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e74bf3f368
FFmpeg/libavfilter/vf_drawtext.c
Michael Niedermayer e74bf3f368 drawtext: simplify chroma blend and fix chroma alpha. 
Signed-off-by: Anton Khirnov <anton@khirnov.net>
2011-05-07 10:18:16 +02:00

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/*
* Copyright (c) 2011 Stefano Sabatini
* Copyright (c) 2010 S.N. Hemanth Meenakshisundaram
* Copyright (c) 2003 Gustavo Sverzut Barbieri <gsbarbieri@yahoo.com.br>
*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
/**
* @file
* drawtext filter, based on the original FFmpeg vhook/drawtext.c
* filter by Gustavo Sverzut Barbieri
*/
#include <sys/time.h>
#include <time.h>
#include "libavutil/colorspace.h"
#include "libavutil/file.h"
#include "libavutil/opt.h"
#include "libavutil/parseutils.h"
#include "libavutil/pixdesc.h"
#include "libavutil/tree.h"
#include "avfilter.h"
#include "drawutils.h"
#undef time
#include <ft2build.h>
#include <freetype/config/ftheader.h>
#include FT_FREETYPE_H
#include FT_GLYPH_H
typedef struct {
const AVClass *class;
uint8_t *fontfile; ///< font to be used
uint8_t *text; ///< text to be drawn
uint8_t *text_priv; ///< used to detect whether text changed
int ft_load_flags; ///< flags used for loading fonts, see FT_LOAD_*
FT_Vector *positions; ///< positions for each element in the text
char *textfile; ///< file with text to be drawn
unsigned int x; ///< x position to start drawing text
unsigned int y; ///< y position to start drawing text
unsigned int fontsize; ///< font size to use
char *fontcolor_string; ///< font color as string
char *boxcolor_string; ///< box color as string
uint8_t fontcolor[4]; ///< foreground color
uint8_t boxcolor[4]; ///< background color
uint8_t fontcolor_rgba[4]; ///< foreground color in RGBA
uint8_t boxcolor_rgba[4]; ///< background color in RGBA
short int draw_box; ///< draw box around text - true or false
int use_kerning; ///< font kerning is used - true/false
int tabsize; ///< tab size
FT_Library library; ///< freetype font library handle
FT_Face face; ///< freetype font face handle
struct AVTreeNode *glyphs; ///< rendered glyphs, stored using the UTF-32 char code
int hsub, vsub; ///< chroma subsampling values
int is_packed_rgb;
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
} DrawTextContext;
#define OFFSET(x) offsetof(DrawTextContext, x)
static const AVOption drawtext_options[]= {
{"fontfile", "set font file", OFFSET(fontfile), FF_OPT_TYPE_STRING, 0, CHAR_MIN, CHAR_MAX },
{"text", "set text", OFFSET(text), FF_OPT_TYPE_STRING, 0, CHAR_MIN, CHAR_MAX },
{"textfile", "set text file", OFFSET(textfile), FF_OPT_TYPE_STRING, 0, CHAR_MIN, CHAR_MAX },
{"fontcolor","set foreground color", OFFSET(fontcolor_string), FF_OPT_TYPE_STRING, 0, CHAR_MIN, CHAR_MAX },
{"boxcolor", "set box color", OFFSET(boxcolor_string), FF_OPT_TYPE_STRING, 0, CHAR_MIN, CHAR_MAX },
{"box", "set box", OFFSET(draw_box), FF_OPT_TYPE_INT, 0, 0, 1 },
{"fontsize", "set font size", OFFSET(fontsize), FF_OPT_TYPE_INT, 16, 1, 72 },
