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vf_drawtext: make x and y options parametric

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Address trac issue #378.
This commit is contained in:
Stefano Sabatini 2011-09-18 02:41:56 +02:00
parent 163854bca0
commit 482ce0ce4e
3 changed files with 236 additions and 21 deletions
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96
doc/filters.texi
View File

@ -738,10 +738,13 @@ parameter @var{text}.
If both text and textfile are specified, an error is thrown. If both text and textfile are specified, an error is thrown.
@item x, y @item x, y
The offsets where text will be drawn within the video frame. The expressions which specify the offsets where text will be drawn
Relative to the top/left border of the output image. within the video frame. They are relative to the top/left border of the
output image.
The default value of @var{x} and @var{y} is 0. The default value of @var{x} and @var{y} is "0".
See below for the list of accepted constants.
@item fontsize @item fontsize
The font size to be used for drawing text. The font size to be used for drawing text.
@ -809,6 +812,66 @@ The size in number of spaces to use for rendering the tab.
Default value is 4. Default value is 4.
@end table @end table
The parameters for @var{x} and @var{y} are expressions containing the
following constants:
@table @option
@item E, PI, PHI
the corresponding mathematical approximated values for e
(euler number), pi (greek PI), PHI (golden ratio)
@item w, h
the input width and heigth
@item tw, text_w
the width of the rendered text
@item th, text_h
the height of the rendered text
@item lh, line_h
the height of each text line
@item sar
input sample aspect ratio
@item dar
input display aspect ratio, it is the same as (@var{w} / @var{h}) * @var{sar}
@item hsub, vsub
horizontal and vertical chroma subsample values. For example for the
pixel format "yuv422p" @var{hsub} is 2 and @var{vsub} is 1.
@item max_glyph_w
maximum glyph width, that is the maximum width for all the glyphs
contained in the rendered text
@item max_glyph_h
maximum glyph height, that is the maximum height for all the glyphs
contained in the rendered text, it is equivalent to @var{ascent} -
@var{descent}.
@item max_glyph_a, ascent
the maximum distance from the baseline to the highest/upper grid
coordinate used to place a glyph outline point, for all the rendered
glyphs.
It is a positive value, due to the grid's orientation with the Y axis
upwards.
@item max_glyph_d, descent
the maximum distance from the baseline to the lowest grid coordinate
used to place a glyph outline point, for all the rendered glyphs.
This is a negative value, due to the grid's orientation, with the Y axis
upwards.
@item n
the number of input frame, starting from 0
@item t
timestamp expressed in seconds, NAN if the input timestamp is unknown
@end table
Some examples follow. Some examples follow.
@itemize @itemize
@ -835,6 +898,33 @@ drawtext="fontfile=/usr/share/fonts/truetype/freefont/FreeSerif.ttf: text='Test
Note that the double quotes are not necessary if spaces are not used Note that the double quotes are not necessary if spaces are not used
within the parameter list. within the parameter list.
@item
Show the text at the center of the video frame:
@example
drawtext=fontsize=30:fontfile=FreeSerif.ttf:text='hello world':x=(w-text_w)/2:y=(h-text_h-line_h)/2"
@end example
@item
Show a text line sliding from right to left in the last row of the video
frame. The file @file{LONG_LINE} is assumed to contain a single line
with no newlines.
@example
drawtext=fontsize=15:fontfile=FreeSerif.ttf:text=LONG_LINE:y=h-line_h:x=-50*t
@end example
@item
Show the content of file @file{CREDITS} off the bottom of the frame and scroll up.
@example
drawtext=fontsize=20:fontfile=FreeSerif.ttf:textfile=CREDITS:y=h-20*t"
@end example
@item
Draw a single green letter "g", at the center of the input video.
The glyph baseline is placed at half screen height.
