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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 #include <float.h>
40 
41 static const char * const var_names[] = {
42  "in_w" , "iw", ///< width of the input video
43  "in_h" , "ih", ///< height of the input video
44  "out_w", "ow", ///< width of the input video
45  "out_h", "oh", ///< height of the input video
46  "hsub", "vsub",
47  "n", ///< number of frame
48  "t", ///< timestamp expressed in seconds
49  NULL
50 };
51 
52 enum var_name {
61 };
62 
63 typedef struct {
64  const AVClass *class;
65  double angle;
66  char *angle_expr_str; ///< expression for the angle
67  AVExpr *angle_expr; ///< parsed expression for the angle
68  char *outw_expr_str, *outh_expr_str;
69  int outh, outw;
70  uint8_t fillcolor[4]; ///< color expressed either in YUVA or RGBA colorspace for the padding area
73  int hsub, vsub;
74  int nb_planes;
76  float sinx, cosx;
77  double var_values[VAR_VARS_NB];
80 } RotContext;
81 
82 typedef struct ThreadData {
83  AVFrame *in, *out;
84  int inw, inh;
85  int outw, outh;
86  int plane;
87  int xi, yi;
88  int xprime, yprime;
89  int c, s;
90 } ThreadData;
91 
92 #define OFFSET(x) offsetof(RotContext, x)
93 #define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
94 
95 static const AVOption rotate_options[] = {
96  { "angle", "set angle (in radians)", OFFSET(angle_expr_str), AV_OPT_TYPE_STRING, {.str="0"}, CHAR_MIN, CHAR_MAX, .flags=FLAGS },
97  { "a", "set angle (in radians)", OFFSET(angle_expr_str), AV_OPT_TYPE_STRING, {.str="0"}, CHAR_MIN, CHAR_MAX, .flags=FLAGS },
98  { "out_w", "set output width expression", OFFSET(outw_expr_str), AV_OPT_TYPE_STRING, {.str="iw"}, CHAR_MIN, CHAR_MAX, .flags=FLAGS },
99  { "ow", "set output width expression", OFFSET(outw_expr_str), AV_OPT_TYPE_STRING, {.str="iw"}, CHAR_MIN, CHAR_MAX, .flags=FLAGS },
100  { "out_h", "set output height expression", OFFSET(outh_expr_str), AV_OPT_TYPE_STRING, {.str="ih"}, CHAR_MIN, CHAR_MAX, .flags=FLAGS },
101  { "oh", "set output height expression", OFFSET(outh_expr_str), AV_OPT_TYPE_STRING, {.str="ih"}, CHAR_MIN, CHAR_MAX, .flags=FLAGS },
102  { "fillcolor", "set background fill color", OFFSET(fillcolor_str), AV_OPT_TYPE_STRING, {.str="black"}, CHAR_MIN, CHAR_MAX, .flags=FLAGS },
103  { "c", "set background fill color", OFFSET(fillcolor_str), AV_OPT_TYPE_STRING, {.str="black"}, CHAR_MIN, CHAR_MAX, .flags=FLAGS },
104  { "bilinear", "use bilinear interpolation", OFFSET(use_bilinear), AV_OPT_TYPE_INT, {.i64=1}, 0, 1, .flags=FLAGS },
105  { NULL }
106 };
107 
108 AVFILTER_DEFINE_CLASS(rotate);
109 
110 static av_cold int init(AVFilterContext *ctx)
111 {
112  RotContext *rot = ctx->priv;
113 
114  if (!strcmp(rot->fillcolor_str, "none"))
115  rot->fillcolor_enable = 0;
116  else if (av_parse_color(rot->fillcolor, rot->fillcolor_str, -1, ctx) >= 0)
117  rot->fillcolor_enable = 1;
118  else
119  return AVERROR(EINVAL);
120  return 0;
121 }
122 
123 static av_cold void uninit(AVFilterContext *ctx)
124 {
125  RotContext *rot = ctx->priv;
126 
127  av_expr_free(rot->angle_expr);
128  rot->angle_expr = NULL;
129 }
130 
132 {
133  static const enum PixelFormat pix_fmts[] = {
146  };
147 
149  return 0;
150 }
151 
152 static double get_rotated_w(void *opaque, double angle)
153 {
154  RotContext *rot = opaque;
155  double inw = rot->var_values[VAR_IN_W];
156  double inh = rot->var_values[VAR_IN_H];
157  float sinx = sin(angle);
158  float cosx = cos(angle);
