lavfi: add bbox filter

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.

1 files changed, 113 insertions, 0 deletions

diff --git a/libavfilter/vf_bbox.c b/libavfilter/vf_bbox.c
new file mode 100644
index 0000000000..98ae92cabf
--- /dev/null
+++ b/libavfilter/vf_bbox.c
@@ -0,0 +1,113 @@
+/*
+ * 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 void end_frame(AVFilterLink *inlink)
+{
+    AVFilterContext *ctx = inlink->dst;
+    BBoxContext *bbox = ctx->priv;
+    AVFilterBufferRef *picref = inlink->cur_buf;
+    FFBoundingBox box;
+    int has_bbox, w, h;
+
+    has_bbox =
+        ff_calculate_bounding_box(&box,
+                                  picref->data[0], picref->linesize[0],
+                                  inlink->w, inlink->h, 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", bbox->frame,
+           av_ts2str(picref->pts), av_ts2timestr(picref->pts, &inlink->time_base));
+
+    if (has_bbox) {
+        av_log(ctx, AV_LOG_INFO,
+               "x1:%d x2:%d y1:%d y2:%d w:%d h:%d"
+               " crop=%d:%d:%d:%d drawbox=%d:%d:%d:%d",
+               box.x1, box.x2, box.y1, box.y2, w, h,
+               w, h, box.x1, box.y1,    /* crop params */
+               box.x1, box.y1, w, h);   /* drawbox params */
+    }
+    av_log(ctx, AV_LOG_INFO, "\n");
+
+    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,
+          .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 }
+    },
+};