[FFmpeg-devel] [PATCH] avfilter/vf_cropdetect: adjust Default threshold based on bit depth

[Michael Niedermayer]

Signed-off-by: Michael Niedermayer <michaelni at gmx.at>
---
 libavfilter/vf_cropdetect.c |    9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/libavfilter/vf_cropdetect.c b/libavfilter/vf_cropdetect.c
index dd237ef..d49101c 100644
--- a/libavfilter/vf_cropdetect.c
+++ b/libavfilter/vf_cropdetect.c
@@ -137,9 +137,12 @@ static int config_input(AVFilterLink *inlink)
 {
     AVFilterContext *ctx = inlink->dst;
     CropDetectContext *s = ctx->priv;
+    const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format);
 
-    av_image_fill_max_pixsteps(s->max_pixsteps, NULL,
-                               av_pix_fmt_desc_get(inlink->format));
+    av_image_fill_max_pixsteps(s->max_pixsteps, NULL, desc);
+
+    if (s->limit < 0)
+        s->limit = 24 << (desc->comp[0].depth_minus1 - 7);
 
     s->x1 = inlink->w - 1;
     s->y1 = inlink->h - 1;
@@ -238,7 +241,7 @@ static int filter_frame(AVFilterLink *inlink, AVFrame *frame)
 #define FLAGS AV_OPT_FLAG_VIDEO_PARAM|AV_OPT_FLAG_FILTERING_PARAM
 
 static const AVOption cropdetect_options[] = {
-    { "limit", "Threshold below which the pixel is considered black", OFFSET(limit),       AV_OPT_TYPE_INT, { .i64 = 24 }, 0, 65535, FLAGS },
+    { "limit", "Threshold below which the pixel is considered black", OFFSET(limit),       AV_OPT_TYPE_INT, { .i64 = -1 }, -1, 65535, FLAGS },
     { "round", "Value by which the width/height should be divisible", OFFSET(round),       AV_OPT_TYPE_INT, { .i64 = 16 }, 0, INT_MAX, FLAGS },
     { "reset", "Recalculate the crop area after this many frames",    OFFSET(reset_count), AV_OPT_TYPE_INT, { .i64 = 0 },  0, INT_MAX, FLAGS },
     { "reset_count", "Recalculate the crop area after this many frames",OFFSET(reset_count),AV_OPT_TYPE_INT,{ .i64 = 0 },  0, INT_MAX, FLAGS },
-- 
1.7.9.5