[FFmpeg-soc] libavfilter audio work - qualification task
Stefano Sabatini
stefano.sabatini-lala at poste.it
Sun Apr 11 12:51:39 CEST 2010
On date Saturday 2010-04-10 18:59:37 -0700, S.N. Hemanth Meenakshisundaram encoded:
> On 04/09/2010 04:18 PM, Stefano Sabatini wrote:
[...]
> Please let me know if anything else needs to be fixed.
>
> Ronald,
>
> I will use just memcpy instead of fast_memcpy. Is that OK?
>
> Thanks,
> Index: allfilters.c
> ===================================================================
> --- allfilters.c (revision 5734)
> +++ allfilters.c (working copy)
> @@ -54,6 +54,7 @@
> REGISTER_FILTER (SPLIT, split, vf);
> REGISTER_FILTER (TRANSPOSE, transpose, vf);
> REGISTER_FILTER (VFLIP, vflip, vf);
> + REGISTER_FILTER (DRAWTEXT, drawtext, vf);
Alphabetical order.
>
> REGISTER_FILTER (BUFFER, buffer, vsrc);
> REGISTER_FILTER (MOVIE, movie, vsrc);
> Index: diffs/03_libavfilter_doc.diff
> ===================================================================
> --- diffs/03_libavfilter_doc.diff (revision 5734)
> +++ diffs/03_libavfilter_doc.diff (working copy)
> @@ -1,8 +1,8 @@
> -Index: doc/libavfilter.texi
> +Index: libavfilter.texi
> ===================================================================
> ---- doc/libavfilter.texi (revision 22749)
> -+++ doc/libavfilter.texi (working copy)
> -@@ -139,6 +139,20 @@
> +--- libavfilter.texi (revision 22749)
> ++++ libavfilter.texi (working copy)
> +@@ -139,6 +139,30 @@
>
> The default value of ``width'' and ``height'' is 0.
>
> @@ -14,6 +14,16 @@
> +
> +Draw a box with x:y:width:height dimensions in a chosen color.
> +
> ++ at section drawtext
> ++
> ++ at example
> ++./ffmpeg -i in.avi -vfilters drawtext=font=FreeSerif.ttf:text=TestText
> ++ :x=100:y=50:size=24:fgcolor=Yellow:bgcolor=Red:bg=1 out.avi
> ++ at end example
> ++
> ++Draw 'TestText' with font FreeSerif of size 24 at (100,50), text color is yellow,
> ++background color is red, draw a box around text.
Please add a table with the meaning of all the parameters. Check the
pad filter documentation to see how.
[...]
> Index: Makefile
> ===================================================================
> --- Makefile (revision 5734)
> +++ Makefile (working copy)
> @@ -35,6 +35,7 @@
> OBJS-$(CONFIG_SPLIT_FILTER) += vf_split.o
> OBJS-$(CONFIG_TRANSPOSE_FILTER) += vf_transpose.o
> OBJS-$(CONFIG_VFLIP_FILTER) += vf_vflip.o
> +OBJS-$(CONFIG_DRAWTEXT_FILTER) += vf_drawtext.o
Alphabetical order.
> OBJS-$(CONFIG_BUFFER_FILTER) += vsrc_buffer.o
> OBJS-$(CONFIG_MOVIE_FILTER) += vsrc_movie.o
> Index: vf_drawtext.c
> ===================================================================
> --- vf_drawtext.c (revision 0)
> +++ vf_drawtext.c (revision 0)
> @@ -0,0 +1,494 @@
> +/*
> + * vf_drawtext.c: print text over the screen
No need for this, just put the copyright, description may stay in the
@file doxy (also please mention libfreetype in this description).
> + * Original vhook author: Gustavo Sverzut Barbieri <gsbarbieri at yahoo.com.br>
> + * Libavfilter version : S.N. Hemanth Meenakshisundaram <smeenaks at ucsd.edu>
> + *
> + * Example usage with all available options:
> + * ./ffplay -vfilters drawtext=font=FreeSerif.ttf:text=TestText:file=tfil.txt:\
> + * x=100:y=50:size=24:fgcolor=Yellow:bgcolor=Red:outline=1:bg=1 in.avi
> + *
> + * 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 libavfilter/vf_drawtext.c
> + * video filter to draw text over screen
> + */
> +
> +#define MAXSIZE_TEXT 1024
> +
> +#include "avfilter.h"
> +#include "parseutils.h"
> +#include "libavutil/pixdesc.h"
> +#include "libavcodec/colorspace.h"
> +#include <stdio.h>
> +#include <stdlib.h>
These should be unnecessary.
