34 #include <sys/types.h> 
   42 #if CONFIG_LIBFONTCONFIG 
   43 #include <fontconfig/fontconfig.h> 
   69 #include FT_FREETYPE_H 
   79     "max_glyph_a", 
"ascent",  
 
   80     "max_glyph_d", 
"descent", 
 
   98 static double drand(
void *opaque, 
double min, 
double max)
 
  141 #if CONFIG_LIBFONTCONFIG 
  196 #if CONFIG_LIBFRIBIDI 
  202 #define OFFSET(x) offsetof(DrawTextContext, x) 
  203 #define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM 
  225 #if CONFIG_LIBFONTCONFIG 
  242     {
"start_number", 
"start frame number for n/frame_num variable", 
OFFSET(start_number), 
AV_OPT_TYPE_INT, {.i64=0}, 0, INT_MAX, 
FLAGS},
 
  244 #if CONFIG_LIBFRIBIDI 
  249     { 
"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" },
 
  255         { 
"vertical_layout",             
NULL, 0, 
AV_OPT_TYPE_CONST, { .i64 = FT_LOAD_VERTICAL_LAYOUT },             .flags = 
FLAGS, .unit = 
"ft_load_flags" },
 
  259         { 
"ignore_global_advance_width", 
NULL, 0, 
AV_OPT_TYPE_CONST, { .i64 = FT_LOAD_IGNORE_GLOBAL_ADVANCE_WIDTH }, .flags = 
FLAGS, .unit = 
"ft_load_flags" },
 
  261         { 
"ignore_transform",            
NULL, 0, 
AV_OPT_TYPE_CONST, { .i64 = FT_LOAD_IGNORE_TRANSFORM },            .flags = 
FLAGS, .unit = 
"ft_load_flags" },
 
  270 #undef __FTERRORS_H__ 
  271 #define FT_ERROR_START_LIST { 
  272 #define FT_ERRORDEF(e, v, s) { (e), (s) }, 
  273 #define FT_ERROR_END_LIST { 0, NULL } }; 
  281 #define FT_ERRMSG(e) ft_errors[e].err_msg 
  283 typedef struct Glyph {
 
  285     FT_Glyph border_glyph;
 
  287     unsigned int fontsize;
 
  289     FT_Bitmap border_bitmap; 
 
  298     const Glyph *
a = 
key, *bb = 
b;
 
  299     int64_t 
diff = (int64_t)a->code - (int64_t)bb->code;
 
  302          return diff > 0 ? 1 : -1;
 
  304          return FFDIFFSIGN((int64_t)a->fontsize, (int64_t)bb->fontsize);
 
  313     FT_BitmapGlyph bitmapglyph;
 
  330     if (FT_Get_Glyph(s->
face->glyph, &glyph->glyph)) {
 
  335         glyph->border_glyph = glyph->glyph;
 
  336         if (FT_Glyph_StrokeBorder(&glyph->border_glyph, s->
stroker, 0, 0) ||
 
  337             FT_Glyph_To_Bitmap(&glyph->border_glyph, FT_RENDER_MODE_NORMAL, 0, 1)) {
 
  341         bitmapglyph = (FT_BitmapGlyph) glyph->border_glyph;
 
  342         glyph->border_bitmap = bitmapglyph->bitmap;
 
  344     if (FT_Glyph_To_Bitmap(&glyph->glyph, FT_RENDER_MODE_NORMAL, 0, 1)) {
 
  348     bitmapglyph = (FT_BitmapGlyph) glyph->glyph;
 
  350     glyph->bitmap      = bitmapglyph->bitmap;
 
  351     glyph->bitmap_left = bitmapglyph->left;
 
  352     glyph->bitmap_top  = bitmapglyph->top;
 
  353     glyph->advance     = s->
face->glyph->advance.x >> 6;
 
  356     FT_Glyph_Get_CBox(glyph->glyph, ft_glyph_bbox_pixels, &glyph->bbox);
 
  383     if ((err = FT_Set_Pixel_Sizes(s->
face, 0, fontsize))) {
 
  417     double size, roundedsize;
 
