text: /*
   * Simple IDCT
   *
   * Copyright (c) 2001 Michael Niedermayer <michaelni@gmx.at>
   *
   * This file is part of FFmpeg.
   *
   * FFmpeg is free software; you can redistribute it and/or
   * modify it under the terms of the GNU Lesser General Public
   * License as published by the Free Software Foundation; either
   * version 2.1 of the License, or (at your option) any later version.
   *
   * FFmpeg is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   * Lesser General Public License for more details.
   *
   * You should have received a copy of the GNU Lesser General Public
   * License along with FFmpeg; if not, write to the Free Software
   * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
   */
  
  /**
   * @file
   * simpleidct in C.
   */
  
  /* Based upon some commented-out C code from mpeg2dec (idct_mmx.c
   * written by Aaron Holtzman <aholtzma@ess.engr.uvic.ca>). */
  
  #include "simple_idct.h"
  
  #include "bit_depth_template.c"
  
  #undef W1
  #undef W2
  #undef W3
  #undef W4
  #undef W5
  #undef W6
  #undef W7
  #undef ROW_SHIFT
  #undef COL_SHIFT
  #undef DC_SHIFT
  #undef MUL
  #undef MAC
  
  #if BIT_DEPTH == 8
  
  #define W1  22725  //cos(i*M_PI/16)*sqrt(2)*(1<<14) + 0.5
  #define W2  21407  //cos(i*M_PI/16)*sqrt(2)*(1<<14) + 0.5
  #define W3  19266  //cos(i*M_PI/16)*sqrt(2)*(1<<14) + 0.5
  #define W4  16383  //cos(i*M_PI/16)*sqrt(2)*(1<<14) + 0.5
  #define W5  12873  //cos(i*M_PI/16)*sqrt(2)*(1<<14) + 0.5
  #define W6  8867   //cos(i*M_PI/16)*sqrt(2)*(1<<14) + 0.5
  #define W7  4520   //cos(i*M_PI/16)*sqrt(2)*(1<<14) + 0.5
  
  #define ROW_SHIFT 11
  #define COL_SHIFT 20
  #define DC_SHIFT 3
  
  #define MUL(a, b)    MUL16(a, b)
  #define MAC(a, b, c) MAC16(a, b, c)
  
  #elif BIT_DEPTH == 10 || BIT_DEPTH == 12
  
  # if BIT_DEPTH == 10
  #define W1 22725 // 90901
  #define W2 21407 //  85627
  #define W3 19265 //  77062
  #define W4 16384 //  65535
  #define W5 12873 //  51491
  #define W6  8867 //  35468
  #define W7  4520 //  18081
  
  #   ifdef EXTRA_SHIFT
  #define ROW_SHIFT 13
  #define COL_SHIFT 18
  #define DC_SHIFT  1
  #   elif IN_IDCT_DEPTH == 32
  #define ROW_SHIFT 13
  #define COL_SHIFT 21
  #define DC_SHIFT  2
  #   else
  #define ROW_SHIFT 12
  #define COL_SHIFT 19
  #define DC_SHIFT  2
  #   endif
  
  # else
  #define W1 45451
  #define W2 42813
  #define W3 38531
  #define W4 32767
  #define W5 25746
  #define W6 17734
  #define W7 9041
  
  #define ROW_SHIFT 16
  #define COL_SHIFT 17
  #define DC_SHIFT -1
  # endif
  
  #define MUL(a, b)    ((int)((SUINT)(a) * (b)))
  #define MAC(a, b, c) ((a) += (SUINT)(b) * (c))
  
  #else
  
  #error "Unsupported bitdepth"
  
  #endif
  
  #ifdef EXTRA_SHIFT
  static inline void FUNC(idctRowCondDC_extrashift)(int16_t *row, int extra_shift)
  #else
  static inline void FUNC6(idctRowCondDC)(idctin *row, int extra_shift)
  #endif
  {
      SUINT a0, a1, a2, a3, b0, b1, b2, b3;
  
  // TODO: Add DC-only support for int32_t input
  #if IN_IDCT_DEPTH == 16
  #if HAVE_FAST_64BIT
  #define ROW0_MASK (0xffffLL << 48 * HAVE_BIGENDIAN)
      if (((AV_RN64A(row) & ~ROW0_MASK) | AV_RN64A(row+4)) == 0) {
          uint64_t temp;
          if (DC_SHIFT - extra_shift >= 0) {
              temp = (row[0] * (1 << (DC_SHIFT - extra_shift))) & 0xffff;
          } else {
              temp = ((row[0] + (1<<(extra_shift - DC_SHIFT-1))) >> (extra_shift - DC_SHIFT)) & 0xffff;
          }
          temp += temp * (1 << 16);
          temp += temp * ((uint64_t) 1 << 32);
          AV_WN64A(row, temp);
          AV_WN64A(row + 4, temp);
          return;
      }
  #else
      if (!(AV_RN32A(row+2) |
            AV_RN32A(row+4) |
            AV_RN32A(row+6) |
            row[1])) {
          uint32_t temp;
          if (DC_SHIFT - extra_shift >= 0) {
              temp = (row[0] * (1 << (DC_SHIFT - extra_shift))) & 0xffff;
          } else {
              temp = ((row[0] + (1<<(extra_shift - DC_SHIFT-1))) >> (extra_shift - DC_SHIFT)) & 0xffff;
          }
          temp += temp * (1 << 16);
          AV_WN32A(row, temp);
          AV_WN32A(row+2, temp);
          AV_WN32A(row+4, temp);
          AV_WN32A(row+6, temp);
          return;
      }
  #endif
  #endif
  
