Fixed memory leak in dav1d codec
diff --git a/src/codec_dav1d.c b/src/codec_dav1d.c
index 74f8920..2c7f6dc 100644
--- a/src/codec_dav1d.c
+++ b/src/codec_dav1d.c
@@ -25,6 +25,9 @@
 
 static void dav1dCodecDestroyInternal(avifCodec * codec)
 {
+    if (codec->internal->hasPicture) {
+      dav1d_picture_unref(&codec->internal->dav1dPicture);
+    }
     if (codec->internal->dav1dContext) {
         dav1d_close(&codec->internal->dav1dContext);
     }