{"x", "set x", OFFSET(x), FF_OPT_TYPE_INT, 0, 0, INT_MAX },
{"y", "set y", OFFSET(y), FF_OPT_TYPE_INT, 0, 0, INT_MAX },
{"tabsize", "set tab size", OFFSET(tabsize), FF_OPT_TYPE_INT, 4, 0, INT_MAX },
/* FT_LOAD_* flags */
{"ft_load_flags", "set font loading flags for libfreetype", OFFSET(ft_load_flags), FF_OPT_TYPE_FLAGS, FT_LOAD_DEFAULT|FT_LOAD_RENDER, 0, INT_MAX, 0, "ft_load_flags" },
{"default", "set default", 0, FF_OPT_TYPE_CONST, FT_LOAD_DEFAULT, INT_MIN, INT_MAX, 0, "ft_load_flags" },
{"no_scale", "set no_scale", 0, FF_OPT_TYPE_CONST, FT_LOAD_NO_SCALE, INT_MIN, INT_MAX, 0, "ft_load_flags" },
{"no_hinting", "set no_hinting", 0, FF_OPT_TYPE_CONST, FT_LOAD_NO_HINTING, INT_MIN, INT_MAX, 0, "ft_load_flags" },
{"render", "set render", 0, FF_OPT_TYPE_CONST, FT_LOAD_RENDER, INT_MIN, INT_MAX, 0, "ft_load_flags" },
{"no_bitmap", "set no_bitmap", 0, FF_OPT_TYPE_CONST, FT_LOAD_NO_BITMAP, INT_MIN, INT_MAX, 0, "ft_load_flags" },
{"vertical_layout", "set vertical_layout", 0, FF_OPT_TYPE_CONST, FT_LOAD_VERTICAL_LAYOUT, INT_MIN, INT_MAX, 0, "ft_load_flags" },
{"force_autohint", "set force_autohint", 0, FF_OPT_TYPE_CONST, FT_LOAD_FORCE_AUTOHINT, INT_MIN, INT_MAX, 0, "ft_load_flags" },
{"crop_bitmap", "set crop_bitmap", 0, FF_OPT_TYPE_CONST, FT_LOAD_CROP_BITMAP, INT_MIN, INT_MAX, 0, "ft_load_flags" },
{"pedantic", "set pedantic", 0, FF_OPT_TYPE_CONST, FT_LOAD_PEDANTIC, INT_MIN, INT_MAX, 0, "ft_load_flags" },
{"ignore_global_advance_width", "set ignore_global_advance_width", 0, FF_OPT_TYPE_CONST, FT_LOAD_IGNORE_GLOBAL_ADVANCE_WIDTH, INT_MIN, INT_MAX, 0, "ft_load_flags" },
{"no_recurse", "set no_recurse", 0, FF_OPT_TYPE_CONST, FT_LOAD_NO_RECURSE, INT_MIN, INT_MAX, 0, "ft_load_flags" },
{"ignore_transform", "set ignore_transform", 0, FF_OPT_TYPE_CONST, FT_LOAD_IGNORE_TRANSFORM, INT_MIN, INT_MAX, 0, "ft_load_flags" },
{"monochrome", "set monochrome", 0, FF_OPT_TYPE_CONST, FT_LOAD_MONOCHROME, INT_MIN, INT_MAX, 0, "ft_load_flags" },
{"linear_design", "set linear_design", 0, FF_OPT_TYPE_CONST, FT_LOAD_LINEAR_DESIGN, INT_MIN, INT_MAX, 0, "ft_load_flags" },
{"no_autohint", "set no_autohint", 0, FF_OPT_TYPE_CONST, FT_LOAD_NO_AUTOHINT, INT_MIN, INT_MAX, 0, "ft_load_flags" },
{NULL},
};
static const char *drawtext_get_name(void *ctx)
{
return "drawtext";
}
static const AVClass drawtext_class = {
"DrawTextContext",
drawtext_get_name,
drawtext_options
};
#undef __FTERRORS_H__
#define FT_ERROR_START_LIST {
#define FT_ERRORDEF(e, v, s) { (e), (s) },
#define FT_ERROR_END_LIST { 0, NULL } };
struct ft_error
{
int err;
const char *err_msg;
} static ft_errors[] =
#include FT_ERRORS_H
#define FT_ERRMSG(e) ft_errors[e].err_msg
typedef struct {
FT_Glyph *glyph;
uint32_t code;
FT_Bitmap bitmap; ///< array holding bitmaps of font
FT_BBox bbox;
int advance;
int bitmap_left;
int bitmap_top;
} Glyph;
static int glyph_cmp(void *key, const void *b)
{
const Glyph *a = key, *bb = b;
int64_t diff = (int64_t)a->code - (int64_t)bb->code;
return diff > 0 ? 1 : diff < 0 ? -1 : 0;
}
/**
* Load glyphs corresponding to the UTF-32 codepoint code.
