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vf_rotate.c
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1 /*
2  * Copyright (c) 2013 Stefano Sabatini
3  * Copyright (c) 2008 Vitor Sessak
4  *
5  * This file is part of FFmpeg.
6  *
7  * FFmpeg is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU Lesser General Public
9  * License as published by the Free Software Foundation; either
10  * version 2.1 of the License, or (at your option) any later version.
11  *
12  * FFmpeg is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15  * Lesser General Public License for more details.
16  *
17  * You should have received a copy of the GNU Lesser General Public
18  * License along with FFmpeg; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 
22 /**
23  * @file
24  * rotation filter, partially based on the tests/rotozoom.c program
25 */
26 
27 #include "libavutil/avstring.h"
28 #include "libavutil/eval.h"
29 #include "libavutil/opt.h"
30 #include "libavutil/intreadwrite.h"
31 #include "libavutil/parseutils.h"
32 #include "libavutil/pixdesc.h"
33 
34 #include "avfilter.h"
35 #include "drawutils.h"
36 #include "internal.h"
37 #include "video.h"
38 
39 static const char *var_names[] = {
40  "in_w" , "iw", ///< width of the input video
41  "in_h" , "ih", ///< height of the input video
42  "out_w", "ow", ///< width of the input video
43  "out_h", "oh", ///< height of the input video
44  "hsub", "vsub",
45  "n", ///< number of frame
46  "t", ///< timestamp expressed in seconds
47  NULL
48 };
49 
50 enum var_name {
59 };
60 
61 typedef struct {
62  const AVClass *class;
63  double angle;
64  char *angle_expr_str; ///< expression for the angle
65  AVExpr *angle_expr; ///< parsed expression for the angle
66  char *outw_expr_str, *outh_expr_str;
67  int outh, outw;
68  uint8_t fillcolor[4]; ///< color expressed either in YUVA or RGBA colorspace for the padding area
71  int hsub, vsub;
72  int nb_planes;
74  float sinx, cosx;
75  double var_values[VAR_VARS_NB];
78 } RotContext;
79 
80 typedef struct ThreadData {
81  AVFrame *in, *out;
82  int inw, inh;
83  int outw, outh;
84  int plane;
85  int xi, yi;
86  int xprime, yprime;
87  int c, s;
88 } ThreadData;
89 
90 #define OFFSET(x) offsetof(RotContext, x)
91 #define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
92 
93 static const AVOption rotate_options[] = {
94  { "angle", "set angle (in radians)", OFFSET(angle_expr_str), AV_OPT_TYPE_STRING, {.str="0"}, CHAR_MIN, CHAR_MAX, .flags=FLAGS },
95  { "a", "set angle (in radians)", OFFSET(angle_expr_str), AV_OPT_TYPE_STRING, {.str="0"}, CHAR_MIN, CHAR_MAX, .flags=FLAGS },
96  { "out_w", "set output width expression", OFFSET(outw_expr_str), AV_OPT_TYPE_STRING, {.str="iw"}, CHAR_MIN, CHAR_MAX, .flags=FLAGS },
97  { "ow", "set output width expression", OFFSET(outw_expr_str), AV_OPT_TYPE_STRING, {.str="iw"}, CHAR_MIN, CHAR_MAX, .flags=FLAGS },
98  { "out_h", "set output height expression", OFFSET(outh_expr_str), AV_OPT_TYPE_STRING, {.str="ih"}, CHAR_MIN, CHAR_MAX, .flags=FLAGS },
99  { "oh", "set output height expression", OFFSET(outh_expr_str), AV_OPT_TYPE_STRING, {.str="ih"}, CHAR_MIN, CHAR_MAX, .flags=FLAGS },
100  { "fillcolor", "set background fill color", OFFSET(fillcolor_str), AV_OPT_TYPE_STRING, {.str="black"}, CHAR_MIN, CHAR_MAX, .flags=FLAGS },
101  { "c", "set background fill color", OFFSET(fillcolor_str), AV_OPT_TYPE_STRING, {.str="black"}, CHAR_MIN, CHAR_MAX, .flags=FLAGS },
102  { "bilinear", "use bilinear interpolation", OFFSET(use_bilinear), AV_OPT_TYPE_INT, {.i64=1}, 0, 1, .flags=FLAGS },
103  { NULL }
104 };
105 
106 AVFILTER_DEFINE_CLASS(rotate);
107 
108 static av_cold int init(AVFilterContext *ctx)
109 {
110  RotContext *rot = ctx->priv;
111 
112  if (!strcmp(rot->fillcolor_str, "none"))
113  rot->fillcolor_enable = 0;
114  else if (av_parse_color(rot->fillcolor, rot->fillcolor_str, -1, ctx) >= 0)
115  rot->fillcolor_enable = 1;
116  else
117  return AVERROR(EINVAL);
