(input, dest, stride);
  else if (eob <= half)
    aom_idct8x8_12_add(input, dest, stride);
  else
    aom_idct8x8_64_add(input, dest, stride);
}

static void idct16x16_add(const tran_low_t *input, uint8_t *dest, int stride,
                          const INV_TXFM_PARAM *param) {
// The calculation can be simplified if there are not many non-zero dct
// coefficients. Use eobs to separate different cases.
#if CONFIG_ADAPT_SCAN
  const int16_t half = param->eob_threshold[0];
  const int16_t quarter = param->eob_threshold[1];
#else
  const int16_t half = 38;
  const int16_t quarter = 10;
#endif

  const int eob = param->eob;
  if (eob == 1) /* DC only DCT coefficient. */
    aom_idct16x16_1_add(input, dest, stride);
  else if (eob <= quarter)
    aom_idct16x16_10_add(input, dest, stride);
  else if (eob <= half)
    aom_idct16x16_38_add(input, dest, stride);
  else
    aom_idct16x16_256_add(input, dest, stride);
}

static void idct32x32_add(const tran_low_t *input, uint8_t *dest, int stride,
                          const INV_TXFM_PARAM *param) {
#if CONFIG_ADAPT_SCAN
  const int16_t half = param->eob_threshold[0];
  const int16_t quarter = param->eob_threshold[1];
#else
  const int16_t half = 135;
  const int16_t quarter = 34;
#endif

  const int eob = param->eob;
  if (eob == 1)
    aom_idct32x32_1_add(input, dest, stride);
  else if (eob <= quarter)
    // non-zero coeff only in upper-left 8x8
    aom_idct32x32_34_add(input, dest, stride);
  else if (eob <= half)
    // non-zero coeff only in upper-left 16x16
    aom_idct32x32_135_add(input, dest, stride);
  else
    aom_idct32x32_1024_add(input, dest, stride);
}

#if CONFIG_TX64X64
static void idct64x64_add(const tran_low_t *input, uint8_t *dest, int stride,
                          const INV_TXFM_PARAM *param) {
  (void)param;
  av1_iht64x64_4096_add(input, dest, stride, DCT_DCT);
}
#endif  // CONFIG_TX64X64

#if CONFIG_CHROMA_2X2
static void inv_txfm_add_2x2(const tran_low_t *input, uint8_t *dest, int stride,
                             int eob, TX_TYPE tx_type, int lossless) {
  tran_high_t a1 = input[0] >> UNIT_QUANT_SHIFT;
  tran_high_t b1 = input[1] >> UNIT_QUANT_SHIFT;
  tran_high_t c1 = input[2] >> UNIT_QUANT_SHIFT;
  tran_high_t d1 = input[3] >> UNIT_QUANT_SHIFT;

  tran_high_t a2 = a1 + c1;
  tran_high_t b2 = b1 + d1;
  tran_high_t c2 = a1 - c1;
  tran_high_t d2 = b1 - d1;

  (void)tx_type;
  (void)lossless;
  (void)eob;

  a1 = (a2 + b2) >> 2;
  b1 = (a2 - b2) >> 2;
  c1 = (c2 + d2) >> 2;
  d1 = (c2 - d2) >> 2;

  dest[0] = clip_pixel_add(dest[0], WRAPLOW(a1));
  dest[1] = clip_pixel_add(dest[1], WRAPLOW(b1));
  dest[stride] = clip_pixel_add(dest[stride], WRAPLOW(c1));
  dest[stride + 1] = clip_pixel_add(dest[stride + 1], WRAPLOW(d1));
}
#endif

static void inv_txfm_add_4x4(const tran_low_t *input, uint8_t *dest, int stride,
                             int eob, TX_TYPE tx_type, int lossless) {
  if (lossless) {
    assert(tx_type == DCT_DCT);
    av1_iwht4x4_add(input, dest, stride, eob);
    return;
  }

  switch (tx_type) {
    case DCT_DCT: av1_idct4x4_add(input, dest, stride, eob); break;
    case ADST_DCT:
    case DCT_ADST:
    case ADST_ADST:
#if CONFIG_LGT
      // LGT only exists in C verson
      av1_iht4x4_16_add_c(input, dest, stride, tx_type);
      break;
#else
      av1_iht4x4_16_add(input, dest, stride, tx_type);
      break;
#endif
#if CONFIG_EXT_TX
    case FLIPADST_DCT:
    case DCT_FLIPADST:
    case FLIPADST_FLIPADST:
    case ADST_FLIPADST:
    case FLIPADST_ADST:
#if CONFIG_LGT
      av1_iht4x4_16_add_c(input, dest, stride, tx_type);
      break;
#else
      av1_iht4x4_16_add(input, dest, stride, tx_type);
      break;
#endif
    case V_DCT:
    case H_DCT:
    case V_ADST:
    case H_ADST:
    case V_FLIPADST:
    case H_FLIPADST:
      // Use C version since DST only exists in C code
      av1_iht4x4_16_add_c(input, dest, stride, tx_type);
      break;
    case IDTX: inv_idtx_add_c(input, dest, stride, 4, tx_type); break;
#endif  // CONFIG_EXT_TX
    default: assert(0); break;
  }
}

static void inv_txfm_add_4x8(const tran_low_t *input, uint8_t *dest, int stride,
                             int eob, TX_TYPE tx_type) {
  (void)eob;
#if CONFIG_LGT
  av1_iht4x8_32_add_c(input, dest, stride, tx_type);
#else
  av1_iht4x8_32_add(input, dest, stride, tx_type);
#endif
}

static void inv_txfm_add_8x4(const tran_low_t *input, uint8_t *dest, int stride,
                             int eob, TX_TYPE tx_type) {
  (void)eob;
#if CONFIG_LGT
  av1_iht8x4_32_add_c(input, dest, stride, tx_type);
#else
  av1_iht8x4_32_add(input, dest, stride, tx_type);
#endif
}