@example
drawtext=fontsize=60:fontfile=FreeSerif.ttf:fontcolor=green:text=g:x=(w-max_glyph_w)/2:y=h/2-ascent
@end example
@end itemize @end itemize
For more information about libfreetype, check: For more information about libfreetype, check:

2
libavfilter/avfilter.h
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@ -30,7 +30,7 @@
#define LIBAVFILTER_VERSION_MAJOR 2 #define LIBAVFILTER_VERSION_MAJOR 2
#define LIBAVFILTER_VERSION_MINOR 43 #define LIBAVFILTER_VERSION_MINOR 43
#define LIBAVFILTER_VERSION_MICRO 4 #define LIBAVFILTER_VERSION_MICRO 5
#define LIBAVFILTER_VERSION_INT AV_VERSION_INT(LIBAVFILTER_VERSION_MAJOR, \ #define LIBAVFILTER_VERSION_INT AV_VERSION_INT(LIBAVFILTER_VERSION_MAJOR, \
LIBAVFILTER_VERSION_MINOR, \ LIBAVFILTER_VERSION_MINOR, \

159
libavfilter/vf_drawtext.c
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@ -30,6 +30,7 @@
#include <time.h> #include <time.h>
#include "libavutil/colorspace.h" #include "libavutil/colorspace.h"
#include "libavutil/eval.h"
#include "libavutil/file.h" #include "libavutil/file.h"
#include "libavutil/opt.h" #include "libavutil/opt.h"
#include "libavutil/parseutils.h" #include "libavutil/parseutils.h"
@ -45,6 +46,54 @@
#include FT_FREETYPE_H #include FT_FREETYPE_H
#include FT_GLYPH_H #include FT_GLYPH_H
static const char *var_names[] = {
"E",
"PHI",
"PI",
"w", ///< width of the input video
"h", ///< height of the input video
"tw", "text_w", ///< width of the rendered text
"th", "text_h", ///< height of the rendered text
"max_glyph_w", ///< max glyph width
"max_glyph_h", ///< max glyph height
"max_glyph_a", "ascent", ///< max glyph ascent
"max_glyph_d", "descent", ///< min glyph descent
"line_h", "lh", ///< line height, same as max_glyph_h
"sar",
"dar",
"hsub",
"vsub",
"x",
"y",
"n", ///< number of frame
"t", ///< timestamp expressed in seconds
NULL
};
enum var_name {
VAR_E,
VAR_PHI,
VAR_PI,
VAR_W,
VAR_H,
VAR_TW, VAR_TEXT_W,
VAR_TH, VAR_TEXT_H,
VAR_MAX_GLYPH_W,
VAR_MAX_GLYPH_H,
VAR_MAX_GLYPH_A, VAR_ASCENT,
VAR_MAX_GLYPH_D, VAR_DESCENT,
VAR_LINE_H, VAR_LH,
VAR_SAR,
VAR_DAR,
VAR_HSUB,
VAR_VSUB,
VAR_X,
VAR_Y,
VAR_N,
VAR_T,
VAR_VARS_NB
};
typedef struct { typedef struct {
const AVClass *class; const AVClass *class;
uint8_t *fontfile; ///< font to be used uint8_t *fontfile; ///< font to be used
@ -57,6 +106,11 @@ typedef struct {
char *textfile; ///< file with text to be drawn char *textfile; ///< file with text to be drawn
int x; ///< x position to start drawing text int x; ///< x position to start drawing text
int y; ///< y position to start drawing text int y; ///< y position to start drawing text
char *x_expr; ///< expression for x position
char *y_expr; ///< expression for y position
AVExpr *x_pexpr, *y_pexpr; ///< parsed expressions for x and y
int max_glyph_w; ///< max glyph width
int max_glyph_h; ///< max glyph heigth
