RepoMirrors
/
ffmpeg
mirror of https://git.ffmpeg.org/ffmpeg.git
1
0
Fork 0
Code Issues Projects Releases Wiki Activity

avfilter/drawutils: allow drawing opaque text on transparent background 

Signed-off-by: Paul B Mahol <onemda@gmail.com>
This commit is contained in:
Paul B Mahol 2016-09-14 01:37:13 +02:00
parent 6419b4c0cb
commit 9d16e46d9e
3 changed files with 12 additions and 5 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

7
libavfilter/drawutils.c
View File

@ -211,10 +211,11 @@ int ff_draw_init(FFDrawContext *draw, enum AVPixelFormat format, unsigned flags)
draw->desc = desc;
draw->format = format;
draw->nb_planes = nb_planes;
draw->flags = flags;
memcpy(draw->pixelstep, pixelstep, sizeof(draw->pixelstep));
draw->hsub[1] = draw->hsub[2] = draw->hsub_max = desc->log2_chroma_w;
draw->vsub[1] = draw->vsub[2] = draw->vsub_max = desc->log2_chroma_h;
for (i = 0; i < (desc->nb_components - !!(desc->flags & AV_PIX_FMT_FLAG_ALPHA)); i++)
for (i = 0; i < (desc->nb_components - !!(desc->flags & AV_PIX_FMT_FLAG_ALPHA && !(flags & FF_DRAW_PROCESS_ALPHA))); i++)
draw->comp_mask[desc->comp[i].plane] |=
1 << desc->comp[i].offset;
return 0;
@ -452,7 +453,7 @@ void ff_blend_rectangle(FFDrawContext *draw, FFDrawColor *color,
/* 0x101 * alpha is in the [ 2 ; 0x1001] range */
alpha = 0x101 * color->rgba[3] + 0x2;
}
nb_planes = draw->nb_planes - !!(draw->desc->flags & AV_PIX_FMT_FLAG_ALPHA);
nb_planes = draw->nb_planes - !!(draw->desc->flags & AV_PIX_FMT_FLAG_ALPHA && !(draw->flags & FF_DRAW_PROCESS_ALPHA));
nb_planes += !nb_planes;
for (plane = 0; plane < nb_planes; plane++) {
nb_comp = draw->pixelstep[plane];
@ -630,7 +631,7 @@ void ff_blend_mask(FFDrawContext *draw, FFDrawColor *color,
} else {
alpha = (0x101 * color->rgba[3] + 0x2) >> 8;
}
nb_planes = draw->nb_planes - !!(draw->desc->flags & AV_PIX_FMT_FLAG_ALPHA);
nb_planes = draw->nb_planes - !!(draw->desc->flags & AV_PIX_FMT_FLAG_ALPHA && !(draw->flags & FF_DRAW_PROCESS_ALPHA));
nb_planes += !nb_planes;
for (plane = 0; plane < nb_planes; plane++) {
nb_comp = draw->pixelstep[plane];

8
libavfilter/drawutils.h
View File

@ -55,6 +55,7 @@ typedef struct FFDrawContext {
uint8_t vsub[MAX_PLANES]; /*< vertical subsampling */
uint8_t hsub_max;
uint8_t vsub_max;
unsigned flags;
} FFDrawContext;
typedef struct FFDrawColor {
@ -66,12 +67,17 @@ typedef struct FFDrawColor {
} comp[MAX_PLANES];
} FFDrawColor;
/**
* Process alpha pixel component.
*/
#define FF_DRAW_PROCESS_ALPHA 1
/**
* Init a draw context.
*
* Only a limited number of pixel formats are supported, if format is not
* supported the function will return an error.
* No flags currently defined.
* flags is combination of FF_DRAW_* flags.
* @return 0 for success, < 0 for error
*/
int ff_draw_init(FFDrawContext *draw, enum AVPixelFormat format, unsigned flags);

2
libavfilter/vf_drawtext.c
View File

@ -730,7 +730,7 @@ static int config_input(AVFilterLink *inlink)
DrawTextContext *s = ctx->priv;
int ret;
ff_draw_init(&s->dc, inlink->format, 0);
ff_draw_init(&s->dc, inlink->format, FF_DRAW_PROCESS_ALPHA);
ff_draw_color(&s->dc, &s->fontcolor, s->fontcolor.rgba);
ff_draw_color(&s->dc, &s->shadowcolor, s->shadowcolor.rgba);
ff_draw_color(&s->dc, &s->bordercolor, s->bordercolor.rgba);