// These will be used by the masked-tx experiment in the future.
#if CONFIG_RECT_TX && CONFIG_EXT_TX && CONFIG_RECT_TX_EXT
static void inv_txfm_add_4x16(const tran_low_t *input, uint8_t *dest,
                              int stride, int eob, TX_TYPE tx_type) {
  (void)eob;
#if CONFIG_LGT
  av1_iht4x16_64_add_c(input, dest, stride, tx_type);
#else
  av1_iht4x16_64_add(input, dest, stride, tx_type);
#endif
}

static void inv_txfm_add_16x4(const tran_low_t *input, uint8_t *dest,
                              int stride, int eob, TX_TYPE tx_type) {
  (void)eob;
#if CONFIG_LGT
  av1_iht16x4_64_add_c(input, dest, stride, tx_type);
#else
  av1_iht16x4_64_add(input, dest, stride, tx_type);
#endif
}

static void inv_txfm_add_8x32(const tran_low_t *input, uint8_t *dest,
                              int stride, int eob, TX_TYPE tx_type) {
  (void)eob;
#if CONFIG_LGT
  av1_iht8x32_256_add_c(input, dest, stride, tx_type);
#else
  av1_iht8x32_256_add(input, dest, stride, tx_type);
#endif
}

static void inv_txfm_add_32x8(const tran_low_t *input, uint8_t *dest,
                              int stride, int eob, TX_TYPE tx_type) {
  (void)eob;
#if CONFIG_LGT
  av1_iht32x8_256_add_c(input, dest, stride, tx_type);
#else
  av1_iht32x8_256_add(input, dest, stride, tx_type);
#endif
}
#endif

static void inv_txfm_add_8x16(const tran_low_t *input, uint8_t *dest,
                              int stride, int eob, TX_TYPE tx_type) {
  (void)eob;
#if CONFIG_LGT
  av1_iht8x16_128_add_c(input, dest, stride, tx_type);
#else
  av1_iht8x16_128_add(input, dest, stride, tx_type);
#endif
}

static void inv_txfm_add_16x8(const tran_low_t *input, uint8_t *dest,
                              int stride, int eob, TX_TYPE tx_type) {
  (void)eob;
#if CONFIG_LGT
  av1_iht16x8_128_add_c(input, dest, stride, tx_type);
#else
  av1_iht16x8_128_add(input, dest, stride, tx_type);
#endif
}

static void inv_txfm_add_16x32(const tran_low_t *input, uint8_t *dest,
                               int stride, int eob, TX_TYPE tx_type) {
  (void)eob;
  av1_iht16x32_512_add(input, dest, stride, tx_type);
}

static void inv_txfm_add_32x16(const tran_low_t *input, uint8_t *dest,
                               int stride, int eob, TX_TYPE tx_type) {
  (void)eob;
  av1_iht32x16_512_add(input, dest, stride, tx_type);
}

static void inv_txfm_add_8x8(const tran_low_t *input, uint8_t *dest, int stride,
                             const INV_TXFM_PARAM *param) {
  const TX_TYPE tx_type = param->tx_type;
  switch (tx_type) {
    case DCT_DCT: idct8x8_add(input, dest, stride, param); break;
    case ADST_DCT:
    case DCT_ADST:
    case ADST_ADST:
#if CONFIG_LGT
      av1_iht8x8_64_add_c(input, dest, stride, tx_type);
      break;
#else
      av1_iht8x8_64_add(input, dest, stride, tx_type);
      break;
#endif
#if CONFIG_EXT_TX
    case FLIPADST_DCT:
    case DCT_FLIPADST:
    case FLIPADST_FLIPADST:
    case ADST_FLIPADST:
    case FLIPADST_ADST:
#if CONFIG_LGT
      av1_iht8x8_64_add_c(input, dest, stride, tx_type);
      break;
#else
      av1_iht8x8_64_add(input, dest, stride, tx_type);
      break;
#endif
    case V_DCT:
    case H_DCT:
    case V_ADST:
    case H_ADST:
    case V_FLIPADST:
    case H_FLIPADST:
      // Use C version since DST only exists in C code
      av1_iht8x8_64_add_c(input, dest, stride, tx_type);
      break;
    case IDTX: inv_idtx_add_c(input, dest, stride, 8, tx_type); break;
#endif  // CONFIG_EXT_TX
    default: assert(0); break;
  }
}

static void inv_txfm_add_16x16(const tran_low_t *input, uint8_t *dest,
                               int stride, const INV_TXFM_PARAM *param) {
  const TX_TYPE tx_type = param->tx_type;
  switch (tx_type) {
    case DCT_DCT: idct16x16_add(input, dest, stride, param); break;
    case ADST_DCT:
    case DCT_ADST:
    case ADST_ADST: av1_iht16x16_256_add(input, dest, stride, tx_type); break;
#if CONFIG_EXT_TX
    case FLIPADST_DCT:
    case DCT_FLIPADST:
    case FLIPADST_FLIPADST:
    case ADST_FLIPADST:
    case FLIPADST_ADST:
    case V_DCT:
    case H_DCT:
    case V_ADST:
    case H_ADST:
    case V_FLIPADST:
    case H_FLIPADST: av1_iht16x16_256_add(input, dest, stride, tx_type); break;
    case IDTX: inv_idtx_add_c(input, dest, stride, 16, tx_type); break;
#endif  // CONFIG_EXT_TX
    default: assert(0); break;
  }
}

