text: /*
   * This file is part of MPlayer.
   *
   * MPlayer is free software; you can redistribute it and/or modify
   * it under the terms of the GNU General Public License as published by
   * the Free Software Foundation; either version 2 of the License, or
   * (at your option) any later version.
   *
   * MPlayer 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 General Public License for more details.
   *
   * You should have received a copy of the GNU General Public License along
   * with MPlayer; if not, write to the Free Software Foundation, Inc.,
   * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
   */
  
  #include <stdio.h>
  #include <stdlib.h>
  #include <string.h>
  #include <inttypes.h>
  
  #include "config.h"
  #include "mp_msg.h"
  #include "cpudetect.h"
  
  #include "img_format.h"
  #include "mp_image.h"
  #include "vf.h"
  
  #include "libvo/fastmemcpy.h"
  
  struct vf_priv_s {
          int skipline;
          int scalew;
          int scaleh;
  };
  
  static void toright(unsigned char *dst[3], unsigned char *src[3],
                      int dststride[3], int srcstride[3],
                      int w, int h, struct vf_priv_s* p)
  {
          int k;
  
          for (k = 0; k < 3; k++) {
                  unsigned char* fromL = src[k];
                  unsigned char* fromR = src[k];
                  unsigned char* to = dst[k];
                  int src = srcstride[k];
                  int dst = dststride[k];
                  int ss;
                  unsigned int dd;
                  int i;
  
                  if (k > 0) {
                          i = h / 4 - p->skipline / 2;
                          ss = src * (h / 4 + p->skipline / 2);
                          dd = w / 4;
                  } else {
                          i = h / 2 - p->skipline;
                          ss = src * (h / 2 + p->skipline);
                          dd = w / 2;
                  }
                  fromR += ss;
                  for ( ; i > 0; i--) {
                          int j;
                          unsigned char* t = to;
                          unsigned char* sL = fromL;
                          unsigned char* sR = fromR;
  
                          if (p->scalew == 1) {
                                  for (j = dd; j > 0; j--) {
                                          *t++ = (sL[0] + sL[1]) / 2;
                                          sL+=2;
                                  }
                                  for (j = dd ; j > 0; j--) {
                                          *t++ = (sR[0] + sR[1]) / 2;
                                          sR+=2;
                                  }
                          } else {
                                  for (j = dd * 2 ; j > 0; j--)
                                          *t++ = *sL++;
                                  for (j = dd * 2 ; j > 0; j--)
                                          *t++ = *sR++;
                          }
                          if (p->scaleh == 1) {
                                  fast_memcpy(to + dst, to, dst);
                                  to += dst;
                          }
                          to += dst;
                          fromL += src;
                          fromR += src;
                  }
                  //printf("K %d  %d   %d   %d  %d \n", k, w, h,  src, dst);
          }
  }
  
  static int put_image(struct vf_instance *vf, mp_image_t *mpi, double pts, double endpts)
  {
          mp_image_t *dmpi;
  
          // hope we'll get DR buffer:
          dmpi=vf_get_image(vf->next, IMGFMT_YV12,
                            MP_IMGTYPE_TEMP, MP_IMGFLAG_ACCEPT_STRIDE |
                            ((vf->priv->scaleh == 1) ? MP_IMGFLAG_READABLE : 0),
                            mpi->w * vf->priv->scalew,
                            mpi->h / vf->priv->scaleh - vf->priv->skipline);
  
          toright(dmpi->planes, mpi->planes, dmpi->stride,
                  mpi->stride, mpi->w, mpi->h, vf->priv);
  
          return vf_next_put_image(vf, dmpi, pts, endpts);
  }
  
  static int config(struct vf_instance *vf,
                    int width, int height, int d_width, int d_height,
                    unsigned int flags, unsigned int outfmt)
  {
          /* FIXME - also support UYVY output? */
          return vf_next_config(vf, width * vf->priv->scalew,
                                height / vf->priv->scaleh - vf->priv->skipline, d_width, d_height, flags, IMGFMT_YV12);
  }
  
  
  static int query_format(struct vf_instance *vf, unsigned int fmt)
  {
          /* FIXME - really any YUV 4:2:0 input format should work */
          switch (fmt) {
          case IMGFMT_YV12:
          case IMGFMT_IYUV:
          case IMGFMT_I420:
                  return vf_next_query_format(vf, IMGFMT_YV12);
          }
          return 0;
  }
  
  static void uninit(struct vf_instance *vf)
  {
          free(vf->priv);
  }
  
  static int vf_open(vf_instance_t *vf, char *args)
  {
          vf->config=config;
          vf->query_format=query_format;
          vf->put_image=put_image;
          vf->uninit=uninit;
  
          vf->priv = calloc(1, sizeof (struct vf_priv_s));
          vf->priv->skipline = 0;
          vf->priv->scalew = 1;
          vf->priv->scaleh = 2;
          if (args) sscanf(args, "%d:%d:%d", &vf->priv->skipline, &vf->priv->scalew, &vf->priv->scaleh);
  
          return 1;
  }
  
  const vf_info_t vf_info_down3dright = {
          "convert stereo movie from top-bottom to left-right field",
          "down3dright",
          "Zdenek Kabelac",
          "",
          vf_open,
          NULL
  };
  