• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
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 "config.h"
30 
31 #if HAVE_SYS_TIME_H
32 #include <sys/time.h>
33 #endif
34 #include <sys/types.h>
35 #include <sys/stat.h>
36 #include <time.h>
37 #if HAVE_UNISTD_H
38 #include <unistd.h>
39 #endif
40 #include <fenv.h>
41 
42 #if CONFIG_LIBFONTCONFIG
43 #include <fontconfig/fontconfig.h>
44 #endif
45 
46 #include "libavutil/avstring.h"
47 #include "libavutil/bprint.h"
48 #include "libavutil/common.h"
49 #include "libavutil/file.h"
50 #include "libavutil/eval.h"
51 #include "libavutil/opt.h"
52 #include "libavutil/random_seed.h"
53 #include "libavutil/parseutils.h"
54 #include "libavutil/time.h"
55 #include "libavutil/timecode.h"
56 #include "libavutil/time_internal.h"
57 #include "libavutil/tree.h"
58 #include "libavutil/lfg.h"
59 #include "libavutil/detection_bbox.h"
60 #include "avfilter.h"
61 #include "drawutils.h"
62 #include "formats.h"
63 #include "internal.h"
64 #include "video.h"
65 
66 #if CONFIG_LIBFRIBIDI
67 #include <fribidi.h>
68 #endif
69 
70 #include <ft2build.h>
71 #include FT_FREETYPE_H
72 #include FT_GLYPH_H
73 #include FT_STROKER_H
74 
75 static const char *const var_names[] = {
76     "dar",
77     "hsub", "vsub",
78     "line_h", "lh",           ///< line height, same as max_glyph_h
79     "main_h", "h", "H",       ///< height of the input video
80     "main_w", "w", "W",       ///< width  of the input video
81     "max_glyph_a", "ascent",  ///< max glyph ascent
82     "max_glyph_d", "descent", ///< min glyph descent
83     "max_glyph_h",            ///< max glyph height
84     "max_glyph_w",            ///< max glyph width
85     "n",                      ///< number of frame
86     "sar",
87     "t",                      ///< timestamp expressed in seconds
88     "text_h", "th",           ///< height of the rendered text
89     "text_w", "tw",           ///< width  of the rendered text
90     "x",
91     "y",
92     "pict_type",
93     "pkt_pos",
94     "pkt_duration",
95     "pkt_size",
96     NULL
97 };
98 
99 static const char *const fun2_names[] = {
100     "rand"
101 };
102 
drand(void * opaque,double min,double max)103 static double drand(void *opaque, double min, double max)
104 {
105     return min + (max-min) / UINT_MAX * av_lfg_get(opaque);
106 }
107 
108 typedef double (*eval_func2)(void *, double a, double b);
109 
110 static const eval_func2 fun2[] = {
111     drand,
112     NULL
113 };
114 
115 enum var_name {
116     VAR_DAR,
117     VAR_HSUB, VAR_VSUB,
118     VAR_LINE_H, VAR_LH,
119     VAR_MAIN_H, VAR_h, VAR_H,
120     VAR_MAIN_W, VAR_w, VAR_W,
121     VAR_MAX_GLYPH_A, VAR_ASCENT,
122     VAR_MAX_GLYPH_D, VAR_DESCENT,
123     VAR_MAX_GLYPH_H,
124     VAR_MAX_GLYPH_W,
125     VAR_N,
126     VAR_SAR,
127     VAR_T,
128     VAR_TEXT_H, VAR_TH,
129     VAR_TEXT_W, VAR_TW,
130     VAR_X,
131     VAR_Y,
132     VAR_PICT_TYPE,
133     VAR_PKT_POS,
134     VAR_PKT_DURATION,
135     VAR_PKT_SIZE,
136     VAR_VARS_NB
137 };
138 
139 enum expansion_mode {
140     EXP_NONE,
141     EXP_NORMAL,
142     EXP_STRFTIME,
143 };
144 
145 typedef struct DrawTextContext {
146     const AVClass *class;
147     int exp_mode;                   ///< expansion mode to use for the text
148     int reinit;                     ///< tells if the filter is being reinited
149 #if CONFIG_LIBFONTCONFIG
150     uint8_t *font;              ///< font to be used
151 #endif
152     uint8_t *fontfile;              ///< font to be used
153     uint8_t *text;                  ///< text to be drawn
154     AVBPrint expanded_text;         ///< used to contain the expanded text
155     uint8_t *fontcolor_expr;        ///< fontcolor expression to evaluate
156     AVBPrint expanded_fontcolor;    ///< used to contain the expanded fontcolor spec
157     int ft_load_flags;              ///< flags used for loading fonts, see FT_LOAD_*
158     FT_Vector *positions;           ///< positions for each element in the text
159     size_t nb_positions;            ///< number of elements of positions array
160     char *textfile;                 ///< file with text to be drawn
161     int x;                          ///< x position to start drawing text
162     int y;                          ///< y position to start drawing text
163     int max_glyph_w;                ///< max glyph width
164     int max_glyph_h;                ///< max glyph height
165     int shadowx, shadowy;
166     int borderw;                    ///< border width
167     char *fontsize_expr;            ///< expression for fontsize
168     AVExpr *fontsize_pexpr;         ///< parsed expressions for fontsize
169     unsigned int fontsize;          ///< font size to use
170     unsigned int default_fontsize;  ///< default font size to use
171 
172     int line_spacing;               ///< lines spacing in pixels
173     short int draw_box;             ///< draw box around text - true or false
174     int boxborderw;                 ///< box border width
175     int use_kerning;                ///< font kerning is used - true/false
176     int tabsize;                    ///< tab size
177     int fix_bounds;                 ///< do we let it go out of frame bounds - t/f
178 
179     FFDrawContext dc;
180     FFDrawColor fontcolor;          ///< foreground color
181     FFDrawColor shadowcolor;        ///< shadow color
182     FFDrawColor bordercolor;        ///< border color
183     FFDrawColor boxcolor;           ///< background color
184 
185     FT_Library library;             ///< freetype font library handle
186     FT_Face face;                   ///< freetype font face handle
187     FT_Stroker stroker;             ///< freetype stroker handle
188     struct AVTreeNode *glyphs;      ///< rendered glyphs, stored using the UTF-32 char code
189     char *x_expr;                   ///< expression for x position
190     char *y_expr;                   ///< expression for y position
191     AVExpr *x_pexpr, *y_pexpr;      ///< parsed expressions for x and y
192     int64_t basetime;               ///< base pts time in the real world for display
193     double var_values[VAR_VARS_NB];
194     char   *a_expr;
195     AVExpr *a_pexpr;
196     int alpha;
197     AVLFG  prng;                    ///< random
198     char       *tc_opt_string;      ///< specified timecode option string
199     AVRational  tc_rate;            ///< frame rate for timecode
200     AVTimecode  tc;                 ///< timecode context
201     int tc24hmax;                   ///< 1 if timecode is wrapped to 24 hours, 0 otherwise
202     int reload;                     ///< reload text file at specified frame interval
203     int start_number;               ///< starting frame number for n/frame_num var
204     char *text_source_string;       ///< the string to specify text data source
205     enum AVFrameSideDataType text_source;
206 #if CONFIG_LIBFRIBIDI
207     int text_shaping;               ///< 1 to shape the text before drawing it
208 #endif
209     AVDictionary *metadata;
210 } DrawTextContext;
211 
212 #define OFFSET(x) offsetof(DrawTextContext, x)
213 #define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
214 
215 static const AVOption drawtext_options[]= {
216     {"fontfile",    "set font file",        OFFSET(fontfile),           AV_OPT_TYPE_STRING, {.str=NULL},  0, 0, FLAGS},
217     {"text",        "set text",             OFFSET(text),               AV_OPT_TYPE_STRING, {.str=NULL},  0, 0, FLAGS},
218     {"textfile",    "set text file",        OFFSET(textfile),           AV_OPT_TYPE_STRING, {.str=NULL},  0, 0, FLAGS},
219     {"fontcolor",   "set foreground color", OFFSET(fontcolor.rgba),     AV_OPT_TYPE_COLOR,  {.str="black"}, 0, 0, FLAGS},
220     {"fontcolor_expr", "set foreground color expression", OFFSET(fontcolor_expr), AV_OPT_TYPE_STRING, {.str=""}, 0, 0, FLAGS},
221     {"boxcolor",    "set box color",        OFFSET(boxcolor.rgba),      AV_OPT_TYPE_COLOR,  {.str="white"}, 0, 0, FLAGS},
