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 ChromakeyContext {
31 uint8_t chromakey_rgba[4];
32 uint8_t chromakey_uv[2];
43 static uint8_t do_chromakey_pixel(ChromakeyContext *ctx, uint8_t u[9], uint8_t v[9])
48 for (i = 0; i < 9; ++i) {
49 du = (int)u[i] - ctx->chromakey_uv[0];
50 dv = (int)v[i] - ctx->chromakey_uv[1];
52 diff += sqrt((du * du + dv * dv) / (255.0 * 255.0));
57 if (ctx->blend > 0.0001) {
58 return av_clipd((diff - ctx->similarity) / ctx->blend, 0.0, 1.0) * 255.0;
60 return (diff > ctx->similarity) ? 255 : 0;
64 static av_always_inline void get_pixel_uv(AVFrame *frame, int hsub_log2, int vsub_log2, int x, int y, uint8_t *u, uint8_t *v)
66 if (x < 0 || x >= frame->width || y < 0 || y >= frame->height)
72 *u = frame->data[1][frame->linesize[1] * y + x];
73 *v = frame->data[2][frame->linesize[2] * y + x];
76 static int do_chromakey_slice(AVFilterContext *avctx, void *arg, int jobnr, int nb_jobs)
80 const int slice_start = (frame->height * jobnr) / nb_jobs;
81 const int slice_end = (frame->height * (jobnr + 1)) / nb_jobs;
83 ChromakeyContext *ctx = avctx->priv;
88 memset(u, ctx->chromakey_uv[0], sizeof(u));
89 memset(v, ctx->chromakey_uv[1], sizeof(v));
91 for (y = slice_start; y < slice_end; ++y) {
92 for (x = 0; x < frame->width; ++x) {
93 for (yo = 0; yo < 3; ++yo) {
94 for (xo = 0; xo < 3; ++xo) {
95 get_pixel_uv(frame, ctx->hsub_log2, ctx->vsub_log2, x + xo - 1, y + yo - 1, &u[yo * 3 + xo], &v[yo * 3 + xo]);
99 frame->data[3][frame->linesize[3] * y + x] = do_chromakey_pixel(ctx, u, v);
106 static int filter_frame(AVFilterLink *link, AVFrame *frame)
108 AVFilterContext *avctx = link->dst;
111 if (res = avctx->internal->execute(avctx, do_chromakey_slice, frame, NULL, FFMIN(frame->height, ff_filter_get_nb_threads(avctx))))
114 return ff_filter_frame(avctx->outputs[0], frame);
117 #define FIXNUM(x) lrint((x) * (1 << 10))
118 #define RGB_TO_U(rgb) (((- FIXNUM(0.16874) * rgb[0] - FIXNUM(0.33126) * rgb[1] + FIXNUM(0.50000) * rgb[2] + (1 << 9) - 1) >> 10) + 128)
119 #define RGB_TO_V(rgb) ((( FIXNUM(0.50000) * rgb[0] - FIXNUM(0.41869) * rgb[1] - FIXNUM(0.08131) * rgb[2] + (1 << 9) - 1) >> 10) + 128)
121 static av_cold int initialize_chromakey(AVFilterContext *avctx)
123 ChromakeyContext *ctx = avctx->priv;
126 ctx->chromakey_uv[0] = ctx->chromakey_rgba[1];
127 ctx->chromakey_uv[1] = ctx->chromakey_rgba[2];
129 ctx->chromakey_uv[0] = RGB_TO_U(ctx->chromakey_rgba);
130 ctx->chromakey_uv[1] = RGB_TO_V(ctx->chromakey_rgba);
136 static av_cold int query_formats(AVFilterContext *avctx)
138 static const enum AVPixelFormat pixel_fmts[] = {
145 AVFilterFormats *formats = NULL;
147 formats = ff_make_format_list(pixel_fmts);
149 return AVERROR(ENOMEM);
151 return ff_set_common_formats(avctx, formats);
154 static av_cold int config_input(AVFilterLink *inlink)
156 AVFilterContext *avctx = inlink->dst;
157 ChromakeyContext *ctx = avctx->priv;
158 const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format);
160 ctx->hsub_log2 = desc->log2_chroma_w;
161 ctx->vsub_log2 = desc->log2_chroma_h;
166 static const AVFilterPad chromakey_inputs[] = {
169 .type = AVMEDIA_TYPE_VIDEO,
171 .filter_frame = filter_frame,
172 .config_props = config_input,
177 static const AVFilterPad chromakey_outputs[] = {
180 .type = AVMEDIA_TYPE_VIDEO,
185 #define OFFSET(x) offsetof(ChromakeyContext, x)
186 #define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
188 static const AVOption chromakey_options[] = {
189 { "color", "set the chromakey key color", OFFSET(chromakey_rgba), AV_OPT_TYPE_COLOR, { .str = "black" }, CHAR_MIN, CHAR_MAX, FLAGS },
190 { "similarity", "set the chromakey similarity value", OFFSET(similarity), AV_OPT_TYPE_FLOAT, { .dbl = 0.01 }, 0.01, 1.0, FLAGS },
191 { "blend", "set the chromakey key blend value", OFFSET(blend), AV_OPT_TYPE_FLOAT, { .dbl = 0.0 }, 0.0, 1.0, FLAGS },
192 { "yuv", "color parameter is in yuv instead of rgb", OFFSET(is_yuv), AV_OPT_TYPE_BOOL, { .i64 = 0 }, 0, 1, FLAGS },
196 AVFILTER_DEFINE_CLASS(chromakey);
198 AVFilter ff_vf_chromakey = {
200 .description = NULL_IF_CONFIG_SMALL("Turns a certain color into transparency. Operates on YUV colors."),
201 .priv_size = sizeof(ChromakeyContext),
202 .priv_class = &chromakey_class,
203 .init = initialize_chromakey,
204 .query_formats = query_formats,
205 .inputs = chromakey_inputs,
206 .outputs = chromakey_outputs,
207 .flags = AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC | AVFILTER_FLAG_SLICE_THREADS,