FFmpeg
 All Data Structures Namespaces Files Functions Variables Typedefs Enumerations Enumerator Macros Groups Pages
vf_drawtext.c
Go to the documentation of this file.
1 /*
2  * Copyright (c) 2011 Stefano Sabatini
3  * Copyright (c) 2010 S.N. Hemanth Meenakshisundaram
4  * Copyright (c) 2003 Gustavo Sverzut Barbieri <gsbarbieri@yahoo.com.br>
5  *
6  * This file is part of FFmpeg.
7  *
8  * FFmpeg is free software; you can redistribute it and/or
9  * modify it under the terms of the GNU Lesser General Public
10  * License as published by the Free Software Foundation; either
11  * version 2.1 of the License, or (at your option) any later version.
12  *
13  * FFmpeg is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16  * Lesser General Public License for more details.
17  *
18  * You should have received a copy of the GNU Lesser General Public
19  * License along with FFmpeg; if not, write to the Free Software
20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21  */
22 
23 /**
24  * @file
25  * drawtext filter, based on the original vhook/drawtext.c
26  * filter by Gustavo Sverzut Barbieri
27  */
28 
29 #include <sys/time.h>
30 #include <time.h>
31 
32 #include "config.h"
33 #include "libavutil/avstring.h"
34 #include "libavutil/bprint.h"
35 #include "libavutil/common.h"
36 #include "libavutil/file.h"
37 #include "libavutil/eval.h"
38 #include "libavutil/opt.h"
39 #include "libavutil/random_seed.h"
40 #include "libavutil/parseutils.h"
41 #include "libavutil/timecode.h"
42 #include "libavutil/tree.h"
43 #include "libavutil/lfg.h"
44 #include "avfilter.h"
45 #include "drawutils.h"
46 #include "formats.h"
47 #include "internal.h"
48 #include "video.h"
49 
50 #include <ft2build.h>
51 #include <freetype/config/ftheader.h>
52 #include FT_FREETYPE_H
53 #include FT_GLYPH_H
54 #if CONFIG_FONTCONFIG
55 #include <fontconfig/fontconfig.h>
56 #endif
57 
58 static const char *const var_names[] = {
59  "dar",
60  "hsub", "vsub",
61  "line_h", "lh", ///< line height, same as max_glyph_h
62  "main_h", "h", "H", ///< height of the input video
63  "main_w", "w", "W", ///< width of the input video
64  "max_glyph_a", "ascent", ///< max glyph ascent
65  "max_glyph_d", "descent", ///< min glyph descent
66  "max_glyph_h", ///< max glyph height
67  "max_glyph_w", ///< max glyph width
68  "n", ///< number of frame
69  "sar",
70  "t", ///< timestamp expressed in seconds
71  "text_h", "th", ///< height of the rendered text
72  "text_w", "tw", ///< width of the rendered text
73  "x",
74  "y",
75  "pict_type",
76  NULL
77 };
78 
79 static const char *const fun2_names[] = {
80  "rand"
81 };
82 
83 static double drand(void *opaque, double min, double max)
84 {
85  return min + (max-min) / UINT_MAX * av_lfg_get(opaque);
86 }
87 
88 typedef double (*eval_func2)(void *, double a, double b);
89 
90 static const eval_func2 fun2[] = {
91  drand,
92  NULL
93 };
94 
95 enum var_name {
96  VAR_DAR,
97  VAR_HSUB, VAR_VSUB,
98  VAR_LINE_H, VAR_LH,
99  VAR_MAIN_H, VAR_h, VAR_H,
100  VAR_MAIN_W, VAR_w, VAR_W,
101  VAR_MAX_GLYPH_A, VAR_ASCENT,
102  VAR_MAX_GLYPH_D, VAR_DESCENT,
103  VAR_MAX_GLYPH_H,
104  VAR_MAX_GLYPH_W,
105  VAR_N,
106  VAR_SAR,
107  VAR_T,
108  VAR_TEXT_H, VAR_TH,
109  VAR_TEXT_W, VAR_TW,
110  VAR_X,
111  VAR_Y,
112  VAR_PICT_TYPE,
113  VAR_VARS_NB
114 };
115 
116 enum expansion_mode {
117  EXP_NONE,
118  EXP_NORMAL,
119  EXP_STRFTIME,
120 };
121 
122 typedef struct {
123  const AVClass *class;
124  enum expansion_mode exp_mode; ///< expansion mode to use for the text
125  int reinit; ///< tells if the filter is being reinited
126  uint8_t *fontfile; ///< font to be used
127  uint8_t *text; ///< text to be drawn
128  AVBPrint expanded_text; ///< used to contain the expanded text
129  int ft_load_flags; ///< flags used for loading fonts, see FT_LOAD_*
130  FT_Vector *positions; ///< positions for each element in the text
131  size_t nb_positions; ///< number of elements of positions array