159 
160  return FFMAX(0, inh * sinx) + FFMAX(0, -inw * cosx) +
161  FFMAX(0, inw * cosx) + FFMAX(0, -inh * sinx);
162 }
163 
164 static double get_rotated_h(void *opaque, double angle)
165 {
166  RotContext *rot = opaque;
167  double inw = rot->var_values[VAR_IN_W];
168  double inh = rot->var_values[VAR_IN_H];
169  float sinx = sin(angle);
170  float cosx = cos(angle);
171 
172  return FFMAX(0, -inh * cosx) + FFMAX(0, -inw * sinx) +
173  FFMAX(0, inh * cosx) + FFMAX(0, inw * sinx);
174 }
175 
176 static double (* const func1[])(void *, double) = {
179  NULL
180 };
181 
182 static const char * const func1_names[] = {
183  "rotw",
184  "roth",
185  NULL
186 };
187 
188 static int config_props(AVFilterLink *outlink)
189 {
190  AVFilterContext *ctx = outlink->src;
191  RotContext *rot = ctx->priv;
192  AVFilterLink *inlink = ctx->inputs[0];
193  const AVPixFmtDescriptor *pixdesc = av_pix_fmt_desc_get(inlink->format);
194  int ret;
195  double res;
196  char *expr;
197 
198  ff_draw_init(&rot->draw, inlink->format, 0);
199  ff_draw_color(&rot->draw, &rot->color, rot->fillcolor);
200 
201  rot->hsub = pixdesc->log2_chroma_w;
202  rot->vsub = pixdesc->log2_chroma_h;
203 
204  rot->var_values[VAR_IN_W] = rot->var_values[VAR_IW] = inlink->w;
205  rot->var_values[VAR_IN_H] = rot->var_values[VAR_IH] = inlink->h;
206  rot->var_values[VAR_HSUB] = 1<<rot->hsub;
207  rot->var_values[VAR_VSUB] = 1<<rot->vsub;
208  rot->var_values[VAR_N] = NAN;
209  rot->var_values[VAR_T] = NAN;
210  rot->var_values[VAR_OUT_W] = rot->var_values[VAR_OW] = NAN;
211  rot->var_values[VAR_OUT_H] = rot->var_values[VAR_OH] = NAN;
212 
213  av_expr_free(rot->angle_expr);
214  rot->angle_expr = NULL;
215  if ((ret = av_expr_parse(&rot->angle_expr, expr = rot->angle_expr_str, var_names,
216  func1_names, func1, NULL, NULL, 0, ctx)) < 0) {
217  av_log(ctx, AV_LOG_ERROR,
218  "Error occurred parsing angle expression '%s'\n", rot->angle_expr_str);
219  return ret;
220  }
221 
222 #define SET_SIZE_EXPR(name, opt_name) do { \
223  ret = av_expr_parse_and_eval(&res, expr = rot->name##_expr_str, \
224  var_names, rot->var_values, \
225  func1_names, func1, NULL, NULL, rot, 0, ctx); \
226  if (ret < 0 || isnan(res) || isinf(res) || res <= 0) { \
227  av_log(ctx, AV_LOG_ERROR, \
228  "Error parsing or evaluating expression for option %s: " \
229  "invalid expression '%s' or non-positive or indefinite value %f\n", \
230  opt_name, expr, res); \
231  return ret; \
232  } \
233 } while (0)
234 
235  /* evaluate width and height */
236  av_expr_parse_and_eval(&res, expr = rot->outw_expr_str, var_names, rot->var_values,
237  func1_names, func1, NULL, NULL, rot, 0, ctx);
238  rot->var_values[VAR_OUT_W] = rot->var_values[VAR_OW] = res;
239  rot->outw = res + 0.5;
240  SET_SIZE_EXPR(outh, "out_w");
241  rot->var_values[VAR_OUT_H] = rot->var_values[VAR_OH] = res;
242  rot->outh = res + 0.5;
243 
244  /* evaluate the width again, as it may depend on the evaluated output height */
245  SET_SIZE_EXPR(outw, "out_h");
246  rot->var_values[VAR_OUT_W] = rot->var_values[VAR_OW] = res;
247  rot->outw = res + 0.5;
248 
249  /* compute number of planes */
250  rot->nb_planes = av_pix_fmt_count_planes(inlink->format);
251  outlink->w = rot->outw;
252  outlink->h = rot->outh;
253  return 0;
254 }
255 
256 #define FIXP (1<<16)
257 #define FIXP2 (1<<20)
258 #define INT_PI 3294199 //(M_PI * FIXP2)
259 
260 /**
261  * Compute the sin of a using integer values.
