[FFmpeg-devel] [PATCH 2/3] avfilter/vf_minterpolate: Fix left shift of negative value

[Andreas Rheinhardt]

This has happened when initializing the motion estimation context if
width or height of the video was smaller than the block size used
for motion estimation and if the motion interpolation mode indicates
not to use motion estimation.

The solution is of course to only initialize the motion estimation
context if the interpolation mode uses motion estimation.

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt at gmail.com>
---
 libavfilter/vf_minterpolate.c | 27 +++++++++++++++------------
 1 file changed, 15 insertions(+), 12 deletions(-)

diff --git a/libavfilter/vf_minterpolate.c b/libavfilter/vf_minterpolate.c
index e1fe5e32b5..bf45662913 100644
--- a/libavfilter/vf_minterpolate.c
+++ b/libavfilter/vf_minterpolate.c
@@ -368,6 +368,15 @@ static int config_input(AVFilterLink *inlink)
                    2 * mi_ctx->mb_size);
             return AVERROR(EINVAL);
         }
+        ff_me_init_context(me_ctx, mi_ctx->mb_size, mi_ctx->search_param,
+                           width, height, 0, (mi_ctx->b_width - 1) << mi_ctx->log2_mb_size,
+                           0, (mi_ctx->b_height - 1) << mi_ctx->log2_mb_size);
+
+        if (mi_ctx->me_mode == ME_MODE_BIDIR)
+            me_ctx->get_cost = &get_sad_ob;
+        else if (mi_ctx->me_mode == ME_MODE_BILAT)
+            me_ctx->get_cost = &get_sbad_ob;
+
         mi_ctx->pixel_mvs = av_mallocz_array(width * height, sizeof(PixelMVS));
         mi_ctx->pixel_weights = av_mallocz_array(width * height, sizeof(PixelWeights));
         mi_ctx->pixel_refs = av_mallocz_array(width * height, sizeof(PixelRefs));
@@ -395,13 +404,6 @@ static int config_input(AVFilterLink *inlink)
             return AVERROR(EINVAL);
     }
 
-    ff_me_init_context(me_ctx, mi_ctx->mb_size, mi_ctx->search_param, width, height, 0, (mi_ctx->b_width - 1) << mi_ctx->log2_mb_size, 0, (mi_ctx->b_height - 1) << mi_ctx->log2_mb_size);
-
-    if (mi_ctx->me_mode == ME_MODE_BIDIR)
-        me_ctx->get_cost = &get_sad_ob;
-    else if (mi_ctx->me_mode == ME_MODE_BILAT)
-        me_ctx->get_cost = &get_sbad_ob;
-
     return 0;
 fail:
     for (i = 0; i < NB_FRAMES; i++)
@@ -830,9 +832,10 @@ static int inject_frame(AVFilterLink *inlink, AVFrame *avf_in)
     return 0;
 }
 
-static int detect_scene_change(MIContext *mi_ctx)
+static int detect_scene_change(AVFilterContext *ctx)
 {
-    AVMotionEstContext *me_ctx = &mi_ctx->me_ctx;
+    MIContext *mi_ctx = ctx->priv;
+    AVFilterLink *input = ctx->inputs[0];
     uint8_t *p1 = mi_ctx->frames[1].avf->data[0];
     ptrdiff_t linesize1 = mi_ctx->frames[1].avf->linesize[0];
     uint8_t *p2 = mi_ctx->frames[2].avf->data[0];
@@ -841,9 +844,9 @@ static int detect_scene_change(MIContext *mi_ctx)
     if (mi_ctx->scd_method == SCD_METHOD_FDIFF) {
         double ret = 0, mafd, diff;
         uint64_t sad;
-        mi_ctx->sad(p1, linesize1, p2, linesize2, me_ctx->width, me_ctx->height, &sad);
+        mi_ctx->sad(p1, linesize1, p2, linesize2, input->w, input->h, &sad);
         emms_c();
-        mafd = (double) sad * 100.0 / (me_ctx->height * me_ctx->width) / (1 << mi_ctx->bitdepth);
+        mafd = (double) sad * 100.0 / (input->h * input->w) / (1 << mi_ctx->bitdepth);
         diff = fabs(mafd - mi_ctx->prev_mafd);
         ret  = av_clipf(FFMIN(mafd, diff), 0, 100.0);
         mi_ctx->prev_mafd = mafd;
@@ -1191,7 +1194,7 @@ static int filter_frame(AVFilterLink *inlink, AVFrame *avf_in)
     if (!mi_ctx->frames[0].avf)
         return 0;
 
-    mi_ctx->scene_changed = detect_scene_change(mi_ctx);
+    mi_ctx->scene_changed = detect_scene_change(ctx);
 
     for (;;) {
         AVFrame *avf_out;
-- 
2.25.1