int shadowx, shadowy; int shadowx, shadowy;
unsigned int fontsize; ///< font size to use unsigned int fontsize; ///< font size to use
char *fontcolor_string; ///< font color as string char *fontcolor_string; ///< font color as string
@ -82,6 +136,7 @@ typedef struct {
uint8_t rgba_map[4]; ///< map RGBA offsets to the positions in the packed RGBA format 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 uint8_t *box_line[4]; ///< line used for filling the box background
int64_t basetime; ///< base pts time in the real world for display int64_t basetime; ///< base pts time in the real world for display
double var_values[VAR_VARS_NB];
} DrawTextContext; } DrawTextContext;
#define OFFSET(x) offsetof(DrawTextContext, x) #define OFFSET(x) offsetof(DrawTextContext, x)
@ -95,8 +150,8 @@ static const AVOption drawtext_options[]= {
{"shadowcolor", "set shadow color", OFFSET(shadowcolor_string), FF_OPT_TYPE_STRING, {.str=NULL}, CHAR_MIN, CHAR_MAX }, {"shadowcolor", "set shadow color", OFFSET(shadowcolor_string), FF_OPT_TYPE_STRING, {.str=NULL}, CHAR_MIN, CHAR_MAX },
{"box", "set box", OFFSET(draw_box), FF_OPT_TYPE_INT, {.dbl=0}, 0, 1 }, {"box", "set box", OFFSET(draw_box), FF_OPT_TYPE_INT, {.dbl=0}, 0, 1 },
{"fontsize", "set font size", OFFSET(fontsize), FF_OPT_TYPE_INT, {.dbl=16}, 1, INT_MAX }, {"fontsize", "set font size", OFFSET(fontsize), FF_OPT_TYPE_INT, {.dbl=16}, 1, INT_MAX },
{"x", "set x", OFFSET(x), FF_OPT_TYPE_INT, {.dbl=0}, 0, INT_MAX }, {"x", "set x expression", OFFSET(x_expr), FF_OPT_TYPE_STRING, {.str="0"}, CHAR_MIN, CHAR_MAX },
{"y", "set y", OFFSET(y), FF_OPT_TYPE_INT, {.dbl=0}, 0, INT_MAX }, {"y", "set y expression", OFFSET(y_expr), FF_OPT_TYPE_STRING, {.str="0"}, CHAR_MIN, CHAR_MAX },
{"shadowx", "set x", OFFSET(shadowx), FF_OPT_TYPE_INT, {.dbl=0}, INT_MIN, INT_MAX }, {"shadowx", "set x", OFFSET(shadowx), FF_OPT_TYPE_INT, {.dbl=0}, INT_MIN, INT_MAX },
{"shadowy", "set y", OFFSET(shadowy), FF_OPT_TYPE_INT, {.dbl=0}, INT_MIN, INT_MAX }, {"shadowy", "set y", OFFSET(shadowy), FF_OPT_TYPE_INT, {.dbl=0}, INT_MIN, INT_MAX },
{"tabsize", "set tab size", OFFSET(tabsize), FF_OPT_TYPE_INT, {.dbl=4}, 0, INT_MAX }, {"tabsize", "set tab size", OFFSET(tabsize), FF_OPT_TYPE_INT, {.dbl=4}, 0, INT_MAX },
@ -348,12 +403,18 @@ static av_cold void uninit(AVFilterContext *ctx)
DrawTextContext *dtext = ctx->priv; DrawTextContext *dtext = ctx->priv;
int i; int i;
av_expr_free(dtext->x_pexpr); dtext->x_pexpr = NULL;
av_expr_free(dtext->y_pexpr); dtext->y_pexpr = NULL;
av_freep(&dtext->fontfile); av_freep(&dtext->fontfile);
av_freep(&dtext->text); av_freep(&dtext->text);
av_freep(&dtext->expanded_text); av_freep(&dtext->expanded_text);
av_freep(&dtext->fontcolor_string); av_freep(&dtext->fontcolor_string);
av_freep(&dtext->boxcolor_string); av_freep(&dtext->boxcolor_string);