static void inv_txfm_add_32x32(const tran_low_t *input, uint8_t *dest,
                               int stride, const INV_TXFM_PARAM *param) {
  const TX_TYPE tx_type = param->tx_type;
  switch (tx_type) {
    case DCT_DCT: idct32x32_add(input, dest, stride, param); break;
#if CONFIG_EXT_TX
    case ADST_DCT:
    case DCT_ADST:
    case ADST_ADST:
    case FLIPADST_DCT:
    case DCT_FLIPADST:
    case FLIPADST_FLIPADST:
    case ADST_FLIPADST:
    case FLIPADST_ADST:
    case V_DCT:
    case H_DCT:
    case V_ADST:
    case H_ADST:
    case V_FLIPADST:
    case H_FLIPADST:
      av1_iht32x32_1024_add_c(input, dest, stride, tx_type);
      break;
    case IDTX: inv_idtx_add_c(input, dest, stride, 32, tx_type); break;
#endif  // CONFIG_EXT_TX
    default: assert(0); break;
  }
}

#if CONFIG_TX64X64
static void inv_txfm_add_64x64(const tran_low_t *input, uint8_t *dest,
                               int stride, const INV_TXFM_PARAM *param) {
  const TX_TYPE tx_type = param->tx_type;
  switch (tx_type) {
    case DCT_DCT: idct64x64_add(input, dest, stride, param); break;
#if CONFIG_EXT_TX
    case ADST_DCT:
    case DCT_ADST:
    case ADST_ADST:
    case FLIPADST_DCT:
    case DCT_FLIPADST:
    case FLIPADST_FLIPADST:
    case ADST_FLIPADST:
    case FLIPADST_ADST:
    case V_DCT:
    case H_DCT:
    case V_ADST:
    case H_ADST:
    case V_FLIPADST:
    case H_FLIPADST:
      av1_iht64x64_4096_add_c(input, dest, stride, tx_type);
      break;
    case IDTX: inv_idtx_add_c(input, dest, stride, 64, tx_type); break;
#endif  // CONFIG_EXT_TX
    default: assert(0); break;
  }
}
#endif  // CONFIG_TX64X64

// idct
void av1_highbd_idct4x4_add(const tran_low_t *input, uint8_t *dest, int stride,
                            int eob, int bd) {
  if (eob > 1)
    aom_highbd_idct4x4_16_add(input, dest, stride, bd);
  else
    aom_highbd_idct4x4_1_add(input, dest, stride, bd);
}

void av1_highbd_iwht4x4_add(const tran_low_t *input, uint8_t *dest, int stride,
                            int eob, int bd) {
  if (eob > 1)
    aom_highbd_iwht4x4_16_add(input, dest, stride, bd);
  else
    aom_highbd_iwht4x4_1_add(input, dest, stride, bd);
}

#if CONFIG_CHROMA_2X2
static void highbd_inv_txfm_add_2x2(const tran_low_t *input, uint8_t *dest,
                                    int stride, int eob, int bd,
                                    TX_TYPE tx_type, int lossless) {
  tran_high_t a1 = input[0] >> UNIT_QUANT_SHIFT;
  tran_high_t b1 = input[1] >> UNIT_QUANT_SHIFT;
  tran_high_t c1 = input[2] >> UNIT_QUANT_SHIFT;
  tran_high_t d1 = input[3] >> UNIT_QUANT_SHIFT;

  tran_high_t a2 = a1 + c1;
  tran_high_t b2 = b1 + d1;
  tran_high_t c2 = a1 - c1;
  tran_high_t d2 = b1 - d1;

  uint16_t *dst = CONVERT_TO_SHORTPTR(dest);

  (void)tx_type;
  (void)lossless;
  (void)eob;

  a1 = (a2 + b2) >> 2;
  b1 = (a2 - b2) >> 2;
  c1 = (c2 + d2) >> 2;
  d1 = (c2 - d2) >> 2;

  dst[0] = highbd_clip_pixel_add(dst[0], a1, bd);
  dst[1] = highbd_clip_pixel_add(dst[1], b1, bd);
  dst[stride] = highbd_clip_pixel_add(dst[stride], c1, bd);
  dst[stride + 1] = highbd_clip_pixel_add(dst[stride + 1], d1, bd);
}
#endif

void av1_highbd_inv_txfm_add_4x4(const tran_low_t *input, uint8_t *dest,
                                 int stride, int eob, int bd, TX_TYPE tx_type,
                                 int lossless) {
  const int32_t *src = (const int32_t *)input;
  if (lossless) {
    assert(tx_type == DCT_DCT);
    av1_highbd_iwht4x4_add(input, dest, stride, eob, bd);
    return;
  }
  switch (tx_type) {
    case DCT_DCT:
    case ADST_DCT:
    case DCT_ADST:
    case ADST_ADST:
      av1_inv_txfm2d_add_4x4(src, CONVERT_TO_SHORTPTR(dest), stride, tx_type,
                             bd);
      break;
#if CONFIG_EXT_TX
    case FLIPADST_DCT:
    case DCT_FLIPADST:
    case FLIPADST_FLIPADST:
    case ADST_FLIPADST:
    case FLIPADST_ADST:
      av1_inv_txfm2d_add_4x4(src, CONVERT_TO_SHORTPTR(dest), stride, tx_type,
                             bd);
      break;
    // use the c version for anything including identity for now
    case V_DCT:
    case H_DCT:
    case V_ADST:
    case H_ADST:
    case V_FLIPADST:
    case H_FLIPADST:
    case IDTX:
      av1_inv_txfm2d_add_4x4_c(src, CONVERT_TO_SHORTPTR(dest), stride, tx_type,
                               bd);
      break;
#endif  // CONFIG_EXT_TX
    default: assert(0); break;
  }
}