  427             roundedsize = 
round(size);
 
  429             if (!(roundedsize > INT_MIN && roundedsize < INT_MAX)) {
 
  434             fontsize = roundedsize;
 
  453     err = FT_New_Face(s->
library, path, index, &s->
face);
 
  455 #if !CONFIG_LIBFONTCONFIG 
  464 #if CONFIG_LIBFONTCONFIG 
  468     FcConfig *fontconfig;
 
  469     FcPattern *pat, *best;
 
  470     FcResult result = FcResultMatch;
 
  477     fontconfig = FcInitLoadConfigAndFonts();
 
  483                           (
uint8_t *)(intptr_t)
"default");
 
  489     FcPatternAddString(pat, FC_FAMILY, s->font);
 
  500         FcPatternAddDouble(pat, FC_SIZE, size);
 
  503     FcDefaultSubstitute(pat);
 
  505     if (!FcConfigSubstitute(fontconfig, pat, FcMatchPattern)) {
 
  507         FcPatternDestroy(pat);
 
  511     best = FcFontMatch(fontconfig, pat, &result);
 
  512     FcPatternDestroy(pat);
 
  514     if (!best || result != FcResultMatch) {
 
  516                "Cannot find a valid font for the family %s\n",
 
  522         FcPatternGetInteger(best, FC_INDEX, 0, &index   ) != FcResultMatch ||
 
  523         FcPatternGetDouble (best, FC_SIZE,  0, &size    ) != FcResultMatch) {
 
  528     if (FcPatternGetString(best, FC_FILE, 0, &filename) != FcResultMatch) {
 
  541     FcConfigDestroy(fontconfig);
 
  543     FcPatternDestroy(best);
 
  557 #if CONFIG_LIBFONTCONFIG 
  558     err = load_font_fontconfig(ctx);
 
  575                "The text file '%s' could not be read or is empty\n",
 
  580     if (textbuf_size > SIZE_MAX - 1 || !(tmp = 
av_realloc(s->
text, textbuf_size + 1))) {
 
  585     memcpy(s->
text, textbuf, textbuf_size);
 
  586     s->
text[textbuf_size] = 0;
 
  594     return c == 
'\n' || c == 
'\r' || c == 
'\f' || c == 
'\v';
 
  597 #if CONFIG_LIBFRIBIDI 
  603     static const FriBidiFlags 
flags = FRIBIDI_FLAGS_DEFAULT |
 
  604                                       FRIBIDI_FLAGS_ARABIC;
 
  605     FriBidiChar *unicodestr = 
NULL;
 
  607     FriBidiParType direction = FRIBIDI_PAR_LTR;
 
  608     FriBidiStrIndex line_start = 0;
 
  609     FriBidiStrIndex line_end = 0;
 
  610     FriBidiLevel *embedding_levels = 
NULL;
 
  611     FriBidiArabicProp *ar_props = 
NULL;
 
  612     FriBidiCharType *bidi_types = 
NULL;
 
  615     len = strlen(s->
text);
 
  619     len = fribidi_charset_to_unicode(FRIBIDI_CHAR_SET_UTF8,
 
  620                                      s->
text, len, unicodestr);
 
  627     fribidi_get_bidi_types(unicodestr, len, bidi_types);
 
  630     if (!embedding_levels) {
 
  634     if (!fribidi_get_par_embedding_levels(bidi_types, len, &direction,
 
  644     fribidi_get_joining_types(unicodestr, len, ar_props);
 
  645     fribidi_join_arabic(bidi_types, len, embedding_levels, ar_props);
 
  646     fribidi_shape(flags, embedding_levels, len, ar_props, unicodestr);
 
  648     for (line_end = 0, line_start = 0; line_end < 
len; line_end++) {
 
  649         if (
is_newline(unicodestr[line_end]) || line_end == len - 1) {
 
  650             if (!fribidi_reorder_line(flags, bidi_types,
 
  651                                       line_end - line_start + 1, line_start,
 
  652                                       direction, embedding_levels, unicodestr,
 
