From 9d16e46d9eb4643ce119e26ed5c3975cb6cb7aa1 Mon Sep 17 00:00:00 2001 From: Paul B Mahol Date: Wed, 14 Sep 2016 01:37:13 +0200 Subject: avfilter/drawutils: allow drawing opaque text on transparent background Signed-off-by: Paul B Mahol --- libavfilter/drawutils.c | 7 ++++--- libavfilter/drawutils.h | 8 +++++++- libavfilter/vf_drawtext.c | 2 +- 3 files changed, 12 insertions(+), 5 deletions(-) diff --git a/libavfilter/drawutils.c b/libavfilter/drawutils.c index f6760be..f19fc5d 100644 --- a/libavfilter/drawutils.c +++ b/libavfilter/drawutils.c @@ -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]; diff --git a/libavfilter/drawutils.h b/libavfilter/drawutils.h index 1fb3e4f..cf53635 100644 --- a/libavfilter/drawutils.h +++ b/libavfilter/drawutils.h @@ -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 { @@ -67,11 +68,16 @@ typedef struct FFDrawColor { } 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); diff --git a/libavfilter/vf_drawtext.c b/libavfilter/vf_drawtext.c index 214aef0..65d3baa 100644 --- a/libavfilter/vf_drawtext.c +++ b/libavfilter/vf_drawtext.c @@ -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); -- cgit v1.1