1301058 /usr/bin/avconv:avconv: ../../src/xcb_io.c:179: dequeue_pending_request: Assertion `!xcb_xlib_unknown_req_in_deq' failed. 1368481 /usr/bin/avconv:avconv: /build/buildd/libav-11~beta1/libavcodec/put_bits.h:139: put_bits: Assertion `n <= 31 && value < (1U << n)' failed.