Chiebot-Mirror
/
FFmpeg
mirror of https://github.com/FFmpeg/FFmpeg.git
8
0
Fork 0
Code Issues Projects Releases Wiki Activity

drawtext: make x and y parametric

Browse Source 
Introduce variables "E", "PHI", "PI", "main_w"/"W", "main_h"/"H",
"text_w"/"w", "text_h"/"h", "x", "y", "n" and "t" in line with
vf_overlay and refactor the code accordingly.
pull/2/head
Luca Barbato 13 years ago
parent ec11ff8407
commit 2cf74eca70
2 changed files with 152 additions and 8 deletions
Whitespace
Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL
Split View
Diff Options
Show Stats Download Patch File Download Diff File
  1. 27
      doc/filters.texi
  2. 133
      libavfilter/vf_drawtext.c

27
doc/filters.texi
Unescape View File

@ -505,6 +505,32 @@ If both text and textfile are specified, an error is thrown.
@item x, y
The offsets where text will be drawn within the video frame.
Relative to the top/left border of the output image.
They accept expressions similar to the @ref{overlay} filter:
@table @option
@item x, y
the computed values for @var{x} and @var{y}. They are evaluated for
each new frame.
@item main_w, main_h
main input width and height
@item W, H
same as @var{main_w} and @var{main_h}
@item text_w, text_h
rendered text width and height
@item w, h
same as @var{text_w} and @var{text_h}
@item n
the number of frames processed, starting from 0
@item t
timestamp expressed in seconds, NAN if the input timestamp is unknown
@end table
The default value of @var{x} and @var{y} is 0.
@ -1048,6 +1074,7 @@ other parameters is 0.
These parameters correspond to the parameters assigned to the
libopencv function @code{cvSmooth}.
@anchor{overlay}
@section overlay
Overlay one video on top of another.

