mxfdemux: Output "negative" DTS for reordered streams
Submitted by Sebastian Dröge @slomo
Link to original bug (#785126)
Description
Various MXF files that actually have frame reordering output DTS>PTS. We have to offset all DTS backwards by the maximum difference between the two for this to work properly, by looking at the index.
This additionally will need the segment to be adjusted so that negative DTS are possible, just like in qtdemux.