[FFmpeg-devel] [PATCH] lavfi: add bbox filter
Stefano Sabatini
stefasab at gmail.com
Sun Mar 11 04:00:44 CET 2012
Also add bbox.h and bbox.c files, based on the remove-logo filter by
Robert Edele.
These files are useful for sharing code with the pending removelogo port.
---
doc/filters.texi | 9 +++
libavfilter/Makefile | 1 +
libavfilter/allfilters.c | 1 +
libavfilter/bbox.c | 70 ++++++++++++++++++++++++++
libavfilter/bbox.h | 42 ++++++++++++++++
libavfilter/vf_bbox.c | 122 ++++++++++++++++++++++++++++++++++++++++++++++
6 files changed, 245 insertions(+), 0 deletions(-)
create mode 100644 libavfilter/bbox.c
create mode 100644 libavfilter/bbox.h
create mode 100644 libavfilter/vf_bbox.c
diff --git a/doc/filters.texi b/doc/filters.texi
index b13d5f5..62783c0 100644
--- a/doc/filters.texi
+++ b/doc/filters.texi
@@ -761,6 +761,15 @@ video, use the command:
ass=sub.ass
@end example
+ at section bbox
+
+Compute the bounding box for each input frame.
+
+This filter computes the bounding box containing all the pixels with a
+non-null value. The bounding box is computed for each plane in the
+input image, and the corresponding parameters are print on the filter
+log.
+
@section blackdetect
Detect video intervals that are (almost) completely black. Can be
diff --git a/libavfilter/Makefile b/libavfilter/Makefile
index e9c9a4b..6a9a3ad 100644
--- a/libavfilter/Makefile
+++ b/libavfilter/Makefile
@@ -48,6 +48,7 @@ OBJS-$(CONFIG_ABUFFERSINK_FILTER) += sink_buffer.o
OBJS-$(CONFIG_ANULLSINK_FILTER) += asink_anullsink.o
OBJS-$(CONFIG_ASS_FILTER) += vf_ass.o
+OBJS-$(CONFIG_BBOX_FILTER) += bbox.o vf_bbox.o
OBJS-$(CONFIG_BLACKDETECT_FILTER) += vf_blackdetect.o
OBJS-$(CONFIG_BLACKFRAME_FILTER) += vf_blackframe.o
OBJS-$(CONFIG_BOXBLUR_FILTER) += vf_boxblur.o
diff --git a/libavfilter/allfilters.c b/libavfilter/allfilters.c
index f0a7f8b..6972271 100644
--- a/libavfilter/allfilters.c
+++ b/libavfilter/allfilters.c
@@ -56,6 +56,7 @@ void avfilter_register_all(void)
REGISTER_FILTER (ANULLSINK, anullsink, asink);
REGISTER_FILTER (ASS, ass, vf);
+ REGISTER_FILTER (BBOX, bbox, vf);
REGISTER_FILTER (BLACKDETECT, blackdetect, vf);
REGISTER_FILTER (BLACKFRAME, blackframe, vf);
REGISTER_FILTER (BOXBLUR, boxblur, vf);
diff --git a/libavfilter/bbox.c b/libavfilter/bbox.c
new file mode 100644
index 0000000..a43d974
--- /dev/null
+++ b/libavfilter/bbox.c
@@ -0,0 +1,70 @@
+/*
+ * Copyright (c) 2005 Robert Edele <yartrebo at earthlink.net>
+ *
+ * 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 "bbox.h"
+
+void calculate_bounding_rectangle(BoundingBox *bbox,
+ const uint8_t *data, int linesize, int w, int h,
+ int min_val)
+{
+ int x, y;
+ int start_x;
+ int start_y;
+ int end_x = w - 1;
+ int end_y = h - 1;
+ int pixel_found;
+
+ /* left bound */
+ for (pixel_found = 0, start_x = 0; start_x < w; start_x++) {
+ for (y = 0; y < h; y++)
+ pixel_found |= (data[y * linesize + start_x] > min_val);
+ if (pixel_found)
+ break;
+ }
+
+ /* right bound */
+ for (pixel_found = 0, end_x = w - 1; end_x >= start_x; end_x--) {
+ for (y = 0; y < h; y++)
+ pixel_found |= (data[y * linesize + end_x] > min_val);
+ if (pixel_found)
+ break;
+ }
+
+ /* top bound */
+ for (pixel_found = 0, start_y = 0; start_y < h; start_y++) {
+ for (x = 0; x < w; x++)
+ pixel_found |= (data[start_y * linesize + x] > min_val);
+ if (pixel_found)
+ break;
+ }
+
+ /* bottom bound */
+ for (pixel_found = 0, end_y = h - 1; end_y >= start_y; end_y--) {
+ for (x = 0; x < w; x++)
+ pixel_found |= (data[end_y * linesize + x] > min_val);
+ if (pixel_found)
+ break;
+ }
+
+ bbox->x1 = start_x;
+ bbox->y1 = start_y;
+ bbox->x2 = end_x;
+ bbox->y2 = end_y;
+}
diff --git a/libavfilter/bbox.h b/libavfilter/bbox.h
new file mode 100644
index 0000000..dcf1994
--- /dev/null
+++ b/libavfilter/bbox.h
@@ -0,0 +1,42 @@
+/*
+ * Copyright (c) 2005 Robert Edele <yartrebo at earthlink.net>
+ *
+ * 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
+ */
+
+#ifndef AVFILTER_BBOX_H
+#define AVFILTER_BBOX_H
+
+#include <stdint.h>
+
+typedef struct {
+ int x1, x2, y1, y2;
+} BoundingBox;
+
+/**
+ * Calculate the smallest rectangle that will encompass the
+ * region with values > min_val.
