diff --git a/src/pingxelflutsink/imp.rs b/src/pingxelflutsink/imp.rs
index 1701202..6cc2830 100644
--- a/src/pingxelflutsink/imp.rs
+++ b/src/pingxelflutsink/imp.rs
@@ -12,6 +12,7 @@ use gstreamer_base::subclass::prelude::*;
use gstreamer_video::prelude::*;
use gstreamer_video::subclass::prelude::*;
+use gstreamer_video::video_frame::Readable;
use gstreamer_video::{VideoCapsBuilder, VideoFormat, VideoFrame, VideoInfo, VideoSink};
use std::cmp;
@@ -49,6 +50,7 @@ enum State {
pub struct PingxelflutSink {
caps: Mutex