av_freep(&dtext->positions); av_freep(&dtext->positions);
av_freep(&dtext->x_expr);
av_freep(&dtext->y_expr);
dtext->nb_positions = 0; dtext->nb_positions = 0;
av_freep(&dtext->shadowcolor_string); av_freep(&dtext->shadowcolor_string);
av_tree_enumerate(dtext->glyphs, NULL, NULL, glyph_enu_free); av_tree_enumerate(dtext->glyphs, NULL, NULL, glyph_enu_free);
@ -371,6 +432,7 @@ static av_cold void uninit(AVFilterContext *ctx)
static int config_input(AVFilterLink *inlink) static int config_input(AVFilterLink *inlink)
{ {
AVFilterContext *ctx = inlink->dst;
DrawTextContext *dtext = inlink->dst->priv; DrawTextContext *dtext = inlink->dst->priv;
const AVPixFmtDescriptor *pix_desc = &av_pix_fmt_descriptors[inlink->format]; const AVPixFmtDescriptor *pix_desc = &av_pix_fmt_descriptors[inlink->format];
int ret; int ret;
@ -398,6 +460,26 @@ static int config_input(AVFilterLink *inlink)
dtext->shadowcolor[3] = rgba[3]; dtext->shadowcolor[3] = rgba[3];
} }
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_W] = inlink->w;
dtext->var_values[VAR_H] = inlink->h;
dtext->var_values[VAR_SAR] = inlink->sample_aspect_ratio.num ? av_q2d(inlink->sample_aspect_ratio) : 1;
dtext->var_values[VAR_DAR] = (double)inlink->w / inlink->h * dtext->var_values[VAR_SAR];
dtext->var_values[VAR_HSUB] = 1<<pix_desc->log2_chroma_w;
dtext->var_values[VAR_VSUB] = 1<<pix_desc->log2_chroma_h;
dtext->var_values[VAR_X] = NAN;
dtext->var_values[VAR_Y] = NAN;
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);
return 0; return 0;
} }
@ -441,6 +523,9 @@ static inline int draw_glyph_yuv(AVFilterBufferRef *picref, FT_Bitmap *bitmap,
for (r = 0; r < bitmap->rows && r+y < height; r++) { for (r = 0; r < bitmap->rows && r+y < height; r++) {
for (c = 0; c < bitmap->width && c+x < width; c++) { for (c = 0; c < bitmap->width && c+x < width; c++) {
if (c+x < 0 || r+y < 0)
continue;
/* get intensity value in the glyph bitmap (source) */ /* get intensity value in the glyph bitmap (source) */
src_val = GET_BITMAP_VAL(r, c); src_val = GET_BITMAP_VAL(r, c);
if (!src_val) if (!src_val)
@ -471,6 +556,8 @@ static inline int draw_glyph_rgb(AVFilterBufferRef *picref, FT_Bitmap *bitmap,
for (r = 0; r < bitmap->rows && r+y < height; r++) { for (r = 0; r < bitmap->rows && r+y < height; r++) {
for (c = 0; c < bitmap->width && c+x < width; c++) { for (c = 0; c < bitmap->width && c+x < width; c++) {
if (c+x < 0 || r+y < 0)
continue;
/* get intensity value in the glyph bitmap (source) */ /* get intensity value in the glyph bitmap (source) */
src_val = GET_BITMAP_VAL(r, c); src_val = GET_BITMAP_VAL(r, c);
if (!src_val) if (!src_val)
@ -521,7 +608,7 @@ static int draw_glyphs(DrawTextContext *dtext, AVFilterBufferRef *picref,
{ {
char *text = dtext->expanded_text; char *text = dtext->expanded_text;
uint32_t code = 0; uint32_t code = 0;
int i; int i, x1, y1;
uint8_t *p; uint8_t *p;