void av1_highbd_inv_txfm_add_4x8(const tran_low_t *input, uint8_t *dest,
                                 int stride, int eob, int bd, TX_TYPE tx_type) {
  (void)eob;
  const int32_t *src = (const int32_t *)input;
  av1_inv_txfm2d_add_4x8_c(src, CONVERT_TO_SHORTPTR(dest), stride, tx_type, bd);
}

void av1_highbd_inv_txfm_add_8x4(const tran_low_t *input, uint8_t *dest,
                                 int stride, int eob, int bd, TX_TYPE tx_type) {
  (void)eob;
  const int32_t *src = (const int32_t *)input;
  av1_inv_txfm2d_add_8x4_c(src, CONVERT_TO_SHORTPTR(dest), stride, tx_type, bd);
}

static void highbd_inv_txfm_add_8x16(const tran_low_t *input, uint8_t *dest,
                                     int stride, int eob, int bd,
                                     TX_TYPE tx_type) {
  (void)eob;
  const int32_t *src = (const int32_t *)input;
  av1_inv_txfm2d_add_8x16_c(src, CONVERT_TO_SHORTPTR(dest), stride, tx_type,
                            bd);
}

static void highbd_inv_txfm_add_16x8(const tran_low_t *input, uint8_t *dest,
                                     int stride, int eob, int bd,
                                     TX_TYPE tx_type) {
  (void)eob;
  const int32_t *src = (const int32_t *)input;
  av1_inv_txfm2d_add_16x8_c(src, CONVERT_TO_SHORTPTR(dest), stride, tx_type,
                            bd);
}

static void highbd_inv_txfm_add_16x32(const tran_low_t *input, uint8_t *dest,
                                      int stride, int eob, int bd,
                                      TX_TYPE tx_type) {
  (void)eob;
  const int32_t *src = (const int32_t *)input;
  av1_inv_txfm2d_add_16x32_c(src, CONVERT_TO_SHORTPTR(dest), stride, tx_type,
                             bd);
}

static void highbd_inv_txfm_add_32x16(const tran_low_t *input, uint8_t *dest,
                                      int stride, int eob, int bd,
                                      TX_TYPE tx_type) {
  (void)eob;
  const int32_t *src = (const int32_t *)input;
  av1_inv_txfm2d_add_32x16_c(src, CONVERT_TO_SHORTPTR(dest), stride, tx_type,
                             bd);
}

static void highbd_inv_txfm_add_8x8(const tran_low_t *input, uint8_t *dest,
                                    int stride, int eob, int bd,
                                    TX_TYPE tx_type) {
  (void)eob;
  const int32_t *src = (const int32_t *)input;
  switch (tx_type) {
    case DCT_DCT:
    case ADST_DCT:
    case DCT_ADST:
    case ADST_ADST:
      av1_inv_txfm2d_add_8x8(src, CONVERT_TO_SHORTPTR(dest), stride, tx_type,
                             bd);
      break;
#if CONFIG_EXT_TX
    case FLIPADST_DCT:
    case DCT_FLIPADST:
    case FLIPADST_FLIPADST:
    case ADST_FLIPADST:
    case FLIPADST_ADST:
      av1_inv_txfm2d_add_8x8(src, CONVERT_TO_SHORTPTR(dest), stride, tx_type,
                             bd);
      break;
    // use the c version for anything including identity for now
    case V_DCT:
    case H_DCT:
    case V_ADST:
    case H_ADST:
    case V_FLIPADST:
    case H_FLIPADST:
    case IDTX:
      av1_inv_txfm2d_add_8x8_c(src, CONVERT_TO_SHORTPTR(dest), stride, tx_type,
                               bd);
      break;
#endif  // CONFIG_EXT_TX
    default: assert(0);
  }
}

static void highbd_inv_txfm_add_16x16(const tran_low_t *input, uint8_t *dest,
                                      int stride, int eob, int bd,
                                      TX_TYPE tx_type) {
  (void)eob;
  const int32_t *src = (const int32_t *)input;
  switch (tx_type) {
    case DCT_DCT:
    case ADST_DCT:
    case DCT_ADST:
    case ADST_ADST:
      av1_inv_txfm2d_add_16x16(src, CONVERT_TO_SHORTPTR(dest), stride, tx_type,
                               bd);
      break;
#if CONFIG_EXT_TX
    case FLIPADST_DCT:
    case DCT_FLIPADST:
    case FLIPADST_FLIPADST:
    case ADST_FLIPADST:
    case FLIPADST_ADST:
      av1_inv_txfm2d_add_16x16(src, CONVERT_TO_SHORTPTR(dest), stride, tx_type,
                               bd);
      break;
    // use the c version for anything including identity for now
    case V_DCT:
    case H_DCT:
    case V_ADST:
    case H_ADST:
    case V_FLIPADST:
    case H_FLIPADST:
    case IDTX:
      av1_inv_txfm2d_add_16x16_c(src, CONVERT_TO_SHORTPTR(dest), stride,
                                 tx_type, bd);
      break;
#endif  // CONFIG_EXT_TX
    default: assert(0);
  }
}