132  char *textfile; ///< file with text to be drawn
133  int x; ///< x position to start drawing text
134  int y; ///< y position to start drawing text
135  int max_glyph_w; ///< max glyph width
136  int max_glyph_h; ///< max glyph height
137  int shadowx, shadowy;
138  unsigned int fontsize; ///< font size to use
139 
140  short int draw_box; ///< draw box around text - true or false
141  int use_kerning; ///< font kerning is used - true/false
142  int tabsize; ///< tab size
143  int fix_bounds; ///< do we let it go out of frame bounds - t/f
144 
145  FFDrawContext dc;
146  FFDrawColor fontcolor; ///< foreground color
147  FFDrawColor shadowcolor; ///< shadow color
148  FFDrawColor boxcolor; ///< background color
149 
150  FT_Library library; ///< freetype font library handle
151  FT_Face face; ///< freetype font face handle
152  struct AVTreeNode *glyphs; ///< rendered glyphs, stored using the UTF-32 char code
153  char *x_expr; ///< expression for x position
154  char *y_expr; ///< expression for y position
155  AVExpr *x_pexpr, *y_pexpr; ///< parsed expressions for x and y
156  int64_t basetime; ///< base pts time in the real world for display
157  double var_values[VAR_VARS_NB];
158  char *draw_expr; ///< expression for draw
159  AVExpr *draw_pexpr; ///< parsed expression for draw
160  int draw; ///< set to zero to prevent drawing
161  AVLFG prng; ///< random
162  char *tc_opt_string; ///< specified timecode option string
163  AVRational tc_rate; ///< frame rate for timecode
164  AVTimecode tc; ///< timecode context
165  int tc24hmax; ///< 1 if timecode is wrapped to 24 hours, 0 otherwise
166  int reload; ///< reload text file for each frame
167 } DrawTextContext;
168 
169 #define OFFSET(x) offsetof(DrawTextContext, x)
170 #define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
171 
172 static const AVOption drawtext_options[]= {
173  {"fontfile", "set font file", OFFSET(fontfile), AV_OPT_TYPE_STRING, {.str=NULL}, CHAR_MIN, CHAR_MAX, FLAGS},
174  {"text", "set text", OFFSET(text), AV_OPT_TYPE_STRING, {.str=NULL}, CHAR_MIN, CHAR_MAX, FLAGS},
175  {"textfile", "set text file", OFFSET(textfile), AV_OPT_TYPE_STRING, {.str=NULL}, CHAR_MIN, CHAR_MAX, FLAGS},
176  {"fontcolor", "set foreground color", OFFSET(fontcolor.rgba), AV_OPT_TYPE_COLOR, {.str="black"}, CHAR_MIN, CHAR_MAX, FLAGS},
177  {"boxcolor", "set box color", OFFSET(boxcolor.rgba), AV_OPT_TYPE_COLOR, {.str="white"}, CHAR_MIN, CHAR_MAX, FLAGS},
178  {"shadowcolor", "set shadow color", OFFSET(shadowcolor.rgba), AV_OPT_TYPE_COLOR, {.str="black"}, CHAR_MIN, CHAR_MAX, FLAGS},
179  {"box", "set box", OFFSET(draw_box), AV_OPT_TYPE_INT, {.i64=0}, 0, 1 , FLAGS},
180  {"fontsize", "set font size", OFFSET(fontsize), AV_OPT_TYPE_INT, {.i64=0}, 0, INT_MAX , FLAGS},
181  {"x", "set x expression", OFFSET(x_expr), AV_OPT_TYPE_STRING, {.str="0"}, CHAR_MIN, CHAR_MAX, FLAGS},
182  {"y", "set y expression", OFFSET(y_expr), AV_OPT_TYPE_STRING, {.str="0"}, CHAR_MIN, CHAR_MAX, FLAGS},
183  {"shadowx", "set x", OFFSET(shadowx), AV_OPT_TYPE_INT, {.i64=0}, INT_MIN, INT_MAX , FLAGS},
184  {"shadowy", "set y", OFFSET(shadowy), AV_OPT_TYPE_INT, {.i64=0}, INT_MIN, INT_MAX , FLAGS},
185  {"tabsize", "set tab size", OFFSET(tabsize), AV_OPT_TYPE_INT, {.i64=4}, 0, INT_MAX , FLAGS},
186  {"basetime", "set base time", OFFSET(basetime), AV_OPT_TYPE_INT64, {.i64=AV_NOPTS_VALUE}, INT64_MIN, INT64_MAX , FLAGS},
187  {"draw", "if false do not draw", OFFSET(draw_expr), AV_OPT_TYPE_STRING, {.str="1"}, CHAR_MIN, CHAR_MAX, FLAGS},
188 
189  {"expansion", "set the expansion mode", OFFSET(exp_mode), AV_OPT_TYPE_INT, {.i64=EXP_NORMAL}, 0, 2, FLAGS, "expansion"},
190  {"none", "set no expansion", OFFSET(exp_mode), AV_OPT_TYPE_CONST, {.i64=EXP_NONE}, 0, 0, FLAGS, "expansion"},
191  {"normal", "set normal expansion", OFFSET(exp_mode), AV_OPT_TYPE_CONST, {.i64=EXP_NORMAL}, 0, 0, FLAGS, "expansion"},