> +#include <string.h>
> +#undef time
Why undef time? (I know they were in the vhook filter, but there is
some reason for it?).
> +#include <sys/time.h>
> +#include <time.h>
> +
> +#include <ft2build.h>
> +#include <freetype/config/ftheader.h>
> +#include FT_FREETYPE_H
> +#include FT_GLYPH_H
> +
> +#define SCALEBITS 10
> +#define DEF_DRAWTEXT_FONT_SZ 16
> +#define MAX_DRAWTEXT_OPT 10
> +#define ONE_HALF (1 << (SCALEBITS - 1))
> +#define FIX(x) ((int) ((x) * (1<<SCALEBITS) + 0.5))
These and scalebits are already defined in colorspace.h.
> +#define SET_PIXEL(picture, yuv_color, x, y) { \
> + picture->data[0][ (x) + (y)*picture->linesize[0] ] = yuv_color[0]; \
> + picture->data[1][ ((x/2) + (y/2)*picture->linesize[1]) ] = yuv_color[1]; \
> + picture->data[2][ ((x/2) + (y/2)*picture->linesize[2]) ] = yuv_color[2]; \
> +}
> +
> +#define GET_PIXEL(picture, yuv_color, x, y) { \
> + yuv_color[0] = picture->data[0][ (x) + (y)*picture->linesize[0] ]; \
> + yuv_color[1] = picture->data[1][ (x/2) + (y/2)*picture->linesize[1] ]; \
> + yuv_color[2] = picture->data[2][ (x/2) + (y/2)*picture->linesize[2] ]; \
> +}
These macros only work with YUV420P. Also please define them near to
where they're used.
> +typedef struct {
> + const AVClass *class; /* To help parseutils to fill in structure */
Nit: use ///< style for inline doxygen comments.
Nit: I prefer to lowcase the first letter if the text describing the
field is not a complete sentence (missing the verb like here), check
how it is done in main SVN filters.
> + unsigned char *font; /* Font to be used for drawing text */
> + unsigned char *text; /* Text to be drawn */
> + char *file; /* File with text to be drawn */
> + char *fgcolor; /* Text color */
> + char *bgcolor; /* Background/Box colour */
Nit: "color"
fgcolor description should explicitely mention the term "ForeGround"
or you'll have a confused reader, also maybe these fields are not
necessary at all.
> + unsigned int x; /* x position to start drawing text */
> + unsigned int y; /* y position to start drawing text */
> + unsigned int size; /* Font size to use */
> + unsigned char bcolor[3]; /* Text color in YUV */
> + unsigned char fcolor[3]; /* Background/Box color in YUV */
Having two variables names bcolor and bgcolor is horribly confusuing,
I suggest:
bgcolor_string
bgcolor
> + short int bg; /* Draw box around text - true or false */
unexplicative name
> + short int outline; /* Draw outline in bg color around text */
> + int text_height; /* Height of a font symbol */
> + int baseline; /* Baseline to draw fonts from */
> + int use_kerning; /* Font kerning is used - true/false */
> + FT_Library library; /* Freetype font library handle */
> + FT_Face face; /* Freetype font face handle */
> + FT_Glyph glyphs[ 256 ]; /* Array holding glyphs of font */
> + FT_Bitmap bitmaps[ 256 ]; /* Array holding bitmaps of font */
> + /* Glyph bitmap dimensions */
> + int advance[ 256 ];
> + int bitmap_left[ 256 ];
> + int bitmap_top[ 256 ];
> + unsigned int glyphs_index[ 256 ];
vertical align
> +} DrawTextContext;
> +
> +#define OFFSET(x) offsetof(DrawTextContext, x)
> +
> +static const AVOption drawtext_options[]= {
> +{"font", "set font", OFFSET(font), FF_OPT_TYPE_STRING, 0, CHAR_MIN, CHAR_MAX },
