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.
   */
  
  #include "XMFFmpeg/libavutil/intreadwrite.h"
  #include "internal.h"
  #include "dsputil.h"
  #include "mathops.h"
  #include "simple_idct.h"
  
  #define BIT_DEPTH 8
  #include "simple_idct_template.hpp"
  #undef BIT_DEPTH
  
  #define BIT_DEPTH 10
  #include "simple_idct_template.hpp"
  #undef BIT_DEPTH
  
  /* 2x4x8 idct */
  
  #define CN_SHIFT 12
  #define C_FIX(x) ((int)((x) * (1 << CN_SHIFT) + 0.5))
  #define C1 C_FIX(0.6532814824)
  #define C2 C_FIX(0.2705980501)
  
  /* row idct is multiple by 16 * sqrt(2.0), col idct4 is normalized,
     and the butterfly must be multiplied by 0.5 * sqrt(2.0) */
  #define C_SHIFT (4+1+12)
  
  static inline void idct4col_put(uint8_t *dest, int line_size, const DCTELEM *col)
  {
      int c0, c1, c2, c3, a0, a1, a2, a3;
  
      a0 = col[8*0];
      a1 = col[8*2];
      a2 = col[8*4];
      a3 = col[8*6];
      c0 = ((a0 + a2) << (CN_SHIFT - 1)) + (1 << (C_SHIFT - 1));
      c2 = ((a0 - a2) << (CN_SHIFT - 1)) + (1 << (C_SHIFT - 1));
      c1 = a1 * C1 + a3 * C2;
      c3 = a1 * C2 - a3 * C1;
      dest[0] = av_clip_uint8((c0 + c1) >> C_SHIFT);
      dest += line_size;
      dest[0] = av_clip_uint8((c2 + c3) >> C_SHIFT);
      dest += line_size;
      dest[0] = av_clip_uint8((c2 - c3) >> C_SHIFT);
      dest += line_size;
      dest[0] = av_clip_uint8((c0 - c1) >> C_SHIFT);
  }
  
  #define BF(k) \
  {\
      int a0, a1;\
      a0 = ptr[k];\
      a1 = ptr[8 + k];\
      ptr[k] = a0 + a1;\
      ptr[8 + k] = a0 - a1;\
  }
  
  /* only used by DV codec. The input must be interlaced. 128 is added
     to the pixels before clamping to avoid systematic error
     (1024*sqrt(2)) offset would be needed otherwise. */
  /* XXX: I think a 1.0/sqrt(2) normalization should be needed to
     compensate the extra butterfly stage - I don't have the full DV
     specification */
  void ff_simple_idct248_put(uint8_t *dest, int line_size, DCTELEM *block)
  {
      int i;
      DCTELEM *ptr;
  
      /* butterfly */
      ptr = block;
      for(i=0;i<4;i++) {
          BF(0);
          BF(1);
          BF(2);
          BF(3);
          BF(4);
          BF(5);
          BF(6);
          BF(7);
          ptr += 2 * 8;
      }
  
      /* IDCT8 on each line */
      for(i=0; i<8; i++) {
          idctRowCondDC_8(block + i*8, 0);
      }
  
      /* IDCT4 and store */
      for(i=0;i<8;i++) {
          idct4col_put(dest + i, 2 * line_size, block + i);
          idct4col_put(dest + line_size + i, 2 * line_size, block + 8 + i);
      }
  }
  
  /* 8x4 & 4x8 WMV2 IDCT */
  #undef CN_SHIFT
  #undef C_SHIFT
  #undef C_FIX
  #undef C1
  #undef C2
  #define CN_SHIFT 12
  #define C_FIX(x) ((int)((x) * 1.414213562 * (1 << CN_SHIFT) + 0.5))
  #define C1 C_FIX(0.6532814824)
  #define C2 C_FIX(0.2705980501)
  #define C3 C_FIX(0.5)
  #define C_SHIFT (4+1+12)
  static inline void idct4col_add(uint8_t *dest, int line_size, const DCTELEM *col)
  {
      int c0, c1, c2, c3, a0, a1, a2, a3;
  
      a0 = col[8*0];
      a1 = col[8*1];
      a2 = col[8*2];
      a3 = col[8*3];
      c0 = (a0 + a2)*C3 + (1 << (C_SHIFT - 1));
      c2 = (a0 - a2)*C3 + (1 << (C_SHIFT - 1));
      c1 = a1 * C1 + a3 * C2;
      c3 = a1 * C2 - a3 * C1;
      dest[0] = av_clip_uint8(dest[0] + ((c0 + c1) >> C_SHIFT));
      dest += line_size;
      dest[0] = av_clip_uint8(dest[0] + ((c2 + c3) >> C_SHIFT));
      dest += line_size;
      dest[0] = av_clip_uint8(dest[0] + ((c2 - c3) >> C_SHIFT));
      dest += line_size;
      dest[0] = av_clip_uint8(dest[0] + ((c0 - c1) >> C_SHIFT));
  }
  
  #define RN_SHIFT 15
  #define R_FIX(x) ((int)((x) * 1.414213562 * (1 << RN_SHIFT) + 0.5))
  #define R1 R_FIX(0.6532814824)
  #define R2 R_FIX(0.2705980501)
  #define R3 R_FIX(0.5)
  #define R_SHIFT 11
  static inline void idct4row(DCTELEM *row)
  {
      int c0, c1, c2, c3, a0, a1, a2, a3;
  
      a0 = row[0];
      a1 = row[1];
      a2 = row[2];
      a3 = row[3];
      c0 = (a0 + a2)*R3 + (1 << (R_SHIFT - 1));
      c2 = (a0 - a2)*R3 + (1 << (R_SHIFT - 1));
      c1 = a1 * R1 + a3 * R2;
      c3 = a1 * R2 - a3 * R1;
      row[0]= (c0 + c1) >> R_SHIFT;
      row[1]= (c2 + c3) >> R_SHIFT;
      row[2]= (c2 - c3) >> R_SHIFT;
      row[3]= (c0 - c1) >> R_SHIFT;
  }
  
  void ff_simple_idct84_add(uint8_t *dest, int line_size, DCTELEM *block)
  {
      int i;
  
      /* IDCT8 on each line */
      for(i=0; i<4; i++) {
          idctRowCondDC_8(block + i*8, 0);
      }
  
      /* IDCT4 and store */
      for(i=0;i<8;i++) {
          idct4col_add(dest + i, line_size, block + i);
      }
  }
  
  void ff_simple_idct48_add(uint8_t *dest, int line_size, DCTELEM *block)
  {
      int i;
  
      /* IDCT4 on each line */
      for(i=0; i<8; i++) {
          idct4row(block + i*8);
      }
  
      /* IDCT8 and store */
      for(i=0; i<4; i++){
          idctSparseColAdd_8(dest + i, line_size, block + i);
      }
  }
  
  void ff_simple_idct44_add(uint8_t *dest, int line_size, DCTELEM *block)
  {
      int i;
  
      /* IDCT4 on each line */
      for(i=0; i<4; i++) {
          idct4row(block + i*8);
      }
  
      /* IDCT4 and store */
      for(i=0; i<4; i++){
          idct4col_add(dest + i, line_size, block + i);
      }
  }
  
  void ff_prores_idct(DCTELEM *block, const int16_t *qmat)
  {
      int i;
  
      for (i = 0; i < 64; i++)
          block[i] *= qmat[i];
  
      for (i = 0; i < 8; i++)
          idctRowCondDC_10(block + i*8, 2);
  
      for (i = 0; i < 8; i++)
          idctSparseCol_10(block + i);
  }
  