192  {"strftime", "set strftime expansion (deprecated)", OFFSET(exp_mode), AV_OPT_TYPE_CONST, {.i64=EXP_STRFTIME}, 0, 0, FLAGS, "expansion"},
193 
194  {"timecode", "set initial timecode", OFFSET(tc_opt_string), AV_OPT_TYPE_STRING, {.str=NULL}, CHAR_MIN, CHAR_MAX, FLAGS},
195  {"tc24hmax", "set 24 hours max (timecode only)", OFFSET(tc24hmax), AV_OPT_TYPE_INT, {.i64=0}, 0, 1, FLAGS},
196  {"timecode_rate", "set rate (timecode only)", OFFSET(tc_rate), AV_OPT_TYPE_RATIONAL, {.dbl=0}, 0, INT_MAX, FLAGS},
197  {"r", "set rate (timecode only)", OFFSET(tc_rate), AV_OPT_TYPE_RATIONAL, {.dbl=0}, 0, INT_MAX, FLAGS},
198  {"rate", "set rate (timecode only)", OFFSET(tc_rate), AV_OPT_TYPE_RATIONAL, {.dbl=0}, 0, INT_MAX, FLAGS},
199  {"reload", "reload text file for each frame", OFFSET(reload), AV_OPT_TYPE_INT, {.i64=0}, 0, 1, FLAGS},
200  {"fix_bounds", "if true, check and fix text coords to avoid clipping", OFFSET(fix_bounds), AV_OPT_TYPE_INT, {.i64=1}, 0, 1, FLAGS},
201 
202  /* FT_LOAD_* flags */
203  { "ft_load_flags", "set font loading flags for libfreetype", OFFSET(ft_load_flags), AV_OPT_TYPE_FLAGS, { .i64 = FT_LOAD_DEFAULT | FT_LOAD_RENDER}, 0, INT_MAX, FLAGS, "ft_load_flags" },
204  { "default", NULL, 0, AV_OPT_TYPE_CONST, { .i64 = FT_LOAD_DEFAULT }, .flags = FLAGS, .unit = "ft_load_flags" },
205  { "no_scale", NULL, 0, AV_OPT_TYPE_CONST, { .i64 = FT_LOAD_NO_SCALE }, .flags = FLAGS, .unit = "ft_load_flags" },
206  { "no_hinting", NULL, 0, AV_OPT_TYPE_CONST, { .i64 = FT_LOAD_NO_HINTING }, .flags = FLAGS, .unit = "ft_load_flags" },
207  { "render", NULL, 0, AV_OPT_TYPE_CONST, { .i64 = FT_LOAD_RENDER }, .flags = FLAGS, .unit = "ft_load_flags" },
208  { "no_bitmap", NULL, 0, AV_OPT_TYPE_CONST, { .i64 = FT_LOAD_NO_BITMAP }, .flags = FLAGS, .unit = "ft_load_flags" },
209  { "vertical_layout", NULL, 0, AV_OPT_TYPE_CONST, { .i64 = FT_LOAD_VERTICAL_LAYOUT }, .flags = FLAGS, .unit = "ft_load_flags" },
210  { "force_autohint", NULL, 0, AV_OPT_TYPE_CONST, { .i64 = FT_LOAD_FORCE_AUTOHINT }, .flags = FLAGS, .unit = "ft_load_flags" },
211  { "crop_bitmap", NULL, 0, AV_OPT_TYPE_CONST, { .i64 = FT_LOAD_CROP_BITMAP }, .flags = FLAGS, .unit = "ft_load_flags" },
212  { "pedantic", NULL, 0, AV_OPT_TYPE_CONST, { .i64 = FT_LOAD_PEDANTIC }, .flags = FLAGS, .unit = "ft_load_flags" },
213  { "ignore_global_advance_width", NULL, 0, AV_OPT_TYPE_CONST, { .i64 = FT_LOAD_IGNORE_GLOBAL_ADVANCE_WIDTH }, .flags = FLAGS, .unit = "ft_load_flags" },
214  { "no_recurse", NULL, 0, AV_OPT_TYPE_CONST, { .i64 = FT_LOAD_NO_RECURSE }, .flags = FLAGS, .unit = "ft_load_flags" },
215  { "ignore_transform", NULL, 0, AV_OPT_TYPE_CONST, { .i64 = FT_LOAD_IGNORE_TRANSFORM }, .flags = FLAGS, .unit = "ft_load_flags" },
216  { "monochrome", NULL, 0, AV_OPT_TYPE_CONST, { .i64 = FT_LOAD_MONOCHROME }, .flags = FLAGS, .unit = "ft_load_flags" },
217  { "linear_design", NULL, 0, AV_OPT_TYPE_CONST, { .i64 = FT_LOAD_LINEAR_DESIGN }, .flags = FLAGS, .unit = "ft_load_flags" },
218  { "no_autohint", NULL, 0, AV_OPT_TYPE_CONST, { .i64 = FT_LOAD_NO_AUTOHINT }, .flags = FLAGS, .unit = "ft_load_flags" },
219  { NULL},
220 };
221 
222 AVFILTER_DEFINE_CLASS(drawtext);
223 
224 #undef __FTERRORS_H__
225 #define FT_ERROR_START_LIST {
226 #define FT_ERRORDEF(e, v, s) { (e), (s) },
227 #define FT_ERROR_END_LIST { 0, NULL } };
228 
229 struct ft_error
230 {
231  int err;
232  const char *err_msg;
233 } static ft_errors[] =
234 #include FT_ERRORS_H
235 
236 #define FT_ERRMSG(e) ft_errors[e].err_msg
237 
238 typedef struct {
239  FT_Glyph *glyph;
240  uint32_t code;
241  FT_Bitmap bitmap; ///< array holding bitmaps of font
242  FT_BBox bbox;
243  int advance;
244  int bitmap_left;
245  int bitmap_top;
246 } Glyph;
247 
248 static int glyph_cmp(void *key, const void *b)
249 {
250  const Glyph *a = key, *bb = b;
251  int64_t diff = (int64_t)a->code - (int64_t)bb->code;
252  return diff > 0 ? 1 : diff < 0 ? -1 : 0;
253 }
254 
255 /**
256  * Load glyphs corresponding to the UTF-32 codepoint code.