+ *
+ * The bounding rectangle is calculated by testing successive lines
+ * (from the four sides of the rectangle) until no more can be removed
+ * without removing logo pixels.
+ */
+void calculate_bounding_rectangle(BoundingBox *bbox,
+ const uint8_t *data, int linesize,
+ int w, int h, int min_val);
+
+#endif /* AVFILTER_BBOX_H */
diff --git a/libavfilter/vf_bbox.c b/libavfilter/vf_bbox.c
new file mode 100644
index 0000000..0b0a265
--- /dev/null
+++ b/libavfilter/vf_bbox.c
@@ -0,0 +1,122 @@
+/*
+ * Copyright (c) 2012 Stefano Sabatini
+ *
+ * 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
+ */
+
+/**
+ * @file
+ * bounding box detection filter
+ */
+
+#include "libavutil/pixdesc.h"
+#include "libavutil/timestamp.h"
+#include "avfilter.h"
+#include "bbox.h"
+
+typedef struct {
+ unsigned int frame;
+ int vsub, hsub;
+} BBoxContext;
+
+static av_cold int init(AVFilterContext *ctx, const char *args, void *opaque)
+{
+ BBoxContext *bbox = ctx->priv;
+ bbox->frame = 0;
+ return 0;
+}
+
+static int query_formats(AVFilterContext *ctx)
+{
+ static const enum PixelFormat pix_fmts[] = {
+ PIX_FMT_YUV420P,
+ PIX_FMT_YUV444P,
+ PIX_FMT_YUV440P,
+ PIX_FMT_YUV422P,
+ PIX_FMT_YUV411P,
+ PIX_FMT_NONE,
+ };
+
+ avfilter_set_common_pixel_formats(ctx, avfilter_make_format_list(pix_fmts));
+ return 0;
+}
+
+static int config_props_input(AVFilterLink *inlink)
+{
+ AVFilterContext *ctx = inlink->dst;
+ BBoxContext *bbox = ctx->priv;
+ bbox->hsub = av_pix_fmt_descriptors[inlink->format].log2_chroma_w;
+ bbox->vsub = av_pix_fmt_descriptors[inlink->format].log2_chroma_h;
+ return 0;
+}
+
+static void end_frame(AVFilterLink *inlink)
+{
+ AVFilterContext *ctx = inlink->dst;
+ BBoxContext *bbox = ctx->priv;
+ AVFilterBufferRef *picref = inlink->cur_buf;
+ BoundingBox box;
+ int plane;
+
+ for (plane = 0; picref->data[plane] && plane < 4; plane++) {
+ int w, h, vsub = 0, hsub = 0;
+ if (plane == 1 || plane == 2) {
+ hsub = bbox->hsub;
+ vsub = bbox->vsub;
+ }
+ calculate_bounding_rectangle(&box, picref->data[plane], picref->linesize[plane],
+ inlink->w>>hsub, inlink->h>>vsub, 16);
+ w = box.x2 - box.x1 + 1;
+ h = box.y2 - box.y1 + 1;
+ av_log(ctx, AV_LOG_INFO,
+ "n:%d pts:%s pts_time:%s plane:%d x1:%d x2:%d y1:%d y2:%d w:%d h:%d"
+ " crop=%d:%d:%d:%d drawbox=%d:%d:%d:%d\n",
+ bbox->frame,
+ av_ts2str(picref->pts), av_ts2timestr(picref->pts, &inlink->time_base),
+ plane, box.x1, box.x2, box.y1, box.y2, w, h,
+ w, h, box.x1, box.x2, /* crop params */
+ box.x1, box.y1, w, h); /* drawbox params */
+ }
+
+ bbox->frame++;
+ avfilter_end_frame(inlink->dst->outputs[0]);
+}
+
+AVFilter avfilter_vf_bbox = {
+ .name = "bbox",
+ .description = NULL_IF_CONFIG_SMALL("Compute bounding box for each frame."),
+ .priv_size = sizeof(BBoxContext),
+ .query_formats = query_formats,
+ .init = init,
+
+ .inputs = (const AVFilterPad[]) {
+ { .name = "default",
+ .type = AVMEDIA_TYPE_VIDEO,
+ .get_video_buffer = avfilter_null_get_video_buffer,
+ .config_props = config_props_input,
+ .start_frame = avfilter_null_start_frame,
+ .end_frame = end_frame,
+ .min_perms = AV_PERM_READ, },
+ { .name = NULL }
+ },
+
+ .outputs = (const AVFilterPad[]) {
+ { .name = "default",
+ .type = AVMEDIA_TYPE_VIDEO },
+ { .name = NULL }
+ },
+};
--
1.7.5.4
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