*/
static int load_glyph(AVFilterContext *ctx, Glyph **glyph_ptr, uint32_t code)
{
DrawTextContext *dtext = ctx->priv;
Glyph *glyph;
struct AVTreeNode *node = NULL;
int ret;
/* load glyph into dtext->face->glyph */
if (FT_Load_Char(dtext->face, code, dtext->ft_load_flags))
return AVERROR(EINVAL);
/* save glyph */
if (!(glyph = av_mallocz(sizeof(*glyph))) ||
!(glyph->glyph = av_mallocz(sizeof(*glyph->glyph)))) {
ret = AVERROR(ENOMEM);
goto error;
}
glyph->code = code;
if (FT_Get_Glyph(dtext->face->glyph, glyph->glyph)) {
ret = AVERROR(EINVAL);
goto error;
}
glyph->bitmap = dtext->face->glyph->bitmap;
glyph->bitmap_left = dtext->face->glyph->bitmap_left;
glyph->bitmap_top = dtext->face->glyph->bitmap_top;
glyph->advance = dtext->face->glyph->advance.x >> 6;
/* measure text height to calculate text_height (or the maximum text height) */
FT_Glyph_Get_CBox(*glyph->glyph, ft_glyph_bbox_pixels, &glyph->bbox);
/* cache the newly created glyph */
if (!(node = av_mallocz(av_tree_node_size))) {
ret = AVERROR(ENOMEM);
goto error;
}
av_tree_insert(&dtext->glyphs, glyph, glyph_cmp, &node);
if (glyph_ptr)
*glyph_ptr = glyph;
return 0;
error:
if (glyph)
av_freep(&glyph->glyph);
av_freep(&glyph);
av_freep(&node);
return ret;
}
static av_cold int init(AVFilterContext *ctx, const char *args, void *opaque)
{
int err;
DrawTextContext *dtext = ctx->priv;
Glyph *glyph;
dtext->class = &drawtext_class;
av_opt_set_defaults2(dtext, 0, 0);
dtext->fontcolor_string = av_strdup("black");
dtext->boxcolor_string = av_strdup("white");
if ((err = (av_set_options_string(dtext, args, "=", ":"))) < 0) {
av_log(ctx, AV_LOG_ERROR, "Error parsing options string: '%s'\n", args);
return err;
}
if (!dtext->fontfile) {
av_log(ctx, AV_LOG_ERROR, "No font filename provided\n");
return AVERROR(EINVAL);
}
if (dtext->textfile) {
uint8_t *textbuf;
size_t textbuf_size;
if (dtext->text) {
av_log(ctx, AV_LOG_ERROR,
"Both text and text file provided. Please provide only one\n");
return AVERROR(EINVAL);
}
if ((err = av_file_map(dtext->textfile, &textbuf, &textbuf_size, 0, ctx)) < 0) {
av_log(ctx, AV_LOG_ERROR,
"The text file '%s' could not be read or is empty\n",
dtext->textfile);
return err;
}
if (!(dtext->text = av_malloc(textbuf_size+1)))
return AVERROR(ENOMEM);
memcpy(dtext->text, textbuf, textbuf_size);
dtext->text[textbuf_size] = 0;
av_file_unmap(textbuf, textbuf_size);
}
if (!dtext->text) {
av_log(ctx, AV_LOG_ERROR,
"Either text or a valid file must be provided\n");
return AVERROR(EINVAL);
}
if ((err = av_parse_color(dtext->fontcolor_rgba, dtext->fontcolor_string, -1, ctx))) {
av_log(ctx, AV_LOG_ERROR,
"Invalid font color '%s'\n", dtext->fontcolor_string);
return err;
}
if ((err = av_parse_color(dtext->boxcolor_rgba, dtext->boxcolor_string, -1, ctx))) {
av_log(ctx, AV_LOG_ERROR,
"Invalid box color '%s'\n", dtext->boxcolor_string);
