FFmpeg: libavfilter/vf_rotate.c Source File

FFmpeg
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 {
51   VAR_IN_W , VAR_IW,
52   VAR_IN_H , VAR_IH,
53   VAR_OUT_W, VAR_OW,
54   VAR_OUT_H, VAR_OH,
55   VAR_HSUB, VAR_VSUB,
56   VAR_N,
57   VAR_T,
58   VAR_VARS_NB
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
69   char *fillcolor_str;
70   int fillcolor_enable;
71   int hsub, vsub;
72   int nb_planes;
73   int use_bilinear;
74   float sinx, cosx;
75   double var_values[VAR_VARS_NB];
76   FFDrawContext draw;
77   FFDrawColor color;
78 } RotContext;
79 
80  #define OFFSET(x) offsetof(RotContext, x)
81  #define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
82 
83  static const AVOption rotate_options[] = {
84  { "angle", "set angle (in radians)", OFFSET(angle_expr_str), AV_OPT_TYPE_STRING, {.str="0"}, CHAR_MIN, CHAR_MAX, .flags=FLAGS },
85  { "a", "set angle (in radians)", OFFSET(angle_expr_str), AV_OPT_TYPE_STRING, {.str="0"}, CHAR_MIN, CHAR_MAX, .flags=FLAGS },
86  { "out_w", "set output width expression", OFFSET(outw_expr_str), AV_OPT_TYPE_STRING, {.str="iw"}, CHAR_MIN, CHAR_MAX, .flags=FLAGS },
87  { "ow", "set output width expression", OFFSET(outw_expr_str), AV_OPT_TYPE_STRING, {.str="iw"}, CHAR_MIN, CHAR_MAX, .flags=FLAGS },
88  { "out_h", "set output height expression", OFFSET(outh_expr_str), AV_OPT_TYPE_STRING, {.str="ih"}, CHAR_MIN, CHAR_MAX, .flags=FLAGS },
89  { "oh", "set output width expression", OFFSET(outh_expr_str), AV_OPT_TYPE_STRING, {.str="ih"}, CHAR_MIN, CHAR_MAX, .flags=FLAGS },
90  { "fillcolor", "set background fill color", OFFSET(fillcolor_str), AV_OPT_TYPE_STRING, {.str="black"}, CHAR_MIN, CHAR_MAX, .flags=FLAGS },
91  { "c", "set background fill color", OFFSET(fillcolor_str), AV_OPT_TYPE_STRING, {.str="black"}, CHAR_MIN, CHAR_MAX, .flags=FLAGS },
92  { "bilinear", "use bilinear interpolation", OFFSET(use_bilinear), AV_OPT_TYPE_INT, {.i64=1}, 0, 1, .flags=FLAGS },
93  { NULL }
94 };
95 
96 AVFILTER_DEFINE_CLASS(rotate);
97 
98  static av_cold int init(AVFilterContext *ctx)
99 {
100  RotContext *rot = ctx->priv;
101 
102  if (!strcmp(rot->fillcolor_str, "none"))
103  rot->fillcolor_enable = 0;
104  else if (av_parse_color(rot->fillcolor, rot->fillcolor_str, -1, ctx) >= 0)
105  rot->fillcolor_enable = 1;
106  else
107  return AVERROR(EINVAL);
108  return 0;
109 }
110 
111  static av_cold void uninit(AVFilterContext *ctx)
112 {
113  RotContext *rot = ctx->priv;
114 
115  av_expr_free(rot->angle_expr);
116  rot->angle_expr = NULL;
117 }
118 
119  static int query_formats(AVFilterContext *ctx)
120 {
121  static enum PixelFormat pix_fmts[] = {
122  AV_PIX_FMT_GBRP, AV_PIX_FMT_GBRAP,
123  AV_PIX_FMT_ARGB, AV_PIX_FMT_RGBA,
124  AV_PIX_FMT_ABGR, AV_PIX_FMT_BGRA,
125  AV_PIX_FMT_0RGB, AV_PIX_FMT_RGB0,
126  AV_PIX_FMT_0BGR, AV_PIX_FMT_BGR0,
127  AV_PIX_FMT_RGB24, AV_PIX_FMT_BGR24,
128  AV_PIX_FMT_GRAY8,
129  AV_PIX_FMT_YUV410P,
130  AV_PIX_FMT_YUV444P, AV_PIX_FMT_YUVJ444P,
131  AV_PIX_FMT_YUV420P, AV_PIX_FMT_YUVJ420P,
132  AV_PIX_FMT_YUVA444P, AV_PIX_FMT_YUVA420P,
133  AV_PIX_FMT_NONE
134  };
135 
136  ff_set_common_formats(ctx, ff_make_format_list(pix_fmts));
137  return 0;
138 }
139 
140  static double get_rotated_w(void *opaque, double angle)
141 {
142  RotContext *rot = opaque;
143  double inw = rot->var_values[VAR_IN_W];
144  double inh = rot->var_values[VAR_IN_H];