  656             line_start = line_end + 1;
 
  661     for (i = 0, j = 0; i < 
len; i++)
 
  662         if (unicodestr[i] != FRIBIDI_CHAR_FILL)
 
  663             unicodestr[j++] = unicodestr[i];
 
  672     len = fribidi_unicode_to_charset(FRIBIDI_CHAR_SET_UTF8,
 
  673                                      unicodestr, len, s->
text);
 
  697     if (!s->
fontfile && !CONFIG_LIBFONTCONFIG) {
 
  705                    "Both text and text file provided. Please provide only one\n");
 
  728                "Either text, a valid file or a timecode must be provided\n");
 
  732 #if CONFIG_LIBFRIBIDI 
  734         if ((err = shape_text(ctx)) < 0)
 
  738     if ((err = FT_Init_FreeType(&(s->
library)))) {
 
  740                "Could not load FreeType: %s\n", 
FT_ERRMSG(err));
 
  755         FT_Stroker_Set(s->
stroker, s->
borderw << 6, FT_STROKER_LINECAP_ROUND,
 
  756                        FT_STROKER_LINEJOIN_ROUND, 0);
 
  765     if ((err = 
load_glyph(ctx, &glyph, 
' ')) < 0) {
 
  772         (strchr(s->
text, 
'%') || strchr(s->
text, 
'\\')))
 
  790     FT_Done_Glyph(glyph->glyph);
 
  791     FT_Done_Glyph(glyph->border_glyph);
 
  814     FT_Done_Face(s->
face);
 
  867     if (!strcmp(cmd, 
"reinit")) {
 
  873         if ((ret = 
init(ctx)) < 0)
 
  882                           char *fct, 
unsigned argc, 
char **argv, 
int tag)
 
  891                     char *fct, 
unsigned argc, 
char **argv, 
int tag)
 
  898     fmt = argc >= 1 ? argv[0] : 
"flt";
 
  907     if (!strcmp(fmt, 
"flt")) {
 
  909     } 
else if (!strcmp(fmt, 
"hms")) {
 
  913             int64_t ms = 
llrint(pts * 1000);
 
  920                        (
int)(ms / (60 * 60 * 1000)),
 
  921                        (
int)(ms / (60 * 1000)) % 60,
 
  922                        (
int)(ms / 1000) % 60,
 
  925     } 
else if (!strcmp(fmt, 
"localtime") ||
 
  926                !strcmp(fmt, 
"gmtime")) {
 
  928         time_t ms = (time_t)pts;
 
  929         const char *timefmt = argc >= 3 ? argv[2] : 
"%Y-%m-%d %H:%M:%S";
 
  930         if (!strcmp(fmt, 
"localtime"))
 
  943                           char *fct, 
unsigned argc, 
char **argv, 
int tag)
 
  952                          char *fct, 
unsigned argc, 
char **argv, 
int tag)
 
  965                          char *fct, 
unsigned argc, 
char **argv, 
int tag)
 
  967     const char *
fmt = argc ? argv[0] : 
"%Y-%m-%d %H:%M:%S";
 
  981                           char *fct, 
unsigned argc, 
char **argv, 
int tag)
 
  992                "Expression '%s' for the expr text expansion function is not valid\n",
 
 1001                           char *fct, 
unsigned argc, 
char **argv, 
int tag)
 
 1008     char fmt_str[30] = 
"%";
 
 1021                "Expression '%s' for the expr text expansion function is not valid\n",
 
 1026     if (!strchr(
"xXdu", argv[1][0])) {
 
 1028                 " allowed values: 'x', 'X', 'd', 'u'\n", argv[1][0]);
 
 1033         ret = sscanf(argv[2], 
"%u", &positions);
 
 1036                     " to print: '%s'\n", argv[2]);
 
 1041     feclearexcept(FE_ALL_EXCEPT);
 
 1043     if ((ret = fetestexcept(FE_INVALID|FE_OVERFLOW|FE_UNDERFLOW))) {
 
 1044         av_log(ctx, 
AV_LOG_ERROR, 
"Conversion of floating-point result to int failed. Control register: 0x%08x. Conversion result: %d\n", ret, intval);
 
