diff --git a/libavcodec/vcr1.c b/libavcodec/vcr1.c
index 675ada87e4..d6b617a11e 100644
--- a/libavcodec/vcr1.c
+++ b/libavcodec/vcr1.c
@@ -123,7 +123,7 @@ static int vcr1_decode_frame(AVCodecContext *avctx, void *data,
 
     *got_frame = 1;
 
-    return buf_size;
+    return bytestream - avpkt->data;
 }
 
 AVCodec ff_vcr1_decoder = {