libavfilter/libmpcodecs/vf_perspective.c
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00001 /*
00002  * Copyright (C) 2002 Michael Niedermayer <michaelni@gmx.at>
00003  *
00004  * This file is part of MPlayer.
00005  *
00006  * MPlayer is free software; you can redistribute it and/or modify
00007  * it under the terms of the GNU General Public License as published by
00008  * the Free Software Foundation; either version 2 of the License, or
00009  * (at your option) any later version.
00010  *
00011  * MPlayer is distributed in the hope that it will be useful,
00012  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00013  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
00014  * GNU General Public License for more details.
00015  *
00016  * You should have received a copy of the GNU General Public License along
00017  * with MPlayer; if not, write to the Free Software Foundation, Inc.,
00018  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
00019  */
00020 
00021 #include <stdio.h>
00022 #include <stdlib.h>
00023 #include <string.h>
00024 #include <inttypes.h>
00025 #include <assert.h>
00026 #include <math.h>
00027 
00028 #include "config.h"
00029 #include "mp_msg.h"
00030 
00031 #if HAVE_MALLOC_H
00032 #include <malloc.h>
00033 #endif
00034 
00035 #include "libavutil/mem.h"
00036 
00037 #include "img_format.h"
00038 #include "mp_image.h"
00039 #include "vf.h"
00040 
00041 #define SUB_PIXEL_BITS 8
00042 #define SUB_PIXELS (1<<SUB_PIXEL_BITS)
00043 #define COEFF_BITS 11
00044 
00045 //===========================================================================//
00046 
00047 struct vf_priv_s {
00048     double ref[4][2];
00049     int32_t coeff[1<<SUB_PIXEL_BITS][4];
00050     int32_t (*pv)[2];
00051     int pvStride;
00052     int cubic;
00053 };
00054 
00055 
00056 /***************************************************************************/
00057 
00058 static void initPv(struct vf_priv_s *priv, int W, int H){
00059     double a,b,c,d,e,f,g,h,D;
00060     double (*ref)[2]= priv->ref;
00061     int x,y;
00062 
00063     g= (  (ref[0][0] - ref[1][0] - ref[2][0] + ref[3][0])*(ref[2][1] - ref[3][1])
00064         - (ref[0][1] - ref[1][1] - ref[2][1] + ref[3][1])*(ref[2][0] - ref[3][0]))*H;
00065     h= (  (ref[0][1] - ref[1][1] - ref[2][1] + ref[3][1])*(ref[1][0] - ref[3][0])
00066         - (ref[0][0] - ref[1][0] - ref[2][0] + ref[3][0])*(ref[1][1] - ref[3][1]))*W;
00067     D=   (ref[1][0] - ref[3][0])*(ref[2][1] - ref[3][1])
00068        - (ref[2][0] - ref[3][0])*(ref[1][1] - ref[3][1]);
00069 
00070     a= D*(ref[1][0] - ref[0][0])*H + g*ref[1][0];
00071     b= D*(ref[2][0] - ref[0][0])*W + h*ref[2][0];
00072     c= D*ref[0][0]*W*H;
00073     d= D*(ref[1][1] - ref[0][1])*H + g*ref[1][1];
00074     e= D*(ref[2][1] - ref[0][1])*W + h*ref[2][1];
00075     f= D*ref[0][1]*W*H;
00076 
00077     for(y=0; y<H; y++){
00078         for(x=0; x<W; x++){
00079             int u, v;
00080 
00081             u= (int)floor( SUB_PIXELS*(a*x + b*y + c)/(g*x + h*y + D*W*H) + 0.5);
00082             v= (int)floor( SUB_PIXELS*(d*x + e*y + f)/(g*x + h*y + D*W*H) + 0.5);
00083 
00084             priv->pv[x + y*W][0]= u;
00085             priv->pv[x + y*W][1]= v;
00086         }
00087     }
00088 }
00089 
00090 static double getCoeff(double d){
00091     double A= -0.60;
00092     double coeff;