118  return 0;
119 }
120 
121 static av_cold void uninit(AVFilterContext *ctx)
122 {
123  RotContext *rot = ctx->priv;
124 
125  av_expr_free(rot->angle_expr);
126  rot->angle_expr = NULL;
127 }
128 
130 {
131  static enum PixelFormat pix_fmts[] = {
144  };
145 
147  return 0;
148 }
149 
150 static double get_rotated_w(void *opaque, double angle)
151 {
152  RotContext *rot = opaque;
153  double inw = rot->var_values[VAR_IN_W];
154  double inh = rot->var_values[VAR_IN_H];
155  float sinx = sin(angle);
156  float cosx = cos(angle);
157 
158  return FFMAX(0, inh * sinx) + FFMAX(0, -inw * cosx) +
159  FFMAX(0, inw * cosx) + FFMAX(0, -inh * sinx);
160 }
161 
162 static double get_rotated_h(void *opaque, double angle)
163 {
164  RotContext *rot = opaque;
165  double inw = rot->var_values[VAR_IN_W];
166  double inh = rot->var_values[VAR_IN_H];
167  float sinx = sin(angle);
168  float cosx = cos(angle);
169 
170  return FFMAX(0, -inh * cosx) + FFMAX(0, -inw * sinx) +
171  FFMAX(0, inh * cosx) + FFMAX(0, inw * sinx);
172 }
173 
174 static double (* const func1[])(void *, double) = {
177  NULL
178 };
179 
180 static const char * const func1_names[] = {
181  "rotw",
182  "roth",
183  NULL
184 };
185 
186 static int config_props(AVFilterLink *outlink)
187 {
188  AVFilterContext *ctx = outlink->src;
189  RotContext *rot = ctx->priv;
190  AVFilterLink *inlink = ctx->inputs[0];
191  const AVPixFmtDescriptor *pixdesc = av_pix_fmt_desc_get(inlink->format);
192  int ret;
193  double res;
194  char *expr;
195 
196  ff_draw_init(&rot->draw, inlink->format, 0);
197  ff_draw_color(&rot->draw, &rot->color, rot->fillcolor);
198 
199  rot->hsub = pixdesc->log2_chroma_w;
200  rot->vsub = pixdesc->log2_chroma_h;
201 
202  rot->var_values[VAR_IN_W] = rot->var_values[VAR_IW] = inlink->w;
203  rot->var_values[VAR_IN_H] = rot->var_values[VAR_IH] = inlink->h;
204  rot->var_values[VAR_HSUB] = 1<<rot->hsub;
205  rot->var_values[VAR_VSUB] = 1<<rot->vsub;
206  rot->var_values[VAR_N] = NAN;
207  rot->var_values[VAR_T] = NAN;
208  rot->var_values[VAR_OUT_W] = rot->var_values[VAR_OW] = NAN;
209  rot->var_values[VAR_OUT_H] = rot->var_values[VAR_OH] = NAN;
210 
211  av_expr_free(rot->angle_expr);
212  rot->angle_expr = NULL;
213  if ((ret = av_expr_parse(&rot->angle_expr, expr = rot->angle_expr_str, var_names,
214  func1_names, func1, NULL, NULL, 0, ctx)) < 0) {
215  av_log(ctx, AV_LOG_ERROR,
216  "Error occurred parsing angle expression '%s'\n", rot->angle_expr_str);
217  return ret;
218  }
219 
220 #define SET_SIZE_EXPR(name, opt_name) do { \
221  ret = av_expr_parse_and_eval(&res, expr = rot->name##_expr_str, \
222  var_names, rot->var_values, \
223  func1_names, func1, NULL, NULL, rot, 0, ctx); \
224  if (ret < 0 || isnan(res) || isinf(res) || res <= 0) { \
225  av_log(ctx, AV_LOG_ERROR, \
226  "Error parsing or evaluating expression for option %s: " \
227  "invalid expression '%s' or non-positive or indefinite value %f\n", \
228  opt_name, expr, res); \
229  return ret; \
230  } \
231 } while (0)
232 
233  /* evaluate width and height */
234  av_expr_parse_and_eval(&res, expr = rot->outw_expr_str, var_names, rot->var_values,
235  func1_names, func1, NULL, NULL, rot, 0, ctx);
236  rot->var_values[VAR_OUT_W] = rot->var_values[VAR_OW] = res;
237  rot->outw = res + 0.5;
238  SET_SIZE_EXPR(outh, "out_w");
239  rot->var_values[VAR_OUT_H] = rot->var_values[VAR_OH] = res;
240  rot->outh = res + 0.5;
241 
242  /* evaluate the width again, as it may depend on the evaluated output height */
243  SET_SIZE_EXPR(outw, "out_h");
244  rot->var_values[VAR_OUT_W] = rot->var_values[VAR_OW] = res;
245  rot->outw = res + 0.5;
246 
247  /* compute number of planes */
248  rot->nb_planes = av_pix_fmt_count_planes(inlink->format);
249  outlink->w = rot->outw;
250  outlink->h = rot->outh;
251  return 0;
252 }
253 
254 #define FIXP (1<<16)
255 #define INT_PI 205887 //(M_PI * FIXP)
256 
257 /**
258  * Compute the sin of a using integer values.
