[FFmpeg-devel] [PATCH v2] avfilter/vf_freezedetect: add discard option to force drop freezen frame

[lance.lmwang at gmail.com]

From: Limin Wang <lance.lmwang at gmail.com>

How to tested it, please try with the following command:
./ffmpeg  -f lavfi -i "smptebars=duration=5:size=1280x720:rate=30,freezedetect=d=1:discard=0"  -f null -
frame=  150 fps=0.0 q=-0.0 Lsize=N/A time=00:00:05.00 bitrate=N/A speed= 234x

./ffmpeg  -f lavfi -i "smptebars=duration=5:size=1280x720:rate=30,freezedetect=d=1:discard=1"  -f null -
frame=   30 fps=0.0 q=-0.0 Lsize=N/A time=00:00:01.00 bitrate=N/A speed=59.7x

Signed-off-by: Limin Wang <lance.lmwang at gmail.com>
---
 doc/filters.texi              | 10 ++++++++++
 libavfilter/vf_freezedetect.c |  8 +++++++-
 2 files changed, 17 insertions(+), 1 deletion(-)

diff --git a/doc/filters.texi b/doc/filters.texi
index 333f502083..8aa7471f7e 100644
--- a/doc/filters.texi
+++ b/doc/filters.texi
@@ -10678,6 +10678,9 @@ timestamp of the first frame of the freeze. The
 @code{lavfi.freezedetect.freeze_duration} and
 @code{lavfi.freezedetect.freeze_end} metadata keys are set on the first frame
 after the freeze.
+In addition, you can choose to discard the freezen frames instead of report
+by metadata. Please note the first few freezen frames (the detection interval)
+won't be dropped for the filter doesn't buffer any frames.
 
 The filter accepts the following options:
 
@@ -10689,6 +10692,13 @@ specified value) or as a difference ratio between 0 and 1. Default is -60dB, or
 
 @item duration, d
 Set freeze duration until notification (default is 2 seconds).
+
+ at item discard
+Set force to discard freezen frame.
+ 0:  do nothing
+ 1:  discard freezen frame
+
+Default is 0
 @end table
 
 @anchor{frei0r}
diff --git a/libavfilter/vf_freezedetect.c b/libavfilter/vf_freezedetect.c
index cc086afee6..cc115eb521 100644
--- a/libavfilter/vf_freezedetect.c
+++ b/libavfilter/vf_freezedetect.c
@@ -45,6 +45,8 @@ typedef struct FreezeDetectContext {
 
     double noise;
     int64_t duration;            ///< minimum duration of frozen frame until notification
+
+    int discard;                 ///< 0: no discard, 1: discard freezen frame
 } FreezeDetectContext;
 
 #define OFFSET(x) offsetof(FreezeDetectContext, x)
@@ -56,6 +58,7 @@ static const AVOption freezedetect_options[] = {
     { "noise",               "set noise tolerance",                       OFFSET(noise),  AV_OPT_TYPE_DOUBLE,   {.dbl=0.001},     0,       1.0, V|F },
     { "d",                   "set minimum duration in seconds",        OFFSET(duration),  AV_OPT_TYPE_DURATION, {.i64=2000000},   0, INT64_MAX, V|F },
     { "duration",            "set minimum duration in seconds",        OFFSET(duration),  AV_OPT_TYPE_DURATION, {.i64=2000000},   0, INT64_MAX, V|F },
+    { "discard",             "set frame discard flag",                 OFFSET(discard),   AV_OPT_TYPE_BOOL,     {.i64=0},         0,         1, V|F },
 
     {NULL}
 };
@@ -196,7 +199,10 @@ static int activate(AVFilterContext *ctx)
                 return AVERROR(ENOMEM);
             }
         }
-        return ff_filter_frame(outlink, frame);
+        if (s->discard && s->frozen) {
+            av_frame_free(&frame);
+        } else
+            return ff_filter_frame(outlink, frame);
     }
 
     FF_FILTER_FORWARD_STATUS(inlink, outlink);
-- 
2.21.0