00093 
00094     d= fabs(d);
00095 
00096     // Equation is from VirtualDub
00097     if(d<1.0)
00098         coeff = (1.0 - (A+3.0)*d*d + (A+2.0)*d*d*d);
00099     else if(d<2.0)
00100         coeff = (-4.0*A + 8.0*A*d - 5.0*A*d*d + A*d*d*d);
00101     else
00102         coeff=0.0;
00103 
00104     return coeff;
00105 }
00106 
00107 static int config(struct vf_instance *vf,
00108     int width, int height, int d_width, int d_height,
00109     unsigned int flags, unsigned int outfmt){
00110     int i, j;
00111 
00112     vf->priv->pvStride= width;
00113     vf->priv->pv= av_malloc(width*height*2*sizeof(int32_t));
00114     initPv(vf->priv, width, height);
00115 
00116     for(i=0; i<SUB_PIXELS; i++){
00117         double d= i/(double)SUB_PIXELS;
00118         double temp[4];
00119         double sum=0;
00120 
00121         for(j=0; j<4; j++)
00122             temp[j]= getCoeff(j - d - 1);
00123 
00124         for(j=0; j<4; j++)
00125             sum+= temp[j];
00126 
00127         for(j=0; j<4; j++)
00128             vf->priv->coeff[i][j]= (int)floor((1<<COEFF_BITS)*temp[j]/sum + 0.5);
00129     }
00130 
00131     return vf_next_config(vf,width,height,d_width,d_height,flags,outfmt);
00132 }
00133 
00134 static void uninit(struct vf_instance *vf){
00135     if(!vf->priv) return;
00136 
00137     av_free(vf->priv->pv);
00138     vf->priv->pv= NULL;
00139 
00140     free(vf->priv);
00141     vf->priv=NULL;
00142 }
00143 
00144 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){
00145     int x, y;
00146     struct vf_priv_s priv= *privParam;
00147 
00148     for(y=0; y<h; y++){
00149         for(x=0; x<w; x++){
00150             int u, v, subU, subV, sum, sx, sy;
00151 
00152             sx= x << xShift;
00153             sy= y << yShift;
00154             u= priv.pv[sx + sy*priv.pvStride][0]>>xShift;
00155             v= priv.pv[sx + sy*priv.pvStride][1]>>yShift;
00156             subU= u & (SUB_PIXELS-1);
00157             subV= v & (SUB_PIXELS-1);
00158             u >>= SUB_PIXEL_BITS;
00159             v >>= SUB_PIXEL_BITS;
00160 
00161             if(u>0 && v>0 && u<w-2 && v<h-2){
00162                 const int index= u + v*srcStride;
00163                 const int a= priv.coeff[subU][0];
00164                 const int b= priv.coeff[subU][1];
00165                 const int c= priv.coeff[subU][2];
00166                 const int d= priv.coeff[subU][3];
00167 
00168                 sum=
00169                  priv.coeff[subV][0]*(  a*src[index - 1 - srcStride] + b*src[index - 0 - srcStride]
00170                                       + c*src[index + 1 - srcStride] + d*src[index + 2 - srcStride])
00171                 +priv.coeff[subV][1]*(  a*src[index - 1            ] + b*src[index - 0            ]
00172                                       + c*src[index + 1            ] + d*src[index + 2            ])
00173                 +priv.coeff[subV][2]*(  a*src[index - 1 + srcStride] + b*src[index - 0 + srcStride]
00174                                       + c*src[index + 1 + srcStride] + d*src[index + 2 + srcStride])
00175                 +priv.coeff[subV][3]*(  a*src[index - 1+2*srcStride] + b*src[index - 0+2*srcStride]
00176                                       + c*src[index + 1+2*srcStride] + d*src[index + 2+2*srcStride]);
00177             }else{
00178                 int dx, dy;