257  */
258 static int load_glyph(AVFilterContext *ctx, Glyph **glyph_ptr, uint32_t code)
259 {
260  DrawTextContext *s = ctx->priv;
261  Glyph *glyph;
262  struct AVTreeNode *node = NULL;
263  int ret;
264 
265  /* load glyph into s->face->glyph */
266  if (FT_Load_Char(s->face, code, s->ft_load_flags))
267  return AVERROR(EINVAL);
268 
269  /* save glyph */
270  if (!(glyph = av_mallocz(sizeof(*glyph))) ||
271  !(glyph->glyph = av_mallocz(sizeof(*glyph->glyph)))) {
272  ret = AVERROR(ENOMEM);
273  goto error;
274  }
275  glyph->code = code;
276 
277  if (FT_Get_Glyph(s->face->glyph, glyph->glyph)) {
278  ret = AVERROR(EINVAL);
279  goto error;
280  }
281 
282  glyph->bitmap = s->face->glyph->bitmap;
283  glyph->bitmap_left = s->face->glyph->bitmap_left;
284  glyph->bitmap_top = s->face->glyph->bitmap_top;
285  glyph->advance = s->face->glyph->advance.x >> 6;
286 
287  /* measure text height to calculate text_height (or the maximum text height) */
288  FT_Glyph_Get_CBox(*glyph->glyph, ft_glyph_bbox_pixels, &glyph->bbox);
289 
290  /* cache the newly created glyph */
291  if (!(node = av_tree_node_alloc())) {
292  ret = AVERROR(ENOMEM);
293  goto error;
294  }
295  av_tree_insert(&s->glyphs, glyph, glyph_cmp, &node);
296 
297  if (glyph_ptr)
298  *glyph_ptr = glyph;
299  return 0;
300 
301 error:
302  if (glyph)
303  av_freep(&glyph->glyph);
304  av_freep(&glyph);
305  av_freep(&node);
306  return ret;
307 }
308 
309 static int load_font_file(AVFilterContext *ctx, const char *path, int index,
310  const char **error)
311 {
312  DrawTextContext *s = ctx->priv;
313  int err;
314 
315  err = FT_New_Face(s->library, path, index, &s->face);
316  if (err) {
317  *error = FT_ERRMSG(err);
318  return AVERROR(EINVAL);
319  }
320  return 0;
321 }
322 
323 #if CONFIG_FONTCONFIG
324 static int load_font_fontconfig(AVFilterContext *ctx, const char **error)
325 {
326  DrawTextContext *s = ctx->priv;
327  FcConfig *fontconfig;
328  FcPattern *pattern, *fpat;
329  FcResult result = FcResultMatch;
330  FcChar8 *filename;
331  int err, index;
332  double size;
333 
334  fontconfig = FcInitLoadConfigAndFonts();
335  if (!fontconfig) {
336  *error = "impossible to init fontconfig\n";
337  return AVERROR(EINVAL);
338  }
339  pattern = FcNameParse(s->fontfile ? s->fontfile :
340  (uint8_t *)(intptr_t)"default");
341  if (!pattern) {
342  *error = "could not parse fontconfig pattern";
343  return AVERROR(EINVAL);
344  }
345  if (!FcConfigSubstitute(fontconfig, pattern, FcMatchPattern)) {
346  *error = "could not substitue fontconfig options"; /* very unlikely */
347  return AVERROR(EINVAL);
348  }
349  FcDefaultSubstitute(pattern);
350  fpat = FcFontMatch(fontconfig, pattern, &result);
351  if (!fpat || result != FcResultMatch) {
352  *error = "impossible to find a matching font";
353  return AVERROR(EINVAL);
354  }
355  if (FcPatternGetString (fpat, FC_FILE, 0, &filename) != FcResultMatch ||
356  FcPatternGetInteger(fpat, FC_INDEX, 0, &index ) != FcResultMatch ||
357  FcPatternGetDouble (fpat, FC_SIZE, 0, &size ) != FcResultMatch) {
358  *error = "impossible to find font information";
359  return AVERROR(EINVAL);
360  }
361  av_log(ctx, AV_LOG_INFO, "Using \"%s\"\n", filename);
362  if (!s->fontsize)
363  s->fontsize = size + 0.5;
364  err = load_font_file(ctx, filename, index, error);
365  if (err)
366  return err;
367  FcPatternDestroy(fpat);
368  FcPatternDestroy(pattern);
369  FcConfigDestroy(fontconfig);
370  return 0;
371 }
372 #endif
373 
374 static int load_font(AVFilterContext *ctx)
375 {
376  DrawTextContext *s = ctx->priv;
377  int err;
378  const char *error = "unknown error\n";
379 
380  /* load the face, and set up the encoding, which is by default UTF-8 */
381  err = load_font_file(ctx, s->fontfile, 0, &error);
382  if (!err)
383  return 0;
384 #if CONFIG_FONTCONFIG
385  err = load_font_fontconfig(ctx, &error);
386  if (!err)
387  return 0;
388 #endif
389  av_log(ctx, AV_LOG_ERROR, "Could not load font \"%s\": %s\n",
390  s->fontfile, error);
391  return err;
392 }
393 
394 static int load_textfile(AVFilterContext *ctx)
395 {
396  DrawTextContext *s = ctx->priv;
397  int err;
398  uint8_t *textbuf;
399  size_t textbuf_size;
400 
401  if ((err = av_file_map(s->textfile, &textbuf, &textbuf_size, 0, ctx)) < 0) {
402  av_log(ctx, AV_LOG_ERROR,
403  "The text file '%s' could not be read or is empty\n",
404  s->textfile);
405  return err;
406  }
407 
408  if (!(s->text = av_realloc(s->text, textbuf_size + 1)))
409  return AVERROR(ENOMEM);
