text: /*
   * 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
   */
  
  #include "config.h"
  #include "libavutil/attributes.h"
  #include "libavutil/common.h"
  #include "mpegvideodsp.h"
  
  static void gmc1_c(uint8_t *dst, uint8_t *src, int stride, int h,
                     int x16, int y16, int rounder)
  {
      const int A = (16 - x16) * (16 - y16);
      const int B = (x16)      * (16 - y16);
      const int C = (16 - x16) * (y16);
      const int D = (x16)      * (y16);
      int i;
  
      for (i = 0; i < h; i++) {
          dst[0] = (A * src[0] + B * src[1] + C * src[stride + 0] + D * src[stride + 1] + rounder) >> 8;
          dst[1] = (A * src[1] + B * src[2] + C * src[stride + 1] + D * src[stride + 2] + rounder) >> 8;
          dst[2] = (A * src[2] + B * src[3] + C * src[stride + 2] + D * src[stride + 3] + rounder) >> 8;
          dst[3] = (A * src[3] + B * src[4] + C * src[stride + 3] + D * src[stride + 4] + rounder) >> 8;
          dst[4] = (A * src[4] + B * src[5] + C * src[stride + 4] + D * src[stride + 5] + rounder) >> 8;
          dst[5] = (A * src[5] + B * src[6] + C * src[stride + 5] + D * src[stride + 6] + rounder) >> 8;
          dst[6] = (A * src[6] + B * src[7] + C * src[stride + 6] + D * src[stride + 7] + rounder) >> 8;
          dst[7] = (A * src[7] + B * src[8] + C * src[stride + 7] + D * src[stride + 8] + rounder) >> 8;
          dst   += stride;
          src   += stride;
      }
  }
  
  void ff_gmc_c(uint8_t *dst, uint8_t *src, int stride, int h, int ox, int oy,
                int dxx, int dxy, int dyx, int dyy, int shift, int r,
                int width, int height)
  {
      int y, vx, vy;
      const int s = 1 << shift;
  
      width--;
      height--;
  
      for (y = 0; y < h; y++) {
          int x;
  
          vx = ox;
          vy = oy;
          for (x = 0; x < 8; x++) { // FIXME: optimize
              int index;
              int src_x  = vx >> 16;
              int src_y  = vy >> 16;
              int frac_x = src_x & (s - 1);
              int frac_y = src_y & (s - 1);
  
              src_x >>= shift;
              src_y >>= shift;
  
              if ((unsigned) src_x < width) {
                  if ((unsigned) src_y < height) {
                      index = src_x + src_y * stride;
                      dst[y * stride + x] =
                          ((src[index]                        * (s - frac_x) +
                            src[index + 1]          * frac_x) * (s - frac_y) +
                           (src[index + stride]               * (s - frac_x) +
                            src[index + stride + 1] * frac_x) *      frac_y  +
                           r) >> (shift * 2);
                  } else {
                      index = src_x + av_clip(src_y, 0, height) * stride;
                      dst[y * stride + x] =
                          ((src[index]               * (s - frac_x) +
                            src[index + 1] * frac_x) *  s           +
                           r) >> (shift * 2);
                  }
              } else {
                  if ((unsigned) src_y < height) {
                      index = av_clip(src_x, 0, width) + src_y * stride;
                      dst[y * stride + x] =
                          ((src[index]                    * (s - frac_y) +
                            src[index + stride] * frac_y) *  s           +
                           r) >> (shift * 2);
                  } else {
                      index = av_clip(src_x, 0, width) +
                              av_clip(src_y, 0, height) * stride;
                      dst[y * stride + x] = src[index];
                  }
              }
  
              vx += dxx;
              vy += dyx;
          }
          ox += dxy;
          oy += dyy;
      }
  }
  
  av_cold void ff_mpegvideodsp_init(MpegVideoDSPContext *c)
  {
      c->gmc1 = gmc1_c;
      c->gmc  = ff_gmc_c;
  
      if (ARCH_PPC)
          ff_mpegvideodsp_init_ppc(c);
      if (ARCH_X86)
          ff_mpegvideodsp_init_x86(c);
  }
  