avcodec/vvcdec: refact out is_available from is_a0_available

libavcodec/vvc/mvs.c

@@ -545,6 +545,16 @@ typedef struct NeighbourContext {
     const VVCLocalContext *lc;
 } NeighbourContext;
 
+static int is_available(const VVCFrameContext *fc, const int x0, const int y0)
+{
+    const VVCSPS *sps      = fc->ps.sps;
+    const int x            = x0 >> sps->min_cb_log2_size_y;
+    const int y            = y0 >> sps->min_cb_log2_size_y;
+    const int min_cb_width = fc->ps.pps->min_cb_width;
+
+    return SAMPLE_CTB(fc->tab.cb_width[0], x, y) != 0;
+}
+
 static int is_a0_available(const VVCLocalContext *lc, const CodingUnit *cu)
 {
     const VVCFrameContext *fc   = lc->fc;
@@ -555,15 +565,11 @@ static int is_a0_available(const VVCLocalContext *lc, const CodingUnit *cu)
     if (!x0b && !lc->ctb_left_flag) {
         cand_bottom_left = 0;
     } else {
-        const int log2_min_cb_size  = sps->min_cb_log2_size_y;
-        const int min_cb_width      = fc->ps.pps->min_cb_width;
-        const int x                 = (cu->x0 - 1) >> log2_min_cb_size;
-        const int y                 = (cu->y0 + cu->cb_height) >> log2_min_cb_size;
-        const int max_y             = FFMIN(fc->ps.pps->height, ((cu->y0 >> sps->ctb_log2_size_y) + 1) << sps->ctb_log2_size_y);
+        const int max_y = FFMIN(fc->ps.pps->height, ((cu->y0 >> sps->ctb_log2_size_y) + 1) << sps->ctb_log2_size_y);
         if (cu->y0 + cu->cb_height >= max_y)
             cand_bottom_left = 0;
         else
-            cand_bottom_left = SAMPLE_CTB(fc->tab.cb_width[0], x, y) != 0;
+            cand_bottom_left = is_available(fc, cu->x0 - 1, cu->y0 + cu->cb_height);
     }
     return cand_bottom_left;
 }