[FFmpeg-devel] [PATCH] avfilter: add lumakey filter
Paul B Mahol
onemda at gmail.com
Sun Apr 23 21:47:27 EEST 2017
Signed-off-by: Paul B Mahol <onemda at gmail.com>
---
doc/filters.texi | 16 +++++
libavfilter/Makefile | 1 +
libavfilter/allfilters.c | 1 +
libavfilter/vf_lumakey.c | 174 +++++++++++++++++++++++++++++++++++++++++++++++
4 files changed, 192 insertions(+)
create mode 100644 libavfilter/vf_lumakey.c
diff --git a/doc/filters.texi b/doc/filters.texi
index 4c733f0..d7ac4cf 100644
--- a/doc/filters.texi
+++ b/doc/filters.texi
@@ -9278,6 +9278,22 @@ Interpolate values using a tetrahedron.
@end table
@end table
+ at section lumakey
+
+Turn certain luma values into transparency.
+
+The filter accepts the following options:
+
+ at table @option
+ at item threshold
+Set the luma which will be used as base for transparency.
+Default value is @code{0}.
+
+ at item tolerance
+Set the range of luma values to be keyed out.
+Default value is @code{0}.
+ at end table
+
@section lut, lutrgb, lutyuv
Compute a look-up table for binding each pixel component input value
diff --git a/libavfilter/Makefile b/libavfilter/Makefile
index 50c5132..074c690 100644
--- a/libavfilter/Makefile
+++ b/libavfilter/Makefile
@@ -212,6 +212,7 @@ OBJS-$(CONFIG_INTERLEAVE_FILTER) += f_interleave.o
OBJS-$(CONFIG_KERNDEINT_FILTER) += vf_kerndeint.o
OBJS-$(CONFIG_LENSCORRECTION_FILTER) += vf_lenscorrection.o
OBJS-$(CONFIG_LOOP_FILTER) += f_loop.o
+OBJS-$(CONFIG_LUMAKEY_FILTER) += vf_lumakey.o
OBJS-$(CONFIG_LUT_FILTER) += vf_lut.o
OBJS-$(CONFIG_LUT2_FILTER) += vf_lut2.o framesync.o
OBJS-$(CONFIG_LUT3D_FILTER) += vf_lut3d.o
diff --git a/libavfilter/allfilters.c b/libavfilter/allfilters.c
index f482adb..c69f79e 100644
--- a/libavfilter/allfilters.c
+++ b/libavfilter/allfilters.c
@@ -223,6 +223,7 @@ static void register_all(void)
REGISTER_FILTER(KERNDEINT, kerndeint, vf);
REGISTER_FILTER(LENSCORRECTION, lenscorrection, vf);
REGISTER_FILTER(LOOP, loop, vf);
+ REGISTER_FILTER(LUMAKEY, lumakey, vf);
REGISTER_FILTER(LUT, lut, vf);
REGISTER_FILTER(LUT2, lut2, vf);
REGISTER_FILTER(LUT3D, lut3d, vf);
diff --git a/libavfilter/vf_lumakey.c b/libavfilter/vf_lumakey.c
new file mode 100644
index 0000000..4ab17a9
--- /dev/null
+++ b/libavfilter/vf_lumakey.c
@@ -0,0 +1,174 @@
+/*
+ * Copyright (c) 2017 Paul B Mahol
+ *
+ * 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 LumakeyContext {
+ const AVClass *class;
+
+ int threshold;
+ int tolerance;
+
+ int (*do_lumakey_slice)(AVFilterContext *ctx, void *arg, int jobnr, int nb_jobs);
+} LumakeyContext;
+
+static int do_lumakey_slice8(AVFilterContext *ctx, void *arg, int jobnr, int nb_jobs)
+{
+ LumakeyContext *s = ctx->priv;
+ AVFrame *frame = arg;
+ const int slice_start = (frame->height * jobnr) / nb_jobs;
+ const int slice_end = (frame->height * (jobnr + 1)) / nb_jobs;
+ uint8_t *alpha = frame->data[3] + slice_start * frame->linesize[3];
+ const uint8_t *luma = frame->data[0] + slice_start * frame->linesize[0];
+ const int thr = s->threshold;
+ const int tol = s->tolerance;
+ int x, y;
+
+ for (y = slice_start; y < slice_end; ++y) {
+ for (x = 0; x < frame->width; ++x) {
+ if (luma[x] >= thr - tol && luma[x] <= thr + tol) {
+ alpha[x] = 0;
+ }
+ }
+ luma += frame->linesize[0];
+ alpha += frame->linesize[3];
+ }
+
+ return 0;
+}
+
