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vf_perspective.c
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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 //===========================================================================//
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