Glyph *glyph = NULL; Glyph *glyph = NULL;
@ -540,13 +627,16 @@ static int draw_glyphs(DrawTextContext *dtext, AVFilterBufferRef *picref,
glyph->bitmap.pixel_mode != FT_PIXEL_MODE_GRAY) glyph->bitmap.pixel_mode != FT_PIXEL_MODE_GRAY)
return AVERROR(EINVAL); return AVERROR(EINVAL);
x1 = dtext->positions[i].x+dtext->x+x;
y1 = dtext->positions[i].y+dtext->y+y;
if (dtext->is_packed_rgb) { if (dtext->is_packed_rgb) {
draw_glyph_rgb(picref, &glyph->bitmap, draw_glyph_rgb(picref, &glyph->bitmap,
dtext->positions[i].x+x, dtext->positions[i].y+y, width, height, x1, y1, width, height,
dtext->pixel_step[0], rgbcolor, dtext->rgba_map); dtext->pixel_step[0], rgbcolor, dtext->rgba_map);
} else { } else {
draw_glyph_yuv(picref, &glyph->bitmap, draw_glyph_yuv(picref, &glyph->bitmap,
dtext->positions[i].x+x, dtext->positions[i].y+y, width, height, x1, y1, width, height,
yuvcolor, dtext->hsub, dtext->vsub); yuvcolor, dtext->hsub, dtext->vsub);
} }
} }
@ -560,11 +650,12 @@ static int draw_text(AVFilterContext *ctx, AVFilterBufferRef *picref,
DrawTextContext *dtext = ctx->priv; DrawTextContext *dtext = ctx->priv;
uint32_t code = 0, prev_code = 0; uint32_t code = 0, prev_code = 0;
int x = 0, y = 0, i = 0, ret; int x = 0, y = 0, i = 0, ret;
int text_height; int max_text_line_w = 0, len;
int box_w, box_h;
char *text = dtext->text; char *text = dtext->text;
uint8_t *p; uint8_t *p;
int str_w = 0, len;
int y_min = 32000, y_max = -32000; int y_min = 32000, y_max = -32000;
int x_min = 32000, x_max = -32000;
FT_Vector delta; FT_Vector delta;
Glyph *glyph = NULL, *prev_glyph = NULL; Glyph *glyph = NULL, *prev_glyph = NULL;
Glyph dummy = { 0 }; Glyph dummy = { 0 };
@ -607,8 +698,8 @@ static int draw_text(AVFilterContext *ctx, AVFilterBufferRef *picref,
dtext->nb_positions = len; dtext->nb_positions = len;
} }
x = dtext->x; x = 0;
y = dtext->y; y = 0;
/* load and cache glyphs */ /* load and cache glyphs */
for (i = 0, p = text; *p; i++) { for (i = 0, p = text; *p; i++) {
@ -622,8 +713,11 @@ static int draw_text(AVFilterContext *ctx, AVFilterBufferRef *picref,
y_min = FFMIN(glyph->bbox.yMin, y_min); y_min = FFMIN(glyph->bbox.yMin, y_min);
y_max = FFMAX(glyph->bbox.yMax, y_max); y_max = FFMAX(glyph->bbox.yMax, y_max);
x_min = FFMIN(glyph->bbox.xMin, x_min);
x_max = FFMAX(glyph->bbox.xMax, x_max);
} }
text_height = y_max - y_min; dtext->max_glyph_h = y_max - y_min;
dtext->max_glyph_w = x_max - x_min;
/* compute and save position for each glyph */ /* compute and save position for each glyph */
glyph = NULL; glyph = NULL;
@ -636,9 +730,9 @@ static int draw_text(AVFilterContext *ctx, AVFilterBufferRef *picref,
prev_code = code; prev_code = code;
if (is_newline(code)) { if (is_newline(code)) {
str_w = FFMAX(str_w, x - dtext->x); max_text_line_w = FFMAX(max_text_line_w, x);
y += text_height; y += dtext->max_glyph_h;