+static int do_lumakey_slice16(AVFilterContext *ctx, void *arg, int jobnr, int nb_jobs)
+{
+ LumakeyContext *s = ctx->priv;
+ AVFrame *frame = arg;
+ const int slice_start = (frame->height * jobnr) / nb_jobs;
+ const int slice_end = (frame->height * (jobnr + 1)) / nb_jobs;
+ uint16_t *alpha = (uint16_t *)(frame->data[3] + slice_start * frame->linesize[3]);
+ const uint16_t *luma = (const uint16_t *)(frame->data[0] + slice_start * frame->linesize[0]);
+ const int thr = s->threshold;
+ const int tol = s->tolerance;
+ int x, y;
+
+ for (y = slice_start; y < slice_end; ++y) {
+ for (x = 0; x < frame->width; ++x) {
+ if (luma[x] >= thr - tol && luma[x] <= thr + tol) {
+ alpha[x] = 0;
+ }
+ }
+ luma += frame->linesize[0] / 2;
+ alpha += frame->linesize[3] / 2;
+ }
+
+ return 0;
+}
+
+static int config_input(AVFilterLink *inlink)
+{
+ const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format);
+ AVFilterContext *ctx = inlink->dst;
+ LumakeyContext *s = ctx->priv;
+ int depth;
+
+ depth = desc->comp[0].depth;
+ if (depth == 8)
+ s->do_lumakey_slice = do_lumakey_slice8;
+ else
+ s->do_lumakey_slice = do_lumakey_slice16;
+
+ return 0;
+}
+
+static int filter_frame(AVFilterLink *link, AVFrame *frame)
+{
+ AVFilterContext *ctx = link->dst;
+ LumakeyContext *s = ctx->priv;
+ int ret;
+
+ if (ret = av_frame_make_writable(frame))
+ return ret;
+
+ if (ret = ctx->internal->execute(ctx, s->do_lumakey_slice, frame, NULL, FFMIN(frame->height, ff_filter_get_nb_threads(ctx))))
+ return ret;
+
+ return ff_filter_frame(ctx->outputs[0], frame);
+}
+
+static av_cold int query_formats(AVFilterContext *ctx)
+{
+ static const enum AVPixelFormat pixel_fmts[] = {
+ AV_PIX_FMT_YUVA444P, AV_PIX_FMT_YUVA422P, AV_PIX_FMT_YUVA420P,
+ AV_PIX_FMT_YUVA444P9, AV_PIX_FMT_YUVA422P9, AV_PIX_FMT_YUVA420P9,
+ AV_PIX_FMT_YUVA444P10, AV_PIX_FMT_YUVA422P10, AV_PIX_FMT_YUVA420P10,
+ AV_PIX_FMT_YUVA444P16, AV_PIX_FMT_YUVA422P16, AV_PIX_FMT_YUVA420P16,
+ AV_PIX_FMT_NONE
+ };
+ AVFilterFormats *formats;
+
+ formats = ff_make_format_list(pixel_fmts);
+ if (!formats)
+ return AVERROR(ENOMEM);
+
+ return ff_set_common_formats(ctx, formats);
+}
+
+static const AVFilterPad lumakey_inputs[] = {
+ {
+ .name = "default",
+ .type = AVMEDIA_TYPE_VIDEO,
+ .filter_frame = filter_frame,
+ .config_props = config_input,
+ },
+ { NULL }
+};
+
+static const AVFilterPad lumakey_outputs[] = {
+ {
+ .name = "default",
+ .type = AVMEDIA_TYPE_VIDEO,
+ },
+ { NULL }
+};
+
+#define OFFSET(x) offsetof(LumakeyContext, x)
+#define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
+
+static const AVOption lumakey_options[] = {
+ { "threshold", "set the threshold value", OFFSET(threshold), AV_OPT_TYPE_INT, {.i64=0}, 0, UINT16_MAX, FLAGS },
+ { "tolerance", "set the tolerance value", OFFSET(tolerance), AV_OPT_TYPE_INT, {.i64=1}, 0, UINT16_MAX, FLAGS },
+ { NULL }
+};
+
+AVFILTER_DEFINE_CLASS(lumakey);
+
+AVFilter ff_vf_lumakey = {
+ .name = "lumakey",
+ .description = NULL_IF_CONFIG_SMALL("Turns a certain luma into transparency."),
+ .priv_size = sizeof(LumakeyContext),
+ .priv_class = &lumakey_class,
+ .query_formats = query_formats,
+ .inputs = lumakey_inputs,
+ .outputs = lumakey_outputs,
+ .flags = AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC,
+};
--
2.9.3
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