diff --git a/api/frame_transformer_interface.h b/api/frame_transformer_interface.h
index 2cfe6ed..753c7f4 100644
--- a/api/frame_transformer_interface.h
+++ b/api/frame_transformer_interface.h
@@ -50,7 +50,14 @@
   // webrtc::RtpDescriptorAuthentication is exposed in api/.
   virtual std::vector<uint8_t> GetAdditionalData() const = 0;
 
-  virtual const VideoFrameMetadata& GetMetadata() const = 0;
+  // TODO(bugs.webrtc.org/11380) make pure virtual after implementating it
+  // downstream.
+  virtual const VideoFrameMetadata& GetMetadata() const { return metadata_; }
+
+ private:
+  // TODO(bugs.webrtc.org/11380) remove from interface once GetRtpVideoHeader is
+  // pure virtual.
+  VideoFrameMetadata metadata_;
 };
 
 // Extends the TransformableFrameInterface to expose audio-specific information.
diff --git a/api/video/video_frame_metadata.h b/api/video/video_frame_metadata.h
index 2e93098..ce9b2a1 100644
--- a/api/video/video_frame_metadata.h
+++ b/api/video/video_frame_metadata.h
@@ -27,6 +27,7 @@
 class VideoFrameMetadata {
  public:
   explicit VideoFrameMetadata(const RTPVideoHeader& header);
+  VideoFrameMetadata() = default;
   VideoFrameMetadata(const VideoFrameMetadata&) = default;
   VideoFrameMetadata& operator=(const VideoFrameMetadata&) = default;