avfilter/vf_delogo: add auto set the area inside of the frame

when the area outside of the frame, then use expr should
give user warning message and auto set to the area inside of the frame.

Signed-off-by: Steven Liu <lq@chinaffmpeg.org>

diff --git a/libavfilter/vf_delogo.c b/libavfilter/vf_delogo.c
index 376c5e850ffe1afee2ae9f3d4567841edc7d3e65..9c58418e115cd3971b9946e2625b501da9468722 100644 (file)
--- a/libavfilter/vf_delogo.c
+++ b/libavfilter/vf_delogo.c
@@ -327,6 +327,21 @@ static int filter_frame(AVFilterLink *inlink, AVFrame *in)
     s->w = av_expr_eval(s->w_pexpr, s->var_values, s);
     s->h = av_expr_eval(s->h_pexpr, s->var_values, s);
 
+    if (s->x + (s->band - 1) <= 0 || s->x + s->w - (s->band*2 - 2) > inlink->w ||
+        s->y + (s->band - 1) <= 0 || s->y + s->h - (s->band*2 - 2) > inlink->h) {
+        av_log(s, AV_LOG_WARNING, "Logo area is outside of the frame,"
+               " auto set the area inside of the frame\n");
+    }
+
+    if (s->x + (s->band - 1) <= 0)
+        s->x = 1 + s->band;
+    if (s->y + (s->band - 1) <= 0)
+        s->y = 1 + s->band;
+    if (s->x + s->w - (s->band*2 - 2) > inlink->w)
+        s->w = inlink->w - s->x - (s->band*2 - 2);
+    if (s->y + s->h - (s->band*2 - 2) > inlink->h)
+        s->h = inlink->h - s->y - (s->band*2 - 2);
+
     ret = config_input(inlink);
     if (ret < 0) {
         av_frame_free(&in);