af_resample: switch to child_class_iterate()

libavfilter/af_resample.c

@@ -306,10 +306,19 @@ fail:
     return ret;
 }
 
+#if FF_API_CHILD_CLASS_NEXT
 static const AVClass *resample_child_class_next(const AVClass *prev)
 {
     return prev ? NULL : avresample_get_class();
 }
+#endif
+
+static const AVClass *resample_child_class_iterate(void **iter)
+{
+    const AVClass *c = *iter ? NULL : avresample_get_class();
+    *iter = (void*)(uintptr_t)c;
+    return c;
+}
 
 static void *resample_child_next(void *obj, void *prev)
 {
@@ -321,7 +330,10 @@ static const AVClass resample_class = {
     .class_name       = "resample",
     .item_name        = av_default_item_name,
     .version          = LIBAVUTIL_VERSION_INT,
+#if FF_API_CHILD_CLASS_NEXT
     .child_class_next = resample_child_class_next,
+#endif
+    .child_class_iterate = resample_child_class_iterate,
     .child_next       = resample_child_next,
 };