222     {"bordercolor", "set border color",     OFFSET(bordercolor.rgba),   AV_OPT_TYPE_COLOR,  {.str="black"}, 0, 0, FLAGS},
223     {"shadowcolor", "set shadow color",     OFFSET(shadowcolor.rgba),   AV_OPT_TYPE_COLOR,  {.str="black"}, 0, 0, FLAGS},
224     {"box",         "set box",              OFFSET(draw_box),           AV_OPT_TYPE_BOOL,   {.i64=0},     0,        1       , FLAGS},
225     {"boxborderw",  "set box border width", OFFSET(boxborderw),         AV_OPT_TYPE_INT,    {.i64=0},     INT_MIN,  INT_MAX , FLAGS},
226     {"line_spacing",  "set line spacing in pixels", OFFSET(line_spacing),   AV_OPT_TYPE_INT,    {.i64=0},     INT_MIN,  INT_MAX,FLAGS},
227     {"fontsize",    "set font size",        OFFSET(fontsize_expr),      AV_OPT_TYPE_STRING, {.str=NULL},  0, 0 , FLAGS},
228     {"x",           "set x expression",     OFFSET(x_expr),             AV_OPT_TYPE_STRING, {.str="0"},   0, 0, FLAGS},
229     {"y",           "set y expression",     OFFSET(y_expr),             AV_OPT_TYPE_STRING, {.str="0"},   0, 0, FLAGS},
230     {"shadowx",     "set shadow x offset",  OFFSET(shadowx),            AV_OPT_TYPE_INT,    {.i64=0},     INT_MIN,  INT_MAX , FLAGS},
231     {"shadowy",     "set shadow y offset",  OFFSET(shadowy),            AV_OPT_TYPE_INT,    {.i64=0},     INT_MIN,  INT_MAX , FLAGS},
232     {"borderw",     "set border width",     OFFSET(borderw),            AV_OPT_TYPE_INT,    {.i64=0},     INT_MIN,  INT_MAX , FLAGS},
233     {"tabsize",     "set tab size",         OFFSET(tabsize),            AV_OPT_TYPE_INT,    {.i64=4},     0,        INT_MAX , FLAGS},
234     {"basetime",    "set base time",        OFFSET(basetime),           AV_OPT_TYPE_INT64,  {.i64=AV_NOPTS_VALUE}, INT64_MIN, INT64_MAX , FLAGS},
235 #if CONFIG_LIBFONTCONFIG
236     { "font",        "Font name",            OFFSET(font),               AV_OPT_TYPE_STRING, { .str = "Sans" },           .flags = FLAGS },
237 #endif
238 
239     {"expansion", "set the expansion mode", OFFSET(exp_mode), AV_OPT_TYPE_INT, {.i64=EXP_NORMAL}, 0, 2, FLAGS, "expansion"},
240         {"none",     "set no expansion",                    OFFSET(exp_mode), AV_OPT_TYPE_CONST, {.i64=EXP_NONE},     0, 0, FLAGS, "expansion"},
241         {"normal",   "set normal expansion",                OFFSET(exp_mode), AV_OPT_TYPE_CONST, {.i64=EXP_NORMAL},   0, 0, FLAGS, "expansion"},
242         {"strftime", "set strftime expansion (deprecated)", OFFSET(exp_mode), AV_OPT_TYPE_CONST, {.i64=EXP_STRFTIME}, 0, 0, FLAGS, "expansion"},
243 
244     {"timecode",        "set initial timecode",             OFFSET(tc_opt_string), AV_OPT_TYPE_STRING,   {.str=NULL}, 0, 0, FLAGS},
245     {"tc24hmax",        "set 24 hours max (timecode only)", OFFSET(tc24hmax),      AV_OPT_TYPE_BOOL,     {.i64=0},           0,        1, FLAGS},
246     {"timecode_rate",   "set rate (timecode only)",         OFFSET(tc_rate),       AV_OPT_TYPE_RATIONAL, {.dbl=0},           0,  INT_MAX, FLAGS},
247     {"r",               "set rate (timecode only)",         OFFSET(tc_rate),       AV_OPT_TYPE_RATIONAL, {.dbl=0},           0,  INT_MAX, FLAGS},
248     {"rate",            "set rate (timecode only)",         OFFSET(tc_rate),       AV_OPT_TYPE_RATIONAL, {.dbl=0},           0,  INT_MAX, FLAGS},
249     {"reload",     "reload text file at specified frame interval", OFFSET(reload),     AV_OPT_TYPE_INT, {.i64=0}, 0, INT_MAX, FLAGS},
250     { "alpha",       "apply alpha while rendering", OFFSET(a_expr),      AV_OPT_TYPE_STRING, { .str = "1"     },          .flags = FLAGS },
251     {"fix_bounds", "check and fix text coords to avoid clipping", OFFSET(fix_bounds), AV_OPT_TYPE_BOOL, {.i64=0}, 0, 1, FLAGS},
252     {"start_number", "start frame number for n/frame_num variable", OFFSET(start_number), AV_OPT_TYPE_INT, {.i64=0}, 0, INT_MAX, FLAGS},
253     {"text_source", "the source of text", OFFSET(text_source_string), AV_OPT_TYPE_STRING, {.str=NULL}, 0, 1, FLAGS },
254 
255 #if CONFIG_LIBFRIBIDI
256     {"text_shaping", "attempt to shape text before drawing", OFFSET(text_shaping), AV_OPT_TYPE_BOOL, {.i64=1}, 0, 1, FLAGS},
257 #endif
258 
259     /* FT_LOAD_* flags */
260     { "ft_load_flags", "set font loading flags for libfreetype", OFFSET(ft_load_flags), AV_OPT_TYPE_FLAGS, { .i64 = FT_LOAD_DEFAULT }, 0, INT_MAX, FLAGS, "ft_load_flags" },
261         { "default",                     NULL, 0, AV_OPT_TYPE_CONST, { .i64 = FT_LOAD_DEFAULT },                     .flags = FLAGS, .unit = "ft_load_flags" },
262         { "no_scale",                    NULL, 0, AV_OPT_TYPE_CONST, { .i64 = FT_LOAD_NO_SCALE },                    .flags = FLAGS, .unit = "ft_load_flags" },
263         { "no_hinting",                  NULL, 0, AV_OPT_TYPE_CONST, { .i64 = FT_LOAD_NO_HINTING },                  .flags = FLAGS, .unit = "ft_load_flags" },
264         { "render",                      NULL, 0, AV_OPT_TYPE_CONST, { .i64 = FT_LOAD_RENDER },                      .flags = FLAGS, .unit = "ft_load_flags" },
265         { "no_bitmap",                   NULL, 0, AV_OPT_TYPE_CONST, { .i64 = FT_LOAD_NO_BITMAP },                   .flags = FLAGS, .unit = "ft_load_flags" },
266         { "vertical_layout",             NULL, 0, AV_OPT_TYPE_CONST, { .i64 = FT_LOAD_VERTICAL_LAYOUT },             .flags = FLAGS, .unit = "ft_load_flags" },
267         { "force_autohint",              NULL, 0, AV_OPT_TYPE_CONST, { .i64 = FT_LOAD_FORCE_AUTOHINT },              .flags = FLAGS, .unit = "ft_load_flags" },
268         { "crop_bitmap",                 NULL, 0, AV_OPT_TYPE_CONST, { .i64 = FT_LOAD_CROP_BITMAP },                 .flags = FLAGS, .unit = "ft_load_flags" },
269         { "pedantic",                    NULL, 0, AV_OPT_TYPE_CONST, { .i64 = FT_LOAD_PEDANTIC },                    .flags = FLAGS, .unit = "ft_load_flags" },
270         { "ignore_global_advance_width", NULL, 0, AV_OPT_TYPE_CONST, { .i64 = FT_LOAD_IGNORE_GLOBAL_ADVANCE_WIDTH }, .flags = FLAGS, .unit = "ft_load_flags" },
271         { "no_recurse",                  NULL, 0, AV_OPT_TYPE_CONST, { .i64 = FT_LOAD_NO_RECURSE },                  .flags = FLAGS, .unit = "ft_load_flags" },
272         { "ignore_transform",            NULL, 0, AV_OPT_TYPE_CONST, { .i64 = FT_LOAD_IGNORE_TRANSFORM },            .flags = FLAGS, .unit = "ft_load_flags" },
273         { "monochrome",                  NULL, 0, AV_OPT_TYPE_CONST, { .i64 = FT_LOAD_MONOCHROME },                  .flags = FLAGS, .unit = "ft_load_flags" },
274         { "linear_design",               NULL, 0, AV_OPT_TYPE_CONST, { .i64 = FT_LOAD_LINEAR_DESIGN },               .flags = FLAGS, .unit = "ft_load_flags" },
275         { "no_autohint",                 NULL, 0, AV_OPT_TYPE_CONST, { .i64 = FT_LOAD_NO_AUTOHINT },                 .flags = FLAGS, .unit = "ft_load_flags" },
276     { NULL }
277 };
278 
279 AVFILTER_DEFINE_CLASS(drawtext);
280 
281 #undef __FTERRORS_H__
282 #define FT_ERROR_START_LIST {
283 #define FT_ERRORDEF(e, v, s) { (e), (s) },
284 #define FT_ERROR_END_LIST { 0, NULL } };
285 
286 static const struct ft_error {
287     int err;
288     const char *err_msg;
289 } ft_errors[] =
290 #include FT_ERRORS_H
291 
292 #define FT_ERRMSG(e) ft_errors[e].err_msg
293 
294 typedef struct Glyph {
295     FT_Glyph glyph;
296     FT_Glyph border_glyph;
297     uint32_t code;
298     unsigned int fontsize;
299     FT_Bitmap bitmap; ///< array holding bitmaps of font
300     FT_Bitmap border_bitmap; ///< array holding bitmaps of font border
301     FT_BBox bbox;
302     int advance;
303     int bitmap_left;
304     int bitmap_top;
305 } Glyph;
306 
glyph_cmp(const void * key,const void * b)307 static int glyph_cmp(const void *key, const void *b)
308 {
309     const Glyph *a = key, *bb = b;
310     int64_t diff = (int64_t)a->code - (int64_t)bb->code;
311 
312     if (diff != 0)
313          return diff > 0 ? 1 : -1;
314     else
315          return FFDIFFSIGN((int64_t)a->fontsize, (int64_t)bb->fontsize);
316 }
317 
318 /**
319  * Load glyphs corresponding to the UTF-32 codepoint code.
