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drawtext: make x and y parametric

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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.
This commit is contained in:
Luca Barbato 2011-12-01 11:43:11 +01:00
parent ec11ff8407
commit 2cf74eca70
2 changed files with 152 additions and 8 deletions
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27
doc/filters.texi
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
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,