return err;
}
if ((err = FT_Init_FreeType(&(dtext->library)))) {
av_log(ctx, AV_LOG_ERROR,
"Could not load FreeType: %s\n", FT_ERRMSG(err));
return AVERROR(EINVAL);
}
/* load the face, and set up the encoding, which is by default UTF-8 */
if ((err = FT_New_Face(dtext->library, dtext->fontfile, 0, &dtext->face))) {
av_log(ctx, AV_LOG_ERROR, "Could not load fontface from file '%s': %s\n",
dtext->fontfile, FT_ERRMSG(err));
return AVERROR(EINVAL);
}
if ((err = FT_Set_Pixel_Sizes(dtext->face, 0, dtext->fontsize))) {
av_log(ctx, AV_LOG_ERROR, "Could not set font size to %d pixels: %s\n",
dtext->fontsize, FT_ERRMSG(err));
return AVERROR(EINVAL);
}
dtext->use_kerning = FT_HAS_KERNING(dtext->face);
/* load the fallback glyph with code 0 */
load_glyph(ctx, NULL, 0);
/* set the tabsize in pixels */
if ((err = load_glyph(ctx, &glyph, ' ') < 0)) {
av_log(ctx, AV_LOG_ERROR, "Could not set tabsize.\n");
return err;
}
dtext->tabsize *= glyph->advance;
#if !HAVE_LOCALTIME_R
av_log(ctx, AV_LOG_WARNING, "strftime() expansion unavailable!\n");
#endif
return 0;
}
static int query_formats(AVFilterContext *ctx)
{
static const enum PixelFormat pix_fmts[] = {
PIX_FMT_ARGB, PIX_FMT_RGBA,
PIX_FMT_ABGR, PIX_FMT_BGRA,
PIX_FMT_RGB24, PIX_FMT_BGR24,
PIX_FMT_YUV420P, PIX_FMT_YUV444P,
PIX_FMT_YUV422P, PIX_FMT_YUV411P,
PIX_FMT_YUV410P, PIX_FMT_YUV440P,
PIX_FMT_NONE
};
avfilter_set_common_formats(ctx, avfilter_make_format_list(pix_fmts));
return 0;
}
static int glyph_enu_free(void *opaque, void *elem)
{
av_free(elem);
return 0;
}
static av_cold void uninit(AVFilterContext *ctx)
{
DrawTextContext *dtext = ctx->priv;
int i;
av_freep(&dtext->fontfile);
av_freep(&dtext->text);
av_freep(&dtext->fontcolor_string);
av_freep(&dtext->boxcolor_string);
av_freep(&dtext->positions);
av_tree_enumerate(dtext->glyphs, NULL, NULL, glyph_enu_free);
av_tree_destroy(dtext->glyphs);
dtext->glyphs = 0;
FT_Done_Face(dtext->face);
FT_Done_FreeType(dtext->library);
for (i = 0; i < 4; i++) {
av_freep(&dtext->box_line[i]);
dtext->pixel_step[i] = 0;
}
}
static int config_input(AVFilterLink *inlink)
{
DrawTextContext *dtext = inlink->dst->priv;
const AVPixFmtDescriptor *pix_desc = &av_pix_fmt_descriptors[inlink->format];
int ret;
dtext->hsub = pix_desc->log2_chroma_w;
dtext->vsub = pix_desc->log2_chroma_h;
if ((ret =
ff_fill_line_with_color(dtext->box_line, dtext->pixel_step,
inlink->w, dtext->boxcolor,
inlink->format, dtext->boxcolor_rgba,
&dtext->is_packed_rgb, dtext->rgba_map)) < 0)
return ret;
if (!dtext->is_packed_rgb) {
uint8_t *rgba = dtext->fontcolor_rgba;
dtext->fontcolor[0] = RGB_TO_Y_CCIR(rgba[0], rgba[1], rgba[2]);
dtext->fontcolor[1] = RGB_TO_U_CCIR(rgba[0], rgba[1], rgba[2], 0);
dtext->fontcolor[2] = RGB_TO_V_CCIR(rgba[0], rgba[1], rgba[2], 0);
dtext->fontcolor[3] = rgba[3];
}
return 0;
}
#define GET_BITMAP_VAL(r, c) \
bitmap->pixel_mode == FT_PIXEL_MODE_MONO ? \