x = dtext->x; x = 0;
continue; continue;
} }
@ -661,12 +755,31 @@ static int draw_text(AVFilterContext *ctx, AVFilterBufferRef *picref,
else x += glyph->advance; else x += glyph->advance;
} }
str_w = FFMIN(width - dtext->x - 1, FFMAX(str_w, x - dtext->x)); max_text_line_w = FFMAX(x, max_text_line_w);
y = FFMIN(y + text_height, height - 1);
dtext->var_values[VAR_TW] = dtext->var_values[VAR_TEXT_W] = max_text_line_w;
dtext->var_values[VAR_TH] = dtext->var_values[VAR_TEXT_H] = y + dtext->max_glyph_h;
dtext->var_values[VAR_MAX_GLYPH_W] = dtext->max_glyph_w;
dtext->var_values[VAR_MAX_GLYPH_H] = dtext->max_glyph_h;
dtext->var_values[VAR_MAX_GLYPH_A] = dtext->var_values[VAR_ASCENT ] = y_max;
dtext->var_values[VAR_MAX_GLYPH_D] = dtext->var_values[VAR_DESCENT] = y_min;
dtext->var_values[VAR_LINE_H] = dtext->var_values[VAR_LH] = dtext->max_glyph_h;
dtext->x = dtext->var_values[VAR_X] = av_expr_eval(dtext->x_pexpr, dtext->var_values, NULL);
dtext->y = dtext->var_values[VAR_Y] = av_expr_eval(dtext->y_pexpr, dtext->var_values, NULL);
dtext->x = dtext->var_values[VAR_X] = av_expr_eval(dtext->x_pexpr, dtext->var_values, NULL);
dtext->x &= ~((1 << dtext->hsub) - 1);
dtext->y &= ~((1 << dtext->vsub) - 1);
box_w = FFMIN(width - 1 , max_text_line_w);
box_h = FFMIN(height - 1, y + dtext->max_glyph_h);
/* draw box */ /* draw box */
if (dtext->draw_box) if (dtext->draw_box)
drawbox(picref, dtext->x, dtext->y, str_w, y-dtext->y, drawbox(picref, dtext->x, dtext->y, box_w, box_h,
dtext->box_line, dtext->pixel_step, dtext->boxcolor_rgba, dtext->box_line, dtext->pixel_step, dtext->boxcolor_rgba,
dtext->hsub, dtext->vsub, dtext->is_packed_rgb, dtext->rgba_map); dtext->hsub, dtext->vsub, dtext->is_packed_rgb, dtext->rgba_map);
@ -688,9 +801,21 @@ static void null_draw_slice(AVFilterLink *link, int y, int h, int slice_dir) { }
static void end_frame(AVFilterLink *inlink) static void end_frame(AVFilterLink *inlink)
{ {
AVFilterLink *outlink = inlink->dst->outputs[0]; AVFilterLink *outlink = inlink->dst->outputs[0];
AVFilterContext *ctx = inlink->dst;
DrawTextContext *dtext = inlink->dst->priv;
AVFilterBufferRef *picref = inlink->cur_buf; AVFilterBufferRef *picref = inlink->cur_buf;
draw_text(inlink->dst, picref, picref->video->w, picref->video->h); dtext->var_values[VAR_T] = picref->pts == AV_NOPTS_VALUE ?
NAN : picref->pts * av_q2d(inlink->time_base);
draw_text(ctx, picref, picref->video->w, picref->video->h);
av_log(ctx, AV_LOG_DEBUG, "n:%d t:%f text_w:%d text_h:%d x:%d y:%d\n",
(int)dtext->var_values[VAR_N], dtext->var_values[VAR_T],
(int)dtext->var_values[VAR_TEXT_W], (int)dtext->var_values[VAR_TEXT_H],
dtext->x, dtext->y);
dtext->var_values[VAR_N] += 1.0;
avfilter_draw_slice(outlink, 0, picref->video->h, 1); avfilter_draw_slice(outlink, 0, picref->video->h, 1);
avfilter_end_frame(outlink); avfilter_end_frame(outlink);