[FFmpeg-devel] [PATCH v1] avfilter/vf_freezedetect: add force_discard option to force discard freeze/non-freeze 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:f=0"  -f null -
 frame=  150 fps=0.0 q=-0.0 Lsize=N/A time=00:00:05.00 bitrate=N/A speed= 232x

 ./ffmpeg  -f lavfi -i "smptebars=duration=5:size=1280x720:rate=30,freezedetect=d=1:f=-1"  -f null -
 frame=  120 fps=0.0 q=-0.0 Lsize=N/A time=00:00:04.00 bitrate=N/A speed= 211x

 ./ffmpeg  -f lavfi -i "smptebars=duration=5:size=1280x720:rate=30,freezedetect=d=1:f=1"  -f null -
 frame=   30 fps=0.0 q=-0.0 Lsize=N/A time=00:00:01.00 bitrate=N/A speed=93.9x

Signed-off-by: Limin Wang <lance.lmwang at gmail.com>
---
 doc/filters.texi              | 10 ++++++++++
 libavfilter/vf_freezedetect.c | 23 ++++++++++++++++++++++-
 2 files changed, 32 insertions(+), 1 deletion(-)

diff --git a/doc/filters.texi b/doc/filters.texi
index 6ed1c8fa75..2be8b93c53 100644
--- a/doc/filters.texi
+++ b/doc/filters.texi
@@ -10678,6 +10678,8 @@ 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 freeze/non-freezee frames instead of
+report by metadata.
 
 The filter accepts the following options:
 
@@ -10689,6 +10691,14 @@ 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 force_discard, f
+Set force to discard or keep freeze frame.
+ 0:  do nothing
+-1:  discard non-freeze frame
+ 1:  discard freeze frame
+
+Default is 0
 @end table
 
 @anchor{frei0r}
diff --git a/libavfilter/vf_freezedetect.c b/libavfilter/vf_freezedetect.c
index cc086afee6..fc08c235f7 100644
--- a/libavfilter/vf_freezedetect.c
+++ b/libavfilter/vf_freezedetect.c
@@ -45,6 +45,9 @@ typedef struct FreezeDetectContext {
 
     double noise;
     int64_t duration;            ///< minimum duration of frozen frame until notification
+
+    int force_discard;           ///< 0: no discard, -1: discard non-freeze frame, 1: discard freeze frame
+    int drop_count;
 } FreezeDetectContext;
 
 #define OFFSET(x) offsetof(FreezeDetectContext, x)
@@ -56,6 +59,8 @@ 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 },
+    { "f",                   "set frame discard",                      OFFSET(force_discard), AV_OPT_TYPE_INT,  {.i64=0},         -1,        1, V|F },
+    { "force_discard",       "set frame discard",                      OFFSET(force_discard), AV_OPT_TYPE_INT,  {.i64=0},         -1,        1, V|F },
 
     {NULL}
 };
@@ -115,6 +120,7 @@ static int config_input(AVFilterLink *inlink)
     if (!s->sad)
         return AVERROR(EINVAL);
 
+    s->drop_count = 0;
     return 0;
 }
 
@@ -184,10 +190,22 @@ static int activate(AVFilterContext *ctx)
                     set_meta(s, frame, "lavfi.freezedetect.freeze_end", av_ts2timestr(frame->pts, &inlink->time_base));
                 }
                 s->frozen = frozen;
+                if ( s->force_discard > 0 && frozen)
+                    s->drop_count++;
+                else if ( s->force_discard < 0 && frozen && s->drop_count < 0) {
+                    s->drop_count = 0;
+                }
+            } else {
+                if ( s->force_discard < 0)
+                    s->drop_count--;
             }
         }
 
         if (!frozen) {
+            if (s->force_discard > 0) {
+                s->drop_count = 0;
+            } else if ( s->force_discard < 0)
+                s->drop_count--;
             av_frame_free(&s->reference_frame);
             s->reference_frame = av_frame_clone(frame);
             s->reference_n = s->n;
@@ -196,7 +214,10 @@ static int activate(AVFilterContext *ctx)
                 return AVERROR(ENOMEM);
             }
         }
-        return ff_filter_frame(outlink, frame);
+        if (s->drop_count > 0 || s->drop_count < 0) {
+            av_frame_free(&frame);
+        } else
+            return ff_filter_frame(outlink, frame);
     }
 
     FF_FILTER_FORWARD_STATUS(inlink, outlink);
-- 
2.21.0