git.sesse.net Git - ffmpeg/blob - libavfilter/libmpcodecs/vf_perspective.c

   1 /*
   2  * Copyright (C) 2002 Michael Niedermayer <michaelni@gmx.at>
   3  *
   4  * This file is part of MPlayer.
   5  *
   6  * MPlayer is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * MPlayer is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License along
  17  * with MPlayer; if not, write to the Free Software Foundation, Inc.,
  18  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  19  */
  20
  21 #include <stdio.h>
  22 #include <stdlib.h>
  23 #include <string.h>
  24 #include <inttypes.h>
  25 #include <assert.h>
  26 #include <math.h>
  27
  28 #include "config.h"
  29 #include "mp_msg.h"
  30
  31 #if HAVE_MALLOC_H
  32 #include <malloc.h>
  33 #endif
  34
  35 #include "libavutil/mem.h"
  36
  37 #include "img_format.h"
  38 #include "mp_image.h"
  39 #include "vf.h"
  40
  41 #define SUB_PIXEL_BITS 8
  42 #define SUB_PIXELS (1<<SUB_PIXEL_BITS)
  43 #define COEFF_BITS 11
  44
  45 //===========================================================================//
  46
  47 struct vf_priv_s {
  48     double ref[4][2];
  49     int32_t coeff[1<<SUB_PIXEL_BITS][4];
  50     int32_t (*pv)[2];
  51     int pvStride;
  52     int cubic;
  53 };
  54
  55
  56 /***************************************************************************/
  57
  58 static void initPv(struct vf_priv_s *priv, int W, int H){
  59     double a,b,c,d,e,f,g,h,D;
  60     double (*ref)[2]= priv->ref;
  61     int x,y;
  62
  63     g= (  (ref[0][0] - ref[1][0] - ref[2][0] + ref[3][0])*(ref[2][1] - ref[3][1])
  64         - (ref[0][1] - ref[1][1] - ref[2][1] + ref[3][1])*(ref[2][0] - ref[3][0]))*H;
  65     h= (  (ref[0][1] - ref[1][1] - ref[2][1] + ref[3][1])*(ref[1][0] - ref[3][0])
  66         - (ref[0][0] - ref[1][0] - ref[2][0] + ref[3][0])*(ref[1][1] - ref[3][1]))*W;
  67     D=   (ref[1][0] - ref[3][0])*(ref[2][1] - ref[3][1])
  68        - (ref[2][0] - ref[3][0])*(ref[1][1] - ref[3][1]);
  69
  70     a= D*(ref[1][0] - ref[0][0])*H + g*ref[1][0];
  71     b= D*(ref[2][0] - ref[0][0])*W + h*ref[2][0];
  72     c= D*ref[0][0]*W*H;
  73     d= D*(ref[1][1] - ref[0][1])*H + g*ref[1][1];
  74     e= D*(ref[2][1] - ref[0][1])*W + h*ref[2][1];
  75     f= D*ref[0][1]*W*H;
  76
  77     for(y=0; y<H; y++){
  78         for(x=0; x<W; x++){
  79             int u, v;
  80
  81             u= (int)floor( SUB_PIXELS*(a*x + b*y + c)/(g*x + h*y + D*W*H) + 0.5);
  82             v= (int)floor( SUB_PIXELS*(d*x + e*y + f)/(g*x + h*y + D*W*H) + 0.5);
  83
  84             priv->pv[x + y*W][0]= u;
  85             priv->pv[x + y*W][1]= v;
  86         }
  87     }
  88 }
  89
  90 static double getCoeff(double d){
  91     double A= -0.60;
  92     double coeff;
  93
  94     d= fabs(d);
  95
  96     // Equation is from VirtualDub
  97     if(d<1.0)
  98         coeff = (1.0 - (A+3.0)*d*d + (A+2.0)*d*d*d);
  99     else if(d<2.0)
 100         coeff = (-4.0*A + 8.0*A*d - 5.0*A*d*d + A*d*d*d);
 101     else
 102         coeff=0.0;
 103
 104     return coeff;
 105 }
 106
 107 static int config(struct vf_instance *vf,
 108     int width, int height, int d_width, int d_height,
 109     unsigned int flags, unsigned int outfmt){
 110     int i, j;
 111
 112     vf->priv->pvStride= width;
 113     vf->priv->pv= av_malloc(width*height*2*sizeof(int32_t));
 114     initPv(vf->priv, width, height);
 115
 116     for(i=0; i<SUB_PIXELS; i++){
 117         double d= i/(double)SUB_PIXELS;
 118         double temp[4];
 119         double sum=0;
 120
 121         for(j=0; j<4; j++)
 122             temp[j]= getCoeff(j - d - 1);
 123
 124         for(j=0; j<4; j++)
 125             sum+= temp[j];
 126
 127         for(j=0; j<4; j++)
 128             vf->priv->coeff[i][j]= (int)floor((1<<COEFF_BITS)*temp[j]/sum + 0.5);
 129     }
 130
 131     return ff_vf_next_config(vf,width,height,d_width,d_height,flags,outfmt);
 132 }
 133
 134 static void uninit(struct vf_instance *vf){
 135     if(!vf->priv) return;
 136
 137     av_free(vf->priv->pv);
 138     vf->priv->pv= NULL;
 139
 140     free(vf->priv);
 141     vf->priv=NULL;
 142 }
 143
