lavfi: complain and exit for invalid named values in ff_parse_packing_format()

libavfilter/formats.c

@@ -283,8 +283,11 @@ int ff_parse_packing_format(int *ret, const char *arg, void *log_ctx)
     char *tail;
     int planar = strtol(arg, &tail, 10);
     if (*tail) {
-        planar = (strcmp(arg, "packed") != 0);
-    } else if (planar != 0 && planar != 1) {
+        planar = !strcmp(arg, "packed") ? 0:
+                 !strcmp(arg, "planar") ? 1: -1;
+    }
+
+    if (planar != 0 && planar != 1) {
         av_log(log_ctx, AV_LOG_ERROR, "Invalid packing format '%s'\n", arg);
         return AVERROR(EINVAL);
     }