diff --git a/libavcodec/rv10enc.c b/libavcodec/rv10enc.c
index 37efe6cca4..45f11365c9 100644
--- a/libavcodec/rv10enc.c
+++ b/libavcodec/rv10enc.c
@@ -49,7 +49,8 @@ int ff_rv10_encode_picture_header(MpegEncContext *s, int picture_number)
        to display the macroblocks is coded here */
     if(!full_frame){
         if (s->mb_width * s->mb_height >= (1U << 12)) {
-            avpriv_report_missing_feature(s, "Encoding frames with 4096 or more macroblocks");
+            avpriv_report_missing_feature(s->avctx, "Encoding frames with %d (>= 4096) macroblocks",
+                                          s->mb_width * s->mb_height);
             return AVERROR(ENOSYS);
         }
         put_bits(&s->pb, 6, 0); /* mb_x */