145  float sinx = sin(angle);
146  float cosx = cos(angle);
147 
148  return FFMAX(0, inh * sinx) + FFMAX(0, -inw * cosx) +
149  FFMAX(0, inw * cosx) + FFMAX(0, -inh * sinx);
150 }
151 
152  static double get_rotated_h(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 * cosx) + FFMAX(0, -inw * sinx) +
161  FFMAX(0, inh * cosx) + FFMAX(0, inw * sinx);
162 }
163 
164  static double (* const func1[])(void *, double) = {
165  get_rotated_w,
166  get_rotated_h,
167  NULL
168 };
169 
170  static const char * const func1_names[] = {
171  "rotw",
172  "roth",
173  NULL
174 };
175 
176  static int config_props(AVFilterLink *outlink)
177 {
178  AVFilterContext *ctx = outlink->src;
179  RotContext *rot = ctx->priv;
180  AVFilterLink *inlink = ctx->inputs[0];
181  const AVPixFmtDescriptor *pixdesc = av_pix_fmt_desc_get(inlink->format);
182  int ret;
183  double res;
184  char *expr;
185 
186  ff_draw_init(&rot->draw, inlink->format, 0);
187  ff_draw_color(&rot->draw, &rot->color, rot->fillcolor);
188 
189  rot->hsub = pixdesc->log2_chroma_w;
190  rot->vsub = pixdesc->log2_chroma_h;
191 
192  rot->var_values[VAR_IN_W] = rot->var_values[VAR_IW] = inlink->w;
193  rot->var_values[VAR_IN_H] = rot->var_values[VAR_IH] = inlink->h;
194  rot->var_values[VAR_HSUB] = 1<<rot->hsub;
195  rot->var_values[VAR_VSUB] = 1<<rot->vsub;
196  rot->var_values[VAR_N] = NAN;
197  rot->var_values[VAR_T] = NAN;
198  rot->var_values[VAR_OUT_W] = rot->var_values[VAR_OW] = NAN;
199  rot->var_values[VAR_OUT_H] = rot->var_values[VAR_OH] = NAN;
200 
201  av_expr_free(rot->angle_expr);
202  rot->angle_expr = NULL;
203  if ((ret = av_expr_parse(&rot->angle_expr, expr = rot->angle_expr_str, var_names,
204  func1_names, func1, NULL, NULL, 0, ctx)) < 0) {
205  av_log(ctx, AV_LOG_ERROR,
206  "Error occurred parsing angle expression '%s'\n", rot->angle_expr_str);
207  return ret;
208  }
209 
210 #define SET_SIZE_EXPR(name, opt_name) do { \
211  ret = av_expr_parse_and_eval(&res, expr = rot->name##_expr_str, \
212  var_names, rot->var_values, \
213  func1_names, func1, NULL, NULL, rot, 0, ctx); \
214  if (ret < 0 || isnan(res) || isinf(res) || res <= 0) { \
215  av_log(ctx, AV_LOG_ERROR, \
216  "Error parsing or evaluating expression for option %s: " \
217  "invalid expression '%s' or non-positive or indefinite value %f\n", \
218  opt_name, expr, res); \
219  return ret; \
220  } \
221 } while (0)
222 
223  /* evaluate width and height */
224  av_expr_parse_and_eval(&res, expr = rot->outw_expr_str, var_names, rot->var_values,
225  func1_names, func1, NULL, NULL, rot, 0, ctx);
226  rot->var_values[VAR_OUT_W] = rot->var_values[VAR_OW] = res;
227  rot->outw = res + 0.5;
228  SET_SIZE_EXPR(outh, "out_w");
229  rot->var_values[VAR_OUT_H] = rot->var_values[VAR_OH] = res;
230  rot->outh = res + 0.5;
231 
232  /* evaluate the width again, as it may depend on the evaluated output height */
233  SET_SIZE_EXPR(outw, "out_h");
234  rot->var_values[VAR_OUT_W] = rot->var_values[VAR_OW] = res;
235  rot->outw = res + 0.5;
236 
237  /* compute number of planes */
238  rot->nb_planes = av_pix_fmt_count_planes(inlink->format);
239  outlink->w = rot->outw;
240  outlink->h = rot->outh;
241  return 0;
242 }
243 
244  #define FIXP (1<<16)
245  #define INT_PI 205887 //(M_PI * FIXP)
246 
247 /**
248  * Compute the sin of a using integer values.