320  */
load_glyph(AVFilterContext * ctx,Glyph ** glyph_ptr,uint32_t code)321 static int load_glyph(AVFilterContext *ctx, Glyph **glyph_ptr, uint32_t code)
322 {
323     DrawTextContext *s = ctx->priv;
324     FT_BitmapGlyph bitmapglyph;
325     Glyph *glyph;
326     struct AVTreeNode *node = NULL;
327     int ret;
328 
329     /* load glyph into s->face->glyph */
330     if (FT_Load_Char(s->face, code, s->ft_load_flags))
331         return AVERROR(EINVAL);
332 
333     glyph = av_mallocz(sizeof(*glyph));
334     if (!glyph) {
335         ret = AVERROR(ENOMEM);
336         goto error;
337     }
338     glyph->code  = code;
339     glyph->fontsize = s->fontsize;
340 
341     if (FT_Get_Glyph(s->face->glyph, &glyph->glyph)) {
342         ret = AVERROR(EINVAL);
343         goto error;
344     }
345     if (s->borderw) {
346         glyph->border_glyph = glyph->glyph;
347         if (FT_Glyph_StrokeBorder(&glyph->border_glyph, s->stroker, 0, 0) ||
348             FT_Glyph_To_Bitmap(&glyph->border_glyph, FT_RENDER_MODE_NORMAL, 0, 1)) {
349             ret = AVERROR_EXTERNAL;
350             goto error;
351         }
352         bitmapglyph = (FT_BitmapGlyph) glyph->border_glyph;
353         glyph->border_bitmap = bitmapglyph->bitmap;
354     }
355     if (FT_Glyph_To_Bitmap(&glyph->glyph, FT_RENDER_MODE_NORMAL, 0, 1)) {
356         ret = AVERROR_EXTERNAL;
357         goto error;
358     }
359     bitmapglyph = (FT_BitmapGlyph) glyph->glyph;
360 
361     glyph->bitmap      = bitmapglyph->bitmap;
362     glyph->bitmap_left = bitmapglyph->left;
363     glyph->bitmap_top  = bitmapglyph->top;
364     glyph->advance     = s->face->glyph->advance.x >> 6;
365 
366     /* measure text height to calculate text_height (or the maximum text height) */
367     FT_Glyph_Get_CBox(glyph->glyph, ft_glyph_bbox_pixels, &glyph->bbox);
368 
369     /* cache the newly created glyph */
370     if (!(node = av_tree_node_alloc())) {
371         ret = AVERROR(ENOMEM);
372         goto error;
373     }
374     av_tree_insert(&s->glyphs, glyph, glyph_cmp, &node);
375 
376     if (glyph_ptr)
377         *glyph_ptr = glyph;
378     return 0;
379 
380 error:
381     if (glyph)
382         av_freep(&glyph->glyph);
383 
384     av_freep(&glyph);
385     av_freep(&node);
386     return ret;
387 }
388 
set_fontsize(AVFilterContext * ctx,unsigned int fontsize)389 static av_cold int set_fontsize(AVFilterContext *ctx, unsigned int fontsize)
390 {
391     int err;
392     DrawTextContext *s = ctx->priv;
393 
394     if ((err = FT_Set_Pixel_Sizes(s->face, 0, fontsize))) {
395         av_log(ctx, AV_LOG_ERROR, "Could not set font size to %d pixels: %s\n",
396                fontsize, FT_ERRMSG(err));
397         return AVERROR(EINVAL);
398     }
399 
400     s->fontsize = fontsize;
401 
402     return 0;
403 }
404 
parse_fontsize(AVFilterContext * ctx)405 static av_cold int parse_fontsize(AVFilterContext *ctx)
406 {
407     DrawTextContext *s = ctx->priv;
408     int err;
409 
410     if (s->fontsize_pexpr)
411         return 0;
412 
413     if (s->fontsize_expr == NULL)
414         return AVERROR(EINVAL);
415 
416     if ((err = av_expr_parse(&s->fontsize_pexpr, s->fontsize_expr, var_names,
417                              NULL, NULL, fun2_names, fun2, 0, ctx)) < 0)
418         return err;
419 
420     return 0;
421 }
422 
update_fontsize(AVFilterContext * ctx)423 static av_cold int update_fontsize(AVFilterContext *ctx)
424 {
425     DrawTextContext *s = ctx->priv;
426     unsigned int fontsize = s->default_fontsize;
427     int err;
428     double size, roundedsize;
429 
430     // if no fontsize specified use the default
431     if (s->fontsize_expr != NULL) {
432         if ((err = parse_fontsize(ctx)) < 0)
433            return err;
434 
435         size = av_expr_eval(s->fontsize_pexpr, s->var_values, &s->prng);
436 
437         if (!isnan(size)) {
438             roundedsize = round(size);
439             // test for overflow before cast
440             if (!(roundedsize > INT_MIN && roundedsize < INT_MAX)) {
441                 av_log(ctx, AV_LOG_ERROR, "fontsize overflow\n");
442                 return AVERROR(EINVAL);
443             }
444 
445             fontsize = roundedsize;
446         }
447     }
448 
449     if (fontsize == 0)
450         fontsize = 1;
451 
452     // no change
453     if (fontsize == s->fontsize)
454         return 0;
455 
456     return set_fontsize(ctx, fontsize);
457 }
458 
load_font_file(AVFilterContext * ctx,const char * path,int index)459 static int load_font_file(AVFilterContext *ctx, const char *path, int index)
460 {
461     DrawTextContext *s = ctx->priv;
462     int err;
463 
464     err = FT_New_Face(s->library, path, index, &s->face);
465     if (err) {
466 #if !CONFIG_LIBFONTCONFIG
467         av_log(ctx, AV_LOG_ERROR, "Could not load font \"%s\": %s\n",
468                s->fontfile, FT_ERRMSG(err));
469 #endif
470         return AVERROR(EINVAL);
471     }
472     return 0;
473 }
474 
475 #if CONFIG_LIBFONTCONFIG
load_font_fontconfig(AVFilterContext * ctx)476 static int load_font_fontconfig(AVFilterContext *ctx)
477 {
478     DrawTextContext *s = ctx->priv;
479     FcConfig *fontconfig;
480     FcPattern *pat, *best;
481     FcResult result = FcResultMatch;
482     FcChar8 *filename;
483     int index;
484     double size;
485     int err = AVERROR(ENOENT);
486     int parse_err;
487 
488     fontconfig = FcInitLoadConfigAndFonts();
489     if (!fontconfig) {
490         av_log(ctx, AV_LOG_ERROR, "impossible to init fontconfig\n");
491         return AVERROR_UNKNOWN;
492     }
493     pat = FcNameParse(s->fontfile ? s->fontfile :
494                           (uint8_t *)(intptr_t)"default");
495     if (!pat) {
496         av_log(ctx, AV_LOG_ERROR, "could not parse fontconfig pat");
497         return AVERROR(EINVAL);
498     }
499 
500     FcPatternAddString(pat, FC_FAMILY, s->font);
501 
502     parse_err = parse_fontsize(ctx);
503     if (!parse_err) {
504         double size = av_expr_eval(s->fontsize_pexpr, s->var_values, &s->prng);
505 
506         if (isnan(size)) {
507             av_log(ctx, AV_LOG_ERROR, "impossible to find font information");
508             return AVERROR(EINVAL);
509         }
510 
511         FcPatternAddDouble(pat, FC_SIZE, size);
512     }
513 
514     FcDefaultSubstitute(pat);
515 
516     if (!FcConfigSubstitute(fontconfig, pat, FcMatchPattern)) {
517         av_log(ctx, AV_LOG_ERROR, "could not substitue fontconfig options"); /* very unlikely */
518         FcPatternDestroy(pat);
519         return AVERROR(ENOMEM);
520     }
521 
522     best = FcFontMatch(fontconfig, pat, &result);
523     FcPatternDestroy(pat);
524 
525     if (!best || result != FcResultMatch) {
526         av_log(ctx, AV_LOG_ERROR,
527                "Cannot find a valid font for the family %s\n",
528                s->font);
529         goto fail;
530     }
531 
532     if (
533         FcPatternGetInteger(best, FC_INDEX, 0, &index   ) != FcResultMatch ||
534         FcPatternGetDouble (best, FC_SIZE,  0, &size    ) != FcResultMatch) {
535         av_log(ctx, AV_LOG_ERROR, "impossible to find font information");
536         return AVERROR(EINVAL);
537     }
538 
539     if (FcPatternGetString(best, FC_FILE, 0, &filename) != FcResultMatch) {
540         av_log(ctx, AV_LOG_ERROR, "No file path for %s\n",
541                s->font);
542         goto fail;
543     }
544 
545     av_log(ctx, AV_LOG_INFO, "Using \"%s\"\n", filename);
546     if (parse_err)
547         s->default_fontsize = size + 0.5;
548 
549     err = load_font_file(ctx, filename, index);
550     if (err)
551         return err;
552     FcConfigDestroy(fontconfig);
553 fail:
554     FcPatternDestroy(best);
555     return err;
556 }
557 #endif
558 
load_font(AVFilterContext * ctx)559 static int load_font(AVFilterContext *ctx)
560 {
561     DrawTextContext *s = ctx->priv;
562     int err;
563 
564     /* load the face, and set up the encoding, which is by default UTF-8 */
565     err = load_font_file(ctx, s->fontfile, 0);
566     if (!err)
567         return 0;
568 #if CONFIG_LIBFONTCONFIG
569     err = load_font_fontconfig(ctx);
570     if (!err)
571         return 0;
572 #endif
573     return err;
574 }
575 
is_newline(uint32_t c)576 static inline int is_newline(uint32_t c)
577 {
578     return c == '\n' || c == '\r' || c == '\f' || c == '\v';
579 }
580 