262  * Input is scaled by FIXP2 and output values are scaled by FIXP.
263  */
264 static int64_t int_sin(int64_t a)
265 {
266  int64_t a2, res = 0;
267  int i;
268  if (a < 0) a = INT_PI-a; // 0..inf
269  a %= 2 * INT_PI; // 0..2PI
270 
271  if (a >= INT_PI*3/2) a -= 2*INT_PI; // -PI/2 .. 3PI/2
272  if (a >= INT_PI/2 ) a = INT_PI - a; // -PI/2 .. PI/2
273 
274  /* compute sin using Taylor series approximated to the fifth term */
275  a2 = (a*a)/(FIXP2);
276  for (i = 2; i < 11; i += 2) {
277  res += a;
278  a = -a*a2 / (FIXP2*i*(i+1));
279  }
280  return (res + 8)>>4;
281 }
282 
283 /**
284  * Interpolate the color in src at position x and y using bilinear
285  * interpolation.
286  */
288  const uint8_t *src, int src_linesize, int src_linestep,
289  int x, int y, int max_x, int max_y)
290 {
291  int int_x = av_clip(x>>16, 0, max_x);
292  int int_y = av_clip(y>>16, 0, max_y);
293  int frac_x = x&0xFFFF;
294  int frac_y = y&0xFFFF;
295  int i;
296  int int_x1 = FFMIN(int_x+1, max_x);
297  int int_y1 = FFMIN(int_y+1, max_y);
298 
299  for (i = 0; i < src_linestep; i++) {
300  int s00 = src[src_linestep * int_x + i + src_linesize * int_y ];
301  int s01 = src[src_linestep * int_x1 + i + src_linesize * int_y ];
302  int s10 = src[src_linestep * int_x + i + src_linesize * int_y1];
303  int s11 = src[src_linestep * int_x1 + i + src_linesize * int_y1];
304  int s0 = (((1<<16) - frac_x)*s00 + frac_x*s01);
305  int s1 = (((1<<16) - frac_x)*s10 + frac_x*s11);
306 
307  dst_color[i] = ((int64_t)((1<<16) - frac_y)*s0 + (int64_t)frac_y*s1) >> 32;
308  }
309 
310  return dst_color;
311 }
312 
313 static av_always_inline void copy_elem(uint8_t *pout, const uint8_t *pin, int elem_size)
314 {
315  int v;
316  switch (elem_size) {
317  case 1:
318  *pout = *pin;
319  break;
320  case 2:
321  *((uint16_t *)pout) = *((uint16_t *)pin);
322  break;
323  case 3:
324  v = AV_RB24(pin);
325  AV_WB24(pout, v);
326  break;
327  case 4:
328  *((uint32_t *)pout) = *((uint32_t *)pin);
329  break;
330  default:
331  memcpy(pout, pin, elem_size);
332  break;
333  }
334 }
335 
336 static av_always_inline void simple_rotate_internal(uint8_t *dst, const uint8_t *src, int src_linesize, int angle, int elem_size, int len)
337 {
338  int i;
339  switch(angle) {
340  case 0:
341  memcpy(dst, src, elem_size * len);
342  break;
343  case 1:
344  for (i = 0; i<len; i++)
345  copy_elem(dst + i*elem_size, src + (len-i-1)*src_linesize, elem_size);
346  break;
347  case 2:
348  for (i = 0; i<len; i++)
349  copy_elem(dst + i*elem_size, src + (len-i-1)*elem_size, elem_size);
350  break;
351  case 3:
352  for (i = 0; i<len; i++)
353  copy_elem(dst + i*elem_size, src + i*src_linesize, elem_size);
354  break;
355  }
356 }
357 
358 static av_always_inline void simple_rotate(uint8_t *dst, const uint8_t *src, int src_linesize, int angle, int elem_size, int len)
359 {
360  switch(elem_size) {
361  case 1 : simple_rotate_internal(dst, src, src_linesize, angle, 1, len); break;
362  case 2 : simple_rotate_internal(dst, src, src_linesize, angle, 2, len); break;
363  case 3 : simple_rotate_internal(dst, src, src_linesize, angle, 3, len); break;
364  case 4 : simple_rotate_internal(dst, src, src_linesize, angle, 4, len); break;