249  * Input and output values are scaled by FIXP.
250  */
251  static int64_t int_sin(int64_t a)
252 {
253  int64_t a2, res = 0;
254  int i;
255  if (a < 0) a = INT_PI-a; // 0..inf
256  a %= 2 * INT_PI; // 0..2PI
257 
258  if (a >= INT_PI*3/2) a -= 2*INT_PI; // -PI/2 .. 3PI/2
259  if (a >= INT_PI/2 ) a = INT_PI - a; // -PI/2 .. PI/2
260 
261  /* compute sin using Taylor series approximated to the third term */
262  a2 = (a*a)/FIXP;
263  for (i = 2; i < 7; i += 2) {
264  res += a;
265  a = -a*a2 / (FIXP*i*(i+1));
266  }
267  return res;
268 }
269 
270 /**
271  * Interpolate the color in src at position x and y using bilinear
272  * interpolation.
273  */
274  static uint8_t *interpolate_bilinear(uint8_t *dst_color,
275  const uint8_t *src, int src_linesize, int src_linestep,
276  int x, int y, int max_x, int max_y)
277 {
278  int int_x = av_clip(x>>16, 0, max_x);
279  int int_y = av_clip(y>>16, 0, max_y);
280  int frac_x = x&0xFFFF;
281  int frac_y = y&0xFFFF;
282  int i;
283  int int_x1 = FFMIN(int_x+1, max_x);
284  int int_y1 = FFMIN(int_y+1, max_y);
285 
286  for (i = 0; i < src_linestep; i++) {
287  int s00 = src[src_linestep * int_x + i + src_linesize * int_y ];
288  int s01 = src[src_linestep * int_x1 + i + src_linesize * int_y ];
289  int s10 = src[src_linestep * int_x + i + src_linesize * int_y1];
290  int s11 = src[src_linestep * int_x1 + i + src_linesize * int_y1];
291  int s0 = (((1<<16) - frac_x)*s00 + frac_x*s01);
292  int s1 = (((1<<16) - frac_x)*s10 + frac_x*s11);
293 
294  dst_color[i] = ((int64_t)((1<<16) - frac_y)*s0 + (int64_t)frac_y*s1) >> 32;
295  }
296 
297  return dst_color;
298 }
299 
300  #define TS2T(ts, tb) ((ts) == AV_NOPTS_VALUE ? NAN : (double)(ts)*av_q2d(tb))
301 
302  static int filter_frame(AVFilterLink *inlink, AVFrame *in)
303 {
304  AVFilterContext *ctx = inlink->dst;
305  AVFilterLink *outlink = ctx->outputs[0];
306  AVFrame *out;
307  RotContext *rot = ctx->priv;
308  int angle_int, s, c, plane;
309  double res;
310 
311  out = ff_get_video_buffer(outlink, outlink->w, outlink->h);
312  if (!out) {
313  av_frame_free(&in);
314  return AVERROR(ENOMEM);
315  }
316  av_frame_copy_props(out, in);
317 
318  rot->var_values[VAR_N] = inlink->frame_count;
319  rot->var_values[VAR_T] = TS2T(in->pts, inlink->time_base);
320  rot->angle = res = av_expr_eval(rot->angle_expr, rot->var_values, rot);
321 
322  av_log(ctx, AV_LOG_DEBUG, "n:%f time:%f angle:%f/PI\n",
323  rot->var_values[VAR_N], rot->var_values[VAR_T], rot->angle/M_PI);
324 
325  angle_int = res * FIXP;
326  s = int_sin(angle_int);
327  c = int_sin(angle_int + INT_PI/2);
328 
329  /* fill background */
330  if (rot->fillcolor_enable)
331  ff_fill_rectangle(&rot->draw, &rot->color, out->data, out->linesize,
332  0, 0, outlink->w, outlink->h);
333 
334  for (plane = 0; plane < rot->nb_planes; plane++) {
335  int hsub = plane == 1 || plane == 2 ? rot->hsub : 0;
336  int vsub = plane == 1 || plane == 2 ? rot->vsub : 0;
337  int inw = FF_CEIL_RSHIFT(inlink->w, hsub);
338  int inh = FF_CEIL_RSHIFT(inlink->h, vsub);
339  int outw = FF_CEIL_RSHIFT(outlink->w, hsub);
340  int outh = FF_CEIL_RSHIFT(outlink->h, hsub);