load_textfile(AVFilterContext * ctx)581 static int load_textfile(AVFilterContext *ctx)
582 {
583     DrawTextContext *s = ctx->priv;
584     int err;
585     uint8_t *textbuf;
586     uint8_t *tmp;
587     size_t textbuf_size;
588 
589     if ((err = av_file_map(s->textfile, &textbuf, &textbuf_size, 0, ctx)) < 0) {
590         av_log(ctx, AV_LOG_ERROR,
591                "The text file '%s' could not be read or is empty\n",
592                s->textfile);
593         return err;
594     }
595 
596     if (textbuf_size > 0 && is_newline(textbuf[textbuf_size - 1]))
597         textbuf_size--;
598     if (textbuf_size > SIZE_MAX - 1 || !(tmp = av_realloc(s->text, textbuf_size + 1))) {
599         av_file_unmap(textbuf, textbuf_size);
600         return AVERROR(ENOMEM);
601     }
602     s->text = tmp;
603     memcpy(s->text, textbuf, textbuf_size);
604     s->text[textbuf_size] = 0;
605     av_file_unmap(textbuf, textbuf_size);
606 
607     return 0;
608 }
609 
610 #if CONFIG_LIBFRIBIDI
shape_text(AVFilterContext * ctx)611 static int shape_text(AVFilterContext *ctx)
612 {
613     DrawTextContext *s = ctx->priv;
614     uint8_t *tmp;
615     int ret = AVERROR(ENOMEM);
616     static const FriBidiFlags flags = FRIBIDI_FLAGS_DEFAULT |
617                                       FRIBIDI_FLAGS_ARABIC;
618     FriBidiChar *unicodestr = NULL;
619     FriBidiStrIndex len;
620     FriBidiParType direction = FRIBIDI_PAR_LTR;
621     FriBidiStrIndex line_start = 0;
622     FriBidiStrIndex line_end = 0;
623     FriBidiLevel *embedding_levels = NULL;
624     FriBidiArabicProp *ar_props = NULL;
625     FriBidiCharType *bidi_types = NULL;
626     FriBidiStrIndex i,j;
627 
628     len = strlen(s->text);
629     if (!(unicodestr = av_malloc_array(len, sizeof(*unicodestr)))) {
630         goto out;
631     }
632     len = fribidi_charset_to_unicode(FRIBIDI_CHAR_SET_UTF8,
633                                      s->text, len, unicodestr);
634 
635     bidi_types = av_malloc_array(len, sizeof(*bidi_types));
636     if (!bidi_types) {
637         goto out;
638     }
639 
640     fribidi_get_bidi_types(unicodestr, len, bidi_types);
641 
642     embedding_levels = av_malloc_array(len, sizeof(*embedding_levels));
643     if (!embedding_levels) {
644         goto out;
645     }
646 
647     if (!fribidi_get_par_embedding_levels(bidi_types, len, &direction,
648                                           embedding_levels)) {
649         goto out;
650     }
651 
652     ar_props = av_malloc_array(len, sizeof(*ar_props));
653     if (!ar_props) {
654         goto out;
655     }
656 
657     fribidi_get_joining_types(unicodestr, len, ar_props);
658     fribidi_join_arabic(bidi_types, len, embedding_levels, ar_props);
659     fribidi_shape(flags, embedding_levels, len, ar_props, unicodestr);
660 
661     for (line_end = 0, line_start = 0; line_end < len; line_end++) {
662         if (is_newline(unicodestr[line_end]) || line_end == len - 1) {
663             if (!fribidi_reorder_line(flags, bidi_types,
664                                       line_end - line_start + 1, line_start,
665                                       direction, embedding_levels, unicodestr,
666                                       NULL)) {
667                 goto out;
668             }
669             line_start = line_end + 1;
670         }
671     }
672 
673     /* Remove zero-width fill chars put in by libfribidi */
674     for (i = 0, j = 0; i < len; i++)
675         if (unicodestr[i] != FRIBIDI_CHAR_FILL)
676             unicodestr[j++] = unicodestr[i];
677     len = j;
678 
679     if (!(tmp = av_realloc(s->text, (len * 4 + 1) * sizeof(*s->text)))) {
680         /* Use len * 4, as a unicode character can be up to 4 bytes in UTF-8 */
681         goto out;
682     }
683 
684     s->text = tmp;
685     len = fribidi_unicode_to_charset(FRIBIDI_CHAR_SET_UTF8,
686                                      unicodestr, len, s->text);
687     ret = 0;
688 
689 out:
690     av_free(unicodestr);
691     av_free(embedding_levels);
692     av_free(ar_props);
693     av_free(bidi_types);
694     return ret;
695 }
696 #endif
697 
text_source_string_parse(const char * text_source_string)698 static enum AVFrameSideDataType text_source_string_parse(const char *text_source_string)
699 {
700     av_assert0(text_source_string);
701     if (!strcmp(text_source_string, "side_data_detection_bboxes")) {
702         return AV_FRAME_DATA_DETECTION_BBOXES;
703     } else {
704         return AVERROR(EINVAL);
705     }
706 }
707 
init(AVFilterContext * ctx)708 static av_cold int init(AVFilterContext *ctx)
709 {
710     int err;
711     DrawTextContext *s = ctx->priv;
712     Glyph *glyph;
713 
714     av_expr_free(s->fontsize_pexpr);
715     s->fontsize_pexpr = NULL;
716 
717     s->fontsize = 0;
718     s->default_fontsize = 16;
719 
720     if (!s->fontfile && !CONFIG_LIBFONTCONFIG) {
721         av_log(ctx, AV_LOG_ERROR, "No font filename provided\n");
722         return AVERROR(EINVAL);
723     }
724 
725     if (s->textfile) {
726         if (s->text) {
727             av_log(ctx, AV_LOG_ERROR,
728                    "Both text and text file provided. Please provide only one\n");
729             return AVERROR(EINVAL);
730         }
731         if ((err = load_textfile(ctx)) < 0)
732             return err;
733     }
734 
735     if (s->reload && !s->textfile)
736         av_log(ctx, AV_LOG_WARNING, "No file to reload\n");
737 
738     if (s->tc_opt_string) {
739         int ret = av_timecode_init_from_string(&s->tc, s->tc_rate,
740                                                s->tc_opt_string, ctx);
741         if (ret < 0)
742             return ret;
743         if (s->tc24hmax)
744             s->tc.flags |= AV_TIMECODE_FLAG_24HOURSMAX;
745         if (!s->text)
746             s->text = av_strdup("");
747     }
748 
749     if (s->text_source_string) {
750         s->text_source = text_source_string_parse(s->text_source_string);
751         if ((int)s->text_source < 0) {
752             av_log(ctx, AV_LOG_ERROR, "Error text source: %s\n", s->text_source_string);
753             return AVERROR(EINVAL);
754         }
755     }
756 
757     if (s->text_source == AV_FRAME_DATA_DETECTION_BBOXES) {
758         if (s->text) {
759             av_log(ctx, AV_LOG_WARNING, "Multiple texts provided, will use text_source only\n");
760             av_free(s->text);
761         }
762         s->text = av_mallocz(AV_DETECTION_BBOX_LABEL_NAME_MAX_SIZE *
763                              (AV_NUM_DETECTION_BBOX_CLASSIFY + 1));
764         if (!s->text)
765             return AVERROR(ENOMEM);
766     }
767 
768     if (!s->text) {
769         av_log(ctx, AV_LOG_ERROR,
770                "Either text, a valid file, a timecode or text source must be provided\n");
771         return AVERROR(EINVAL);
772     }
773 
774 #if CONFIG_LIBFRIBIDI
775     if (s->text_shaping)
776         if ((err = shape_text(ctx)) < 0)
777             return err;
778 #endif
779 
780     if ((err = FT_Init_FreeType(&(s->library)))) {
781         av_log(ctx, AV_LOG_ERROR,
782                "Could not load FreeType: %s\n", FT_ERRMSG(err));
783         return AVERROR(EINVAL);
784     }
785 
786     if ((err = load_font(ctx)) < 0)
787         return err;
788 
789     if ((err = update_fontsize(ctx)) < 0)
790         return err;
791 
792     if (s->borderw) {
793         if (FT_Stroker_New(s->library, &s->stroker)) {
794             av_log(ctx, AV_LOG_ERROR, "Coult not init FT stroker\n");
795             return AVERROR_EXTERNAL;
796         }
797         FT_Stroker_Set(s->stroker, s->borderw << 6, FT_STROKER_LINECAP_ROUND,
798                        FT_STROKER_LINEJOIN_ROUND, 0);
799     }
800 
801     s->use_kerning = FT_HAS_KERNING(s->face);
802 
803     /* load the fallback glyph with code 0 */
804     load_glyph(ctx, NULL, 0);
805 
806     /* set the tabsize in pixels */
807     if ((err = load_glyph(ctx, &glyph, ' ')) < 0) {
808         av_log(ctx, AV_LOG_ERROR, "Could not set tabsize.\n");
809         return err;
810     }
811     s->tabsize *= glyph->advance;
812 
813     if (s->exp_mode == EXP_STRFTIME &&
814         (strchr(s->text, '%') || strchr(s->text, '\\')))
815         av_log(ctx, AV_LOG_WARNING, "expansion=strftime is deprecated.\n");
816 
817     av_bprint_init(&s->expanded_text, 0, AV_BPRINT_SIZE_UNLIMITED);
818     av_bprint_init(&s->expanded_fontcolor, 0, AV_BPRINT_SIZE_UNLIMITED);
819 
820     return 0;
821 }
