From time to time we work on other things beyond DVB broadcast encoding where Open Source can be used to transform closed broadcast workflows. The file delivery specification from the Digital Production Partnership (DPP) is one such area. However, the AVC-Intra codec used in DPP is effectively a proprietary codec with implementation in the real world being more complex than the SMPTE RP2027 that AS-11 recommends and in a number of areas implemented incorrectly. However, we have now successfully reverse engineered AVC-Intra from available samples which allows a fully open source DPP creation workflow. Leveraging existing Open Source projects for manipulation and creation of mxf files, a fully compliant DPP file can be delivered to UK broadcasters. Tests at interoperability events have showed that this implementation has no interoperability issues.