 144 static inline void resampleCubic(uint8_t *dst, uint8_t *src, int w, int h, int dstStride, int srcStride, struct vf_priv_s *privParam, int xShift, int yShift){
 145     int x, y;
 146     struct vf_priv_s priv= *privParam;
 147
 148     for(y=0; y<h; y++){
 149         for(x=0; x<w; x++){
 150             int u, v, subU, subV, sum, sx, sy;
 151
 152             sx= x << xShift;
 153             sy= y << yShift;
 154             u= priv.pv[sx + sy*priv.pvStride][0]>>xShift;
 155             v= priv.pv[sx + sy*priv.pvStride][1]>>yShift;
 156             subU= u & (SUB_PIXELS-1);
 157             subV= v & (SUB_PIXELS-1);
 158             u >>= SUB_PIXEL_BITS;
 159             v >>= SUB_PIXEL_BITS;
 160
 161             if(u>0 && v>0 && u<w-2 && v<h-2){
 162                 const int index= u + v*srcStride;
 163                 const int a= priv.coeff[subU][0];
 164                 const int b= priv.coeff[subU][1];
 165                 const int c= priv.coeff[subU][2];
 166                 const int d= priv.coeff[subU][3];
 167
 168                 sum=
 169                  priv.coeff[subV][0]*(  a*src[index - 1 - srcStride] + b*src[index - 0 - srcStride]
 170                                       + c*src[index + 1 - srcStride] + d*src[index + 2 - srcStride])
 171                 +priv.coeff[subV][1]*(  a*src[index - 1            ] + b*src[index - 0            ]
 172                                       + c*src[index + 1            ] + d*src[index + 2            ])
 173                 +priv.coeff[subV][2]*(  a*src[index - 1 + srcStride] + b*src[index - 0 + srcStride]
 174                                       + c*src[index + 1 + srcStride] + d*src[index + 2 + srcStride])
 175                 +priv.coeff[subV][3]*(  a*src[index - 1+2*srcStride] + b*src[index - 0+2*srcStride]
 176                                       + c*src[index + 1+2*srcStride] + d*src[index + 2+2*srcStride]);
 177             }else{
 178                 int dx, dy;
 179                 sum=0;
 180
 181                 for(dy=0; dy<4; dy++){
 182                     int iy= v + dy - 1;
 183                     if     (iy< 0) iy=0;
 184                     else if(iy>=h) iy=h-1;
 185                     for(dx=0; dx<4; dx++){
 186                         int ix= u + dx - 1;
 187                         if     (ix< 0) ix=0;
 188                         else if(ix>=w) ix=w-1;
 189
 190                         sum+=  priv.coeff[subU][dx]*priv.coeff[subV][dy]
 191                               *src[ ix + iy*srcStride];
 192                     }
 193                 }
 194             }
 195             sum= (sum + (1<<(COEFF_BITS*2-1)) ) >> (COEFF_BITS*2);
 196             if(sum&~255){
 197                 if(sum<0) sum=0;
 198                 else      sum=255;
 199             }
 200             dst[ x + y*dstStride]= sum;
 201         }
 202     }
 203 }
 204
 205 static inline void resampleLinear(uint8_t *dst, uint8_t *src, int w, int h, int dstStride, int srcStride,
 206                   struct vf_priv_s *privParam, int xShift, int yShift){
 207     int x, y;
 208     struct vf_priv_s priv= *privParam;
 209
 210     for(y=0; y<h; y++){
 211         for(x=0; x<w; x++){
 212             int u, v, subU, subV, sum, sx, sy, index, subUI, subVI;
 213
 214             sx= x << xShift;
 215             sy= y << yShift;
 216             u= priv.pv[sx + sy*priv.pvStride][0]>>xShift;
 217             v= priv.pv[sx + sy*priv.pvStride][1]>>yShift;
 218             subU= u & (SUB_PIXELS-1);
 219             subV= v & (SUB_PIXELS-1);
 220             u >>= SUB_PIXEL_BITS;
 221             v >>= SUB_PIXEL_BITS;
 222             index= u + v*srcStride;
 223             subUI= SUB_PIXELS - subU;
 224             subVI= SUB_PIXELS - subV;
 225
 226             if((unsigned)u < (unsigned)(w - 1)){
 227                 if((unsigned)v < (unsigned)(h - 1)){
 228                     sum= subVI*(subUI*src[index          ] + subU*src[index          +1])
 229                         +subV *(subUI*src[index+srcStride] + subU*src[index+srcStride+1]);
 230                     sum= (sum + (1<<(SUB_PIXEL_BITS*2-1)) ) >> (SUB_PIXEL_BITS*2);
 231                 }else{
 232                     if(v<0) v= 0;
 233                     else    v= h-1;