410  memcpy(s->text, textbuf, textbuf_size);
411  s->text[textbuf_size] = 0;
412  av_file_unmap(textbuf, textbuf_size);
413 
414  return 0;
415 }
416 
417 static av_cold int init(AVFilterContext *ctx)
418 {
419  int err;
420  DrawTextContext *s = ctx->priv;
421  Glyph *glyph;
422 
423  if (!s->fontfile && !CONFIG_FONTCONFIG) {
424  av_log(ctx, AV_LOG_ERROR, "No font filename provided\n");
425  return AVERROR(EINVAL);
426  }
427 
428  if (s->textfile) {
429  if (s->text) {
430  av_log(ctx, AV_LOG_ERROR,
431  "Both text and text file provided. Please provide only one\n");
432  return AVERROR(EINVAL);
433  }
434  if ((err = load_textfile(ctx)) < 0)
435  return err;
436  }
437 
438  if (s->reload && !s->textfile)
439  av_log(ctx, AV_LOG_WARNING, "No file to reload\n");
440 
441  if (s->tc_opt_string) {
442  int ret = av_timecode_init_from_string(&s->tc, s->tc_rate,
443  s->tc_opt_string, ctx);
444  if (ret < 0)
445  return ret;
446  if (s->tc24hmax)
447  s->tc.flags |= AV_TIMECODE_FLAG_24HOURSMAX;
448  if (!s->text)
449  s->text = av_strdup("");
450  }
451 
452  if (!s->text) {
453  av_log(ctx, AV_LOG_ERROR,
454  "Either text, a valid file or a timecode must be provided\n");
455  return AVERROR(EINVAL);
456  }
457 
458  if ((err = FT_Init_FreeType(&(s->library)))) {
459  av_log(ctx, AV_LOG_ERROR,
460  "Could not load FreeType: %s\n", FT_ERRMSG(err));
461  return AVERROR(EINVAL);
462  }
463 
464  err = load_font(ctx);
465  if (err)
466  return err;
467  if (!s->fontsize)
468  s->fontsize = 16;
469  if ((err = FT_Set_Pixel_Sizes(s->face, 0, s->fontsize))) {
470  av_log(ctx, AV_LOG_ERROR, "Could not set font size to %d pixels: %s\n",
471  s->fontsize, FT_ERRMSG(err));
472  return AVERROR(EINVAL);
473  }
474 
475  s->use_kerning = FT_HAS_KERNING(s->face);
476 
477  /* load the fallback glyph with code 0 */
478  load_glyph(ctx, NULL, 0);
479 
480  /* set the tabsize in pixels */
481  if ((err = load_glyph(ctx, &glyph, ' ')) < 0) {
482  av_log(ctx, AV_LOG_ERROR, "Could not set tabsize.\n");
483  return err;
484  }
485  s->tabsize *= glyph->advance;
486 
487  if (s->exp_mode == EXP_STRFTIME &&
488  (strchr(s->text, '%') || strchr(s->text, '\\')))
489  av_log(ctx, AV_LOG_WARNING, "expansion=strftime is deprecated.\n");
490 
491  av_bprint_init(&s->expanded_text, 0, AV_BPRINT_SIZE_UNLIMITED);
492 
493  return 0;
494 }
495 
496 static int query_formats(AVFilterContext *ctx)
497 {
498  ff_set_common_formats(ctx, ff_draw_supported_pixel_formats(0));
499  return 0;
500 }
501 
502 static int glyph_enu_free(void *opaque, void *elem)
503 {
504  Glyph *glyph = elem;
505 
506  FT_Done_Glyph(*glyph->glyph);
507  av_freep(&glyph->glyph);
508  av_free(elem);
509  return 0;
510 }
511 
512 static av_cold void uninit(AVFilterContext *ctx)
513 {
514  DrawTextContext *s = ctx->priv;
515 
516  av_expr_free(s->x_pexpr);
517  av_expr_free(s->y_pexpr);
518  av_expr_free(s->draw_pexpr);
519  s->x_pexpr = s->y_pexpr = s->draw_pexpr = NULL;
520  av_freep(&s->positions);
521  s->nb_positions = 0;
522 
523 
524  av_tree_enumerate(s->glyphs, NULL, NULL, glyph_enu_free);
525  av_tree_destroy(s->glyphs);
526  s->glyphs = NULL;
527 
528  FT_Done_Face(s->face);
529  FT_Done_FreeType(s->library);
530 
531  av_bprint_finalize(&s->expanded_text, NULL);
532 }
533 
534 static inline int is_newline(uint32_t c)
535 {
536  return c == '\n' || c == '\r' || c == '\f' || c == '\v';
537 }
538 
539 static int config_input(AVFilterLink *inlink)
540 {
541  AVFilterContext *ctx = inlink->dst;
542  DrawTextContext *s = ctx->priv;
543  int ret;
544 
545  ff_draw_init(&s->dc, inlink->format, 0);
546  ff_draw_color(&s->dc, &s->fontcolor, s->fontcolor.rgba);
547  ff_draw_color(&s->dc, &s->shadowcolor, s->shadowcolor.rgba);
548  ff_draw_color(&s->dc, &s->boxcolor, s->boxcolor.rgba);
549 
550  s->var_values[VAR_w] = s->var_values[VAR_W] = s->var_values[VAR_MAIN_W] = inlink->w;
551  s->var_values[VAR_h] = s->var_values[VAR_H] = s->var_values[VAR_MAIN_H] = inlink->h;
552  s->var_values[VAR_SAR] = inlink->sample_aspect_ratio.num ? av_q2d(inlink->sample_aspect_ratio) : 1;
553  s->var_values[VAR_DAR] = (double)inlink->w / inlink->h * s->var_values[VAR_SAR];
554  s->var_values[VAR_HSUB] = 1 << s->dc.hsub_max;
555  s->var_values[VAR_VSUB] = 1 << s->dc.vsub_max;
556  s->var_values[VAR_X] = NAN;
557  s->var_values[VAR_Y] = NAN;
558  s->var_values[VAR_T] = NAN;
559 
560  av_lfg_init(&s->prng, av_get_random_seed());
561 
562  av_expr_free(s->x_pexpr);
563  av_expr_free(s->y_pexpr);
564  av_expr_free(s->draw_pexpr);