 1049         av_strlcatf(fmt_str, 
sizeof(fmt_str), 
"0%u", positions);
 
 1050     av_strlcatf(fmt_str, 
sizeof(fmt_str), 
"%c", argv[1][0]);
 
 1053             res, argv[0], fmt_str);
 
 1080                          unsigned argc, 
char **argv)
 
 1108     const char *text = *rtext;
 
 1109     char *argv[16] = { 
NULL };
 
 1110     unsigned argc = 0, i;
 
 1135     if ((ret = 
eval_function(ctx, bp, argv[0], argc - 1, argv + 1)) < 0)
 
 1138     *rtext = (
char *)text + 1;
 
 1141     for (i = 0; i < argc; i++)
 
 1152         if (*text == 
'\\' && text[1]) {
 
 1155         } 
else if (*text == 
'%') {
 
 1172                        int x, 
int y, 
int borderw)
 
 1178     Glyph *glyph = 
NULL;
 
 1180     for (i = 0, p = text; *p; i++) {
 
 1182         Glyph 
dummy = { 0 };
 
 1186         if (code == 
'\n' || code == 
'\r' || code == 
'\t')
 
 1193         bitmap = borderw ? glyph->border_bitmap : glyph->bitmap;
 
 1195         if (glyph->bitmap.pixel_mode != FT_PIXEL_MODE_MONO &&
 
 1196             glyph->bitmap.pixel_mode != FT_PIXEL_MODE_GRAY)
 
 1204                       bitmap.buffer, bitmap.pitch,
 
 1205                       bitmap.width, bitmap.rows,
 
 1206                       bitmap.pixel_mode == FT_PIXEL_MODE_MONO ? 0 : 3,
 
 1230     else if (alpha <= 0)
 
 1242     uint32_t code = 0, prev_code = 0;
 
 1243     int x = 0, y = 0, i = 0, ret;
 
 1244     int max_text_line_w = 0, 
len;
 
 1248     int y_min = 32000, y_max = -32000;
 
 1249     int x_min = 32000, x_max = -32000;
 
 1251     Glyph *glyph = 
NULL, *prev_glyph = 
NULL;
 
 1252     Glyph 
dummy = { 0 };
 
 1254     time_t now = time(0);
 
 1320     for (i = 0, p = text; *p; i++) {
 
 1333         y_min = 
FFMIN(glyph->bbox.yMin, y_min);
 
 1334         y_max = 
FFMAX(glyph->bbox.yMax, y_max);
 
 1335         x_min = 
FFMIN(glyph->bbox.xMin, x_min);
 
 1336         x_max = 
FFMAX(glyph->bbox.xMax, x_max);
 
 1343     for (i = 0, p = text; *p; i++) {
 
 1347         if (prev_code == 
'\r' && code == 
'\n')
 
 1353             max_text_line_w = 
FFMAX(max_text_line_w, x);
 
 1366         if (s->
use_kerning && prev_glyph && glyph->code) {
 
 1367             FT_Get_Kerning(s->
face, prev_glyph->code, glyph->code,
 
 1368                            ft_kerning_default, &delta);
 
 1373         s->
positions[i].x = x + glyph->bitmap_left;
 
 1374         s->
positions[i].y = y - glyph->bitmap_top + y_max;
 
 1376         else              x += glyph->advance;
 
 1379     max_text_line_w = 
FFMAX(x, max_text_line_w);
 
 1402     box_w = 
FFMIN(width - 1 , max_text_line_w);
 
 1411         int offsetleft = 
FFMAX3(boxoffset, borderoffset,
 
 1413         int offsettop = 
FFMAX3(boxoffset, borderoffset,
 
 1416         int offsetright = 
FFMAX3(boxoffset, borderoffset,
 
 1418         int offsetbottom = 
FFMAX3(boxoffset, borderoffset,
 
 1422         if (s->
x - offsetleft < 0) s->
x = offsetleft;
 