 234                     index= u + v*srcStride;
 235                     sum= subUI*src[index] + subU*src[index+1];
 236                     sum= (sum + (1<<(SUB_PIXEL_BITS-1)) ) >> SUB_PIXEL_BITS;
 237                 }
 238             }else{
 239                 if((unsigned)v < (unsigned)(h - 1)){
 240                     if(u<0) u= 0;
 241                     else    u= w-1;
 242                     index= u + v*srcStride;
 243                     sum= subVI*src[index] + subV*src[index+srcStride];
 244                     sum= (sum + (1<<(SUB_PIXEL_BITS-1)) ) >> SUB_PIXEL_BITS;
 245                 }else{
 246                     if(u<0) u= 0;
 247                     else    u= w-1;
 248                     if(v<0) v= 0;
 249                     else    v= h-1;
 250                     index= u + v*srcStride;
 251                     sum= src[index];
 252                 }
 253             }
 254             if(sum&~255){
 255                 if(sum<0) sum=0;
 256                 else      sum=255;
 257             }
 258             dst[ x + y*dstStride]= sum;
 259         }
 260     }
 261 }
 262
 263 static int put_image(struct vf_instance *vf, mp_image_t *mpi, double pts){
 264     int cw= mpi->w >> mpi->chroma_x_shift;
 265     int ch= mpi->h >> mpi->chroma_y_shift;
 266
 267     mp_image_t *dmpi=ff_vf_get_image(vf->next,mpi->imgfmt,
 268         MP_IMGTYPE_TEMP, MP_IMGFLAG_ACCEPT_STRIDE,
 269         mpi->w,mpi->h);
 270
 271     assert(mpi->flags&MP_IMGFLAG_PLANAR);
 272
 273     if(vf->priv->cubic){
 274         resampleCubic(dmpi->planes[0], mpi->planes[0], mpi->w,mpi->h, dmpi->stride[0], mpi->stride[0],
 275                 vf->priv, 0, 0);
 276         resampleCubic(dmpi->planes[1], mpi->planes[1], cw    , ch   , dmpi->stride[1], mpi->stride[1],
 277                 vf->priv, mpi->chroma_x_shift, mpi->chroma_y_shift);
 278         resampleCubic(dmpi->planes[2], mpi->planes[2], cw    , ch   , dmpi->stride[2], mpi->stride[2],
 279                 vf->priv, mpi->chroma_x_shift, mpi->chroma_y_shift);
 280     }else{
 281         resampleLinear(dmpi->planes[0], mpi->planes[0], mpi->w,mpi->h, dmpi->stride[0], mpi->stride[0],
 282                 vf->priv, 0, 0);
 283         resampleLinear(dmpi->planes[1], mpi->planes[1], cw    , ch   , dmpi->stride[1], mpi->stride[1],
 284                 vf->priv, mpi->chroma_x_shift, mpi->chroma_y_shift);
 285         resampleLinear(dmpi->planes[2], mpi->planes[2], cw    , ch   , dmpi->stride[2], mpi->stride[2],
 286                 vf->priv, mpi->chroma_x_shift, mpi->chroma_y_shift);
 287     }
 288
 289     return ff_vf_next_put_image(vf,dmpi, pts);
 290 }
 291
 292 //===========================================================================//
 293
 294 static int query_format(struct vf_instance *vf, unsigned int fmt){
 295     switch(fmt)
 296     {
 297     case IMGFMT_YV12:
 298     case IMGFMT_I420:
 299     case IMGFMT_IYUV:
 300     case IMGFMT_YVU9:
 301     case IMGFMT_444P:
 302     case IMGFMT_422P:
 303     case IMGFMT_411P:
 304         return ff_vf_next_query_format(vf, fmt);
 305     }
 306     return 0;
 307 }
 308
 309 static int vf_open(vf_instance_t *vf, char *args){
 310     int e;
 311
 312     vf->config=config;
 313     vf->put_image=put_image;
 314 //  vf->get_image=get_image;
 315     vf->query_format=query_format;
 316     vf->uninit=uninit;
 317     vf->priv=malloc(sizeof(struct vf_priv_s));
 318     memset(vf->priv, 0, sizeof(struct vf_priv_s));
 319
 320     if(args==NULL) return 0;
 321
 322     e=sscanf(args, "%lf:%lf:%lf:%lf:%lf:%lf:%lf:%lf:%d",
 323         &vf->priv->ref[0][0], &vf->priv->ref[0][1],
 324         &vf->priv->ref[1][0], &vf->priv->ref[1][1],
 325         &vf->priv->ref[2][0], &vf->priv->ref[2][1],
 326         &vf->priv->ref[3][0], &vf->priv->ref[3][1],
 327         &vf->priv->cubic
 328         );
 329
 330     if(e!=9)
 331         return 0;
 332
 333     return 1;
 334 }
 335
 336 const vf_info_t ff_vf_info_perspective = {
 337     "perspective correcture",
 338     "perspective",
 339     "Michael Niedermayer",
 340     "",
 341     vf_open,
 342     NULL
 343 };
 344
 345 //===========================================================================//