static void highbd_inv_txfm_add_32x32(const tran_low_t *input, uint8_t *dest,
                                      int stride, int eob, int bd,
                                      TX_TYPE tx_type) {
  (void)eob;
  const int32_t *src = (const int32_t *)input;
  switch (tx_type) {
    case DCT_DCT:
    case ADST_DCT:
    case DCT_ADST:
    case ADST_ADST:
      av1_inv_txfm2d_add_32x32(src, CONVERT_TO_SHORTPTR(dest), stride, tx_type,
                               bd);
      break;
#if CONFIG_EXT_TX
    case FLIPADST_DCT:
    case DCT_FLIPADST:
    case FLIPADST_FLIPADST:
    case ADST_FLIPADST:
    case FLIPADST_ADST:
      av1_inv_txfm2d_add_32x32(src, CONVERT_TO_SHORTPTR(dest), stride, tx_type,
                               bd);
      break;
    // use the c version for anything including identity for now
    case V_DCT:
    case H_DCT:
    case V_ADST:
    case H_ADST:
    case V_FLIPADST:
    case H_FLIPADST:
    case IDTX:
      av1_inv_txfm2d_add_32x32_c(src, CONVERT_TO_SHORTPTR(dest), stride,
                                 tx_type, bd);
      break;
#endif  // CONFIG_EXT_TX
    default: assert(0);
  }
}

#if CONFIG_TX64X64
static void highbd_inv_txfm_add_64x64(const tran_low_t *input, uint8_t *dest,
                                      int stride, int eob, int bd,
                                      TX_TYPE tx_type) {
  (void)eob;
  const int32_t *src = (const int32_t *)input;
  switch (tx_type) {
    case DCT_DCT:
      av1_inv_txfm2d_add_64x64(src, CONVERT_TO_SHORTPTR(dest), stride, DCT_DCT,
                               bd);
      break;
#if CONFIG_EXT_TX
    case ADST_DCT:
    case DCT_ADST:
    case ADST_ADST:
    case FLIPADST_DCT:
    case DCT_FLIPADST:
    case FLIPADST_FLIPADST:
    case ADST_FLIPADST:
    case FLIPADST_ADST:
    case V_DCT:
    case H_DCT:
    case V_ADST:
    case H_ADST:
    case V_FLIPADST:
    case H_FLIPADST:
      // TODO(sarahparker)
      // I've deleted the 64x64 implementations that existed in lieu
      // of adst, flipadst and identity for simplicity but will bring back
      // in a later change. This shouldn't impact performance since
      // DCT_DCT is the only extended type currently allowed for 64x64,
      // as dictated by get_ext_tx_set_type in blockd.h.
      av1_inv_txfm2d_add_64x64_c(src, CONVERT_TO_SHORTPTR(dest), stride,
                                 DCT_DCT, bd);
      break;
    case IDTX:
      highbd_inv_idtx_add_c(input, dest, stride, 64, tx_type, bd);
      break;
#endif  // CONFIG_EXT_TX
    default: assert(0); break;
  }
}
#endif  // CONFIG_TX64X64

void av1_inv_txfm_add(const tran_low_t *input, uint8_t *dest, int stride,
                      INV_TXFM_PARAM *param) {
  const TX_TYPE tx_type = param->tx_type;
  const TX_SIZE tx_size = param->tx_size;
  const int eob = param->eob;
  const int lossless = param->lossless;

  switch (tx_size) {
#if CONFIG_TX64X64
    case TX_64X64: inv_txfm_add_64x64(input, dest, stride, param); break;
#endif  // CONFIG_TX64X64
    case TX_32X32: inv_txfm_add_32x32(input, dest, stride, param); break;
    case TX_16X16: inv_txfm_add_16x16(input, dest, stride, param); break;
    case TX_8X8: inv_txfm_add_8x8(input, dest, stride, param); break;
    case TX_4X8: inv_txfm_add_4x8(input, dest, stride, eob, tx_type); break;
    case TX_8X4: inv_txfm_add_8x4(input, dest, stride, eob, tx_type); break;
    case TX_8X16: inv_txfm_add_8x16(input, dest, stride, eob, tx_type); break;
    case TX_16X8: inv_txfm_add_16x8(input, dest, stride, eob, tx_type); break;
    case TX_16X32: inv_txfm_add_16x32(input, dest, stride, eob, tx_type); break;
    case TX_32X16: inv_txfm_add_32x16(input, dest, stride, eob, tx_type); break;
    case TX_4X4:
      // this is like av1_short_idct4x4 but has a special case around eob<=1
      // which is significant (not just an optimization) for the lossless
      // case.
      inv_txfm_add_4x4(input, dest, stride, eob, tx_type, lossless);
      break;
#if CONFIG_CHROMA_2X2
    case TX_2X2:
      inv_txfm_add_2x2(input, dest, stride, eob, tx_type, lossless);
      break;
#endif
#if CONFIG_EXT_TX && CONFIG_RECT_TX && CONFIG_RECT_TX_EXT
    case TX_32X8: inv_txfm_add_32x8(input, dest, stride, eob, tx_type); break;
    case TX_8X32: inv_txfm_add_8x32(input, dest, stride, eob, tx_type); break;
    case TX_16X4: inv_txfm_add_16x4(input, dest, stride, eob, tx_type); break;
    case TX_4X16: inv_txfm_add_4x16(input, dest, stride, eob, tx_type); break;
#endif
    default: assert(0 && "Invalid transform size"); break;
  }
}