00179                 sum=0;
00180 
00181                 for(dy=0; dy<4; dy++){
00182                     int iy= v + dy - 1;
00183                     if     (iy< 0) iy=0;
00184                     else if(iy>=h) iy=h-1;
00185                     for(dx=0; dx<4; dx++){
00186                         int ix= u + dx - 1;
00187                         if     (ix< 0) ix=0;
00188                         else if(ix>=w) ix=w-1;
00189 
00190                         sum+=  priv.coeff[subU][dx]*priv.coeff[subV][dy]
00191                               *src[ ix + iy*srcStride];
00192                     }
00193                 }
00194             }
00195             sum= (sum + (1<<(COEFF_BITS*2-1)) ) >> (COEFF_BITS*2);
00196             if(sum&~255){
00197                 if(sum<0) sum=0;
00198                 else      sum=255;
00199             }
00200             dst[ x + y*dstStride]= sum;
00201         }
00202     }
00203 }
00204 
00205 static inline void resampleLinear(uint8_t *dst, uint8_t *src, int w, int h, int dstStride, int srcStride,
00206                   struct vf_priv_s *privParam, int xShift, int yShift){
00207     int x, y;
00208     struct vf_priv_s priv= *privParam;
00209 
00210     for(y=0; y<h; y++){
00211         for(x=0; x<w; x++){
00212             int u, v, subU, subV, sum, sx, sy, index, subUI, subVI;
00213 
00214             sx= x << xShift;
00215             sy= y << yShift;
00216             u= priv.pv[sx + sy*priv.pvStride][0]>>xShift;
00217             v= priv.pv[sx + sy*priv.pvStride][1]>>yShift;
00218             subU= u & (SUB_PIXELS-1);
00219             subV= v & (SUB_PIXELS-1);
00220             u >>= SUB_PIXEL_BITS;
00221             v >>= SUB_PIXEL_BITS;
00222             index= u + v*srcStride;
00223             subUI= SUB_PIXELS - subU;
00224             subVI= SUB_PIXELS - subV;
00225 
00226             if((unsigned)u < (unsigned)(w - 1)){
00227                 if((unsigned)v < (unsigned)(h - 1)){
00228                     sum= subVI*(subUI*src[index          ] + subU*src[index          +1])
00229                         +subV *(subUI*src[index+srcStride] + subU*src[index+srcStride+1]);
00230                     sum= (sum + (1<<(SUB_PIXEL_BITS*2-1)) ) >> (SUB_PIXEL_BITS*2);
00231                 }else{
00232                     if(v<0) v= 0;
00233                     else    v= h-1;
00234                     index= u + v*srcStride;
00235                     sum= subUI*src[index] + subU*src[index+1];
00236                     sum= (sum + (1<<(SUB_PIXEL_BITS-1)) ) >> SUB_PIXEL_BITS;
00237                 }
00238             }else{
00239                 if((unsigned)v < (unsigned)(h - 1)){
00240                     if(u<0) u= 0;
00241                     else    u= w-1;
00242                     index= u + v*srcStride;
00243                     sum= subVI*src[index] + subV*src[index+srcStride];
00244                     sum= (sum + (1<<(SUB_PIXEL_BITS-1)) ) >> SUB_PIXEL_BITS;
00245                 }else{
00246                     if(u<0) u= 0;
00247                     else    u= w-1;
00248                     if(v<0) v= 0;
00249                     else    v= h-1;
00250                     index= u + v*srcStride;
00251                     sum= src[index];
00252                 }
00253             }
00254             if(sum&~255){
00255                 if(sum<0) sum=0;
