If I play .mkv files in my app, then seeking to a position is not performed 
correctly.
I have an filesrc, decodbin and an appsink.
If I call 
    gst_element_seek(GST_ELEMENT(m_pipeline), 1.0, GST_FORMAT_DEFAULT, 
GST_SEEK_FLAG_FLUSH,
      GST_SEEK_TYPE_SET, qMin(i_stamp, m_duration), GST_SEEK_TYPE_NONE, 
GST_CLOCK_TIME_NONE);


    gst_element_query_position(GST_ELEMENT(m_pipeline), 
GST_FORMAT_DEFAULT, &stamp);

then stamp contains same value as i_stamp, the stamp I want to set. It 
does not matter if I use stamp or frame mode (GST_FORMAT_DEFAULT or 
GST_FORMAT_TIME) behaviour is same in both modes.
The problem is that the next buffer I get in my appsink has a stamp which 
is about 2-3 frames behind the frame or stamp I set. The problem occurs only in some .mkv files.