822 
query_formats(AVFilterContext * ctx)823 static int query_formats(AVFilterContext *ctx)
824 {
825     return ff_set_common_formats(ctx, ff_draw_supported_pixel_formats(0));
826 }
827 
glyph_enu_free(void * opaque,void * elem)828 static int glyph_enu_free(void *opaque, void *elem)
829 {
830     Glyph *glyph = elem;
831 
832     FT_Done_Glyph(glyph->glyph);
833     FT_Done_Glyph(glyph->border_glyph);
834     av_free(elem);
835     return 0;
836 }
837 
uninit(AVFilterContext * ctx)838 static av_cold void uninit(AVFilterContext *ctx)
839 {
840     DrawTextContext *s = ctx->priv;
841 
842     av_expr_free(s->x_pexpr);
843     av_expr_free(s->y_pexpr);
844     av_expr_free(s->a_pexpr);
845     av_expr_free(s->fontsize_pexpr);
846 
847     s->x_pexpr = s->y_pexpr = s->a_pexpr = s->fontsize_pexpr = NULL;
848 
849     av_freep(&s->positions);
850     s->nb_positions = 0;
851 
852     av_tree_enumerate(s->glyphs, NULL, NULL, glyph_enu_free);
853     av_tree_destroy(s->glyphs);
854     s->glyphs = NULL;
855 
856     FT_Done_Face(s->face);
857     FT_Stroker_Done(s->stroker);
858     FT_Done_FreeType(s->library);
859 
860     av_bprint_finalize(&s->expanded_text, NULL);
861     av_bprint_finalize(&s->expanded_fontcolor, NULL);
862 }
863 
config_input(AVFilterLink * inlink)864 static int config_input(AVFilterLink *inlink)
865 {
866     AVFilterContext *ctx = inlink->dst;
867     DrawTextContext *s = ctx->priv;
868     char *expr;
869     int ret;
870 
871     ff_draw_init(&s->dc, inlink->format, FF_DRAW_PROCESS_ALPHA);
872     ff_draw_color(&s->dc, &s->fontcolor,   s->fontcolor.rgba);
873     ff_draw_color(&s->dc, &s->shadowcolor, s->shadowcolor.rgba);
874     ff_draw_color(&s->dc, &s->bordercolor, s->bordercolor.rgba);
875     ff_draw_color(&s->dc, &s->boxcolor,    s->boxcolor.rgba);
876 
877     s->var_values[VAR_w]     = s->var_values[VAR_W]     = s->var_values[VAR_MAIN_W] = inlink->w;
878     s->var_values[VAR_h]     = s->var_values[VAR_H]     = s->var_values[VAR_MAIN_H] = inlink->h;
879     s->var_values[VAR_SAR]   = inlink->sample_aspect_ratio.num ? av_q2d(inlink->sample_aspect_ratio) : 1;
880     s->var_values[VAR_DAR]   = (double)inlink->w / inlink->h * s->var_values[VAR_SAR];
881     s->var_values[VAR_HSUB]  = 1 << s->dc.hsub_max;
882     s->var_values[VAR_VSUB]  = 1 << s->dc.vsub_max;
883     s->var_values[VAR_X]     = NAN;
884     s->var_values[VAR_Y]     = NAN;
885     s->var_values[VAR_T]     = NAN;
886 
887     av_lfg_init(&s->prng, av_get_random_seed());
888 
889     av_expr_free(s->x_pexpr);
890     av_expr_free(s->y_pexpr);
891     av_expr_free(s->a_pexpr);
892     s->x_pexpr = s->y_pexpr = s->a_pexpr = NULL;
893 
894     if ((ret = av_expr_parse(&s->x_pexpr, expr = s->x_expr, var_names,
895                              NULL, NULL, fun2_names, fun2, 0, ctx)) < 0 ||
896         (ret = av_expr_parse(&s->y_pexpr, expr = s->y_expr, var_names,
897                              NULL, NULL, fun2_names, fun2, 0, ctx)) < 0 ||
898         (ret = av_expr_parse(&s->a_pexpr, expr = s->a_expr, var_names,
899                              NULL, NULL, fun2_names, fun2, 0, ctx)) < 0) {
900         av_log(ctx, AV_LOG_ERROR, "Failed to parse expression: %s \n", expr);
901         return AVERROR(EINVAL);
902     }
903 
904     return 0;
905 }
906 
command(AVFilterContext * ctx,const char * cmd,const char * arg,char * res,int res_len,int flags)907 static int command(AVFilterContext *ctx, const char *cmd, const char *arg, char *res, int res_len, int flags)
908 {
909     DrawTextContext *old = ctx->priv;
910     DrawTextContext *new = NULL;
911     int ret;
912 
913     if (!strcmp(cmd, "reinit")) {
914         new = av_mallocz(sizeof(DrawTextContext));
915         if (!new)
916             return AVERROR(ENOMEM);
917 
918         new->class = &drawtext_class;
919         ret = av_opt_copy(new, old);
920         if (ret < 0)
921             goto fail;
922 
923         ctx->priv = new;
924         ret = av_set_options_string(ctx, arg, "=", ":");
925         if (ret < 0) {
926             ctx->priv = old;
927             goto fail;
928         }
929 
930         ret = init(ctx);
931         if (ret < 0) {
932             uninit(ctx);
933             ctx->priv = old;
934             goto fail;
935         }
936 
937         new->reinit = 1;
938 
939         ctx->priv = old;
940         uninit(ctx);
941         av_freep(&old);
942 
943         ctx->priv = new;
944         return config_input(ctx->inputs[0]);
945     } else
946         return AVERROR(ENOSYS);
947 
948 fail:
949     av_log(ctx, AV_LOG_ERROR, "Failed to process command. Continuing with existing parameters.\n");
950     av_freep(&new);
951     return ret;
952 }
953 
func_pict_type(AVFilterContext * ctx,AVBPrint * bp,char * fct,unsigned argc,char ** argv,int tag)954 static int func_pict_type(AVFilterContext *ctx, AVBPrint *bp,
955                           char *fct, unsigned argc, char **argv, int tag)
956 {
957     DrawTextContext *s = ctx->priv;
958 
959     av_bprintf(bp, "%c", av_get_picture_type_char(s->var_values[VAR_PICT_TYPE]));
960     return 0;
961 }
962 
func_pts(AVFilterContext * ctx,AVBPrint * bp,char * fct,unsigned argc,char ** argv,int tag)963 static int func_pts(AVFilterContext *ctx, AVBPrint *bp,
964                     char *fct, unsigned argc, char **argv, int tag)
965 {
966     DrawTextContext *s = ctx->priv;
967     const char *fmt;
968     double pts = s->var_values[VAR_T];
969     int ret;
970 
971     fmt = argc >= 1 ? argv[0] : "flt";
972     if (argc >= 2) {
973         int64_t delta;
974         if ((ret = av_parse_time(&delta, argv[1], 1)) < 0) {
975             av_log(ctx, AV_LOG_ERROR, "Invalid delta '%s'\n", argv[1]);
976             return ret;
977         }
978         pts += (double)delta / AV_TIME_BASE;
979     }
980     if (!strcmp(fmt, "flt")) {
981         av_bprintf(bp, "%.6f", pts);
982     } else if (!strcmp(fmt, "hms")) {
983         if (isnan(pts)) {
984             av_bprintf(bp, " ??:??:??.???");
985         } else {
986             int64_t ms = llrint(pts * 1000);
987             char sign = ' ';
988             if (ms < 0) {
989                 sign = '-';
990                 ms = -ms;
991             }
992             if (argc >= 3) {
993                 if (!strcmp(argv[2], "24HH")) {
994                     ms %= 24 * 60 * 60 * 1000;
995                 } else {
996                     av_log(ctx, AV_LOG_ERROR, "Invalid argument '%s'\n", argv[2]);
997                     return AVERROR(EINVAL);
998                 }
999             }
1000             av_bprintf(bp, "%c%02d:%02d:%02d.%03d", sign,
1001                        (int)(ms / (60 * 60 * 1000)),
1002                        (int)(ms / (60 * 1000)) % 60,
1003                        (int)(ms / 1000) % 60,
1004                        (int)(ms % 1000));
1005         }
1006     } else if (!strcmp(fmt, "localtime") ||
1007                !strcmp(fmt, "gmtime")) {
1008         struct tm tm;
1009         time_t ms = (time_t)pts;
1010         const char *timefmt = argc >= 3 ? argv[2] : "%Y-%m-%d %H:%M:%S";
1011         if (!strcmp(fmt, "localtime"))
1012             localtime_r(&ms, &tm);
1013         else
1014             gmtime_r(&ms, &tm);
1015         av_bprint_strftime(bp, timefmt, &tm);
1016     } else {
1017         av_log(ctx, AV_LOG_ERROR, "Invalid format '%s'\n", fmt);
1018         return AVERROR(EINVAL);
1019     }
1020     return 0;
1021 }
1022 
func_frame_num(AVFilterContext * ctx,AVBPrint * bp,char * fct,unsigned argc,char ** argv,int tag)1023 static int func_frame_num(AVFilterContext *ctx, AVBPrint *bp,
1024                           char *fct, unsigned argc, char **argv, int tag)
1025 {
1026     DrawTextContext *s = ctx->priv;
1027 
1028     av_bprintf(bp, "%d", (int)s->var_values[VAR_N]);
1029     return 0;
1030 }
1031 
func_metadata(AVFilterContext * ctx,AVBPrint * bp,char * fct,unsigned argc,char ** argv,int tag)1032 static int func_metadata(AVFilterContext *ctx, AVBPrint *bp,
1033                          char *fct, unsigned argc, char **argv, int tag)
1034 {
1035     DrawTextContext *s = ctx->priv;
1036     AVDictionaryEntry *e = av_dict_get(s->metadata, argv[0], NULL, 0);
1037 
1038     if (e && e->value)
1039         av_bprintf(bp, "%s", e->value);
1040     else if (argc >= 2)
1041         av_bprintf(bp, "%s", argv[1]);
1042     return 0;
1043 }
1044 