565  s->x_pexpr = s->y_pexpr = s->draw_pexpr = NULL;
566  if ((ret = av_expr_parse(&s->x_pexpr, s->x_expr, var_names,
567  NULL, NULL, fun2_names, fun2, 0, ctx)) < 0 ||
568  (ret = av_expr_parse(&s->y_pexpr, s->y_expr, var_names,
569  NULL, NULL, fun2_names, fun2, 0, ctx)) < 0 ||
570  (ret = av_expr_parse(&s->draw_pexpr, s->draw_expr, var_names,
571  NULL, NULL, fun2_names, fun2, 0, ctx)) < 0)
572 
573  return AVERROR(EINVAL);
574 
575  return 0;
576 }
577 
578 static int command(AVFilterContext *ctx, const char *cmd, const char *arg, char *res, int res_len, int flags)
579 {
580  DrawTextContext *s = ctx->priv;
581 
582  if (!strcmp(cmd, "reinit")) {
583  int ret;
584  uninit(ctx);
585  s->reinit = 1;
586  if ((ret = init(ctx)) < 0)
587  return ret;
588  return config_input(ctx->inputs[0]);
589  }
590 
591  return AVERROR(ENOSYS);
592 }
593 
594 static int func_pict_type(AVFilterContext *ctx, AVBPrint *bp,
595  char *fct, unsigned argc, char **argv, int tag)
596 {
597  DrawTextContext *s = ctx->priv;
598 
599  av_bprintf(bp, "%c", av_get_picture_type_char(s->var_values[VAR_PICT_TYPE]));
600  return 0;
601 }
602 
603 static int func_pts(AVFilterContext *ctx, AVBPrint *bp,
604  char *fct, unsigned argc, char **argv, int tag)
605 {
606  DrawTextContext *s = ctx->priv;
607 
608  av_bprintf(bp, "%.6f", s->var_values[VAR_T]);
609  return 0;
610 }
611 
612 static int func_frame_num(AVFilterContext *ctx, AVBPrint *bp,
613  char *fct, unsigned argc, char **argv, int tag)
614 {
615  DrawTextContext *s = ctx->priv;
616 
617  av_bprintf(bp, "%d", (int)s->var_values[VAR_N]);
618  return 0;
619 }
620 
621 #if !HAVE_LOCALTIME_R
622 static void localtime_r(const time_t *t, struct tm *tm)
623 {
624  *tm = *localtime(t);
625 }
626 #endif
627 
628 static int func_strftime(AVFilterContext *ctx, AVBPrint *bp,
629  char *fct, unsigned argc, char **argv, int tag)
630 {
631  const char *fmt = argc ? argv[0] : "%Y-%m-%d %H:%M:%S";
632  time_t now;
633  struct tm tm;
634 
635  time(&now);
636  if (tag == 'L')
637  localtime_r(&now, &tm);
638  else
639  tm = *gmtime(&now);
640  av_bprint_strftime(bp, fmt, &tm);
641  return 0;
642 }
643 
644 static int func_eval_expr(AVFilterContext *ctx, AVBPrint *bp,
645  char *fct, unsigned argc, char **argv, int tag)
646 {
647  DrawTextContext *s = ctx->priv;
648  double res;
649  int ret;
650 
651  ret = av_expr_parse_and_eval(&res, argv[0], var_names, s->var_values,
652  NULL, NULL, fun2_names, fun2,
653  &s->prng, 0, ctx);
654  if (ret < 0)
655  av_log(ctx, AV_LOG_ERROR,
656  "Expression '%s' for the expr text expansion function is not valid\n",
657  argv[0]);
658  else
659  av_bprintf(bp, "%f", res);
660 
661  return ret;
662 }
663 
664 static const struct drawtext_function {
665  const char *name;
666  unsigned argc_min, argc_max;
667  int tag; /**< opaque argument to func */
668  int (*func)(AVFilterContext *, AVBPrint *, char *, unsigned, char **, int);
669 } functions[] = {
670  { "expr", 1, 1, 0, func_eval_expr },
671  { "e", 1, 1, 0, func_eval_expr },
672  { "pict_type", 0, 0, 0, func_pict_type },
673  { "pts", 0, 0, 0, func_pts },
674  { "gmtime", 0, 1, 'G', func_strftime },
675  { "localtime", 0, 1, 'L', func_strftime },
676  { "frame_num", 0, 0, 0, func_frame_num },
677  { "n", 0, 0, 0, func_frame_num },
678 };
679 
680 static int eval_function(AVFilterContext *ctx, AVBPrint *bp, char *fct,
681  unsigned argc, char **argv)
682 {
683  unsigned i;
684 
685  for (i = 0; i < FF_ARRAY_ELEMS(functions); i++) {
686  if (strcmp(fct, functions[i].name))
687  continue;
688  if (argc < functions[i].argc_min) {
689  av_log(ctx, AV_LOG_ERROR, "%%{%s} requires at least %d arguments\n",
690  fct, functions[i].argc_min);
691  return AVERROR(EINVAL);
692  }
693  if (argc > functions[i].argc_max) {
694  av_log(ctx, AV_LOG_ERROR, "%%{%s} requires at most %d arguments\n",
695  fct, functions[i].argc_max);
696  return AVERROR(EINVAL);
697  }
698  break;
699  }
700  if (i >= FF_ARRAY_ELEMS(functions)) {
701  av_log(ctx, AV_LOG_ERROR, "%%{%s} is not known\n", fct);
702  return AVERROR(EINVAL);
703  }
704  return functions[i].func(ctx, bp, fct, argc, argv, functions[i].tag);
705 }
706 
707 static int expand_function(AVFilterContext *ctx, AVBPrint *bp, char **rtext)
708 {
709  const char *text = *rtext;
710  char *argv[16] = { NULL };
711  unsigned argc = 0, i;
712  int ret;
713 
714  if (*text != '{') {
715  av_log(ctx, AV_LOG_ERROR, "Stray %% near '%s'\n", text);
716  return AVERROR(EINVAL);
717  }
718  text++;
719  while (1) {