 1423         if (s->
y - offsettop < 0)  s->
y = offsettop;
 
 1425         if (s->
x + box_w + offsetright > width)
 
 1426             s->
x = 
FFMAX(width - box_w - offsetright, 0);
 
 1427         if (s->
y + box_h + offsetbottom > height)
 
 1428             s->
y = 
FFMAX(height - box_h - offsetbottom, 0);
 
 1446                                &bordercolor, 0, 0, s->
borderw)) < 0)
 
 1450                            &fontcolor, 0, 0, 0)) < 0)
 
 1468 #if CONFIG_LIBFRIBIDI 
 1469         if (s->text_shaping)
 
 1470             if ((ret = shape_text(ctx)) < 0) {
 
 1500         .needs_writable = 1,
 
 1515     .description   = 
NULL_IF_CONFIG_SMALL(
"Draw text on top of video frames using libfreetype library."),
 
 1517     .priv_class    = &drawtext_class,
 
 1521     .
inputs        = avfilter_vf_drawtext_inputs,
 
 1522     .
outputs       = avfilter_vf_drawtext_outputs,
 
AVFilterFormats * ff_draw_supported_pixel_formats(unsigned flags)
Return the list of pixel formats supported by the draw functions. 
 
static int func_frame_num(AVFilterContext *ctx, AVBPrint *bp, char *fct, unsigned argc, char **argv, int tag)
 
char * y_expr
expression for y position 
 
void av_bprintf(AVBPrint *buf, const char *fmt,...)
 
#define GET_UTF8(val, GET_BYTE, ERROR)
Convert a UTF-8 character (up to 4 bytes) to its 32-bit UCS-4 encoded form. 
 
static float alpha(float a)
 
int tc24hmax
1 if timecode is wrapped to 24 hours, 0 otherwise 
 
This structure describes decoded (raw) audio or video data. 
 
uint8_t * fontcolor_expr
fontcolor expression to evaluate 
 
void * av_realloc(void *ptr, size_t size)
Allocate, reallocate, or free a block of memory. 
 
int x
x position to start drawing text 
 
static double drand(void *opaque, double min, double max)
 
static int func_metadata(AVFilterContext *ctx, AVBPrint *bp, char *fct, unsigned argc, char **argv, int tag)
 
static const AVOption drawtext_options[]
 
unsigned int fontsize
font size to use 
 
FFDrawColor boxcolor
background color 
 
#define AV_LOG_WARNING
Something somehow does not look correct. 
 
static av_cold int parse_fontsize(AVFilterContext *ctx)
 
char * x_expr
expression for x position 
 
Main libavfilter public API header. 
 
uint8_t * fontfile
font to be used 
 
int av_parse_time(int64_t *timeval, const char *timestr, int duration)
Parse timestr and return in *time a corresponding number of microseconds. 
 
int h
agreed upon image height 
 
static const struct drawtext_function functions[]
 
int av_set_options_string(void *ctx, const char *opts, const char *key_val_sep, const char *pairs_sep)
Parse the key/value pairs list in opts. 
 
static int draw_text(AVFilterContext *ctx, AVFrame *frame, int width, int height)
 
uint8_t * text
text to be drawn 
 
void * av_tree_find(const AVTreeNode *t, void *key, int(*cmp)(const void *key, const void *b), void *next[2])
 
void * av_mallocz(size_t size)
Allocate a memory block with alignment suitable for all memory accesses (including vectors if availab...
 
int av_expr_parse(AVExpr **expr, const char *s, const char *const *const_names, const char *const *func1_names, double(*const *funcs1)(void *, double), const char *const *func2_names, double(*const *funcs2)(void *, double, double), int log_offset, void *log_ctx)
Parse an expression. 
 
char * tc_opt_string
specified timecode option string 
 
static void drawtext(AVFrame *pic, int x, int y, const char *txt, int o)
 
static int draw_glyphs(DrawTextContext *s, AVFrame *frame, int width, int height, FFDrawColor *color, int x, int y, int borderw)
 
int(* func)(AVFilterContext *, AVBPrint *, char *, unsigned, char **, int)
 
int av_bprint_finalize(AVBPrint *buf, char **ret_str)
Finalize a print buffer. 
 
int boxborderw
box border width 
 
#define AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC
Some filters support a generic "enable" expression option that can be used to enable or disable a fil...
 
struct AVTreeNode * av_tree_node_alloc(void)
Allocate an AVTreeNode. 
 
const char * name
Pad name. 
 