func_strftime(AVFilterContext * ctx,AVBPrint * bp,char * fct,unsigned argc,char ** argv,int tag)1045 static int func_strftime(AVFilterContext *ctx, AVBPrint *bp,
1046                          char *fct, unsigned argc, char **argv, int tag)
1047 {
1048     const char *fmt = argc ? argv[0] : "%Y-%m-%d %H:%M:%S";
1049     const char *fmt_begin = fmt;
1050     int64_t unow;
1051     time_t now;
1052     struct tm tm;
1053     const char *begin;
1054     const char *tmp;
1055     int len;
1056     int div;
1057     AVBPrint fmt_bp;
1058 
1059     av_bprint_init(&fmt_bp, 0, AV_BPRINT_SIZE_UNLIMITED);
1060 
1061     unow = av_gettime();
1062     now  = unow / 1000000;
1063     if (tag == 'L' || tag == 'm')
1064         localtime_r(&now, &tm);
1065     else
1066         tm = *gmtime_r(&now, &tm);
1067 
1068     // manually parse format for %N (fractional seconds)
1069     begin = fmt;
1070     while ((begin = strchr(begin, '%'))) {
1071         tmp = begin + 1;
1072         len = 0;
1073 
1074         // skip escaped "%%"
1075         if (*tmp == '%') {
1076             begin = tmp + 1;
1077             continue;
1078         }
1079 
1080         // count digits between % and possible N
1081         while (*tmp != '\0' && av_isdigit((int)*tmp)) {
1082             len++;
1083             tmp++;
1084         }
1085 
1086         // N encountered, insert time
1087         if (*tmp == 'N') {
1088             int num_digits = 3; // default show millisecond [1,6]
1089 
1090             // if digit given, expect [1,6], warn & clamp otherwise
1091             if (len == 1) {
1092                 num_digits = av_clip(*(begin + 1) - '0', 1, 6);
1093             } else if (len > 1) {
1094                 av_log(ctx, AV_LOG_WARNING, "Invalid number of decimals for %%N, using default of %i\n", num_digits);
1095             }
1096 
1097             len += 2; // add % and N to get length of string part
1098 
1099             div = pow(10, 6 - num_digits);
1100 
1101             av_bprintf(&fmt_bp, "%.*s%0*d", (int)(begin - fmt_begin), fmt_begin, num_digits, (int)(unow % 1000000) / div);
1102 
1103             begin += len;
1104             fmt_begin = begin;
1105 
1106             continue;
1107         }
1108 
1109         begin = tmp;
1110     }
1111 
1112     av_bprintf(&fmt_bp, "%s", fmt_begin);
1113     if (!av_bprint_is_complete(&fmt_bp)) {
1114         av_log(ctx, AV_LOG_WARNING, "Format string truncated at %u/%u.", fmt_bp.size, fmt_bp.len);
1115     }
1116 
1117     av_bprint_strftime(bp, fmt_bp.str, &tm);
1118 
1119     av_bprint_finalize(&fmt_bp, NULL);
1120 
1121     return 0;
1122 }
1123 
func_eval_expr(AVFilterContext * ctx,AVBPrint * bp,char * fct,unsigned argc,char ** argv,int tag)1124 static int func_eval_expr(AVFilterContext *ctx, AVBPrint *bp,
1125                           char *fct, unsigned argc, char **argv, int tag)
1126 {
1127     DrawTextContext *s = ctx->priv;
1128     double res;
1129     int ret;
1130 
1131     ret = av_expr_parse_and_eval(&res, argv[0], var_names, s->var_values,
1132                                  NULL, NULL, fun2_names, fun2,
1133                                  &s->prng, 0, ctx);
1134     if (ret < 0)
1135         av_log(ctx, AV_LOG_ERROR,
1136                "Expression '%s' for the expr text expansion function is not valid\n",
1137                argv[0]);
1138     else
1139         av_bprintf(bp, "%f", res);
1140 
1141     return ret;
1142 }
1143 
func_eval_expr_int_format(AVFilterContext * ctx,AVBPrint * bp,char * fct,unsigned argc,char ** argv,int tag)1144 static int func_eval_expr_int_format(AVFilterContext *ctx, AVBPrint *bp,
1145                           char *fct, unsigned argc, char **argv, int tag)
1146 {
1147     DrawTextContext *s = ctx->priv;
1148     double res;
1149     int intval;
1150     int ret;
1151     unsigned int positions = 0;
1152     char fmt_str[30] = "%";
1153 
1154     /*
1155      * argv[0] expression to be converted to `int`
1156      * argv[1] format: 'x', 'X', 'd' or 'u'
1157      * argv[2] positions printed (optional)
1158      */
1159 
1160     ret = av_expr_parse_and_eval(&res, argv[0], var_names, s->var_values,
1161                                  NULL, NULL, fun2_names, fun2,
1162                                  &s->prng, 0, ctx);
1163     if (ret < 0) {
1164         av_log(ctx, AV_LOG_ERROR,
1165                "Expression '%s' for the expr text expansion function is not valid\n",
1166                argv[0]);
1167         return ret;
1168     }
1169 
1170     if (!strchr("xXdu", argv[1][0])) {
1171         av_log(ctx, AV_LOG_ERROR, "Invalid format '%c' specified,"
1172                 " allowed values: 'x', 'X', 'd', 'u'\n", argv[1][0]);
1173         return AVERROR(EINVAL);
1174     }
1175 
1176     if (argc == 3) {
1177         ret = sscanf(argv[2], "%u", &positions);
1178         if (ret != 1) {
1179             av_log(ctx, AV_LOG_ERROR, "expr_int_format(): Invalid number of positions"
1180                     " to print: '%s'\n", argv[2]);
1181             return AVERROR(EINVAL);
1182         }
1183     }
1184 
1185     feclearexcept(FE_ALL_EXCEPT);
1186     intval = res;
1187 #if defined(FE_INVALID) && defined(FE_OVERFLOW) && defined(FE_UNDERFLOW)
1188     if ((ret = fetestexcept(FE_INVALID|FE_OVERFLOW|FE_UNDERFLOW))) {
1189         av_log(ctx, AV_LOG_ERROR, "Conversion of floating-point result to int failed. Control register: 0x%08x. Conversion result: %d\n", ret, intval);
1190         return AVERROR(EINVAL);
1191     }
1192 #endif
1193 
1194     if (argc == 3)
1195         av_strlcatf(fmt_str, sizeof(fmt_str), "0%u", positions);
1196     av_strlcatf(fmt_str, sizeof(fmt_str), "%c", argv[1][0]);
1197 
1198     av_log(ctx, AV_LOG_DEBUG, "Formatting value %f (expr '%s') with spec '%s'\n",
1199             res, argv[0], fmt_str);
1200 
1201     av_bprintf(bp, fmt_str, intval);
1202 
1203     return 0;
1204 }
1205 
1206 static const struct drawtext_function {
1207     const char *name;
1208     unsigned argc_min, argc_max;
1209     int tag;                            /**< opaque argument to func */
1210     int (*func)(AVFilterContext *, AVBPrint *, char *, unsigned, char **, int);
1211 } functions[] = {
1212     { "expr",      1, 1, 0,   func_eval_expr },
1213     { "e",         1, 1, 0,   func_eval_expr },
1214     { "expr_int_format", 2, 3, 0, func_eval_expr_int_format },
1215     { "eif",       2, 3, 0,   func_eval_expr_int_format },
1216     { "pict_type", 0, 0, 0,   func_pict_type },
1217     { "pts",       0, 3, 0,   func_pts      },
1218     { "gmtime",    0, 1, 'G', func_strftime },
1219     { "localtime", 0, 1, 'L', func_strftime },
1220     { "frame_num", 0, 0, 0,   func_frame_num },
1221     { "n",         0, 0, 0,   func_frame_num },
1222     { "metadata",  1, 2, 0,   func_metadata },
1223 };
1224 
eval_function(AVFilterContext * ctx,AVBPrint * bp,char * fct,unsigned argc,char ** argv)1225 static int eval_function(AVFilterContext *ctx, AVBPrint *bp, char *fct,
1226                          unsigned argc, char **argv)
1227 {
1228     unsigned i;
1229 
1230     for (i = 0; i < FF_ARRAY_ELEMS(functions); i++) {
1231         if (strcmp(fct, functions[i].name))
1232             continue;
1233         if (argc < functions[i].argc_min) {
1234             av_log(ctx, AV_LOG_ERROR, "%%{%s} requires at least %d arguments\n",
1235                    fct, functions[i].argc_min);
1236             return AVERROR(EINVAL);
1237         }
1238         if (argc > functions[i].argc_max) {
1239             av_log(ctx, AV_LOG_ERROR, "%%{%s} requires at most %d arguments\n",
1240                    fct, functions[i].argc_max);
1241             return AVERROR(EINVAL);
1242         }
1243         break;
1244     }
1245     if (i >= FF_ARRAY_ELEMS(functions)) {
1246         av_log(ctx, AV_LOG_ERROR, "%%{%s} is not known\n", fct);
1247         return AVERROR(EINVAL);
1248     }
1249     return functions[i].func(ctx, bp, fct, argc, argv, functions[i].tag);
1250 }
1251 
expand_function(AVFilterContext * ctx,AVBPrint * bp,char ** rtext)1252 static int expand_function(AVFilterContext *ctx, AVBPrint *bp, char **rtext)
1253 {
1254     const char *text = *rtext;
1255     char *argv[16] = { NULL };
1256     unsigned argc = 0, i;
1257     int ret;
1258 
1259     if (*text != '{') {
1260         av_log(ctx, AV_LOG_ERROR, "Stray %% near '%s'\n", text);
1261         return AVERROR(EINVAL);
1262     }
1263     text++;
1264     while (1) {
1265         if (!(argv[argc++] = av_get_token(&text, ":}"))) {