(bitmap->buffer[(r) * bitmap->pitch + ((c)>>3)] & (0x80 >> ((c)&7))) * 255 : \
bitmap->buffer[(r) * bitmap->pitch + (c)]
#define SET_PIXEL_YUV(picref, yuva_color, val, x, y, hsub, vsub) { \
luma_pos = ((x) ) + ((y) ) * picref->linesize[0]; \
chroma_pos1 = ((x) >> (hsub)) + ((y) >> (vsub)) * picref->linesize[1]; \
chroma_pos2 = ((x) >> (hsub)) + ((y) >> (vsub)) * picref->linesize[2]; \
alpha = (yuva_color[3] * (val)) / 255; \
picref->data[0][luma_pos] = (alpha * yuva_color[0] + (255 - alpha) * picref->data[0][luma_pos]) >> 8; \
picref->data[1][chroma_pos1] = (alpha * yuva_color[1] + (255 - alpha) * picref->data[1][chroma_pos1]) >> 8; \
picref->data[2][chroma_pos2] = (alpha * yuva_color[2] + (255 - alpha) * picref->data[2][chroma_pos2]) >> 8; \
}
static inline int draw_glyph_yuv(AVFilterBufferRef *picref, FT_Bitmap *bitmap, unsigned int x,
unsigned int y, unsigned int width, unsigned int height,
const uint8_t yuva_color[4], int hsub, int vsub)
{
int r, c, alpha;
unsigned int luma_pos, chroma_pos1, chroma_pos2;
uint8_t src_val, dst_pixel[4];
for (r = 0; r < bitmap->rows && r+y < height; r++) {
for (c = 0; c < bitmap->width && c+x < width; c++) {
/* get pixel in the picref (destination) */
dst_pixel[0] = picref->data[0][ c+x + (y+r) * picref->linesize[0]];
dst_pixel[1] = picref->data[1][((c+x) >> hsub) + ((y+r) >> vsub) * picref->linesize[1]];
dst_pixel[2] = picref->data[2][((c+x) >> hsub) + ((y+r) >> vsub) * picref->linesize[2]];
/* get intensity value in the glyph bitmap (source) */
src_val = GET_BITMAP_VAL(r, c);
if (!src_val)
continue;
SET_PIXEL_YUV(picref, yuva_color, src_val, c+x, y+r, hsub, vsub);
}
}
return 0;
}
#define SET_PIXEL_RGB(picref, rgba_color, val, x, y, pixel_step, r_off, g_off, b_off, a_off) { \
p = picref->data[0] + (x) * pixel_step + ((y) * picref->linesize[0]); \
alpha = (rgba_color[3] * (val)) / 255; \
*(p+r_off) = (alpha * rgba_color[0] + (255 - alpha) * *(p+r_off)) >> 8; \
*(p+g_off) = (alpha * rgba_color[1] + (255 - alpha) * *(p+g_off)) >> 8; \
*(p+b_off) = (alpha * rgba_color[2] + (255 - alpha) * *(p+b_off)) >> 8; \
}
static inline int draw_glyph_rgb(AVFilterBufferRef *picref, FT_Bitmap *bitmap,
unsigned int x, unsigned int y,
unsigned int width, unsigned int height, int pixel_step,
const uint8_t rgba_color[4], const uint8_t rgba_map[4])
{
int r, c, alpha;
uint8_t *p;
uint8_t src_val, dst_pixel[4];
for (r = 0; r < bitmap->rows && r+y < height; r++) {
for (c = 0; c < bitmap->width && c+x < width; c++) {
/* get pixel in the picref (destination) */
dst_pixel[0] = picref->data[0][(c+x + rgba_map[0]) * pixel_step +
(y+r) * picref->linesize[0]];
dst_pixel[1] = picref->data[0][(c+x + rgba_map[1]) * pixel_step +
(y+r) * picref->linesize[0]];
dst_pixel[2] = picref->data[0][(c+x + rgba_map[2]) * pixel_step +
(y+r) * picref->linesize[0]];