AVFilterLink ** inputs
array of pointers to input links 
 
int av_timecode_init_from_string(AVTimecode *tc, AVRational rate, const char *str, void *log_ctx)
Parse timecode representation (hh:mm:ss[:;. 
 
int ff_filter_frame(AVFilterLink *link, AVFrame *frame)
Send a frame of data to the next filter. 
 
FT_Stroker stroker
freetype stroker handle 
 
static int glyph_enu_free(void *opaque, void *elem)
 
static int func_pict_type(AVFilterContext *ctx, AVBPrint *bp, char *fct, unsigned argc, char **argv, int tag)
 
AVExpr * fontsize_pexpr
parsed expressions for fontsize 
 
static av_cold int end(AVCodecContext *avctx)
 
FT_Face face
freetype font face handle 
 
static int glyph_cmp(const void *key, const void *b)
 
int64_t pts
Presentation timestamp in time_base units (time when frame should be shown to user). 
 
static av_cold int init(AVFilterContext *ctx)
 
int start_number
starting frame number for n/frame_num var 
 
static int load_font_file(AVFilterContext *ctx, const char *path, int index)
 
static const AVFilterPad avfilter_vf_drawtext_inputs[]
 
AVDictionaryEntry * av_dict_get(const AVDictionary *m, const char *key, const AVDictionaryEntry *prev, int flags)
Get a dictionary entry with matching key. 
 
static double av_q2d(AVRational a)
Convert an AVRational to a double. 
 
char av_get_picture_type_char(enum AVPictureType pict_type)
Return a single letter to describe the given picture type pict_type. 
 
AVDictionary * metadata
metadata. 
 
static av_cold void uninit(AVFilterContext *ctx)
 
FT_Vector * positions
positions for each element in the text 
 
void av_tree_destroy(AVTreeNode *t)
 
int av_parse_color(uint8_t *rgba_color, const char *color_string, int slen, void *log_ctx)
Put the RGBA values that correspond to color_string in rgba_color. 
 
A filter pad used for either input or output. 
 
A link between two filters. 
 
int av_expr_parse_and_eval(double *d, const char *s, const char *const *const_names, const double *const_values, const char *const *func1_names, double(*const *funcs1)(void *, double), const char *const *func2_names, double(*const *funcs2)(void *, double, double), void *opaque, int log_offset, void *log_ctx)
Parse and evaluate an expression. 
 
double var_values[VAR_VARS_NB]
 
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered. 
 
void av_file_unmap(uint8_t *bufptr, size_t size)
Unmap or free the buffer bufptr created by av_file_map(). 
 
AVBPrint expanded_text
used to contain the expanded text 
 
int av_file_map(const char *filename, uint8_t **bufptr, size_t *size, int log_offset, void *log_ctx)
Read the file with name filename, and put its content in a newly allocated buffer or map it with mmap...
 
#define AV_BPRINT_SIZE_UNLIMITED
 
static const uint16_t positions[][14][3]
 
void av_frame_free(AVFrame **frame)
Free the frame and any dynamically allocated objects in it, e.g. 
 