133
libavfilter/vf_drawtext.c
Unescape View File

@ -31,7 +31,9 @@
#include "libavutil/colorspace.h"
#include "libavutil/file.h"
#include "libavutil/eval.h"
#include "libavutil/opt.h"
#include "libavutil/mathematics.h"
#include "libavutil/parseutils.h"
#include "libavutil/pixdesc.h"
#include "libavutil/tree.h"
@ -45,6 +47,36 @@
#include FT_FREETYPE_H
#include FT_GLYPH_H
static const char *var_names[] = {
"E",
"PHI",
"PI",
"main_w", "W", ///< width of the main video
"main_h", "H", ///< height of the main video
"text_w", "w", ///< width of the overlay text
"text_h", "h", ///< height of the overlay text
"x",
"y",
"n", ///< number of processed frames
"t", ///< timestamp expressed in seconds
NULL
};
enum var_name {
VAR_E,
VAR_PHI,
VAR_PI,
VAR_MAIN_W, VAR_MW,
VAR_MAIN_H, VAR_MH,
VAR_TEXT_W, VAR_TW,
VAR_TEXT_H, VAR_TH,
VAR_X,
VAR_Y,
VAR_N,
VAR_T,
VAR_VARS_NB
};
typedef struct {
const AVClass *class;
uint8_t *fontfile; ///< font to be used
@ -81,6 +113,10 @@ typedef struct {
int pixel_step[4]; ///< distance in bytes between the component of each pixel
uint8_t rgba_map[4]; ///< map RGBA offsets to the positions in the packed RGBA format
uint8_t *box_line[4]; ///< line used for filling the box background
char *x_expr, *y_expr;
AVExpr *x_pexpr, *y_pexpr; ///< parsed expressions for x and y
double var_values[VAR_VARS_NB];
int draw; ///< set to zero to prevent drawing
} DrawTextContext;
#define OFFSET(x) offsetof(DrawTextContext, x)
@ -94,8 +130,8 @@ static const AVOption drawtext_options[]= {
{"shadowcolor", "set shadow color", OFFSET(shadowcolor_string), AV_OPT_TYPE_STRING, {.str=NULL}, CHAR_MIN, CHAR_MAX },
{"box", "set box", OFFSET(draw_box), AV_OPT_TYPE_INT, {.dbl=0}, 0, 1 },
{"fontsize", "set font size", OFFSET(fontsize), AV_OPT_TYPE_INT, {.dbl=16}, 1, 72 },
{"x", "set x", OFFSET(x), AV_OPT_TYPE_INT, {.dbl=0}, 0, INT_MAX },
{"y", "set y", OFFSET(y), AV_OPT_TYPE_INT, {.dbl=0}, 0, INT_MAX },
{"x", "set x", OFFSET(x_expr), AV_OPT_TYPE_STRING, {.str="0"}, CHAR_MIN, CHAR_MAX },
{"y", "set y", OFFSET(y_expr), AV_OPT_TYPE_STRING, {.str="0"}, CHAR_MIN, CHAR_MAX },
{"shadowx", "set x", OFFSET(shadowx), AV_OPT_TYPE_INT, {.dbl=0}, INT_MIN, INT_MAX },
{"shadowy", "set y", OFFSET(shadowy), AV_OPT_TYPE_INT, {.dbl=0}, INT_MIN, INT_MAX },
{"tabsize", "set tab size", OFFSET(tabsize), AV_OPT_TYPE_INT, {.dbl=4}, 0, INT_MAX },
@ -374,7 +410,7 @@ static inline int is_newline(uint32_t c)
return (c == '\n' || c == '\r' || c == '\f' || c == '\v');
}
static int dtext_prepare_text(AVFilterContext *ctx, int width, int height)
static int dtext_prepare_text(AVFilterContext *ctx)
{
DrawTextContext *dtext = ctx->priv;
uint32_t code = 0, prev_code = 0;
@ -387,6 +423,8 @@ static int dtext_prepare_text(AVFilterContext *ctx, int width, int height)
FT_Vector delta;
Glyph *glyph = NULL, *prev_glyph = NULL;
Glyph dummy = { 0 };
int width = ctx->inputs[0]->w;
int height = ctx->inputs[0]->h;
#if HAVE_LOCALTIME_R
time_t now = time(0);
@ -504,6 +542,27 @@ static int config_input(AVFilterLink *inlink)
dtext->hsub = pix_desc->log2_chroma_w;
dtext->vsub = pix_desc->log2_chroma_h;
dtext->var_values[VAR_E ] = M_E;
dtext->var_values[VAR_PHI] = M_PHI;
dtext->var_values[VAR_PI ] = M_PI;
dtext->var_values[VAR_MAIN_W] =
dtext->var_values[VAR_MW] = ctx->inputs[0]->w;
dtext->var_values[VAR_MAIN_H] =
dtext->var_values[VAR_MH] = ctx->inputs[0]->h;
dtext->var_values[VAR_X] = 0;
dtext->var_values[VAR_Y] = 0;
dtext->var_values[VAR_N] = 0;
dtext->var_values[VAR_T] = NAN;
if ((ret = av_expr_parse(&dtext->x_pexpr, dtext->x_expr, var_names,
NULL, NULL, NULL, NULL, 0, ctx)) < 0 ||
(ret = av_expr_parse(&dtext->y_pexpr, dtext->y_expr, var_names,
NULL, NULL, NULL, NULL, 0, ctx)) < 0)
return AVERROR(EINVAL);
if ((ret =
ff_fill_line_with_color(dtext->box_line, dtext->pixel_step,
inlink->w, dtext->boxcolor,
@ -524,7 +583,9 @@ static int config_input(AVFilterLink *inlink)
dtext->shadowcolor[3] = rgba[3];
}
return dtext_prepare_text(ctx, ctx->inputs[0]->w, ctx->inputs[0]->h);
dtext->draw = 1;
return dtext_prepare_text(ctx);
}
#define GET_BITMAP_VAL(r, c) \
@ -697,15 +758,71 @@ static int draw_text(AVFilterContext *ctx, AVFilterBufferRef *picref,
static void null_draw_slice(AVFilterLink *link, int y, int h, int slice_dir) { }
static inline int normalize_double(int *n, double d)
{
int ret = 0;
if (isnan(d)) {
ret = AVERROR(EINVAL);
} else if (d > INT_MAX || d < INT_MIN) {
*n = d > INT_MAX ? INT_MAX : INT_MIN;
ret = AVERROR(EINVAL);
} else
*n = round(d);
return ret;
}
static void start_frame(AVFilterLink *inlink, AVFilterBufferRef *inpicref)
{
AVFilterContext *ctx = inlink->dst;
DrawTextContext *dtext = ctx->priv;
if (dtext_prepare_text(ctx) < 0) {
av_log(ctx, AV_LOG_ERROR, "Can't draw text\n");
dtext->draw = 0;
}
dtext->var_values[VAR_T] = inpicref->pts == AV_NOPTS_VALUE ?
NAN : inpicref->pts * av_q2d(inlink->time_base);
dtext->var_values[VAR_X] =
av_expr_eval(dtext->x_pexpr, dtext->var_values, NULL);
dtext->var_values[VAR_Y] =
av_expr_eval(dtext->y_pexpr, dtext->var_values, NULL);
dtext->var_values[VAR_X] =
av_expr_eval(dtext->x_pexpr, dtext->var_values, NULL);
normalize_double(&dtext->x, dtext->var_values[VAR_X]);
normalize_double(&dtext->y, dtext->var_values[VAR_Y]);
if (dtext->x < 0) dtext->x = 0;
if (dtext->y < 0) dtext->y = 0;
if ((unsigned)dtext->x + (unsigned)dtext->w > inlink->w)
dtext->x = inlink->w - dtext->w;
if ((unsigned)dtext->y + (unsigned)dtext->h > inlink->h)
dtext->y = inlink->h - dtext->h;
dtext->x &= ~((1 << dtext->hsub) - 1);
dtext->y &= ~((1 << dtext->vsub) - 1);
av_dlog(ctx, "n:%d t:%f x:%d y:%d x+w:%d y+h:%d\n",
(int)dtext->var_values[VAR_N], dtext->var_values[VAR_T],
dtext->x, dtext->y, dtext->x+dtext->w, dtext->y+dtext->h);
avfilter_start_frame(inlink->dst->outputs[0], inpicref);
}
static void end_frame(AVFilterLink *inlink)
{
AVFilterLink *outlink = inlink->dst->outputs[0];
AVFilterBufferRef *picref = inlink->cur_buf;
int err = dtext_prepare_text(inlink->dst,
picref->video->w, picref->video->h);
if (!err)
DrawTextContext *dtext = inlink->dst->priv;
if (dtext->draw)
draw_text(inlink->dst, picref, picref->video->w, picref->video->h);
dtext->var_values[VAR_N] += 1.0;
avfilter_draw_slice(outlink, 0, picref->video->h, 1);
avfilter_end_frame(outlink);
}
@ -721,7 +838,7 @@ AVFilter avfilter_vf_drawtext = {
.inputs = (AVFilterPad[]) {{ .name = "default",
.type = AVMEDIA_TYPE_VIDEO,
.get_video_buffer = avfilter_null_get_video_buffer,
.start_frame = avfilter_null_start_frame,
.start_frame = start_frame,
.draw_slice = null_draw_slice,
.end_frame = end_frame,
.config_props = config_input,

Write Preview
Loading…
Cancel
Save