1266             ret = AVERROR(ENOMEM);
1267             goto end;
1268         }
1269         if (!*text) {
1270             av_log(ctx, AV_LOG_ERROR, "Unterminated %%{} near '%s'\n", *rtext);
1271             ret = AVERROR(EINVAL);
1272             goto end;
1273         }
1274         if (argc == FF_ARRAY_ELEMS(argv))
1275             av_freep(&argv[--argc]); /* error will be caught later */
1276         if (*text == '}')
1277             break;
1278         text++;
1279     }
1280 
1281     if ((ret = eval_function(ctx, bp, argv[0], argc - 1, argv + 1)) < 0)
1282         goto end;
1283     ret = 0;
1284     *rtext = (char *)text + 1;
1285 
1286 end:
1287     for (i = 0; i < argc; i++)
1288         av_freep(&argv[i]);
1289     return ret;
1290 }
1291 
expand_text(AVFilterContext * ctx,char * text,AVBPrint * bp)1292 static int expand_text(AVFilterContext *ctx, char *text, AVBPrint *bp)
1293 {
1294     int ret;
1295 
1296     av_bprint_clear(bp);
1297     while (*text) {
1298         if (*text == '\\' && text[1]) {
1299             av_bprint_chars(bp, text[1], 1);
1300             text += 2;
1301         } else if (*text == '%') {
1302             text++;
1303             if ((ret = expand_function(ctx, bp, &text)) < 0)
1304                 return ret;
1305         } else {
1306             av_bprint_chars(bp, *text, 1);
1307             text++;
1308         }
1309     }
1310     if (!av_bprint_is_complete(bp))
1311         return AVERROR(ENOMEM);
1312     return 0;
1313 }
1314 
draw_glyphs(DrawTextContext * s,AVFrame * frame,int width,int height,FFDrawColor * color,int x,int y,int borderw)1315 static int draw_glyphs(DrawTextContext *s, AVFrame *frame,
1316                        int width, int height,
1317                        FFDrawColor *color,
1318                        int x, int y, int borderw)
1319 {
1320     char *text = s->expanded_text.str;
1321     uint32_t code = 0;
1322     int i, x1, y1;
1323     uint8_t *p;
1324     Glyph *glyph = NULL;
1325 
1326     for (i = 0, p = text; *p; i++) {
1327         FT_Bitmap bitmap;
1328         Glyph dummy = { 0 };
1329         GET_UTF8(code, *p ? *p++ : 0, code = 0xfffd; goto continue_on_invalid;);
1330 continue_on_invalid:
1331 
1332         /* skip new line chars, just go to new line */
1333         if (code == '\n' || code == '\r' || code == '\t')
1334             continue;
1335 
1336         dummy.code = code;
1337         dummy.fontsize = s->fontsize;
1338         glyph = av_tree_find(s->glyphs, &dummy, glyph_cmp, NULL);
1339 
1340         bitmap = borderw ? glyph->border_bitmap : glyph->bitmap;
1341 
1342         if (glyph->bitmap.pixel_mode != FT_PIXEL_MODE_MONO &&
1343             glyph->bitmap.pixel_mode != FT_PIXEL_MODE_GRAY)
1344             return AVERROR(EINVAL);
1345 
1346         x1 = s->positions[i].x+s->x+x - borderw;
1347         y1 = s->positions[i].y+s->y+y - borderw;
1348 
1349         ff_blend_mask(&s->dc, color,
1350                       frame->data, frame->linesize, width, height,
1351                       bitmap.buffer, bitmap.pitch,
1352                       bitmap.width, bitmap.rows,
1353                       bitmap.pixel_mode == FT_PIXEL_MODE_MONO ? 0 : 3,
1354                       0, x1, y1);
1355     }
1356 
1357     return 0;
1358 }
1359 
1360 
update_color_with_alpha(DrawTextContext * s,FFDrawColor * color,const FFDrawColor incolor)1361 static void update_color_with_alpha(DrawTextContext *s, FFDrawColor *color, const FFDrawColor incolor)
1362 {
1363     *color = incolor;
1364     color->rgba[3] = (color->rgba[3] * s->alpha) / 255;
1365     ff_draw_color(&s->dc, color, color->rgba);
1366 }
1367 
update_alpha(DrawTextContext * s)1368 static void update_alpha(DrawTextContext *s)
1369 {
1370     double alpha = av_expr_eval(s->a_pexpr, s->var_values, &s->prng);
1371 
1372     if (isnan(alpha))
1373         return;
1374 
1375     if (alpha >= 1.0)
1376         s->alpha = 255;
1377     else if (alpha <= 0)
1378         s->alpha = 0;
1379     else
1380         s->alpha = 256 * alpha;
1381 }
1382 
draw_text(AVFilterContext * ctx,AVFrame * frame,int width,int height)1383 static int draw_text(AVFilterContext *ctx, AVFrame *frame,
1384                      int width, int height)
1385 {
1386     DrawTextContext *s = ctx->priv;
1387     AVFilterLink *inlink = ctx->inputs[0];
1388 
1389     uint32_t code = 0, prev_code = 0;
1390     int x = 0, y = 0, i = 0, ret;
1391     int max_text_line_w = 0, len;
1392     int box_w, box_h;
1393     char *text;
1394     uint8_t *p;
1395     int y_min = 32000, y_max = -32000;
1396     int x_min = 32000, x_max = -32000;
1397     FT_Vector delta;
1398     Glyph *glyph = NULL, *prev_glyph = NULL;
1399     Glyph dummy = { 0 };
1400 
1401     time_t now = time(0);
1402     struct tm ltime;
1403     AVBPrint *bp = &s->expanded_text;
1404 
1405     FFDrawColor fontcolor;
1406     FFDrawColor shadowcolor;
1407     FFDrawColor bordercolor;
1408     FFDrawColor boxcolor;
1409 
1410     av_bprint_clear(bp);
1411 
1412     if(s->basetime != AV_NOPTS_VALUE)
1413         now= frame->pts*av_q2d(ctx->inputs[0]->time_base) + s->basetime/1000000;
1414 
1415     switch (s->exp_mode) {
1416     case EXP_NONE:
1417         av_bprintf(bp, "%s", s->text);
1418         break;
1419     case EXP_NORMAL:
1420         if ((ret = expand_text(ctx, s->text, &s->expanded_text)) < 0)
1421             return ret;
1422         break;
1423     case EXP_STRFTIME:
1424         localtime_r(&now, &ltime);
1425         av_bprint_strftime(bp, s->text, &ltime);
1426         break;
1427     }
1428 
1429     if (s->tc_opt_string) {
1430         char tcbuf[AV_TIMECODE_STR_SIZE];
1431         av_timecode_make_string(&s->tc, tcbuf, inlink->frame_count_out);
1432         av_bprint_clear(bp);
1433         av_bprintf(bp, "%s%s", s->text, tcbuf);
1434     }
1435 
1436     if (!av_bprint_is_complete(bp))
1437         return AVERROR(ENOMEM);
1438     text = s->expanded_text.str;
1439     if ((len = s->expanded_text.len) > s->nb_positions) {
1440         if (!(s->positions =
1441               av_realloc(s->positions, len*sizeof(*s->positions))))
1442             return AVERROR(ENOMEM);
1443         s->nb_positions = len;
1444     }
1445 
1446     if (s->fontcolor_expr[0]) {
1447         /* If expression is set, evaluate and replace the static value */
1448         av_bprint_clear(&s->expanded_fontcolor);
1449         if ((ret = expand_text(ctx, s->fontcolor_expr, &s->expanded_fontcolor)) < 0)
1450             return ret;
1451         if (!av_bprint_is_complete(&s->expanded_fontcolor))
1452             return AVERROR(ENOMEM);
1453         av_log(s, AV_LOG_DEBUG, "Evaluated fontcolor is '%s'\n", s->expanded_fontcolor.str);
1454         ret = av_parse_color(s->fontcolor.rgba, s->expanded_fontcolor.str, -1, s);
1455         if (ret)
1456             return ret;
1457         ff_draw_color(&s->dc, &s->fontcolor, s->fontcolor.rgba);
1458     }
1459 
1460     x = 0;
1461     y = 0;
1462 
1463     if ((ret = update_fontsize(ctx)) < 0)
1464         return ret;
1465 
1466     /* load and cache glyphs */
1467     for (i = 0, p = text; *p; i++) {
1468         GET_UTF8(code, *p ? *p++ : 0, code = 0xfffd; goto continue_on_invalid;);
1469 continue_on_invalid:
1470 
1471         /* get glyph */
1472         dummy.code = code;
1473         dummy.fontsize = s->fontsize;
1474         glyph = av_tree_find(s->glyphs, &dummy, glyph_cmp, NULL);
1475         if (!glyph) {
1476             ret = load_glyph(ctx, &glyph, code);
1477             if (ret < 0)
1478                 return ret;
1479         }
1480 
1481         y_min = FFMIN(glyph->bbox.yMin, y_min);
1482         y_max = FFMAX(glyph->bbox.yMax, y_max);
1483         x_min = FFMIN(glyph->bbox.xMin, x_min);
1484         x_max = FFMAX(glyph->bbox.xMax, x_max);
1485     }
1486     s->max_glyph_h = y_max - y_min;
1487     s->max_glyph_w = x_max - x_min;
1488 
1489     /* compute and save position for each glyph */
1490     glyph = NULL;
1491     for (i = 0, p = text; *p; i++) {
1492         GET_UTF8(code, *p ? *p++ : 0, code = 0xfffd; goto continue_on_invalid2;);
1493 continue_on_invalid2:
1494 
1495         /* skip the \n in the sequence \r\n */
1496         if (prev_code == '\r' && code == '\n')
1497             continue;
1498 
1499         prev_code = code;
1500         if (is_newline(code)) {
1501 
1502             max_text_line_w = FFMAX(max_text_line_w, x);
