[FFmpeg-devel] [PATCH v2] drawtext: add fontcolor_expr
Andrey Utkin
andrey.krieger.utkin at gmail.com
Thu Jul 3 15:36:12 CEST 2014
An option for fontcolor, dynamically evaluated
---
doc/filters.texi | 25 +++++++++++++
libavfilter/vf_drawtext.c | 89 ++++++++++++++++++++++++++++++++++++++++++++---
2 files changed, 109 insertions(+), 5 deletions(-)
diff --git a/doc/filters.texi b/doc/filters.texi
index a5f6965..3f9dc8e 100644
--- a/doc/filters.texi
+++ b/doc/filters.texi
@@ -3660,6 +3660,11 @@ the "Color" section in the ffmpeg-utils manual.
The default value of @var{fontcolor} is "black".
+ at item fontcolor_expr
+String which is expanded the same way as @var{text} to obtain dynamic
+ at var{fontcolor} value. By default this option has empty value and is not
+processed.
+
@item font
The font family to be used for drawing text. By default Sans.
@@ -3867,6 +3872,15 @@ example the text size is not known when evaluating the expression, so
the constants @var{text_w} and @var{text_h} will have an undefined
value.
+ at item eif
+Evaluate the expression's value and output as formatted integer.
+
+First argument is expression to be evaluated, same as for @var{expr} function.
+Second argument specifies output format. Allowed values are 'x', 'X', 'd' and
+'u', they are treated exactly as in printf function.
+Third parameter is optional and sets the number of positions taken by output.
+Effectively this allows to add padding with zeros from the left.
+
@item gmtime
The time at which the filter is running, expressed in UTC.
It can accept an argument: a strftime() format string.
@@ -3966,6 +3980,17 @@ Print the date of a real-time encoding (see strftime(3)):
drawtext='fontfile=FreeSans.ttf:text=%@{localtime:%a %b %d %Y@}'
@end example
+ at item
+Text fading in and out (appearing/disappearing).
+ at example
+#!/bin/bash
+DS=1.0 # display start
+DE=10.0 # display end
+FID=1.5 # fade in duration
+FOD=5 # fade out duration
+ffplay -f lavfi -i "drawtext=text=TEST:fontsize=50:fontfile=FreeSerif.ttf:fontcolor_expr=ff0000%@{eif\\\\: max(0\\, min(255\\, 255*(1*between(t\\, $DS + $FID\\, $DE - $FOD) + ((t - $DS)/$FID)*between(t\\, $DS\\, $DS + $FID) + (-(t - $DE)/$FOD)*between(t\\, $DE - $FOD\\, $DE) ) )) \\\\: x\\\\: 2 @}"
+ at end example
+
@end itemize
For more information about libfreetype, check:
diff --git a/libavfilter/vf_drawtext.c b/libavfilter/vf_drawtext.c
index adc587e..4f4354e 100644
--- a/libavfilter/vf_drawtext.c
+++ b/libavfilter/vf_drawtext.c
@@ -35,6 +35,7 @@
#include <sys/stat.h>
#include <time.h>
#include <unistd.h>
+#include <fenv.h>
#if CONFIG_LIBFONTCONFIG
#include <fontconfig/fontconfig.h>
@@ -136,6 +137,8 @@ typedef struct DrawTextContext {
uint8_t *fontfile; ///< font to be used
uint8_t *text; ///< text to be drawn
AVBPrint expanded_text; ///< used to contain the expanded text
+ uint8_t *fontcolor_expr; ///< fontcolor expression to evaluate
+ AVBPrint expanded_fontcolor; ///< used to contain the expanded fontcolor spec
int ft_load_flags; ///< flags used for loading fonts, see FT_LOAD_*
FT_Vector *positions; ///< positions for each element in the text
size_t nb_positions; ///< number of elements of positions array
@@ -191,6 +194,7 @@ static const AVOption drawtext_options[]= {
{"text", "set text", OFFSET(text), AV_OPT_TYPE_STRING, {.str=NULL}, CHAR_MIN, CHAR_MAX, FLAGS},
{"textfile", "set text file", OFFSET(textfile), AV_OPT_TYPE_STRING, {.str=NULL}, CHAR_MIN, CHAR_MAX, FLAGS},
{"fontcolor", "set foreground color", OFFSET(fontcolor.rgba), AV_OPT_TYPE_COLOR, {.str="black"}, CHAR_MIN, CHAR_MAX, FLAGS},
+ {"fontcolor_expr", "set foreground color expression", OFFSET(fontcolor_expr), AV_OPT_TYPE_STRING, {.str=""}, CHAR_MIN, CHAR_MAX, FLAGS},
{"boxcolor", "set box color", OFFSET(boxcolor.rgba), AV_OPT_TYPE_COLOR, {.str="white"}, CHAR_MIN, CHAR_MAX, FLAGS},
{"bordercolor", "set border color", OFFSET(bordercolor.rgba), AV_OPT_TYPE_COLOR, {.str="black"}, CHAR_MIN, CHAR_MAX, FLAGS},
{"shadowcolor", "set shadow color", OFFSET(shadowcolor.rgba), AV_OPT_TYPE_COLOR, {.str="black"}, CHAR_MIN, CHAR_MAX, FLAGS},