      a0 = ((SUINT)W4 * row[0]) + (1 << (ROW_SHIFT + extra_shift - 1));
      a1 = a0;
      a2 = a0;
      a3 = a0;
  
      a0 += (SUINT)W2 * row[2];
      a1 += (SUINT)W6 * row[2];
      a2 -= (SUINT)W6 * row[2];
      a3 -= (SUINT)W2 * row[2];
  
      b0 = MUL(W1, row[1]);
      MAC(b0, W3, row[3]);
      b1 = MUL(W3, row[1]);
      MAC(b1, -W7, row[3]);
      b2 = MUL(W5, row[1]);
      MAC(b2, -W1, row[3]);
      b3 = MUL(W7, row[1]);
      MAC(b3, -W5, row[3]);
  
  #if IN_IDCT_DEPTH == 32
      if (AV_RN64A(row + 4) | AV_RN64A(row + 6)) {
  #else
      if (AV_RN64A(row + 4)) {
  #endif
          a0 += (SUINT)  W4*row[4] + (SUINT)W6*row[6];
          a1 += (SUINT)- W4*row[4] - (SUINT)W2*row[6];
          a2 += (SUINT)- W4*row[4] + (SUINT)W2*row[6];
          a3 += (SUINT)  W4*row[4] - (SUINT)W6*row[6];
  
          MAC(b0,  W5, row[5]);
          MAC(b0,  W7, row[7]);
  
          MAC(b1, -W1, row[5]);
          MAC(b1, -W5, row[7]);
  
          MAC(b2,  W7, row[5]);
          MAC(b2,  W3, row[7]);
  
          MAC(b3,  W3, row[5]);
          MAC(b3, -W1, row[7]);
      }
  
      row[0] = (int)(a0 + b0) >> (ROW_SHIFT + extra_shift);
      row[7] = (int)(a0 - b0) >> (ROW_SHIFT + extra_shift);
      row[1] = (int)(a1 + b1) >> (ROW_SHIFT + extra_shift);
      row[6] = (int)(a1 - b1) >> (ROW_SHIFT + extra_shift);
      row[2] = (int)(a2 + b2) >> (ROW_SHIFT + extra_shift);
      row[5] = (int)(a2 - b2) >> (ROW_SHIFT + extra_shift);
      row[3] = (int)(a3 + b3) >> (ROW_SHIFT + extra_shift);
      row[4] = (int)(a3 - b3) >> (ROW_SHIFT + extra_shift);
  }
  
  #define IDCT_COLS do {                                  \
          a0 = (SUINT)W4 * (col[8*0] + ((1<<(COL_SHIFT-1))/W4)); \
          a1 = a0;                                        \
          a2 = a0;                                        \
          a3 = a0;                                        \
                                                          \
          a0 += (SUINT) W2*col[8*2];                             \
          a1 += (SUINT) W6*col[8*2];                             \
          a2 += (SUINT)-W6*col[8*2];                             \
          a3 += (SUINT)-W2*col[8*2];                             \
                                                          \
          b0 = MUL(W1, col[8*1]);                         \
          b1 = MUL(W3, col[8*1]);                         \
          b2 = MUL(W5, col[8*1]);                         \
          b3 = MUL(W7, col[8*1]);                         \
                                                          \
          MAC(b0,  W3, col[8*3]);                         \
          MAC(b1, -W7, col[8*3]);                         \
          MAC(b2, -W1, col[8*3]);                         \
          MAC(b3, -W5, col[8*3]);                         \
                                                          \
          if (col[8*4]) {                                 \
              a0 += (SUINT) W4*col[8*4];                         \
              a1 += (SUINT)-W4*col[8*4];                         \
              a2 += (SUINT)-W4*col[8*4];                         \
              a3 += (SUINT) W4*col[8*4];                         \
          }                                               \
                                                          \
          if (col[8*5]) {                                 \
              MAC(b0,  W5, col[8*5]);                     \
              MAC(b1, -W1, col[8*5]);                     \
              MAC(b2,  W7, col[8*5]);                     \
              MAC(b3,  W3, col[8*5]);                     \
          }                                               \
                                                          \
          if (col[8*6]) {                                 \
              a0 += (SUINT) W6*col[8*6];                         \
              a1 += (SUINT)-W2*col[8*6];                         \
              a2 += (SUINT) W2*col[8*6];                         \
              a3 += (SUINT)-W6*col[8*6];                         \
          }                                               \
                                                          \
          if (col[8*7]) {                                 \
              MAC(b0,  W7, col[8*7]);                     \
              MAC(b1, -W5, col[8*7]);                     \
              MAC(b2,  W3, col[8*7]);                     \
              MAC(b3, -W1, col[8*7]);                     \
          }                                               \
      } while (0)
  