static void init_inv_txfm_param(const MACROBLOCKD *xd, TX_SIZE tx_size,
                                TX_TYPE tx_type, int eob, INV_TXFM_PARAM *inv) {
  inv->tx_type = tx_type;
  inv->tx_size = tx_size;
  inv->eob = eob;
  inv->lossless = xd->lossless[xd->mi[0]->mbmi.segment_id];
#if CONFIG_HIGHBITDEPTH
  inv->bd = xd->bd;
#endif
#if CONFIG_ADAPT_SCAN
  inv->eob_threshold =
      (const int16_t *)&xd->eob_threshold_md[tx_size][tx_type][0];
#endif
}

typedef void (*InvTxfmFunc)(const tran_low_t *dqcoeff, uint8_t *dst, int stride,
                            INV_TXFM_PARAM *param);

static InvTxfmFunc inv_txfm_func[2] = { av1_inv_txfm_add,
                                        av1_highbd_inv_txfm_add };

void av1_inverse_transform_block(const MACROBLOCKD *xd,
                                 const tran_low_t *dqcoeff, TX_TYPE tx_type,
                                 TX_SIZE tx_size, uint8_t *dst, int stride,
                                 int eob) {
  if (!eob) return;
#if CONFIG_PVQ
  const BLOCK_SIZE tx_bsize = txsize_to_bsize[tx_size];
  const int txb_width = block_size_wide[tx_bsize];
  const int txb_height = block_size_high[tx_bsize];
  int r, c;
#if CONFIG_HIGHBITDEPTH
  if (xd->cur_buf->flags & YV12_FLAG_HIGHBITDEPTH) {
    for (r = 0; r < txb_height; r++)
      for (c = 0; c < txb_width; c++)
        CONVERT_TO_SHORTPTR(dst)[r * stride + c] = 0;
  } else {
#endif  // CONFIG_HIGHBITDEPTH
    for (r = 0; r < txb_height; r++)
      for (c = 0; c < txb_width; c++) dst[r * stride + c] = 0;
#if CONFIG_HIGHBITDEPTH
  }
#endif  // CONFIG_HIGHBITDEPTH
#endif  // CONFIG_PVQ
  INV_TXFM_PARAM inv_txfm_param;
  init_inv_txfm_param(xd, tx_size, tx_type, eob, &inv_txfm_param);

  const int is_hbd = get_bitdepth_data_path_index(xd);
  inv_txfm_func[is_hbd](dqcoeff, dst, stride, &inv_txfm_param);
}

void av1_inverse_transform_block_facade(MACROBLOCKD *xd, int plane, int block,
                                        int blk_row, int blk_col, int eob) {
  struct macroblockd_plane *const pd = &xd->plane[plane];
  tran_low_t *dqcoeff = BLOCK_OFFSET(pd->dqcoeff, block);
  const PLANE_TYPE plane_type = get_plane_type(plane);
  const TX_SIZE tx_size = get_tx_size(plane, xd);
  const TX_TYPE tx_type = get_tx_type(plane_type, xd, block, tx_size);
  const int dst_stride = pd->dst.stride;
  uint8_t *dst =
      &pd->dst.buf[(blk_row * dst_stride + blk_col) << tx_size_wide_log2[0]];
  av1_inverse_transform_block(xd, dqcoeff, tx_type, tx_size, dst, dst_stride,
                              eob);
}

void av1_highbd_inv_txfm_add(const tran_low_t *input, uint8_t *dest, int stride,
                             INV_TXFM_PARAM *inv_txfm_param) {
  const TX_TYPE tx_type = inv_txfm_param->tx_type;
  const TX_SIZE tx_size = inv_txfm_param->tx_size;
  const int eob = inv_txfm_param->eob;
  const int bd = inv_txfm_param->bd;
  const int lossless = inv_txfm_param->lossless;

  switch (tx_size) {
#if CONFIG_TX64X64
    case TX_64X64:
      highbd_inv_txfm_add_64x64(input, dest, stride, eob, bd, tx_type);
      break;
#endif  // CONFIG_TX64X64
    case TX_32X32:
      highbd_inv_txfm_add_32x32(input, dest, stride, eob, bd, tx_type);
      break;
    case TX_16X16:
      highbd_inv_txfm_add_16x16(input, dest, stride, eob, bd, tx_type);
      break;
    case TX_8X8:
      highbd_inv_txfm_add_8x8(input, dest, stride, eob, bd, tx_type);
      break;
    case TX_4X8:
      av1_highbd_inv_txfm_add_4x8(input, dest, stride, eob, bd, tx_type);
      break;
    case TX_8X4:
      av1_highbd_inv_txfm_add_8x4(input, dest, stride, eob, bd, tx_type);
      break;
    case TX_8X16:
      highbd_inv_txfm_add_8x16(input, dest, stride, eob, bd, tx_type);
      break;
    case TX_16X8:
      highbd_inv_txfm_add_16x8(input, dest, stride, eob, bd, tx_type);
      break;
    case TX_16X32:
      highbd_inv_txfm_add_16x32(input, dest, stride, eob, bd, tx_type);
      break;
    case TX_32X16:
      highbd_inv_txfm_add_32x16(input, dest, stride, eob, bd, tx_type);
      break;
    case TX_4X4:
      // this is like av1_short_idct4x4 but has a special case around eob<=1
      // which is significant (not just an optimization) for the lossless
      // case.
      av1_highbd_inv_txfm_add_4x4(input, dest, stride, eob, bd, tx_type,
                                  lossless);
      break;
#if CONFIG_CHROMA_2X2
    case TX_2X2:
      highbd_inv_txfm_add_2x2(input, dest, stride, eob, bd, tx_type, lossless);
      break;
#endif
    default: assert(0 && "Invalid transform size"); break;
  }
}