259  * Input and output values are scaled by FIXP.
260  */
261 static int64_t int_sin(int64_t a)
262 {
263  int64_t a2, res = 0;
264  int i;
265  if (a < 0) a = INT_PI-a; // 0..inf
266  a %= 2 * INT_PI; // 0..2PI
267 
268  if (a >= INT_PI*3/2) a -= 2*INT_PI; // -PI/2 .. 3PI/2
269  if (a >= INT_PI/2 ) a = INT_PI - a; // -PI/2 .. PI/2
270 
271  /* compute sin using Taylor series approximated to the third term */
272  a2 = (a*a)/FIXP;
273  for (i = 2; i < 7; i += 2) {
274  res += a;
275  a = -a*a2 / (FIXP*i*(i+1));
276  }
277  return res;
278 }
279 
280 /**
281  * Interpolate the color in src at position x and y using bilinear
282  * interpolation.
283  */
285  const uint8_t *src, int src_linesize, int src_linestep,
286  int x, int y, int max_x, int max_y)
287 {
288  int int_x = av_clip(x>>16, 0, max_x);
289  int int_y = av_clip(y>>16, 0, max_y);
290  int frac_x = x&0xFFFF;
291  int frac_y = y&0xFFFF;
292  int i;
293  int int_x1 = FFMIN(int_x+1, max_x);
294  int int_y1 = FFMIN(int_y+1, max_y);
295 
296  for (i = 0; i < src_linestep; i++) {
297  int s00 = src[src_linestep * int_x + i + src_linesize * int_y ];
298  int s01 = src[src_linestep * int_x1 + i + src_linesize * int_y ];
299  int s10 = src[src_linestep * int_x + i + src_linesize * int_y1];
300  int s11 = src[src_linestep * int_x1 + i + src_linesize * int_y1];
301  int s0 = (((1<<16) - frac_x)*s00 + frac_x*s01);
302  int s1 = (((1<<16) - frac_x)*s10 + frac_x*s11);
303 
304  dst_color[i] = ((int64_t)((1<<16) - frac_y)*s0 + (int64_t)frac_y*s1) >> 32;
305  }
306 
307  return dst_color;
308 }
309 
310 #define TS2T(ts, tb) ((ts) == AV_NOPTS_VALUE ? NAN : (double)(ts)*av_q2d(tb))
311 
312 static int filter_slice(AVFilterContext *ctx, void *arg, int job, int nb_jobs)
313 {
314  ThreadData *td = arg;
315  AVFrame *in = td->in;
316  AVFrame *out = td->out;
317  RotContext *rot = ctx->priv;
318  const int outw = td->outw, outh = td->outh;
319  const int inw = td->inw, inh = td->inh;
320  const int plane = td->plane;
321  const int xi = td->xi, yi = td->yi;
322  const int c = td->c, s = td->s;
323  const int start = (outh * job ) / nb_jobs;
324  const int end = (outh * (job+1)) / nb_jobs;
325  int xprime = td->xprime + start * s;
326  int yprime = td->yprime + start * c;
327  int i, j, x, y;
328 
329  for (j = start; j < end; j++) {
330  x = xprime + xi + FIXP*inw/2;
331  y = yprime + yi + FIXP*inh/2;
332 
333  for (i = 0; i < outw; i++) {
334  int32_t v;
335  int x1, y1;
336  uint8_t *pin, *pout;
337  x += c;
338  y -= s;
339  x1 = x>>16;
340  y1 = y>>16;
341 
342  /* the out-of-range values avoid border artifacts */
343  if (x1 >= -1 && x1 <= inw && y1 >= -1 && y1 <= inh) {
344  uint8_t inp_inv[4]; /* interpolated input value */
345  pout = out->data[plane] + j * out->linesize[plane] + i * rot->draw.pixelstep[plane];
346  if (rot->use_bilinear) {
347  pin = interpolate_bilinear(inp_inv,
348  in->data[plane], in->linesize[plane], rot->draw.pixelstep[plane],
349  x, y, inw-1, inh-1);
350  } else {
351  int x2 = av_clip(x1, 0, inw-1);
352  int y2 = av_clip(y1, 0, inh-1);
353  pin = in->data[plane] + y2 * in->linesize[plane] + x2 * rot->draw.pixelstep[plane];
354  }
355  switch (rot->draw.pixelstep[plane]) {
356  case 1:
357  *pout = *pin;
358  break;
359  case 2:
360  *((uint16_t *)pout) = *((uint16_t *)pin);
361  break;
362  case 3:
363  v = AV_RB24(pin);
364  AV_WB24(pout, v);