/* get intensity value in the glyph bitmap (source) */
src_val = GET_BITMAP_VAL(r, c);
if (!src_val)
continue;
SET_PIXEL_RGB(picref, rgba_color, src_val, c+x, y+r, pixel_step,
rgba_map[0], rgba_map[1], rgba_map[2], rgba_map[3]);
}
}
return 0;
}
static inline void drawbox(AVFilterBufferRef *picref, unsigned int x, unsigned int y,
unsigned int width, unsigned int height,
uint8_t *line[4], int pixel_step[4], uint8_t color[4],
int hsub, int vsub, int is_rgba_packed, uint8_t rgba_map[4])
{
int i, j, alpha;
if (color[3] != 0xFF) {
if (is_rgba_packed) {
uint8_t *p;
for (j = 0; j < height; j++)
for (i = 0; i < width; i++)
SET_PIXEL_RGB(picref, color, 255, i+x, y+j, pixel_step[0],
rgba_map[0], rgba_map[1], rgba_map[2], rgba_map[3]);
} else {
unsigned int luma_pos, chroma_pos1, chroma_pos2;
for (j = 0; j < height; j++)
for (i = 0; i < width; i++)
SET_PIXEL_YUV(picref, color, 255, i+x, y+j, hsub, vsub);
}
} else {
ff_draw_rectangle(picref->data, picref->linesize,
line, pixel_step, hsub, vsub,
x, y, width, height);
}
}
static inline int is_newline(uint32_t c)
{
return (c == '\n' || c == '\r' || c == '\f' || c == '\v');
}
static int draw_text(AVFilterContext *ctx, AVFilterBufferRef *picref,
int width, int height)
{
DrawTextContext *dtext = ctx->priv;
uint32_t code = 0, prev_code = 0;
int x = 0, y = 0, i = 0;
int text_height, baseline;
uint8_t *p;
int str_w = 0;
int y_min = 32000, y_max = -32000;
FT_Vector delta;
Glyph *glyph = NULL, *prev_glyph = NULL;
Glyph dummy = { 0 };
if (dtext->text != dtext->text_priv) {
#if HAVE_LOCALTIME_R
time_t now = time(0);
struct tm ltime;
uint8_t *buf = NULL;
int buflen = 2*strlen(dtext->text) + 1, len;
localtime_r(&now, &ltime);
while ((buf = av_realloc(buf, buflen))) {
*buf = 1;
if ((len = strftime(buf, buflen, dtext->text, &ltime)) != 0 || *buf == 0)
break;
buflen *= 2;
}
if (!buf)
return AVERROR(ENOMEM);
av_freep(&dtext->text);
dtext->text = dtext->text_priv = buf;
#else
dtext->text_priv = dtext->text;
#endif
if (!(dtext->positions = av_realloc(dtext->positions,
strlen(dtext->text)*sizeof(*dtext->positions))))
return AVERROR(ENOMEM);
}
x = dtext->x;
y = dtext->y;
/* load and cache glyphs */
for (i = 0, p = dtext->text; *p; i++) {
GET_UTF8(code, *p++, continue;);
/* get glyph */
dummy.code = code;
glyph = av_tree_find(dtext->glyphs, &dummy, glyph_cmp, NULL);
if (!glyph)
load_glyph(ctx, &glyph, code);
y_min = FFMIN(glyph->bbox.yMin, y_min);
y_max = FFMAX(glyph->bbox.yMax, y_max);
}
text_height = y_max - y_min;
baseline = y_max;
/* compute and save position for each glyph */
glyph = NULL;
for (i = 0, p = dtext->text; *p; i++) {
GET_UTF8(code, *p++, continue;);
/* skip the \n in the sequence \r\n */
if (prev_code == '\r' && code == '\n')
continue;
prev_code = code;
if (is_newline(code)) {
str_w = FFMAX(str_w, x - dtext->x);
y += text_height;
x = dtext->x;
continue;
}
/* get glyph */
