diff options
| -rw-r--r-- | Changelog | 1 | ||||
| -rw-r--r-- | MAINTAINERS | 1 | ||||
| -rw-r--r-- | doc/filters.texi | 45 | ||||
| -rw-r--r-- | libavfilter/Makefile | 1 | ||||
| -rw-r--r-- | libavfilter/allfilters.c | 1 | ||||
| -rw-r--r-- | libavfilter/vf_chromakey.c | 199 |
6 files changed, 248 insertions, 0 deletions
@@ -11,6 +11,7 @@ version <next>: - rubberband filter - tremolo filter - agate filter +- chromakey filter version 2.8: diff --git a/MAINTAINERS b/MAINTAINERS index cb17f3980a..fd9507cb49 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -359,6 +359,7 @@ Filters: avf_avectorscope.c Paul B Mahol avf_showcqt.c Muhammad Faiz vf_blend.c Paul B Mahol + vf_chromakey.c Timo Rothenpieler vf_colorchannelmixer.c Paul B Mahol vf_colorbalance.c Paul B Mahol vf_colorkey.c Timo Rothenpieler diff --git a/doc/filters.texi b/doc/filters.texi index 88f6093049..044876c7c7 100644 --- a/doc/filters.texi +++ b/doc/filters.texi @@ -3707,6 +3707,51 @@ boxblur=luma_radius=min(h\,w)/10:luma_power=1:chroma_radius=min(cw\,ch)/10:chrom @end example @end itemize +@section chromakey +YUV colorspace color/chroma keying. + +The filter accepts the following options: + +@table @option +@item color +The color which will be replaced with transparency. + +@item similarity +Similarity percentage with the key color. + +0.01 matches only the exact key color, while 1.0 matches everything. + +@item blend +Blend percentage. + +0.0 makes pixels either fully transparent, or not transparent at all. + +Higher values result in semi-transparent pixels, with a higher transparency +the more similar the pixels color is to the key color. + +@item yuv +Signals that the color passed is already in YUV instead of RGB. + +Litteral colors like "green" or "red" don't make sense with this enabled anymore. +This can be used to pass exact YUV values as hexadecimal numbers. +@end table + +@subsection Examples + +@itemize +@item +Make every green pixel in the input image transparent: +@example +ffmpeg -i input.png -vf chromakey=green out.png +@end example + +@item +Overlay a greenscreen-video on top of a static black background. +@example +ffmpeg -f lavfi -i color=c=black:s=1280x720 -i video.mp4 -shortest -filter_complex "[1:v]chromakey=0x70de77:0.1:0.2[ckout];[0:v][ckout]overlay[out]" -map "[out]" output.mkv +@end example +@end itemize + @section codecview Visualize information exported by some codecs. diff --git a/libavfilter/Makefile b/libavfilter/Makefile index be177db4e1..7054275e1f 100644 --- a/libavfilter/Makefile +++ b/libavfilter/Makefile @@ -105,6 +105,7 @@ OBJS-$(CONFIG_BLACKDETECT_FILTER) += vf_blackdetect.o OBJS-$(CONFIG_BLACKFRAME_FILTER) += vf_blackframe.o OBJS-$(CONFIG_BLEND_FILTER) += vf_blend.o dualinput.o framesync.o OBJS-$(CONFIG_BOXBLUR_FILTER) += vf_boxblur.o +OBJS-$(CONFIG_CHROMAKEY_FILTER) += vf_chromakey.o OBJS-$(CONFIG_CODECVIEW_FILTER) += vf_codecview.o OBJS-$(CONFIG_COLORBALANCE_FILTER) += vf_colorbalance.o OBJS-$(CONFIG_COLORCHANNELMIXER_FILTER) += vf_colorchannelmixer.o diff --git a/libavfilter/allfilters.c b/libavfilter/allfilters.c index 7c93c1dcda..c21456d62e 100644 --- a/libavfilter/allfilters.c +++ b/libavfilter/allfilters.c @@ -127,6 +127,7 @@ void avfilter_register_all(void) REGISTER_FILTER(BLACKFRAME, blackframe, vf); REGISTER_FILTER(BLEND, blend, vf); REGISTER_FILTER(BOXBLUR, boxblur, vf); + REGISTER_FILTER(CHROMAKEY, chromakey, vf); REGISTER_FILTER(CODECVIEW, codecview, vf); REGISTER_FILTER(COLORBALANCE, colorbalance, vf); REGISTER_FILTER(COLORCHANNELMIXER, colorchannelmixer, vf); diff --git a/libavfilter/vf_chromakey.c b/libavfilter/vf_chromakey.c new file mode 100644 index 0000000000..47fdea631f --- /dev/null +++ b/libavfilter/vf_chromakey.c @@ -0,0 +1,199 @@ +/* + * 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; +} 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 hsub_log2 = 0, vsub_log2 = 0; + 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)); + + if (frame->format == AV_PIX_FMT_YUVA420P || frame->format == AV_PIX_FMT_YUVA422P) + hsub_log2 = 1; + + if (frame->format == AV_PIX_FMT_YUVA420P) + vsub_log2 = 1; + + 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, hsub_log2, 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, avctx->graph->nb_threads))) + 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 const AVFilterPad chromakey_inputs[] = { + { + .name = "default", + .type = AVMEDIA_TYPE_VIDEO, + .needs_writable = 1, + .filter_frame = filter_frame, + }, + { 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, +}; |