libavcodec/vp8.c:1569: error: Uninitialized Value
  The value read from curframe was never initialized.

libavcodec/vp8.c:1569:5: 
1567.     int ret, mb_x, mb_y, i, y, referenced;
1568.     enum AVDiscard skip_thresh;
1569.     AVFrame *av_uninit(curframe), *prev_frame;
          ^
1570. 
1571.     release_queued_segmaps(s, 0);
