From: Limin Wang <lance.lmw...@gmail.com>
Signed-off-by: Limin Wang <lance.lmw...@gmail.com>
---
doc/filters.texi | 10 ++++++++++
libavfilter/vf_drawbox.c | 27 +++++++++++++++++++++++++++
2 files changed, 37 insertions(+)
diff --git a/doc/filters.texi b/doc/filters.texi
index 76e12ef..bf9043c 100644
--- a/doc/filters.texi
+++ b/doc/filters.texi
@@ -9337,6 +9337,10 @@ See below for the list of accepted constants.
Applicable if the input has alpha. With value @code{1}, the pixels of the
painted box
will overwrite the video's color and alpha pixels.
Default is @code{0}, which composites the box onto the input, leaving the
video's alpha intact.
+
+@item face
+Draw the box by the facedetect metadata for the specific face.
+
@end table
The parameters for @var{x}, @var{y}, @var{w} and @var{h} and @var{t} are
expressions containing the
@@ -9405,6 +9409,12 @@ Draw a 2-pixel red 2.40:1 mask:
@example
drawbox=x=-t:y=0.5*(ih-iw/2.4)-t:w=iw+t*2:h=iw/2.4+t*2:t=2:c=red
@end example
+
+@item
+draw the box with red color for the first face by metadata if its postion is
detected:
+@example
+ocv=filter_name=facedetect:filter_params=facedetect=./haarcascade_frontalface_alt.xml,drawbox=face=0:color=red
+@end example
@end itemize
@subsection Commands
diff --git a/libavfilter/vf_drawbox.c b/libavfilter/vf_drawbox.c
index 21d520e..239a149 100644
--- a/libavfilter/vf_drawbox.c
+++ b/libavfilter/vf_drawbox.c
@@ -81,6 +81,7 @@ typedef struct DrawBoxContext {
char *t_expr; ///< expression for thickness
int have_alpha;
int replace;
+ int face;
} DrawBoxContext;
static const int NUM_EXPR_EVALS = 5;
@@ -220,6 +221,31 @@ static int filter_frame(AVFilterLink *inlink, AVFrame
*frame)
int plane, x, y, xb = s->x, yb = s->y;
unsigned char *row[4];
+ if (s->face >= 0) {
+ AVDictionaryEntry *ex, *ey, *ew, *eh;
+ char key2[128];
+ AVDictionary *metadata = frame->metadata;
+
+ snprintf(key2, sizeof(key2), "lavfi.facedetect.%d.%s", s->face, "x");
+ ex = av_dict_get(metadata, key2, NULL, AV_DICT_MATCH_CASE);
+
+ snprintf(key2, sizeof(key2), "lavfi.facedetect.%d.%s", s->face, "y");
+ ey = av_dict_get(metadata, key2, NULL, AV_DICT_MATCH_CASE);
+
+ snprintf(key2, sizeof(key2), "lavfi.facedetect.%d.%s", s->face, "w");
+ ew = av_dict_get(metadata, key2, NULL, AV_DICT_MATCH_CASE);
+
+ snprintf(key2, sizeof(key2), "lavfi.facedetect.%d.%s", s->face, "h");
+ eh = av_dict_get(metadata, key2, NULL, AV_DICT_MATCH_CASE);
+
+ if (ex && ey && ew && eh) {
+ xb = s->x = strtol(ex->value, NULL, 10);
+ yb = s->y = strtol(ey->value, NULL, 10);
+ s->w = strtol(ew->value, NULL, 10);
+ s->h = strtol(eh->value, NULL, 10);
+ }
+ }
+
if (s->have_alpha && s->replace) {
for (y = FFMAX(yb, 0); y < frame->height && y < (yb + s->h); y++) {
row[0] = frame->data[0] + y * frame->linesize[0];
@@ -323,6 +349,7 @@ static const AVOption drawbox_options[] = {
{ "thickness", "set the box thickness",
OFFSET(t_expr), AV_OPT_TYPE_STRING, { .str="3" }, 0, 0, FLAGS },
{ "t", "set the box thickness",
OFFSET(t_expr), AV_OPT_TYPE_STRING, { .str="3" }, 0, 0, FLAGS },
{ "replace", "replace color & alpha",
OFFSET(replace), AV_OPT_TYPE_BOOL, { .i64=0 }, 0, 1,
FLAGS },
+ { "face", "set which face to draw with metadata",
OFFSET(face), AV_OPT_TYPE_INT, { .i64=-1 }, -1, 256,
FLAGS },
{ NULL }
};
--
1.8.3.1
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