> +{"text", "set text", OFFSET(text), FF_OPT_TYPE_STRING, 0, CHAR_MIN, CHAR_MAX },
> +{"file", "set file", OFFSET(file), FF_OPT_TYPE_STRING, 0, CHAR_MIN, CHAR_MAX },
> +{"fgcolor", "set fgcolor", OFFSET(fgcolor), FF_OPT_TYPE_STRING, 0, CHAR_MIN, CHAR_MAX },
> +{"bgcolor", "set bgcolor", OFFSET(bgcolor), FF_OPT_TYPE_STRING, 0, CHAR_MIN, CHAR_MAX },
> +{"bg", "set bg", OFFSET(bg), FF_OPT_TYPE_INT, 0, 0, 1 },
> +{"outline", "set outline", OFFSET(outline), FF_OPT_TYPE_INT, 0, 0, 1 },
> +{"size", "set size", OFFSET(size), 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 },
nit: weird align
> +{NULL},
> +};
> +
> +static const char *drawtext_get_name(void *ctx)
> +{
> + return "drawtext";
> +}
> +
> +static const AVClass drawtext_class = {
> + "DrawTextContext",
> + drawtext_get_name,
> + drawtext_options
> +};
> +
> +static int query_formats(AVFilterContext *ctx)
> +{
> + /* FIXME : Supports only YUV now. Add RGB support */
> + enum PixelFormat pix_fmts[] = {
> + PIX_FMT_YUV444P, PIX_FMT_YUV422P, PIX_FMT_YUV420P,
> + PIX_FMT_YUV411P, PIX_FMT_YUV410P,
> + PIX_FMT_YUVJ444P, PIX_FMT_YUVJ422P, PIX_FMT_YUVJ420P,
> + PIX_FMT_YUV440P, PIX_FMT_YUVJ440P,
> + PIX_FMT_NONE
> + };
> +
> + avfilter_set_common_formats(ctx, avfilter_make_format_list(pix_fmts));
> + return 0;
> +}
> +
> +static av_cold int init(AVFilterContext *ctx, const char *args, void *opaque)
> +{
> + unsigned short int c;
> + uint8_t rgba[4];
> + uint8_t err, file_valid = 0;
> + int yMax, yMin;
y_max, y_min
> + char *arg_cpy = NULL;
> + FT_BBox bbox;
> + DrawTextContext *dtext = ctx->priv;
> +
> + dtext->class = &drawtext_class;
> + dtext->font = NULL;
> + dtext->text = NULL;
> + dtext->file = NULL;
> + dtext->fgcolor = NULL;
> + dtext->bgcolor = NULL;
> + dtext->x = dtext->y = 0;
> + dtext->size=DEF_DRAWTEXT_FONT_SZ;
av_opt_set_defaults2()
> + dtext->fcolor[0]=255;
> + dtext->fcolor[1]=128;
> + dtext->fcolor[2]=128;
> + dtext->bcolor[0]=0;
> + dtext->fcolor[1]=128;
> + dtext->fcolor[2]=128;
you can avoid to explicitely initialize these, use:
dtext->fgcolor_string = strdup("white");
dtext->bgcolor_string = strdup("black");
> + dtext->bg = 0;
> + dtext->outline = 0;
> + dtext->text_height = 0;
> +
> + arg_cpy = av_strdup(args);
why this?
> + if (av_set_options_string(dtext, arg_cpy, "=", ":") < 0) {
> + av_log(dtext, AV_LOG_ERROR, "Error parsing options string: '%s'\n", args);
> + return AVERROR(EINVAL);
> + }
> +
> + if (!dtext->font || *(dtext->font) == 0) {
> + av_log(dtext, AV_LOG_ERROR, "No font file provided! (-f filename)\n");
"-f filename" is misleading as we don't support that syntax anymore,
same below.
> + return AVERROR(EINVAL);
> + }
> +
> + if (!dtext->text || *(dtext->text) == 0) {
> + av_log(dtext, AV_LOG_ERROR, "No text provided (-t text)\n");
> + return AVERROR(EINVAL);
> + }
> +
> + if (dtext->file && *(dtext->file) != 0) {
> + FILE *fp;
> + if ((fp=fopen(dtext->file, "r")) == NULL) {
please use "fp = fopen" for increased readability, also !FOO is
preferred over FOO == NULL
> + av_log(dtext, AV_LOG_INFO, "WARNING: The file could not be opened.\
> + Using text provided with -t switch: %s", dtext->text);
> + }
> + else {
nit: "} else {" on the same line, here and below.