1503             y += s->max_glyph_h + s->line_spacing;
1504             x = 0;
1505             continue;
1506         }
1507 
1508         /* get glyph */
1509         prev_glyph = glyph;
1510         dummy.code = code;
1511         dummy.fontsize = s->fontsize;
1512         glyph = av_tree_find(s->glyphs, &dummy, glyph_cmp, NULL);
1513 
1514         /* kerning */
1515         if (s->use_kerning && prev_glyph && glyph->code) {
1516             FT_Get_Kerning(s->face, prev_glyph->code, glyph->code,
1517                            ft_kerning_default, &delta);
1518             x += delta.x >> 6;
1519         }
1520 
1521         /* save position */
1522         s->positions[i].x = x + glyph->bitmap_left;
1523         s->positions[i].y = y - glyph->bitmap_top + y_max;
1524         if (code == '\t') x  = (x / s->tabsize + 1)*s->tabsize;
1525         else              x += glyph->advance;
1526     }
1527 
1528     max_text_line_w = FFMAX(x, max_text_line_w);
1529 
1530     s->var_values[VAR_TW] = s->var_values[VAR_TEXT_W] = max_text_line_w;
1531     s->var_values[VAR_TH] = s->var_values[VAR_TEXT_H] = y + s->max_glyph_h;
1532 
1533     s->var_values[VAR_MAX_GLYPH_W] = s->max_glyph_w;
1534     s->var_values[VAR_MAX_GLYPH_H] = s->max_glyph_h;
1535     s->var_values[VAR_MAX_GLYPH_A] = s->var_values[VAR_ASCENT ] = y_max;
1536     s->var_values[VAR_MAX_GLYPH_D] = s->var_values[VAR_DESCENT] = y_min;
1537 
1538     s->var_values[VAR_LINE_H] = s->var_values[VAR_LH] = s->max_glyph_h;
1539 
1540     if (s->text_source == AV_FRAME_DATA_DETECTION_BBOXES) {
1541         s->var_values[VAR_X] = s->x;
1542         s->var_values[VAR_Y] = s->y;
1543     } else {
1544         s->x = s->var_values[VAR_X] = av_expr_eval(s->x_pexpr, s->var_values, &s->prng);
1545         s->y = s->var_values[VAR_Y] = av_expr_eval(s->y_pexpr, s->var_values, &s->prng);
1546         /* It is necessary if x is expressed from y  */
1547         s->x = s->var_values[VAR_X] = av_expr_eval(s->x_pexpr, s->var_values, &s->prng);
1548     }
1549 
1550     update_alpha(s);
1551     update_color_with_alpha(s, &fontcolor  , s->fontcolor  );
1552     update_color_with_alpha(s, &shadowcolor, s->shadowcolor);
1553     update_color_with_alpha(s, &bordercolor, s->bordercolor);
1554     update_color_with_alpha(s, &boxcolor   , s->boxcolor   );
1555 
1556     box_w = max_text_line_w;
1557     box_h = y + s->max_glyph_h;
1558 
1559     if (s->fix_bounds) {
1560 
1561         /* calculate footprint of text effects */
1562         int boxoffset     = s->draw_box ? FFMAX(s->boxborderw, 0) : 0;
1563         int borderoffset  = s->borderw  ? FFMAX(s->borderw, 0) : 0;
1564 
1565         int offsetleft = FFMAX3(boxoffset, borderoffset,
1566                                 (s->shadowx < 0 ? FFABS(s->shadowx) : 0));
1567         int offsettop = FFMAX3(boxoffset, borderoffset,
1568                                 (s->shadowy < 0 ? FFABS(s->shadowy) : 0));
1569 
1570         int offsetright = FFMAX3(boxoffset, borderoffset,
1571                                  (s->shadowx > 0 ? s->shadowx : 0));
1572         int offsetbottom = FFMAX3(boxoffset, borderoffset,
1573                                   (s->shadowy > 0 ? s->shadowy : 0));
1574 
1575 
1576         if (s->x - offsetleft < 0) s->x = offsetleft;
1577         if (s->y - offsettop < 0)  s->y = offsettop;
1578 
1579         if (s->x + box_w + offsetright > width)
1580             s->x = FFMAX(width - box_w - offsetright, 0);
1581         if (s->y + box_h + offsetbottom > height)
1582             s->y = FFMAX(height - box_h - offsetbottom, 0);
1583     }
1584 
1585     /* draw box */
1586     if (s->draw_box)
1587         ff_blend_rectangle(&s->dc, &boxcolor,
1588                            frame->data, frame->linesize, width, height,
1589                            s->x - s->boxborderw, s->y - s->boxborderw,
1590                            box_w + s->boxborderw * 2, box_h + s->boxborderw * 2);
1591 
1592     if (s->shadowx || s->shadowy) {
1593         if ((ret = draw_glyphs(s, frame, width, height,
1594                                &shadowcolor, s->shadowx, s->shadowy, 0)) < 0)
1595             return ret;
1596     }
1597 
1598     if (s->borderw) {
1599         if ((ret = draw_glyphs(s, frame, width, height,
1600                                &bordercolor, 0, 0, s->borderw)) < 0)
1601             return ret;
1602     }
1603     if ((ret = draw_glyphs(s, frame, width, height,
1604                            &fontcolor, 0, 0, 0)) < 0)
1605         return ret;
1606 
1607     return 0;
1608 }
1609 
filter_frame(AVFilterLink * inlink,AVFrame * frame)1610 static int filter_frame(AVFilterLink *inlink, AVFrame *frame)
1611 {
1612     AVFilterContext *ctx = inlink->dst;
1613     AVFilterLink *outlink = ctx->outputs[0];
1614     DrawTextContext *s = ctx->priv;
1615     int ret;
1616     const AVDetectionBBoxHeader *header = NULL;
1617     const AVDetectionBBox *bbox;
1618     AVFrameSideData *sd;
1619     int loop = 1;
1620 
1621     if (s->text_source == AV_FRAME_DATA_DETECTION_BBOXES) {
1622         sd = av_frame_get_side_data(frame, AV_FRAME_DATA_DETECTION_BBOXES);
1623         if (sd) {
1624             header = (AVDetectionBBoxHeader *)sd->data;
1625             loop = header->nb_bboxes;
1626         } else {
1627             av_log(s, AV_LOG_WARNING, "No detection bboxes.\n");
1628             return ff_filter_frame(outlink, frame);
1629         }
1630     }
1631 
1632     if (s->reload && !(inlink->frame_count_out % s->reload)) {
1633         if ((ret = load_textfile(ctx)) < 0) {
1634             av_frame_free(&frame);
1635             return ret;
1636         }
1637 #if CONFIG_LIBFRIBIDI
1638         if (s->text_shaping)
1639             if ((ret = shape_text(ctx)) < 0) {
1640                 av_frame_free(&frame);
1641                 return ret;
1642             }
1643 #endif
1644     }
1645 
1646     s->var_values[VAR_N] = inlink->frame_count_out + s->start_number;
1647     s->var_values[VAR_T] = frame->pts == AV_NOPTS_VALUE ?
1648         NAN : frame->pts * av_q2d(inlink->time_base);
1649 
1650     s->var_values[VAR_PICT_TYPE] = frame->pict_type;
1651     s->var_values[VAR_PKT_POS] = frame->pkt_pos;
1652     s->var_values[VAR_PKT_DURATION] = frame->pkt_duration * av_q2d(inlink->time_base);
1653     s->var_values[VAR_PKT_SIZE] = frame->pkt_size;
1654     s->metadata = frame->metadata;
1655 
1656     for (int i = 0; i < loop; i++) {
1657         if (header) {
1658             bbox = av_get_detection_bbox(header, i);
1659             strcpy(s->text, bbox->detect_label);
1660             for (int j = 0; j < bbox->classify_count; j++) {
1661                 strcat(s->text, ", ");
1662                 strcat(s->text, bbox->classify_labels[j]);
1663             }
1664             s->x = bbox->x;
1665             s->y = bbox->y - s->fontsize;
1666         }
1667         draw_text(ctx, frame, frame->width, frame->height);
1668     }
1669 
1670     av_log(ctx, AV_LOG_DEBUG, "n:%d t:%f text_w:%d text_h:%d x:%d y:%d\n",
1671            (int)s->var_values[VAR_N], s->var_values[VAR_T],
1672            (int)s->var_values[VAR_TEXT_W], (int)s->var_values[VAR_TEXT_H],
1673            s->x, s->y);
1674 
1675     return ff_filter_frame(outlink, frame);
1676 }
1677 
1678 static const AVFilterPad avfilter_vf_drawtext_inputs[] = {
1679     {
1680         .name           = "default",
1681         .type           = AVMEDIA_TYPE_VIDEO,
1682         .flags          = AVFILTERPAD_FLAG_NEEDS_WRITABLE,
1683         .filter_frame   = filter_frame,
1684         .config_props   = config_input,
1685     },
1686 };
1687 
1688 static const AVFilterPad avfilter_vf_drawtext_outputs[] = {
1689     {
1690         .name = "default",
1691         .type = AVMEDIA_TYPE_VIDEO,
1692     },
1693 };
1694 
1695 const AVFilter ff_vf_drawtext = {
1696     .name          = "drawtext",
1697     .description   = NULL_IF_CONFIG_SMALL("Draw text on top of video frames using libfreetype library."),
1698     .priv_size     = sizeof(DrawTextContext),
1699     .priv_class    = &drawtext_class,
1700     .init          = init,
1701     .uninit        = uninit,
1702     FILTER_INPUTS(avfilter_vf_drawtext_inputs),
1703     FILTER_OUTPUTS(avfilter_vf_drawtext_outputs),
1704     FILTER_QUERY_FUNC(query_formats),
1705     .process_command = command,
1706     .flags         = AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC,
1707 };
1708