/* * Copyright (c) 2015 Timo Rothenpieler <timo@rothenpieler.org> * * This file is part of FFmpeg. * * FFmpeg is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * FFmpeg is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with FFmpeg; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ #include "libavutil/opt.h" #include "libavutil/imgutils.h" #include "avfilter.h" #include "formats.h" #include "internal.h" #include "video.h" typedef struct ChromakeyContext { const AVClass *class; uint8_t chromakey_rgba[4]; uint8_t chromakey_uv[2]; float similarity; float blend; int is_yuv; int hsub_log2; int vsub_log2; } ChromakeyContext; static uint8_t do_chromakey_pixel(ChromakeyContext *ctx, uint8_t u[9], uint8_t v[9]) { double diff = 0.0; int du, dv, i; for (i = 0; i < 9; ++i) { du = (int)u[i] - ctx->chromakey_uv[0]; dv = (int)v[i] - ctx->chromakey_uv[1]; diff += sqrt((du * du + dv * dv) / (255.0 * 255.0)); } diff /= 9.0; if (ctx->blend > 0.0001) { return av_clipd((diff - ctx->similarity) / ctx->blend, 0.0, 1.0) * 255.0; } else { return (diff > ctx->similarity) ? 255 : 0; } } 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) { if (x < 0 || x >= frame->width || y < 0 || y >= frame->height) return; x >>= hsub_log2; y >>= vsub_log2; *u = frame->data[1][frame->linesize[1] * y + x]; *v = frame->data[2][frame->linesize[2] * y + x]; } static int do_chromakey_slice(AVFilterContext *avctx, void *arg, int jobnr, int nb_jobs) { AVFrame *frame = arg; const int slice_start = (frame->height * jobnr) / nb_jobs; const int slice_end = (frame->height * (jobnr + 1)) / nb_jobs; ChromakeyContext *ctx = avctx->priv; int x, y, xo, yo; uint8_t u[9], v[9]; memset(u, ctx->chromakey_uv[0], sizeof(u)); memset(v, ctx->chromakey_uv[1], sizeof(v)); for (y = slice_start; y < slice_end; ++y) { for (x = 0; x < frame->width; ++x) { for (yo = 0; yo < 3; ++yo) { for (xo = 0; xo < 3; ++xo) { get_pixel_uv(frame, ctx->hsub_log2, ctx->vsub_log2, x + xo - 1, y + yo - 1, &u[yo * 3 + xo], &v[yo * 3 + xo]); } } frame->data[3][frame->linesize[3] * y + x] = do_chromakey_pixel(ctx, u, v); } } return 0; } static int filter_frame(AVFilterLink *link, AVFrame *frame) { AVFilterContext *avctx = link->dst; int res; if (res = avctx->internal->execute(avctx, do_chromakey_slice, frame, NULL, FFMIN(frame->height, ff_filter_get_nb_threads(avctx)))) return res; return ff_filter_frame(avctx->outputs[0], frame); } #define FIXNUM(x) lrint((x) * (1 << 10)) #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) #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) static av_cold int initialize_chromakey(AVFilterContext *avctx) { ChromakeyContext *ctx = avctx->priv; if (ctx->is_yuv) { ctx->chromakey_uv[0] = ctx->chromakey_rgba[1]; ctx->chromakey_uv[1] = ctx->chromakey_rgba[2]; } else { ctx->chromakey_uv[0] = RGB_TO_U(ctx->chromakey_rgba); ctx->chromakey_uv[1] = RGB_TO_V(ctx->chromakey_rgba); } return 0; } static av_cold int query_formats(AVFilterContext *avctx) { static const enum AVPixelFormat pixel_fmts[] = { AV_PIX_FMT_YUVA420P, AV_PIX_FMT_YUVA422P, AV_PIX_FMT_YUVA444P, AV_PIX_FMT_NONE }; AVFilterFormats *formats = NULL; formats = ff_make_format_list(pixel_fmts); if (!formats) return AVERROR(ENOMEM); return ff_set_common_formats(avctx, formats); } static av_cold int config_input(AVFilterLink *inlink) { AVFilterContext *avctx = inlink->dst; ChromakeyContext *ctx = avctx->priv; const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format); ctx->hsub_log2 = desc->log2_chroma_w; ctx->vsub_log2 = desc->log2_chroma_h; return 0; } static const AVFilterPad chromakey_inputs[] = { { .name = "default", .type = AVMEDIA_TYPE_VIDEO, .needs_writable = 1, .filter_frame = filter_frame, .config_props = config_input, }, { NULL } }; static const AVFilterPad chromakey_outputs[] = { { .name = "default", .type = AVMEDIA_TYPE_VIDEO, }, { NULL } }; #define OFFSET(x) offsetof(ChromakeyContext, x) #define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM static const AVOption chromakey_options[] = { { "color", "set the chromakey key color", OFFSET(chromakey_rgba), AV_OPT_TYPE_COLOR, { .str = "black" }, CHAR_MIN, CHAR_MAX, FLAGS }, { "similarity", "set the chromakey similarity value", OFFSET(similarity), AV_OPT_TYPE_FLOAT, { .dbl = 0.01 }, 0.01, 1.0, FLAGS }, { "blend", "set the chromakey key blend value", OFFSET(blend), AV_OPT_TYPE_FLOAT, { .dbl = 0.0 }, 0.0, 1.0, FLAGS }, { "yuv", "color parameter is in yuv instead of rgb", OFFSET(is_yuv), AV_OPT_TYPE_BOOL, { .i64 = 0 }, 0, 1, FLAGS }, { NULL } }; AVFILTER_DEFINE_CLASS(chromakey); AVFilter ff_vf_chromakey = { .name = "chromakey", .description = NULL_IF_CONFIG_SMALL("Turns a certain color into transparency. Operates on YUV colors."), .priv_size = sizeof(ChromakeyContext), .priv_class = &chromakey_class, .init = initialize_chromakey, .query_formats = query_formats, .inputs = chromakey_inputs, .outputs = chromakey_outputs, .flags = AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC | AVFILTER_FLAG_SLICE_THREADS, };