> + fclose(fp);
> + file_valid = 1;
> + }
> + }
> +
> + if ((dtext->fgcolor) && (av_parse_color(rgba, dtext->fgcolor, dtext) != 0)) {
> + av_log(dtext, AV_LOG_ERROR, "Invalid foreground color: '%s'.\n", dtext->fgcolor);
> + return AVERROR(EINVAL);
> + }
> + dtext->fcolor[0] = RGB_TO_Y(rgba[0], rgba[1], rgba[2]);
> + dtext->fcolor[1] = RGB_TO_U(rgba[0], rgba[1], rgba[2], 0);
> + dtext->fcolor[2] = RGB_TO_V(rgba[0], rgba[1], rgba[2], 0);
> +
> + if ((dtext->bgcolor) && (av_parse_color(rgba, dtext->bgcolor, dtext) != 0)) {
> + av_log(dtext, AV_LOG_ERROR, "Invalid background color: '%s'.\n", dtext->bgcolor);
> + return AVERROR(EINVAL);
> + }
> +
> + dtext->bcolor[0] = RGB_TO_Y(rgba[0], rgba[1], rgba[2]);
> + dtext->bcolor[1] = RGB_TO_U(rgba[0], rgba[1], rgba[2], 0);
> + dtext->bcolor[2] = RGB_TO_V(rgba[0], rgba[1], rgba[2], 0);
> +
> + if ((err = FT_Init_FreeType(&(dtext->library))) != 0) {
> + av_log(dtext, AV_LOG_ERROR, "Could not load FreeType (error# %d).\n", err);
> + return AVERROR(EINVAL);
> + }
Try to use libfreetype error messages, they have a weird system for
setting errors, in my sandbox I have this snippet:
/* build error strings table */
#define FT_ERROR_START_LIST {
#define FT_ERRORDEF( e, v, s ) { e, s },
#define FT_ERROR_END_LIST { 0, 0 } };
#undef __FTERRORS_H__
const struct
{
int code;
const char* msg;
} ft_errors[] =
#include FT_ERRORS_H
#define FT_ERRMSG(e) ft_errors[e].msg
maybe this can be simplified somehow.
> + if ((err = FT_New_Face( dtext->library, dtext->font, 0, &(dtext->face) )) != 0) {
> + av_log(dtext, AV_LOG_ERROR, "Could not load face: %s (error# %d).\n", dtext->font, err);
> + return AVERROR(EINVAL);
> + }
> + if ((err = FT_Set_Pixel_Sizes( dtext->face, 0, dtext->size)) != 0) {
> + av_log(dtext, AV_LOG_ERROR, "Could not set font size to %d pixels (error# %d).\n", dtext->size, err);
> + return AVERROR(EINVAL);
> + }
> +
> + dtext->use_kerning = FT_HAS_KERNING(dtext->face);
> +
> + /* load and cache glyphs */
> + yMax = -32000;
> + yMin = 32000;
> + /* FIXME : Supports only ASCII text now. Add Unicode support */
> + for (c=0; c <= 255; c++) {
> +
> + if (!file_valid && !strrchr(dtext->text,(unsigned char)c))
> + continue;
> +
> + /* Load char */
> + err = FT_Load_Char( dtext->face, (unsigned char) c, FT_LOAD_RENDER | FT_LOAD_MONOCHROME );
> + if (err) continue; /* ignore errors */
> +
> + /* Save bitmap */
> + dtext->bitmaps[c] = dtext->face->glyph->bitmap;
> + /* Save bitmap left */
> + dtext->bitmap_left[c] = dtext->face->glyph->bitmap_left;
> + /* Save bitmap top */
> + dtext->bitmap_top[c] = dtext->face->glyph->bitmap_top;
> + /* Save advance */
> + dtext->advance[c] = dtext->face->glyph->advance.x >> 6;
vertical align, maybe you can remove the comments
> + /* Save glyph */
> + err = FT_Get_Glyph( dtext->face->glyph, &(dtext->glyphs[c]) );
> + /* Save glyph index */
> + av_log(dtext, AV_LOG_ERROR, "c is %d\n", c);
AV_LOG_DEBUG
