diff --git a/libavfilter/vf_drawtext.c b/libavfilter/vf_drawtext.c index ec83ac0b4a..08ed818256 100644 --- a/libavfilter/vf_drawtext.c +++ b/libavfilter/vf_drawtext.c @@ -373,10 +373,10 @@ static int config_input(AVFilterLink *inlink) 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; \ + alpha = yuva_color[3] * (val) * 129; \ + picref->data[0][luma_pos] = (alpha * yuva_color[0] + (255*255*129 - alpha) * picref->data[0][luma_pos] ) >> 23; \ + picref->data[1][chroma_pos1] = (alpha * yuva_color[1] + (255*255*129 - alpha) * picref->data[1][chroma_pos1]) >> 23; \ + picref->data[2][chroma_pos2] = (alpha * yuva_color[2] + (255*255*129 - alpha) * picref->data[2][chroma_pos2]) >> 23; \ } static inline int draw_glyph_yuv(AVFilterBufferRef *picref, FT_Bitmap *bitmap, unsigned int x, @@ -408,10 +408,10 @@ static inline int draw_glyph_yuv(AVFilterBufferRef *picref, FT_Bitmap *bitmap, u #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; \ + alpha = rgba_color[3] * (val) * 129; \ + *(p+r_off) = (alpha * rgba_color[0] + (255*255*129 - alpha) * *(p+r_off)) >> 23; \ + *(p+g_off) = (alpha * rgba_color[1] + (255*255*129 - alpha) * *(p+g_off)) >> 23; \ + *(p+b_off) = (alpha * rgba_color[2] + (255*255*129 - alpha) * *(p+b_off)) >> 23; \ } static inline int draw_glyph_rgb(AVFilterBufferRef *picref, FT_Bitmap *bitmap,