  #ifdef EXTRA_SHIFT
  static inline void FUNC(idctSparseCol_extrashift)(int16_t *col)
  #else
  static inline void FUNC6(idctSparseColPut)(pixel *dest, ptrdiff_t line_size,
                                            idctin *col)
  {
      SUINT a0, a1, a2, a3, b0, b1, b2, b3;
  
      IDCT_COLS;
  
      dest[0] = av_clip_pixel((int)(a0 + b0) >> COL_SHIFT);
      dest += line_size;
      dest[0] = av_clip_pixel((int)(a1 + b1) >> COL_SHIFT);
      dest += line_size;
      dest[0] = av_clip_pixel((int)(a2 + b2) >> COL_SHIFT);
      dest += line_size;
      dest[0] = av_clip_pixel((int)(a3 + b3) >> COL_SHIFT);
      dest += line_size;
      dest[0] = av_clip_pixel((int)(a3 - b3) >> COL_SHIFT);
      dest += line_size;
      dest[0] = av_clip_pixel((int)(a2 - b2) >> COL_SHIFT);
      dest += line_size;
      dest[0] = av_clip_pixel((int)(a1 - b1) >> COL_SHIFT);
      dest += line_size;
      dest[0] = av_clip_pixel((int)(a0 - b0) >> COL_SHIFT);
  }
  
  static inline void FUNC6(idctSparseColAdd)(pixel *dest, ptrdiff_t line_size,
                                            idctin *col)
  {
      int a0, a1, a2, a3, b0, b1, b2, b3;
  
      IDCT_COLS;
  
      dest[0] = av_clip_pixel(dest[0] + ((a0 + b0) >> COL_SHIFT));
      dest += line_size;
      dest[0] = av_clip_pixel(dest[0] + ((a1 + b1) >> COL_SHIFT));
      dest += line_size;
      dest[0] = av_clip_pixel(dest[0] + ((a2 + b2) >> COL_SHIFT));
      dest += line_size;
      dest[0] = av_clip_pixel(dest[0] + ((a3 + b3) >> COL_SHIFT));
      dest += line_size;
      dest[0] = av_clip_pixel(dest[0] + ((a3 - b3) >> COL_SHIFT));
      dest += line_size;
      dest[0] = av_clip_pixel(dest[0] + ((a2 - b2) >> COL_SHIFT));
      dest += line_size;
      dest[0] = av_clip_pixel(dest[0] + ((a1 - b1) >> COL_SHIFT));
      dest += line_size;
      dest[0] = av_clip_pixel(dest[0] + ((a0 - b0) >> COL_SHIFT));
  }
  
  static inline void FUNC6(idctSparseCol)(idctin *col)
  #endif
  {
      int a0, a1, a2, a3, b0, b1, b2, b3;
  
      IDCT_COLS;
  
      col[0 ] = ((a0 + b0) >> COL_SHIFT);
      col[8 ] = ((a1 + b1) >> COL_SHIFT);
      col[16] = ((a2 + b2) >> COL_SHIFT);
      col[24] = ((a3 + b3) >> COL_SHIFT);
      col[32] = ((a3 - b3) >> COL_SHIFT);
      col[40] = ((a2 - b2) >> COL_SHIFT);
      col[48] = ((a1 - b1) >> COL_SHIFT);
      col[56] = ((a0 - b0) >> COL_SHIFT);
  }
  
  #ifndef EXTRA_SHIFT
  void FUNC6(ff_simple_idct_put)(uint8_t *dest_, ptrdiff_t line_size, int16_t *block_)
  {
      idctin *block = (idctin *)block_;
      pixel *dest = (pixel *)dest_;
      int i;
  
      line_size /= sizeof(pixel);
  
      for (i = 0; i < 8; i++)
          FUNC6(idctRowCondDC)(block + i*8, 0);
  
      for (i = 0; i < 8; i++)
          FUNC6(idctSparseColPut)(dest + i, line_size, block + i);
  }
  
  #if IN_IDCT_DEPTH == 16
  void FUNC6(ff_simple_idct_add)(uint8_t *dest_, ptrdiff_t line_size, int16_t *block)
  {
      pixel *dest = (pixel *)dest_;
      int i;
  
      line_size /= sizeof(pixel);
  
      for (i = 0; i < 8; i++)
          FUNC6(idctRowCondDC)(block + i*8, 0);
  
      for (i = 0; i < 8; i++)
          FUNC6(idctSparseColAdd)(dest + i, line_size, block + i);
  }
  
  void FUNC6(ff_simple_idct)(int16_t *block)
  {
      int i;
  
      for (i = 0; i < 8; i++)
          FUNC6(idctRowCondDC)(block + i*8, 0);
  
      for (i = 0; i < 8; i++)
          FUNC6(idctSparseCol)(block + i);
  }
  #endif
  #endif
  