Avoid decoding of 0-size packets. This also fixes that the main loop believes

tehre is an infinite number of delayed frames, thus never finishing (happens
with -demuxer lavf -vc theora).


git-svn-id: svn://svn.mplayerhq.hu/mplayer/trunk@31206 b3059339-0415-0410-9bf9-f77b7e298cf2

libmpcodecs/vd_theora.c

@@ -168,6 +168,10 @@ static mp_image_t* decode(sh_video_t *sh,void* data,int len,int flags)
    yuv_buffer yuv;
    mp_image_t* mpi;
 
+   // no delayed frames
+   if (!data || !len)
+       return NULL;
+
    memset (&op, 0, sizeof (op));
    op.bytes = len;
    op.packet = data;