720  if (!(argv[argc++] = av_get_token(&text, ":}"))) {
721  ret = AVERROR(ENOMEM);
722  goto end;
723  }
724  if (!*text) {
725  av_log(ctx, AV_LOG_ERROR, "Unterminated %%{} near '%s'\n", *rtext);
726  ret = AVERROR(EINVAL);
727  goto end;
728  }
729  if (argc == FF_ARRAY_ELEMS(argv))
730  av_freep(&argv[--argc]); /* error will be caught later */
731  if (*text == '}')
732  break;
733  text++;
734  }
735 
736  if ((ret = eval_function(ctx, bp, argv[0], argc - 1, argv + 1)) < 0)
737  goto end;
738  ret = 0;
739  *rtext = (char *)text + 1;
740 
741 end:
742  for (i = 0; i < argc; i++)
743  av_freep(&argv[i]);
744  return ret;
745 }
746 
747 static int expand_text(AVFilterContext *ctx)
748 {
749  DrawTextContext *s = ctx->priv;
750  char *text = s->text;
751  AVBPrint *bp = &s->expanded_text;
752  int ret;
753 
754  av_bprint_clear(bp);
755  while (*text) {
756  if (*text == '\\' && text[1]) {
757  av_bprint_chars(bp, text[1], 1);
758  text += 2;
759  } else if (*text == '%') {
760  text++;
761  if ((ret = expand_function(ctx, bp, &text)) < 0)
762  return ret;
763  } else {
764  av_bprint_chars(bp, *text, 1);
765  text++;
766  }
767  }
768  if (!av_bprint_is_complete(bp))
769  return AVERROR(ENOMEM);
770  return 0;
771 }
772 
773 static int draw_glyphs(DrawTextContext *s, AVFrame *frame,
774  int width, int height, const uint8_t rgbcolor[4], FFDrawColor *color, int x, int y)
775 {
776  char *text = s->expanded_text.str;
777  uint32_t code = 0;
778  int i, x1, y1;
779  uint8_t *p;
780  Glyph *glyph = NULL;
781 
782  for (i = 0, p = text; *p; i++) {
783  Glyph dummy = { 0 };
784  GET_UTF8(code, *p++, continue;);
785 
786  /* skip new line chars, just go to new line */
787  if (code == '\n' || code == '\r' || code == '\t')
788  continue;
789 
790  dummy.code = code;
791  glyph = av_tree_find(s->glyphs, &dummy, (void *)glyph_cmp, NULL);
792 
793  if (glyph->bitmap.pixel_mode != FT_PIXEL_MODE_MONO &&
794  glyph->bitmap.pixel_mode != FT_PIXEL_MODE_GRAY)
795  return AVERROR(EINVAL);
796 
797  x1 = s->positions[i].x+s->x+x;
798  y1 = s->positions[i].y+s->y+y;
799 
800  ff_blend_mask(&s->dc, color,
801  frame->data, frame->linesize, width, height,
802  glyph->bitmap.buffer, glyph->bitmap.pitch,
803  glyph->bitmap.width, glyph->bitmap.rows,
804  glyph->bitmap.pixel_mode == FT_PIXEL_MODE_MONO ? 0 : 3,
805  0, x1, y1);
806  }
807 
808  return 0;
809 }
810 
811 static int draw_text(AVFilterContext *ctx, AVFrame *frame,
812  int width, int height)
813 {
814  DrawTextContext *s = ctx->priv;
815  AVFilterLink *inlink = ctx->inputs[0];
816 
817  uint32_t code = 0, prev_code = 0;
818  int x = 0, y = 0, i = 0, ret;
819  int max_text_line_w = 0, len;
820  int box_w, box_h;
821  char *text = s->text;
822  uint8_t *p;
823  int y_min = 32000, y_max = -32000;
824  int x_min = 32000, x_max = -32000;
825  FT_Vector delta;
826  Glyph *glyph = NULL, *prev_glyph = NULL;
827  Glyph dummy = { 0 };
828 
829  time_t now = time(0);
830  struct tm ltime;
831  AVBPrint *bp = &s->expanded_text;
832 
833  av_bprint_clear(bp);
834 
835  if(s->basetime != AV_NOPTS_VALUE)
836  now= frame->pts*av_q2d(ctx->inputs[0]->time_base) + s->basetime/1000000;
837 
838  switch (s->exp_mode) {
839  case EXP_NONE:
840  av_bprintf(bp, "%s", s->text);
841  break;
842  case EXP_NORMAL:
843  if ((ret = expand_text(ctx)) < 0)
844  return ret;
845  break;
846  case EXP_STRFTIME:
847  localtime_r(&now, &ltime);
848  av_bprint_strftime(bp, s->text, &ltime);
849  break;
850  }
851 
852  if (s->tc_opt_string) {
853  char tcbuf[AV_TIMECODE_STR_SIZE];
854  av_timecode_make_string(&s->tc, tcbuf, inlink->frame_count);
855  av_bprint_clear(bp);
856  av_bprintf(bp, "%s%s", s->text, tcbuf);
857  }
858 
859  if (!av_bprint_is_complete(bp))
860  return AVERROR(ENOMEM);
861  text = s->expanded_text.str;
862  if ((len = s->expanded_text.len) > s->nb_positions) {
863  if (!(s->positions =
864  av_realloc(s->positions, len*sizeof(*s->positions))))
865  return AVERROR(ENOMEM);
866  s->nb_positions = len;
867  }
868 
869  x = 0;
870  y = 0;
871 
872  /* load and cache glyphs */
873  for (i = 0, p = text; *p; i++) {
874  GET_UTF8(code, *p++, continue;);
875 
876  /* get glyph */
877  dummy.code = code;
878  glyph = av_tree_find(s->glyphs, &dummy, glyph_cmp, NULL);
879  if (!glyph) {
880  load_glyph(ctx, &glyph, code);
881  }
882 
883  y_min = FFMIN(glyph->bbox.yMin, y_min);
884  y_max = FFMAX(glyph->bbox.yMax, y_max);
885  x_min = FFMIN(glyph->bbox.xMin, x_min);
886  x_max = FFMAX(glyph->bbox.xMax, x_max);
887  }