AVExpr * y_pexpr
parsed expressions for x and y 
 
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
 
void av_bprint_init(AVBPrint *buf, unsigned size_init, unsigned size_max)
 
void * priv
private data for use by the filter 
 
#define AV_LOG_DEBUG
Stuff which is only useful for libav* developers. 
 
int y
y position to start drawing text 
 
void ff_draw_color(FFDrawContext *draw, FFDrawColor *color, const uint8_t rgba[4])
Prepare a color. 
 
static int expand_function(AVFilterContext *ctx, AVBPrint *bp, char **rtext)
 
AVRational time_base
Define the time base used by the PTS of the frames/samples which will pass through this link...
 
static av_always_inline av_const double round(double x)
 
FFDrawColor fontcolor
foreground color 
 
char * av_get_token(const char **buf, const char *term)
Unescape the given string until a non escaped terminating char, and return the token corresponding to...
 
static const char *const fun2_names[]
 
static struct tm * gmtime_r(const time_t *clock, struct tm *result)
 
int reload
reload text file for each frame 
 
AVBPrint expanded_fontcolor
used to contain the expanded fontcolor spec 
 
int w
agreed upon image width 
 
#define FFDIFFSIGN(x, y)
Comparator. 
 
static const struct ft_error ft_errors[]
 
enum AVPictureType pict_type
Picture type of the frame. 
 
#define FF_DRAW_PROCESS_ALPHA
Process alpha pixel component. 
 
#define AV_TIME_BASE
Internal time base represented as integer. 
 
static struct tm * localtime_r(const time_t *clock, struct tm *result)
 
int64_t basetime
base pts time in the real world for display 
 
char * fontsize_expr
expression for fontsize 
 
int max_glyph_h
max glyph height 
 
AVRational tc_rate
frame rate for timecode 
 
#define FFABS(a)
Absolute value, Note, INT_MIN / INT64_MIN result in undefined behavior as they are not representable ...
 
static int av_bprint_is_complete(const AVBPrint *buf)
Test if the print buffer is complete (not truncated). 
 
static const AVFilterPad inputs[]
 
static int func_eval_expr(AVFilterContext *ctx, AVBPrint *bp, char *fct, unsigned argc, char **argv, int tag)
 
double(* eval_func2)(void *, double a, double b)
 
static void error(const char *err)
 
static const AVFilterPad outputs[]
 
int format
agreed upon media format 
 
#define FF_ARRAY_ELEMS(a)
 
AVTimecode tc
timecode context 
 
static void update_color_with_alpha(DrawTextContext *s, FFDrawColor *color, const FFDrawColor incolor)
 
void ff_blend_mask(FFDrawContext *draw, FFDrawColor *color, uint8_t *dst[], int dst_linesize[], int dst_w, int dst_h, const uint8_t *mask, int mask_linesize, int mask_w, int mask_h, int l2depth, unsigned endianness, int x0, int y0)
Blend an alpha mask with an uniform color. 
 
static int process_command(AVFilterContext *ctx, const char *cmd, const char *args, char *res, int res_len, int flags)
 
#define AV_LOG_INFO
Standard information. 
 
char * av_strdup(const char *s)
Duplicate a string. 
 
void av_expr_free(AVExpr *e)
Free a parsed expression previously created with av_expr_parse(). 
 
int linesize[AV_NUM_DATA_POINTERS]
For video, size in bytes of each picture line. 
 
static int load_font(AVFilterContext *ctx)
 
static int command(AVFilterContext *ctx, const char *cmd, const char *arg, char *res, int res_len, int flags)
 
timecode wraps after 24 hours 
 
static unsigned int av_lfg_get(AVLFG *c)
Get the next random unsigned 32-bit number using an ALFG. 
 
Describe the class of an AVClass context structure. 
 
static int func_strftime(AVFilterContext *ctx, AVBPrint *bp, char *fct, unsigned argc, char **argv, int tag)
 
Rational number (pair of numerator and denominator). 
 
void ff_blend_rectangle(FFDrawContext *draw, FFDrawColor *color, uint8_t *dst[], int dst_linesize[], int dst_w, int dst_h, int x0, int y0, int w, int h)
Blend a rectangle with an uniform color. 
 
struct AVTreeNode * glyphs
rendered glyphs, stored using the UTF-32 char code 
 
size_t av_strlcatf(char *dst, size_t size, const char *fmt,...)
 
static int is_newline(uint32_t c)
 
const char * name
Filter name. 
 
av_cold void av_lfg_init(AVLFG *c, unsigned int seed)
 
int ff_draw_init(FFDrawContext *draw, enum AVPixelFormat format, unsigned flags)
Init a draw context. 
 
