avfilter/vf_vif: Fix mismatch in number of array elements

The function definition used float *data_buf[14], although there are
only 13 elements (and only 13 are used); the declaration used 13.
Given that the type will be converted to float **data_buf anyway,
this is not in violation of the C specs, but nevertheless a bug.

GCC 11 has a new warning for this -Warray-parameter.

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>

libavfilter/vf_vif.c

@@ -38,6 +38,8 @@
 #include "vif.h"
 #include "video.h"
 
+#define NUM_DATA_BUFS 13
+
 typedef struct VIFContext {
     const AVClass *class;
     FFFrameSync fs;
@@ -46,7 +48,7 @@ typedef struct VIFContext {
     int height;
     int nb_threads;
     float factor;
-    float *data_buf[13];
+    float *data_buf[NUM_DATA_BUFS];
     float **temp;
     float *ref_data;
     float *main_data;
@@ -286,7 +288,7 @@ static int vif_filter1d(AVFilterContext *ctx, void *arg, int jobnr, int nb_jobs)
 int ff_compute_vif2(AVFilterContext *ctx,
                     const float *ref, const float *main, int w, int h,
                     int ref_stride, int main_stride, float *score,
-                    float *data_buf[14], float **temp,
+                    float *data_buf[NUM_DATA_BUFS], float **temp,
                     int gnb_threads)
 {
     ThreadData td;
@@ -515,7 +517,7 @@ static int config_input_ref(AVFilterLink *inlink)
         s->vif_max[i] = -DBL_MAX;
     }
 
-    for (int i = 0; i < 13; i++) {
+    for (int i = 0; i < NUM_DATA_BUFS; i++) {
         if (!(s->data_buf[i] = av_calloc(s->width, s->height * sizeof(float))))
             return AVERROR(ENOMEM);
     }
@@ -608,7 +610,7 @@ static av_cold void uninit(AVFilterContext *ctx)
                    i, s->vif_sum[i] / s->nb_frames, s->vif_min[i], s->vif_max[i]);
     }
 
-    for (int i = 0; i < 13; i++)
+    for (int i = 0; i < NUM_DATA_BUFS; i++)
         av_freep(&s->data_buf[i]);
 
     av_freep(&s->ref_data);