2 * Copyright (c) 2015 Timo Rothenpieler <timo@rothenpieler.org>
4 * This file is part of FFmpeg.
6 * FFmpeg is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2.1 of the License, or (at your option) any later version.
11 * FFmpeg is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Lesser General Public License for more details.
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with FFmpeg; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21 #include "libavutil/opt.h"
22 #include "libavutil/imgutils.h"
28 typedef struct ColorkeyContext {
31 /* color offsets rgba */
34 uint8_t colorkey_rgba[4];
39 static uint8_t do_colorkey_pixel(ColorkeyContext *ctx, uint8_t r, uint8_t g, uint8_t b)
41 int dr = (int)r - ctx->colorkey_rgba[0];
42 int dg = (int)g - ctx->colorkey_rgba[1];
43 int db = (int)b - ctx->colorkey_rgba[2];
45 double diff = sqrt((dr * dr + dg * dg + db * db) / (255.0 * 255.0));
47 if (ctx->blend > 0.0001) {
48 return av_clipd((diff - ctx->similarity) / ctx->blend, 0.0, 1.0) * 255.0;
50 return (diff > ctx->similarity) ? 255 : 0;
54 static int do_colorkey_slice(AVFilterContext *avctx, void *arg, int jobnr, int nb_jobs)
58 const int slice_start = (frame->height * jobnr) / nb_jobs;
59 const int slice_end = (frame->height * (jobnr + 1)) / nb_jobs;
61 ColorkeyContext *ctx = avctx->priv;
65 for (y = slice_start; y < slice_end; ++y) {
66 for (x = 0; x < frame->width; ++x) {
67 o = frame->linesize[0] * y + x * 4;
69 frame->data[0][o + ctx->co[3]] =
70 do_colorkey_pixel(ctx,
71 frame->data[0][o + ctx->co[0]],
72 frame->data[0][o + ctx->co[1]],
73 frame->data[0][o + ctx->co[2]]);
80 static int filter_frame(AVFilterLink *link, AVFrame *frame)
82 AVFilterContext *avctx = link->dst;
85 if (res = av_frame_make_writable(frame))
88 if (res = avctx->internal->execute(avctx, do_colorkey_slice, frame, NULL, FFMIN(frame->height, ff_filter_get_nb_threads(avctx))))
91 return ff_filter_frame(avctx->outputs[0], frame);
94 static av_cold int config_output(AVFilterLink *outlink)
96 AVFilterContext *avctx = outlink->src;
97 ColorkeyContext *ctx = avctx->priv;
98 const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(outlink->format);
101 outlink->w = avctx->inputs[0]->w;
102 outlink->h = avctx->inputs[0]->h;
103 outlink->time_base = avctx->inputs[0]->time_base;
105 for (i = 0; i < 4; ++i)
106 ctx->co[i] = desc->comp[i].offset;
111 static av_cold int query_formats(AVFilterContext *avctx)
113 static const enum AVPixelFormat pixel_fmts[] = {
121 AVFilterFormats *formats = NULL;
123 formats = ff_make_format_list(pixel_fmts);
125 return AVERROR(ENOMEM);
127 return ff_set_common_formats(avctx, formats);
130 static const AVFilterPad colorkey_inputs[] = {
133 .type = AVMEDIA_TYPE_VIDEO,
134 .filter_frame = filter_frame,
139 static const AVFilterPad colorkey_outputs[] = {
142 .type = AVMEDIA_TYPE_VIDEO,
143 .config_props = config_output,
148 #define OFFSET(x) offsetof(ColorkeyContext, x)
149 #define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
151 static const AVOption colorkey_options[] = {
152 { "color", "set the colorkey key color", OFFSET(colorkey_rgba), AV_OPT_TYPE_COLOR, { .str = "black" }, CHAR_MIN, CHAR_MAX, FLAGS },
153 { "similarity", "set the colorkey similarity value", OFFSET(similarity), AV_OPT_TYPE_FLOAT, { .dbl = 0.01 }, 0.01, 1.0, FLAGS },
154 { "blend", "set the colorkey key blend value", OFFSET(blend), AV_OPT_TYPE_FLOAT, { .dbl = 0.0 }, 0.0, 1.0, FLAGS },
158 AVFILTER_DEFINE_CLASS(colorkey);
160 AVFilter ff_vf_colorkey = {
162 .description = NULL_IF_CONFIG_SMALL("Turns a certain color into transparency. Operates on RGB colors."),
163 .priv_size = sizeof(ColorkeyContext),
164 .priv_class = &colorkey_class,
165 .query_formats = query_formats,
166 .inputs = colorkey_inputs,
167 .outputs = colorkey_outputs,
168 .flags = AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC | AVFILTER_FLAG_SLICE_THREADS,