AVRational sample_aspect_ratio
agreed upon sample aspect ratio 
 
static int expand_text(AVFilterContext *ctx, char *text, AVBPrint *bp)
 
AVFilterLink ** outputs
array of pointers to output links 
 
int tag
opaque argument to func 
 
short int draw_box
draw box around text - true or false 
 
static int config_input(AVFilterLink *inlink)
 
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes. 
 
void av_bprint_strftime(AVBPrint *buf, const char *fmt, const struct tm *tm)
Append a formatted date and time to a print buffer. 
 
char * av_timecode_make_string(const AVTimecode *tc, char *buf, int framenum)
Load timecode string in buf. 
 
AVFILTER_DEFINE_CLASS(drawtext)
 
void av_bprint_clear(AVBPrint *buf)
Reset the string to "" but keep internal allocated data. 
 
static void update_alpha(DrawTextContext *s)
 
static const char *const var_names[]
 
int use_kerning
font kerning is used - true/false 
 
common internal and external API header 
 
static int query_formats(AVFilterContext *ctx)
 
FT_Library library
freetype font library handle 
 
#define AVERROR_UNKNOWN
Unknown error, typically from an external library. 
 
static int filter_frame(AVFilterLink *inlink, AVFrame *frame)
 
static const AVFilterPad avfilter_vf_drawtext_outputs[]
 
static av_always_inline int diff(const uint32_t a, const uint32_t b)
 
double av_expr_eval(AVExpr *e, const double *const_values, void *opaque)
Evaluate a previously parsed expression. 
 
AVFilterContext * dst
dest filter 
 
int reinit
tells if the filter is being reinited 
 
FFDrawColor shadowcolor
shadow color 
 
static av_cold int update_fontsize(AVFilterContext *ctx)
 
void * av_tree_insert(AVTreeNode **tp, void *key, int(*cmp)(const void *key, const void *b), AVTreeNode **next)
Insert or remove an element. 
 
int line_spacing
lines spacing in pixels 
 
int max_glyph_w
max glyph width 
 
static const eval_func2 fun2[]
 
static int func_pts(AVFilterContext *ctx, AVBPrint *bp, char *fct, unsigned argc, char **argv, int tag)
 
unsigned int default_fontsize
default font size to use 
 
int fix_bounds
do we let it go out of frame bounds - t/f 
 
uint32_t av_get_random_seed(void)
Get a seed to use in conjunction with random functions. 
 
#define av_malloc_array(a, b)
 
char * textfile
file with text to be drawn 
 
static int load_glyph(AVFilterContext *ctx, Glyph **glyph_ptr, uint32_t code)
Load glyphs corresponding to the UTF-32 codepoint code. 
 
static int load_textfile(AVFilterContext *ctx)
 
static int eval_function(AVFilterContext *ctx, AVBPrint *bp, char *fct, unsigned argc, char **argv)
 
int ft_load_flags
flags used for loading fonts, see FT_LOAD_* 
 
int exp_mode
expansion mode to use for the text 
 
uint32_t flags
flags such as drop frame, +24 hours support, ... 
 
void av_tree_enumerate(AVTreeNode *t, void *opaque, int(*cmp)(void *opaque, void *elem), int(*enu)(void *opaque, void *elem))
Apply enu(opaque, &elem) to all the elements in the tree in a given range. 
 
#define AVERROR_EXTERNAL
Generic error in an external library. 
 
size_t nb_positions
number of elements of positions array 
 
FFDrawColor bordercolor
border color 
 
#define AV_NOPTS_VALUE
Undefined timestamp value. 
 
static av_cold int set_fontsize(AVFilterContext *ctx, unsigned int fontsize)
 
#define AV_TIMECODE_STR_SIZE
 
simple arithmetic expression evaluator 
 
static int func_eval_expr_int_format(AVFilterContext *ctx, AVBPrint *bp, char *fct, unsigned argc, char **argv, int tag)
 
void av_bprint_chars(AVBPrint *buf, char c, unsigned n)
Append char c n times to a print buffer.