00256                 else      sum=255;
00257             }
00258             dst[ x + y*dstStride]= sum;
00259         }
00260     }
00261 }
00262 
00263 static int put_image(struct vf_instance *vf, mp_image_t *mpi, double pts){
00264     int cw= mpi->w >> mpi->chroma_x_shift;
00265     int ch= mpi->h >> mpi->chroma_y_shift;
00266 
00267     mp_image_t *dmpi=vf_get_image(vf->next,mpi->imgfmt,
00268         MP_IMGTYPE_TEMP, MP_IMGFLAG_ACCEPT_STRIDE,
00269         mpi->w,mpi->h);
00270 
00271     assert(mpi->flags&MP_IMGFLAG_PLANAR);
00272 
00273     if(vf->priv->cubic){
00274         resampleCubic(dmpi->planes[0], mpi->planes[0], mpi->w,mpi->h, dmpi->stride[0], mpi->stride[0],
00275                 vf->priv, 0, 0);
00276         resampleCubic(dmpi->planes[1], mpi->planes[1], cw    , ch   , dmpi->stride[1], mpi->stride[1],
00277                 vf->priv, mpi->chroma_x_shift, mpi->chroma_y_shift);
00278         resampleCubic(dmpi->planes[2], mpi->planes[2], cw    , ch   , dmpi->stride[2], mpi->stride[2],
00279                 vf->priv, mpi->chroma_x_shift, mpi->chroma_y_shift);
00280     }else{
00281         resampleLinear(dmpi->planes[0], mpi->planes[0], mpi->w,mpi->h, dmpi->stride[0], mpi->stride[0],
00282                 vf->priv, 0, 0);
00283         resampleLinear(dmpi->planes[1], mpi->planes[1], cw    , ch   , dmpi->stride[1], mpi->stride[1],
00284                 vf->priv, mpi->chroma_x_shift, mpi->chroma_y_shift);
00285         resampleLinear(dmpi->planes[2], mpi->planes[2], cw    , ch   , dmpi->stride[2], mpi->stride[2],
00286                 vf->priv, mpi->chroma_x_shift, mpi->chroma_y_shift);
00287     }
00288 
00289     return vf_next_put_image(vf,dmpi, pts);
00290 }
00291 
00292 //===========================================================================//
00293 
00294 static int query_format(struct vf_instance *vf, unsigned int fmt){
00295     switch(fmt)
00296     {
00297     case IMGFMT_YV12:
00298     case IMGFMT_I420:
00299     case IMGFMT_IYUV:
00300     case IMGFMT_YVU9:
00301     case IMGFMT_444P:
00302     case IMGFMT_422P:
00303     case IMGFMT_411P:
00304         return vf_next_query_format(vf, fmt);
00305     }
00306     return 0;
00307 }
00308 
00309 static int vf_open(vf_instance_t *vf, char *args){
00310     int e;
00311 
00312     vf->config=config;
00313     vf->put_image=put_image;
00314 //  vf->get_image=get_image;
00315     vf->query_format=query_format;
00316     vf->uninit=uninit;
00317     vf->priv=malloc(sizeof(struct vf_priv_s));
00318     memset(vf->priv, 0, sizeof(struct vf_priv_s));
00319 
00320     if(args==NULL) return 0;
00321 
00322     e=sscanf(args, "%lf:%lf:%lf:%lf:%lf:%lf:%lf:%lf:%d",
00323         &vf->priv->ref[0][0], &vf->priv->ref[0][1],
00324         &vf->priv->ref[1][0], &vf->priv->ref[1][1],
00325         &vf->priv->ref[2][0], &vf->priv->ref[2][1],
00326         &vf->priv->ref[3][0], &vf->priv->ref[3][1],
00327         &vf->priv->cubic
00328         );
00329 
00330     if(e!=9)
00331         return 0;
00332 
00333     return 1;
00334 }
00335 
00336 const vf_info_t vf_info_perspective = {
00337     "perspective correcture",
00338     "perspective",
00339     "Michael Niedermayer",
00340     "",
00341     vf_open,
00342     NULL
00343 };
00344 
00345 //===========================================================================//