888  s->max_glyph_h = y_max - y_min;
889  s->max_glyph_w = x_max - x_min;
890 
891  /* compute and save position for each glyph */
892  glyph = NULL;
893  for (i = 0, p = text; *p; i++) {
894  GET_UTF8(code, *p++, continue;);
895 
896  /* skip the \n in the sequence \r\n */
897  if (prev_code == '\r' && code == '\n')
898  continue;
899 
900  prev_code = code;
901  if (is_newline(code)) {
902 
903  max_text_line_w = FFMAX(max_text_line_w, x);
904  y += s->max_glyph_h;
905  x = 0;
906  continue;
907  }
908 
909  /* get glyph */
910  prev_glyph = glyph;
911  dummy.code = code;
912  glyph = av_tree_find(s->glyphs, &dummy, glyph_cmp, NULL);
913 
914  /* kerning */
915  if (s->use_kerning && prev_glyph && glyph->code) {
916  FT_Get_Kerning(s->face, prev_glyph->code, glyph->code,
917  ft_kerning_default, &delta);
918  x += delta.x >> 6;
919  }
920 
921  /* save position */
922  s->positions[i].x = x + glyph->bitmap_left;
923  s->positions[i].y = y - glyph->bitmap_top + y_max;
924  if (code == '\t') x = (x / s->tabsize + 1)*s->tabsize;
925  else x += glyph->advance;
926  }
927 
928  max_text_line_w = FFMAX(x, max_text_line_w);
929 
930  s->var_values[VAR_TW] = s->var_values[VAR_TEXT_W] = max_text_line_w;
931  s->var_values[VAR_TH] = s->var_values[VAR_TEXT_H] = y + s->max_glyph_h;
932 
933  s->var_values[VAR_MAX_GLYPH_W] = s->max_glyph_w;
934  s->var_values[VAR_MAX_GLYPH_H] = s->max_glyph_h;
935  s->var_values[VAR_MAX_GLYPH_A] = s->var_values[VAR_ASCENT ] = y_max;
936  s->var_values[VAR_MAX_GLYPH_D] = s->var_values[VAR_DESCENT] = y_min;
937 
938  s->var_values[VAR_LINE_H] = s->var_values[VAR_LH] = s->max_glyph_h;
939 
940  s->x = s->var_values[VAR_X] = av_expr_eval(s->x_pexpr, s->var_values, &s->prng);
941  s->y = s->var_values[VAR_Y] = av_expr_eval(s->y_pexpr, s->var_values, &s->prng);
942  s->x = s->var_values[VAR_X] = av_expr_eval(s->x_pexpr, s->var_values, &s->prng);
943  s->draw = av_expr_eval(s->draw_pexpr, s->var_values, &s->prng);
944 
945  if(!s->draw)
946  return 0;
947 
948  box_w = FFMIN(width - 1 , max_text_line_w);
949  box_h = FFMIN(height - 1, y + s->max_glyph_h);
950 
951  /* draw box */
952  if (s->draw_box)
953  ff_blend_rectangle(&s->dc, &s->boxcolor,
954  frame->data, frame->linesize, width, height,
955  s->x, s->y, box_w, box_h);
956 
957  if (s->shadowx || s->shadowy) {
958  if ((ret = draw_glyphs(s, frame, width, height, s->shadowcolor.rgba,
959  &s->shadowcolor, s->shadowx, s->shadowy)) < 0)
960  return ret;
961  }
962 
963  if ((ret = draw_glyphs(s, frame, width, height, s->fontcolor.rgba,
964  &s->fontcolor, 0, 0)) < 0)
965  return ret;
966 
967  return 0;
968 }
969 
970 static int filter_frame(AVFilterLink *inlink, AVFrame *frame)
971 {
972  AVFilterContext *ctx = inlink->dst;
973  AVFilterLink *outlink = ctx->outputs[0];
974  DrawTextContext *s = ctx->priv;
975  int ret;
976 
977  if (s->reload)
978  if ((ret = load_textfile(ctx)) < 0)
979  return ret;
980 
981  s->var_values[VAR_N] = inlink->frame_count;
982  s->var_values[VAR_T] = frame->pts == AV_NOPTS_VALUE ?
983  NAN : frame->pts * av_q2d(inlink->time_base);
984 
985  s->var_values[VAR_PICT_TYPE] = frame->pict_type;
986 
987  draw_text(ctx, frame, frame->width, frame->height);
988 
989  av_log(ctx, AV_LOG_DEBUG, "n:%d t:%f text_w:%d text_h:%d x:%d y:%d\n",
990  (int)s->var_values[VAR_N], s->var_values[VAR_T],
991  (int)s->var_values[VAR_TEXT_W], (int)s->var_values[VAR_TEXT_H],
992  s->x, s->y);
993 
994  return ff_filter_frame(outlink, frame);
995 }
996 
997 static const AVFilterPad avfilter_vf_drawtext_inputs[] = {
998  {
999  .name = "default",
1000  .type = AVMEDIA_TYPE_VIDEO,
1001  .get_video_buffer = ff_null_get_video_buffer,
1002  .filter_frame = filter_frame,
1003  .config_props = config_input,
1004  .needs_writable = 1,
1005  },
1006  { NULL }
1007 };
1008 
1009 static const AVFilterPad avfilter_vf_drawtext_outputs[] = {
1010  {
1011  .name = "default",
1012  .type = AVMEDIA_TYPE_VIDEO,
1013  },
1014  { NULL }
1015 };
1016 
1017 AVFilter avfilter_vf_drawtext = {
1018  .name = "drawtext",
1019  .description = NULL_IF_CONFIG_SMALL("Draw text on top of video frames using libfreetype library."),
1020  .priv_size = sizeof(DrawTextContext),
1021  .priv_class = &drawtext_class,
1022  .init = init,
1023  .uninit = uninit,
1024  .query_formats = query_formats,
1025 
1026  .inputs = avfilter_vf_drawtext_inputs,
1027  .outputs = avfilter_vf_drawtext_outputs,
1028  .process_command = command,
1029 };
Generated on Tue Jun 18 2013 19:21:01 for FFmpeg by   doxygen 1.8.2