> + dtext->glyphs_index[c] = FT_Get_Char_Index( dtext->face, (unsigned char) c );
> +
> + /* Measure text height to calculate text_height (or the maximum text height) */
> + FT_Glyph_Get_CBox( dtext->glyphs[ c ], ft_glyph_bbox_pixels, &bbox );
> + if (bbox.yMax > yMax)
> + yMax = bbox.yMax;
> + if (bbox.yMin < yMin)
> + yMin = bbox.yMin;
> + }
> +
> + dtext->text_height = yMax - yMin;
> + dtext->baseline = yMax;
> +
> + return 0;
> +}
> +
> +static av_cold void uninit(AVFilterContext *ctx)
> +{
> + DrawTextContext *dtext = ctx->priv;
> + av_freep(&dtext->font);
> + av_freep(&dtext->text);
> + av_freep(&dtext->file);
> + av_freep(&dtext->fgcolor);
> + av_freep(&dtext->bgcolor);
> + FT_Done_Face(dtext->face);
> + FT_Done_FreeType(dtext->library);
> +}
> +
> +static int config_input(AVFilterLink *link)
> +{
> + return 0;
> +}
> +
> +static inline void draw_glyph(AVPicture *picture, FT_Bitmap *bitmap, unsigned int x,
> + unsigned int y, unsigned int width, unsigned int height,
> + unsigned char yuv_fcolor[3], unsigned char yuv_bcolor[3], short int outline)
weird indent
> +{
> + int r, c;
> + uint8_t spixel, dpixel[3], in_glyph=0;
> +
> + if (bitmap->pixel_mode == ft_pixel_mode_mono) {
> + in_glyph = 0;
> + for (r=0; (r < bitmap->rows) && (r+y < height); r++) {
> + for (c=0; (c < bitmap->width) && (c+x < width); c++) {
> + /* pixel in the picture (destination) */
> + GET_PIXEL(picture, dpixel, (c+x), (y+r));
> +
> + /* pixel in the glyph bitmap (source) */
> + spixel = bitmap->buffer[r*bitmap->pitch +c/8] & (0x80>>(c%8));
> +
> + if (spixel)
> + memcpy(dpixel, yuv_fcolor, 3);
> +
> + if (outline) {
> + /* border detection: */
> + if ( !in_glyph && spixel ) {
> + /* left border detected */
> + in_glyph = 1;
> + /* draw left pixel border */
> + if (c-1 >= 0)
> + SET_PIXEL(picture, yuv_bcolor, (c+x-1), (y+r));
> + }
> + else if ( in_glyph && !spixel ) {
> + /* right border detected */
> + in_glyph = 0;
> + /* 'draw' right pixel border */
> + memcpy(dpixel, yuv_bcolor, 3);
> + }
> +
> + if (in_glyph) {
> + /* see if we have a top/bottom border */
> + /* top */
> + if ((r-1 >= 0) && (! bitmap->buffer[(r-1)*bitmap->pitch +c/8] & (0x80>>(c%8))))
> + /* we have a top border */
> + SET_PIXEL(picture, yuv_bcolor, (c+x), (y+r-1));
> +
> + /* bottom border detection */
> + if ((r+1 < height) && (! bitmap->buffer[(r+1)*bitmap->pitch +c/8] & (0x80>>(c%8))))
> + /* draw bottom border */
> + SET_PIXEL(picture, yuv_bcolor, (c+x), (y+r+1));
> + }
> + }
> + SET_PIXEL(picture, dpixel, (c+x), (y+r));
> + }
> + }
> + }
> +}
> +
> +static inline void draw_box(AVPicture *picture, unsigned int x, unsigned int y,
> + unsigned int width, unsigned int height, unsigned char yuv_color[3])
> +{
> + int i, j;
> +
> + for (j = 0; (j < height); j++)
> + for (i = 0; (i < width); i++) {
> + SET_PIXEL(picture, yuv_color, (i+x), (y+j));
> + }
weird indent.
Also this can be done much faster with a memcpy, see how it is done in
vf_pad.c:draw_rectangle.