365  break;
366  case 4:
367  *((uint32_t *)pout) = *((uint32_t *)pin);
368  break;
369  default:
370  memcpy(pout, pin, rot->draw.pixelstep[plane]);
371  break;
372  }
373  }
374  }
375  xprime += s;
376  yprime += c;
377  }
378 
379  return 0;
380 }
381 
382 static int filter_frame(AVFilterLink *inlink, AVFrame *in)
383 {
384  AVFilterContext *ctx = inlink->dst;
385  AVFilterLink *outlink = ctx->outputs[0];
386  AVFrame *out;
387  RotContext *rot = ctx->priv;
388  int angle_int, s, c, plane;
389  double res;
390 
391  out = ff_get_video_buffer(outlink, outlink->w, outlink->h);
392  if (!out) {
393  av_frame_free(&in);
394  return AVERROR(ENOMEM);
395  }
396  av_frame_copy_props(out, in);
397 
398  rot->var_values[VAR_N] = inlink->frame_count;
399  rot->var_values[VAR_T] = TS2T(in->pts, inlink->time_base);
400  rot->angle = res = av_expr_eval(rot->angle_expr, rot->var_values, rot);
401 
402  av_log(ctx, AV_LOG_DEBUG, "n:%f time:%f angle:%f/PI\n",
403  rot->var_values[VAR_N], rot->var_values[VAR_T], rot->angle/M_PI);
404 
405  angle_int = res * FIXP;
406  s = int_sin(angle_int);
407  c = int_sin(angle_int + INT_PI/2);
408 
409  /* fill background */
410  if (rot->fillcolor_enable)
411  ff_fill_rectangle(&rot->draw, &rot->color, out->data, out->linesize,
412  0, 0, outlink->w, outlink->h);
413 
414  for (plane = 0; plane < rot->nb_planes; plane++) {
415  int hsub = plane == 1 || plane == 2 ? rot->hsub : 0;
416  int vsub = plane == 1 || plane == 2 ? rot->vsub : 0;
417  const int outw = FF_CEIL_RSHIFT(outlink->w, hsub);
418  const int outh = FF_CEIL_RSHIFT(outlink->h, vsub);
419  ThreadData td = { .in = in, .out = out,
420  .inw = FF_CEIL_RSHIFT(inlink->w, hsub),
421  .inh = FF_CEIL_RSHIFT(inlink->h, vsub),
422  .outh = outh, .outw = outw,
423  .xi = -outw/2 * c, .yi = outw/2 * s,
424  .xprime = -outh/2 * s,
425  .yprime = -outh/2 * c,
426  .plane = plane, .c = c, .s = s };
427 
428 
429  ctx->internal->execute(ctx, filter_slice, &td, NULL, FFMIN(outh, ctx->graph->nb_threads));
430  }
431 
432  av_frame_free(&in);
433  return ff_filter_frame(outlink, out);
434 }
435 
436 static int process_command(AVFilterContext *ctx, const char *cmd, const char *args,
437  char *res, int res_len, int flags)
438 {
439  RotContext *rot = ctx->priv;
440  int ret;
441 
442  if (!strcmp(cmd, "angle") || !strcmp(cmd, "a")) {
443  AVExpr *old = rot->angle_expr;
444  ret = av_expr_parse(&rot->angle_expr, args, var_names,
445  NULL, NULL, NULL, NULL, 0, ctx);
446  if (ret < 0) {
447  av_log(ctx, AV_LOG_ERROR,
448  "Error when parsing the expression '%s' for angle command\n", args);
449  rot->angle_expr = old;
450  return ret;
451  }
452  av_expr_free(old);
453  } else
454  ret = AVERROR(ENOSYS);
455 
456  return ret;
457 }
458 
459 static const AVFilterPad rotate_inputs[] = {
460  {
461  .name = "default",
462  .type = AVMEDIA_TYPE_VIDEO,
463  .filter_frame = filter_frame,
464  },
465  { NULL }
466 };
467 
468 static const AVFilterPad rotate_outputs[] = {
469  {
470  .name = "default",
471  .type = AVMEDIA_TYPE_VIDEO,
472  .config_props = config_props,
473  },
474  { NULL }
475 };
476 
478  .name = "rotate",
479  .description = NULL_IF_CONFIG_SMALL("Rotate the input image."),
480  .priv_size = sizeof(RotContext),
481  .init = init,
482  .uninit = uninit,
485  .inputs = rotate_inputs,
486  .outputs = rotate_outputs,
487  .priv_class = &rotate_class,
489 };