diff --git a/video2x/encoder.py b/video2x/encoder.py
index 925569f..ce7efa7 100755
--- a/video2x/encoder.py
+++ b/video2x/encoder.py
@@ -133,8 +133,12 @@ class VideoEncoder(threading.Thread):
                     time.sleep(0.1)
                     continue
 
+                # send the image to FFmpeg for encoding
                 self.encoder.stdin.write(image.tobytes())
 
+                # remove the image from memory
+                self.processed_frames[frame_index] = None
+
                 with self.processed.get_lock():
                     self.processed.value += 1