#if CONFIG_DPCM_INTRA
void av1_dpcm_inv_txfm_add_4_c(const tran_low_t *input, int stride,
                               TX_TYPE_1D tx_type, uint8_t *dest) {
  assert(tx_type < TX_TYPES_1D);
  static const transform_1d IHT[] = { aom_idct4_c, aom_iadst4_c, aom_iadst4_c,
                                      iidtx4_c };
  const transform_1d inv_tx = IHT[tx_type];
  tran_low_t out[4];
  inv_tx(input, out);
  for (int i = 0; i < 4; ++i) {
    out[i] = (tran_low_t)dct_const_round_shift(out[i] * Sqrt2);
    dest[i * stride] =
        clip_pixel_add(dest[i * stride], ROUND_POWER_OF_TWO(out[i], 4));
  }
}

void av1_dpcm_inv_txfm_add_8_c(const tran_low_t *input, int stride,
                               TX_TYPE_1D tx_type, uint8_t *dest) {
  assert(tx_type < TX_TYPES_1D);
  static const transform_1d IHT[] = { aom_idct8_c, aom_iadst8_c, aom_iadst8_c,
                                      iidtx8_c };
  const transform_1d inv_tx = IHT[tx_type];
  tran_low_t out[8];
  inv_tx(input, out);
  for (int i = 0; i < 8; ++i) {
    dest[i * stride] =
        clip_pixel_add(dest[i * stride], ROUND_POWER_OF_TWO(out[i], 4));
  }
}

void av1_dpcm_inv_txfm_add_16_c(const tran_low_t *input, int stride,
                                TX_TYPE_1D tx_type, uint8_t *dest) {
  assert(tx_type < TX_TYPES_1D);
  static const transform_1d IHT[] = { aom_idct16_c, aom_iadst16_c,
                                      aom_iadst16_c, iidtx16_c };
  const transform_1d inv_tx = IHT[tx_type];
  tran_low_t out[16];
  inv_tx(input, out);
  for (int i = 0; i < 16; ++i) {
    out[i] = (tran_low_t)dct_const_round_shift(out[i] * Sqrt2);
    dest[i * stride] =
        clip_pixel_add(dest[i * stride], ROUND_POWER_OF_TWO(out[i], 5));
  }
}

void av1_dpcm_inv_txfm_add_32_c(const tran_low_t *input, int stride,
                                TX_TYPE_1D tx_type, uint8_t *dest) {
  assert(tx_type < TX_TYPES_1D);
  static const transform_1d IHT[] = { aom_idct32_c, ihalfright32_c,
                                      ihalfright32_c, iidtx32_c };
  const transform_1d inv_tx = IHT[tx_type];
  tran_low_t out[32];
  inv_tx(input, out);
  for (int i = 0; i < 32; ++i) {
    dest[i * stride] =
        clip_pixel_add(dest[i * stride], ROUND_POWER_OF_TWO(out[i], 4));
  }
}

dpcm_inv_txfm_add_func av1_get_dpcm_inv_txfm_add_func(int tx_length) {
  switch (tx_length) {
    case 4: return av1_dpcm_inv_txfm_add_4_c;
    case 8: return av1_dpcm_inv_txfm_add_8_c;
    case 16: return av1_dpcm_inv_txfm_add_16_c;
    case 32:
      return av1_dpcm_inv_txfm_add_32_c;
    // TODO(huisu): add support for TX_64X64.
    default: assert(0); return NULL;
  }
}

#if CONFIG_HIGHBITDEPTH
// TODO(sarahparker) I am adding a quick workaround for these functions
// to remove the old hbd transforms. This will be cleaned up in a followup.
void av1_hbd_dpcm_inv_txfm_add_4_c(const tran_low_t *input, int stride,
                                   TX_TYPE_1D tx_type, int bd, uint16_t *dest,
                                   int dir) {
  assert(tx_type < TX_TYPES_1D);
  static const TxfmFunc IHT[] = { av1_idct4_new, av1_iadst4_new, av1_iadst4_new,
                                  av1_iidentity4_c };
  // In order { horizontal, vertical }
  static const TXFM_1D_CFG *inv_txfm_cfg_ls[TX_TYPES_1D][2] = {
    { &inv_txfm_1d_row_cfg_dct_4, &inv_txfm_1d_col_cfg_dct_4 },
    { &inv_txfm_1d_row_cfg_adst_4, &inv_txfm_1d_col_cfg_adst_4 },
    { &inv_txfm_1d_row_cfg_adst_4, &inv_txfm_1d_col_cfg_adst_4 },
    { &inv_txfm_1d_cfg_identity_4, &inv_txfm_1d_cfg_identity_4 }
  };

  const TXFM_1D_CFG *inv_txfm_cfg = inv_txfm_cfg_ls[tx_type][dir];
  const TxfmFunc inv_tx = IHT[tx_type];

  tran_low_t out[4];
  inv_tx(input, out, inv_txfm_cfg->cos_bit, inv_txfm_cfg->stage_range);
  for (int i = 0; i < 4; ++i) {
    out[i] = (tran_low_t)dct_const_round_shift(out[i] * Sqrt2);
    dest[i * stride] = highbd_clip_pixel_add(dest[i * stride],
                                             ROUND_POWER_OF_TWO(out[i], 4), bd);
  }
}