365  default: simple_rotate_internal(dst, src, src_linesize, angle, elem_size, len); break;
366  }
367 }
368 
369 #define TS2T(ts, tb) ((ts) == AV_NOPTS_VALUE ? NAN : (double)(ts)*av_q2d(tb))
370 
371 static int filter_slice(AVFilterContext *ctx, void *arg, int job, int nb_jobs)
372 {
373  ThreadData *td = arg;
374  AVFrame *in = td->in;
375  AVFrame *out = td->out;
376  RotContext *rot = ctx->priv;
377  const int outw = td->outw, outh = td->outh;
378  const int inw = td->inw, inh = td->inh;
379  const int plane = td->plane;
380  const int xi = td->xi, yi = td->yi;
381  const int c = td->c, s = td->s;
382  const int start = (outh * job ) / nb_jobs;
383  const int end = (outh * (job+1)) / nb_jobs;
384  int xprime = td->xprime + start * s;
385  int yprime = td->yprime + start * c;
386  int i, j, x, y;
387 
388  for (j = start; j < end; j++) {
389  x = xprime + xi + FIXP*(inw-1)/2;
390  y = yprime + yi + FIXP*(inh-1)/2;
391 
392  if (fabs(rot->angle - 0) < FLT_EPSILON && outw == inw && outh == inh) {
393  simple_rotate(out->data[plane] + j * out->linesize[plane],
394  in->data[plane] + j * in->linesize[plane],
395  in->linesize[plane], 0, rot->draw.pixelstep[plane], outw);
396  } else if (fabs(rot->angle - M_PI/2) < FLT_EPSILON && outw == inh && outh == inw) {
397  simple_rotate(out->data[plane] + j * out->linesize[plane],
398  in->data[plane] + j * rot->draw.pixelstep[plane],
399  in->linesize[plane], 1, rot->draw.pixelstep[plane], outw);
400  } else if (fabs(rot->angle - M_PI) < FLT_EPSILON && outw == inw && outh == inh) {
401  simple_rotate(out->data[plane] + j * out->linesize[plane],
402  in->data[plane] + (outh-j-1) * in->linesize[plane],
403  in->linesize[plane], 2, rot->draw.pixelstep[plane], outw);
404  } else if (fabs(rot->angle - 3*M_PI/2) < FLT_EPSILON && outw == inh && outh == inw) {
405  simple_rotate(out->data[plane] + j * out->linesize[plane],
406  in->data[plane] + (outh-j-1) * rot->draw.pixelstep[plane],
407  in->linesize[plane], 3, rot->draw.pixelstep[plane], outw);
408  } else {
409 
410  for (i = 0; i < outw; i++) {
411  int32_t v;
412  int x1, y1;
413  uint8_t *pin, *pout;
414  x1 = x>>16;
415  y1 = y>>16;
416 
417  /* the out-of-range values avoid border artifacts */
418  if (x1 >= -1 && x1 <= inw && y1 >= -1 && y1 <= inh) {
419  uint8_t inp_inv[4]; /* interpolated input value */
420  pout = out->data[plane] + j * out->linesize[plane] + i * rot->draw.pixelstep[plane];
421  if (rot->use_bilinear) {
422  pin = interpolate_bilinear(inp_inv,
423  in->data[plane], in->linesize[plane], rot->draw.pixelstep[plane],
424  x, y, inw-1, inh-1);
425  } else {
426  int x2 = av_clip(x1, 0, inw-1);
427  int y2 = av_clip(y1, 0, inh-1);
428  pin = in->data[plane] + y2 * in->linesize[plane] + x2 * rot->draw.pixelstep[plane];
429  }
430  switch (rot->draw.pixelstep[plane]) {
431  case 1:
432  *pout = *pin;
433  break;
434  case 2:
435  *((uint16_t *)pout) = *((uint16_t *)pin);
436  break;
437  case 3:
438  v = AV_RB24(pin);
439  AV_WB24(pout, v);
440  break;
441  case 4:
442  *((uint32_t *)pout) = *((uint32_t *)pin);
443  break;
444  default:
445  memcpy(pout, pin, rot->draw.pixelstep[plane]);
446  break;
447  }
448  }
449  x += c;
450  y -= s;
451  }
452  }
453  xprime += s;