prev_glyph = glyph;
dummy.code = code;
glyph = av_tree_find(dtext->glyphs, &dummy, glyph_cmp, NULL);
/* kerning */
if (dtext->use_kerning && prev_glyph && glyph->code) {
FT_Get_Kerning(dtext->face, prev_glyph->code, glyph->code,
ft_kerning_default, &delta);
x += delta.x >> 6;
}
if (x + glyph->bbox.xMax >= width) {
str_w = FFMAX(str_w, x - dtext->x);
y += text_height;
x = dtext->x;
}
/* save position */
dtext->positions[i].x = x + glyph->bitmap_left;
dtext->positions[i].y = y - glyph->bitmap_top + baseline;
if (code == '\t') x = (x / dtext->tabsize + 1)*dtext->tabsize;
else x += glyph->advance;
}
str_w = FFMIN(width - dtext->x - 1, FFMAX(str_w, x - dtext->x));
y = FFMIN(y + text_height, height - 1);
/* draw box */
if (dtext->draw_box)
drawbox(picref, dtext->x, dtext->y, str_w, y-dtext->y,
dtext->box_line, dtext->pixel_step, dtext->boxcolor,
dtext->hsub, dtext->vsub, dtext->is_packed_rgb, dtext->rgba_map);
/* draw glyphs */
for (i = 0, p = dtext->text; *p; i++) {
Glyph dummy = { 0 };
GET_UTF8(code, *p++, continue;);
/* skip new line chars, just go to new line */
if (is_newline(code) || code == ' ' || code == '\t')
continue;
dummy.code = code;
glyph = av_tree_find(dtext->glyphs, &dummy, glyph_cmp, NULL);
if (glyph->bitmap.pixel_mode != FT_PIXEL_MODE_MONO &&
glyph->bitmap.pixel_mode != FT_PIXEL_MODE_GRAY)
return AVERROR(EINVAL);
if (dtext->is_packed_rgb) {
draw_glyph_rgb(picref, &glyph->bitmap,
dtext->positions[i].x, dtext->positions[i].y, width, height,
dtext->pixel_step[0], dtext->fontcolor_rgba, dtext->rgba_map);
} else {
draw_glyph_yuv(picref, &glyph->bitmap,
dtext->positions[i].x, dtext->positions[i].y, width, height,
dtext->fontcolor, dtext->hsub, dtext->vsub);
}
}
return 0;
}
static void null_draw_slice(AVFilterLink *link, int y, int h, int slice_dir) { }
static void end_frame(AVFilterLink *inlink)
{
AVFilterLink *outlink = inlink->dst->outputs[0];
AVFilterBufferRef *picref = inlink->cur_buf;
draw_text(inlink->dst, picref, picref->video->w, picref->video->h);
avfilter_draw_slice(outlink, 0, picref->video->h, 1);
avfilter_end_frame(outlink);
}
AVFilter avfilter_vf_drawtext = {
.name = "drawtext",
.description = NULL_IF_CONFIG_SMALL("Draw text on top of video frames using libfreetype library."),
.priv_size = sizeof(DrawTextContext),
.init = init,
.uninit = uninit,
.query_formats = query_formats,
.inputs = (AVFilterPad[]) {{ .name = "default",
.type = AVMEDIA_TYPE_VIDEO,
.get_video_buffer = avfilter_null_get_video_buffer,
.start_frame = avfilter_null_start_frame,
.draw_slice = null_draw_slice,
.end_frame = end_frame,
.config_props = config_input,
.min_perms = AV_PERM_WRITE |
AV_PERM_READ,
.rej_perms = AV_PERM_PRESERVE },
{ .name = NULL}},
.outputs = (AVFilterPad[]) {{ .name = "default",
.type = AVMEDIA_TYPE_VIDEO, },
{ .name = NULL}},
};
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