341 
342  const int xi = -outw/2 * c;
343  const int yi = outw/2 * s;
344  int xprime = -outh/2 * s;
345  int yprime = -outh/2 * c;
346  int i, j, x, y;
347 
348  for (j = 0; j < outh; j++) {
349  x = xprime + xi + FIXP*inw/2;
350  y = yprime + yi + FIXP*inh/2;
351 
352  for (i = 0; i < outw; i++) {
353  int32_t v;
354  int x1, y1;
355  uint8_t *pin, *pout;
356  x += c;
357  y -= s;
358  x1 = x>>16;
359  y1 = y>>16;
360 
361  /* the out-of-range values avoid border artifacts */
362  if (x1 >= -1 && x1 <= inw && y1 >= -1 && y1 <= inh) {
363  uint8_t inp_inv[4]; /* interpolated input value */
364  pout = out->data[plane] + j * out->linesize[plane] + i * rot->draw.pixelstep[plane];
365  if (rot->use_bilinear) {
366  pin = interpolate_bilinear(inp_inv,
367  in->data[plane], in->linesize[plane], rot->draw.pixelstep[plane],
368  x, y, inw-1, inh-1);
369  } else {
370  int x2 = av_clip(x1, 0, inw-1);
371  int y2 = av_clip(y1, 0, inh-1);
372  pin = in->data[plane] + y2 * in->linesize[plane] + x2 * rot->draw.pixelstep[plane];
373  }
374  switch (rot->draw.pixelstep[plane]) {
375  case 1:
376  *pout = *pin;
377  break;
378  case 2:
379  *((uint16_t *)pout) = *((uint16_t *)pin);
380  break;
381  case 3:
382  v = AV_RB24(pin);
383  AV_WB24(pout, v);
384  break;
385  case 4:
386  *((uint32_t *)pout) = *((uint32_t *)pin);
387  break;
388  default:
389  memcpy(pout, pin, rot->draw.pixelstep[plane]);
390  break;
391  }
392  }
393  }
394  xprime += s;
395  yprime += c;
396  }
397  }
398 
399  av_frame_free(&in);
400  return ff_filter_frame(outlink, out);
401 }
402 
403  static int process_command(AVFilterContext *ctx, const char *cmd, const char *args,
404  char *res, int res_len, int flags)
405 {
406  RotContext *rot = ctx->priv;
407  int ret;
408 
409  if (!strcmp(cmd, "angle") || !strcmp(cmd, "a")) {
410  AVExpr *old = rot->angle_expr;
411  ret = av_expr_parse(&rot->angle_expr, args, var_names,
412  NULL, NULL, NULL, NULL, 0, ctx);
413  if (ret < 0) {
414  av_log(ctx, AV_LOG_ERROR,
415  "Error when parsing the expression '%s' for angle command\n", args);
416  rot->angle_expr = old;
417  return ret;
418  }
419  av_expr_free(old);
420  } else
421  ret = AVERROR(ENOSYS);
422 
423  return ret;
424 }
425 
426  static const AVFilterPad rotate_inputs[] = {
427  {
428  .name = "default",
429  .type = AVMEDIA_TYPE_VIDEO,
430  .filter_frame = filter_frame,
431  },
432  { NULL }
433 };
434 
435  static const AVFilterPad rotate_outputs[] = {
436  {
437  .name = "default",
438  .type = AVMEDIA_TYPE_VIDEO,
439  .config_props = config_props,
440  },
441  { NULL }
442 };
443 
444  AVFilter avfilter_vf_rotate = {
445  .name = "rotate",
446  .description = NULL_IF_CONFIG_SMALL("Rotate the input image."),
447  .priv_size = sizeof(RotContext),
448  .init = init,
449  .uninit = uninit,
450  .query_formats = query_formats,
451  .process_command = process_command,
452  .inputs = rotate_inputs,
453  .outputs = rotate_outputs,
454  .priv_class = &rotate_class,
455  .flags = AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC,
456 };
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