> +}
> +
> +static void draw_text(DrawTextContext *dtext, AVPicture *picture, int width, int height)
> +{
> + FT_Face face = dtext->face;
> + FT_GlyphSlot slot = face->glyph;
> + FILE *fd = NULL;
> + unsigned char *text = dtext->text;
> + unsigned char c;
> + int x = 0, y = 0, i=0, size=0;
> + unsigned char buff[MAXSIZE_TEXT];
> + unsigned char tbuff[MAXSIZE_TEXT];
> + time_t now = time(0);
> + int str_w, str_w_max;
> + FT_Vector pos[MAXSIZE_TEXT];
> + FT_Vector delta;
> +
> + if (dtext->file) {
> + if ((fd = fopen(dtext->file, "r")) == NULL) {
> + text = dtext->text;
> + av_log(dtext, AV_LOG_INFO, "WARNING: The file could not be opened.\
> + Using text provided with -t switch: %s", strerror(errno));
> + }
> + else {
> + int l = fread(tbuff, sizeof(char), MAXSIZE_TEXT-1, fd);
> + if (l >= 0) {
> + tbuff[l] = 0;
> + text = tbuff;
> + }
> + else {
> + text = dtext->text;
> + av_log(dtext, AV_LOG_INFO, "WARNING: The file could not be read.\
> + Using text provided with -t switch: %s", strerror(errno));
> + }
> + fclose(fd);
> + }
> + }
> + else {
> + text = dtext->text;
> + }
> + strftime(buff, sizeof(buff), text, localtime(&now));
> + text = buff;
> + size = strlen(text);
> +
> + /* measure string size and save glyphs position*/
> + str_w = str_w_max = 0;
> + x = dtext->x;
> + y = dtext->y;
> + for (i=0; i < size; i++) {
> + c = text[i];
> + /* kerning */
> + if ( (dtext->use_kerning) && (i > 0) && (dtext->glyphs_index[c]) ) {
> + FT_Get_Kerning(dtext->face, dtext->glyphs_index[text[i-1]],
> + dtext->glyphs_index[c], ft_kerning_default, &delta);
> + x += delta.x >> 6;
> + }
> +
> + if (( (x + dtext->advance[ c ]) >= width ) || ( c == '\n' )) {
> + if (c != '\n')
> + str_w_max = width - dtext->x - 1;
> + y += dtext->text_height;
> + x = dtext->x;
> + }
> +
> + /* save position */
> + pos[i].x = x + dtext->bitmap_left[c];
> + pos[i].y = y - dtext->bitmap_top[c] + dtext->baseline;
> + x += dtext->advance[c];
> + str_w +=dtext->advance[c];
> + }
> + if (y == 0)
> + y += dtext->text_height;
> + if (str_w_max == 0)
> + str_w_max = str_w;
> + if (dtext->bg) {
> + /* Check if it doesn't pass the limits */
> + if ( str_w_max + dtext->x >= width )
> + str_w_max = width - dtext->x - 1;
> + if ( y >= height )
> + y = height - 1 - 2*dtext->y;
> +
> + /* Draw Background */
> + draw_box( picture, dtext->x, dtext->y, str_w_max, y - dtext->y, dtext->bcolor );
> + }
> +
> + /* Draw Glyphs */
> + for (i=0; i < size; i++) {
> + c = text[i];
> +
> + /* skip '_' (consider as space) if text was specified in cmd line and
> + * skip new line char, just go to new line */
> + if (( (c == '_') && (text == dtext->text) ) || ( c == '\n' ) )
> + continue;
> +
> + /* now, draw to our target surface */
> + draw_glyph( picture,
> + &(dtext->bitmaps[ c ]),
> + pos[i].x,
> + pos[i].y,
> + width,
> + height,
> + dtext->fcolor,
> + dtext->bcolor,
> + dtext->outline );
> +
> + /* increment pen position */
> + x += slot->advance.x >> 6;
> + }
> +}
> +
> +static void end_frame(AVFilterLink *link)
> +{
> + DrawTextContext *context = link->dst->priv;
> + AVFilterLink *output = link->dst->outputs[0];
> + AVFilterPicRef *pic_ref = link->cur_pic;
> + AVPicture *pic = (AVPicture *)&pic_ref->data;
This cast is not needed, you can just work on the AVFilterPicRef, and
avoid a dependancy on libavcodec.
> +
> + draw_text(context, pic, pic_ref->w, pic_ref->h);
> +
> + avfilter_draw_slice(output, 0, pic_ref->h, 1);
> + avfilter_end_frame(output);
> +}
> +
> +AVFilter avfilter_vf_drawtext = {
> + .name = "drawtext",
> + .description = "Draw text on top of video frames.",
please mention libfreetype in the description
> + .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,
> + .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}},
> +};
Regards
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