@@ -569,6 +573,7 @@ static av_cold int init(AVFilterContext *ctx)
av_log(ctx, AV_LOG_WARNING, "expansion=strftime is deprecated.\n");
av_bprint_init(&s->expanded_text, 0, AV_BPRINT_SIZE_UNLIMITED);
+ av_bprint_init(&s->expanded_fontcolor, 0, AV_BPRINT_SIZE_UNLIMITED);
return 0;
}
@@ -612,6 +617,7 @@ static av_cold void uninit(AVFilterContext *ctx)
FT_Done_FreeType(s->library);
av_bprint_finalize(&s->expanded_text, NULL);
+ av_bprint_finalize(&s->expanded_fontcolor, NULL);
}
static inline int is_newline(uint32_t c)
@@ -800,6 +806,66 @@ static int func_eval_expr(AVFilterContext *ctx, AVBPrint *bp,
return ret;
}
+static int func_eval_expr_int_format(AVFilterContext *ctx, AVBPrint *bp,
+ char *fct, unsigned argc, char **argv, int tag)
+{
+ DrawTextContext *s = ctx->priv;
+ double res;
+ int intval;
+ int ret;
+ unsigned int positions = 0;
+ char fmt_str[30] = "%";
+
+ /*
+ * argv[0] expression to be converted to `int`
+ * argv[1] format: 'x', 'X', 'd' or 'u'
+ * argv[2] positions printed (optional)
+ */
+
+ ret = av_expr_parse_and_eval(&res, argv[0], var_names, s->var_values,
+ NULL, NULL, fun2_names, fun2,
+ &s->prng, 0, ctx);
+ if (ret < 0) {
+ av_log(ctx, AV_LOG_ERROR,
+ "Expression '%s' for the expr text expansion function is not valid\n",
+ argv[0]);
+ return ret;
+ }
+
+ if (!strchr("xXdu", argv[1][0])) {
+ av_log(ctx, AV_LOG_ERROR, "Invalid format '%c' specified,"
+ " allowed values: 'x', 'X', 'd', 'u'\n", argv[1][0]);
+ return AVERROR(EINVAL);
+ }
+
+ if (argc == 3) {
+ ret = sscanf(argv[2], "%u", &positions);
+ if (ret != 1) {
+ av_log(ctx, AV_LOG_ERROR, "eif(): Invalid number of positions"
+ " to print: '%s'\n", argv[2]);
+ return AVERROR(EINVAL);
+ }
+ }
+
+ feclearexcept(FE_ALL_EXCEPT);
+ intval = res;
+ if ((ret = fetestexcept(FE_INVALID|FE_OVERFLOW|FE_UNDERFLOW))) {
+ av_log(ctx, AV_LOG_ERROR, "Conversion of floating-point result to int failed. Control register: 0x%08x. Conversion result: %d\n", ret, intval);
+ return AVERROR(EINVAL);
+ }
+
+ if (argc == 3)
+ av_strlcatf(fmt_str, sizeof(fmt_str), "0%u", positions);
+ av_strlcatf(fmt_str, sizeof(fmt_str), "%c", argv[1][0]);
+
+ av_log(ctx, AV_LOG_DEBUG, "Formatting value %f (expr '%s') with spec '%s'\n",
+ res, argv[0], fmt_str);
+
+ av_bprintf(bp, fmt_str, intval);
+
+ return 0;
+}
+
static const struct drawtext_function {
const char *name;
unsigned argc_min, argc_max;
@@ -808,6 +874,7 @@ static const struct drawtext_function {
} functions[] = {
{ "expr", 1, 1, 0, func_eval_expr },
{ "e", 1, 1, 0, func_eval_expr },
+ { "eif", 2, 3, 0, func_eval_expr_int_format },
{ "pict_type", 0, 0, 0, func_pict_type },
{ "pts", 0, 2, 0, func_pts },
{ "gmtime", 0, 1, 'G', func_strftime },
@@ -884,11 +951,8 @@ end:
return ret;
}
-static int expand_text(AVFilterContext *ctx)
+static int expand_text(AVFilterContext *ctx, char *text, AVBPrint *bp)
{
- DrawTextContext *s = ctx->priv;
- char *text = s->text;
- AVBPrint *bp = &s->expanded_text;
int ret;
av_bprint_clear(bp);
@@ -984,7 +1048,7 @@ static int draw_text(AVFilterContext *ctx, AVFrame *frame,
av_bprintf(bp, "%s", s->text);
break;
case EXP_NORMAL:
- if ((ret = expand_text(ctx)) < 0)
+ if ((ret = expand_text(ctx, s->text, &s->expanded_text)) < 0)
return ret;
break;
case EXP_STRFTIME:
@@ -1010,6 +1074,21 @@ static int draw_text(AVFilterContext *ctx, AVFrame *frame,
s->nb_positions = len;
}
+ if (s->fontcolor_expr[0]) {
+ /* If expression is set, evaluate and replace the static value */
+ av_bprint_clear(&s->expanded_fontcolor);
+ if ((ret = expand_text(ctx, s->fontcolor_expr, &s->expanded_fontcolor)) < 0)
+ return ret;
+ if (!av_bprint_is_complete(&s->expanded_fontcolor))
+ return AVERROR(ENOMEM);
+ av_log(s, AV_LOG_DEBUG, "Evaluated fontcolor is '%s'\n", s->expanded_fontcolor.str);
+ ret = av_parse_color(s->fontcolor.rgba, s->expanded_fontcolor.str, -1, s);
+ if (ret)
+ return ret;
+ ff_draw_color(&s->dc, &s->fontcolor, s->fontcolor.rgba);
+ }
+
+
x = 0;
y = 0;
--
1.8.3.2
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