454  yprime += c;
455  }
456 
457  return 0;
458 }
459 
460 static int filter_frame(AVFilterLink *inlink, AVFrame *in)
461 {
462  AVFilterContext *ctx = inlink->dst;
463  AVFilterLink *outlink = ctx->outputs[0];
464  AVFrame *out;
465  RotContext *rot = ctx->priv;
466  int angle_int, s, c, plane;
467  double res;
468 
469  out = ff_get_video_buffer(outlink, outlink->w, outlink->h);
470  if (!out) {
471  av_frame_free(&in);
472  return AVERROR(ENOMEM);
473  }
474  av_frame_copy_props(out, in);
475 
476  rot->var_values[VAR_N] = inlink->frame_count;
477  rot->var_values[VAR_T] = TS2T(in->pts, inlink->time_base);
478  rot->angle = res = av_expr_eval(rot->angle_expr, rot->var_values, rot);
479 
480  av_log(ctx, AV_LOG_DEBUG, "n:%f time:%f angle:%f/PI\n",
481  rot->var_values[VAR_N], rot->var_values[VAR_T], rot->angle/M_PI);
482 
483  angle_int = res * FIXP * 16;
484  s = int_sin(angle_int);
485  c = int_sin(angle_int + INT_PI/2);
486 
487  /* fill background */
488  if (rot->fillcolor_enable)
489  ff_fill_rectangle(&rot->draw, &rot->color, out->data, out->linesize,
490  0, 0, outlink->w, outlink->h);
491 
492  for (plane = 0; plane < rot->nb_planes; plane++) {
493  int hsub = plane == 1 || plane == 2 ? rot->hsub : 0;
494  int vsub = plane == 1 || plane == 2 ? rot->vsub : 0;
495  const int outw = FF_CEIL_RSHIFT(outlink->w, hsub);
496  const int outh = FF_CEIL_RSHIFT(outlink->h, vsub);
497  ThreadData td = { .in = in, .out = out,
498  .inw = FF_CEIL_RSHIFT(inlink->w, hsub),
499  .inh = FF_CEIL_RSHIFT(inlink->h, vsub),
500  .outh = outh, .outw = outw,
501  .xi = -(outw-1) * c / 2, .yi = (outw-1) * s / 2,
502  .xprime = -(outh-1) * s / 2,
503  .yprime = -(outh-1) * c / 2,
504  .plane = plane, .c = c, .s = s };
505 
506 
507  ctx->internal->execute(ctx, filter_slice, &td, NULL, FFMIN(outh, ctx->graph->nb_threads));
508  }
509 
510  av_frame_free(&in);
511  return ff_filter_frame(outlink, out);
512 }
513 
514 static int process_command(AVFilterContext *ctx, const char *cmd, const char *args,
515  char *res, int res_len, int flags)
516 {
517  RotContext *rot = ctx->priv;
518  int ret;
519 
520  if (!strcmp(cmd, "angle") || !strcmp(cmd, "a")) {
521  AVExpr *old = rot->angle_expr;
522  ret = av_expr_parse(&rot->angle_expr, args, var_names,
523  NULL, NULL, NULL, NULL, 0, ctx);
524  if (ret < 0) {
525  av_log(ctx, AV_LOG_ERROR,
526  "Error when parsing the expression '%s' for angle command\n", args);
527  rot->angle_expr = old;
528  return ret;
529  }
530  av_expr_free(old);
531  } else
532  ret = AVERROR(ENOSYS);
533 
534  return ret;
535 }
536 
537 static const AVFilterPad rotate_inputs[] = {
538  {
539  .name = "default",
540  .type = AVMEDIA_TYPE_VIDEO,
541  .filter_frame = filter_frame,
542  },
543  { NULL }
544 };
545 
546 static const AVFilterPad rotate_outputs[] = {
547  {
548  .name = "default",
549  .type = AVMEDIA_TYPE_VIDEO,
550  .config_props = config_props,
551  },
552  { NULL }
553 };
554 
556  .name = "rotate",
557  .description = NULL_IF_CONFIG_SMALL("Rotate the input image."),
558  .priv_size = sizeof(RotContext),
559  .init = init,
560  .uninit = uninit,
563  .inputs = rotate_inputs,
564  .outputs = rotate_outputs,
565  .priv_class = &rotate_class,
567 };