libmpcodecs/vf_perspective.c

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