void av1_hbd_dpcm_inv_txfm_add_8_c(const tran_low_t *input, int stride,
                                   TX_TYPE_1D tx_type, int bd, uint16_t *dest,
                                   int dir) {
  assert(tx_type < TX_TYPES_1D);
  static const TxfmFunc IHT[] = { av1_idct4_new, av1_iadst4_new, av1_iadst4_new,
                                  av1_iidentity4_c };
  // In order { horizontal, vertical }
  static const TXFM_1D_CFG *inv_txfm_cfg_ls[TX_TYPES_1D][2] = {
    { &inv_txfm_1d_row_cfg_dct_8, &inv_txfm_1d_col_cfg_dct_8 },
    { &inv_txfm_1d_row_cfg_adst_8, &inv_txfm_1d_col_cfg_adst_8 },
    { &inv_txfm_1d_row_cfg_adst_8, &inv_txfm_1d_col_cfg_adst_8 },
    { &inv_txfm_1d_cfg_identity_8, &inv_txfm_1d_cfg_identity_8 }
  };

  const TXFM_1D_CFG *inv_txfm_cfg = inv_txfm_cfg_ls[tx_type][dir];
  const TxfmFunc inv_tx = IHT[tx_type];

  tran_low_t out[8];
  inv_tx(input, out, inv_txfm_cfg->cos_bit, inv_txfm_cfg->stage_range);
  for (int i = 0; i < 8; ++i) {
    dest[i * stride] = highbd_clip_pixel_add(dest[i * stride],
                                             ROUND_POWER_OF_TWO(out[i], 4), bd);
  }
}

void av1_hbd_dpcm_inv_txfm_add_16_c(const tran_low_t *input, int stride,
                                    TX_TYPE_1D tx_type, int bd, uint16_t *dest,
                                    int dir) {
  assert(tx_type < TX_TYPES_1D);
  static const TxfmFunc IHT[] = { av1_idct4_new, av1_iadst4_new, av1_iadst4_new,
                                  av1_iidentity4_c };
  // In order { horizontal, vertical }
  static const TXFM_1D_CFG *inv_txfm_cfg_ls[TX_TYPES_1D][2] = {
    { &inv_txfm_1d_row_cfg_dct_16, &inv_txfm_1d_col_cfg_dct_16 },
    { &inv_txfm_1d_row_cfg_adst_16, &inv_txfm_1d_col_cfg_adst_16 },
    { &inv_txfm_1d_row_cfg_adst_16, &inv_txfm_1d_col_cfg_adst_16 },
    { &inv_txfm_1d_cfg_identity_16, &inv_txfm_1d_cfg_identity_16 }
  };

  const TXFM_1D_CFG *inv_txfm_cfg = inv_txfm_cfg_ls[tx_type][dir];
  const TxfmFunc inv_tx = IHT[tx_type];

  tran_low_t out[16];
  inv_tx(input, out, inv_txfm_cfg->cos_bit, inv_txfm_cfg->stage_range);
  for (int i = 0; i < 16; ++i) {
    out[i] = (tran_low_t)dct_const_round_shift(out[i] * Sqrt2);
    dest[i * stride] = highbd_clip_pixel_add(dest[i * stride],
                                             ROUND_POWER_OF_TWO(out[i], 5), bd);
  }
}

void av1_hbd_dpcm_inv_txfm_add_32_c(const tran_low_t *input, int stride,
                                    TX_TYPE_1D tx_type, int bd, uint16_t *dest,
                                    int dir) {
  assert(tx_type < TX_TYPES_1D);
  static const TxfmFunc IHT[] = { av1_idct4_new, av1_iadst4_new, av1_iadst4_new,
                                  av1_iidentity4_c };
  // In order { horizontal, vertical }
  static const TXFM_1D_CFG *inv_txfm_cfg_ls[TX_TYPES_1D][2] = {
    { &inv_txfm_1d_row_cfg_dct_32, &inv_txfm_1d_col_cfg_dct_32 },
    { &inv_txfm_1d_row_cfg_adst_32, &inv_txfm_1d_col_cfg_adst_32 },
    { &inv_txfm_1d_row_cfg_adst_32, &inv_txfm_1d_col_cfg_adst_32 },
    { &inv_txfm_1d_cfg_identity_32, &inv_txfm_1d_cfg_identity_32 }
  };

  const TXFM_1D_CFG *inv_txfm_cfg = inv_txfm_cfg_ls[tx_type][dir];
  const TxfmFunc inv_tx = IHT[tx_type];

  tran_low_t out[32];
  inv_tx(input, out, inv_txfm_cfg->cos_bit, inv_txfm_cfg->stage_range);
  for (int i = 0; i < 32; ++i) {
    dest[i * stride] = highbd_clip_pixel_add(dest[i * stride],
                                             ROUND_POWER_OF_TWO(out[i], 4), bd);
  }
}

hbd_dpcm_inv_txfm_add_func av1_get_hbd_dpcm_inv_txfm_add_func(int tx_length) {
  switch (tx_length) {
    case 4: return av1_hbd_dpcm_inv_txfm_add_4_c;
    case 8: return av1_hbd_dpcm_inv_txfm_add_8_c;
    case 16: return av1_hbd_dpcm_inv_txfm_add_16_c;
    case 32:
      return av1_hbd_dpcm_inv_txfm_add_32_c;
    // TODO(huisu): add support for TX_64X64.
    default: assert(0); return NULL;
  }
}
#endif  // CONFIG_HIGHBITDEPTH
#endif  // CONFIG_DPCM_INTRA