The Impossible Mission of the Interoperable Master Format (IMF)

PFT Blog Team | 14 Sep 2017

By Anthony Matt,
Executive Director, Cloud Media Services, Prime Focus Technologies

A single programme, across its lifetime, can be made into tens, if not hundreds of different versions. From theatrical releases, broadcast or DVD/Blu-ray to VOD, hotel, airline and more – the myriad of distribution channels for a single title can be multiplied further by global translation and censorship requirements. Perhaps most importantly, OTT platforms like Netflix and Amazon need to deliver to an increasing number of devices, globally. This can result in complicated delivery processes, increased costs and long production timelines.

It’s vital to have a high quality master of your content, but just as important is managing the process of international delivery and versioning. The proliferation of versions is often called ‘Versionitis’ by media professionals, who must manage growing numbers of large high quality files for popular titles.  SMPTE (Society of Motion Picture and Television Engineers) created a mastering standard, in 2012 that would enable the creation of multiple versions of programmes, while holding the source material at the highest possible quality. The standard that was created was IMF (Inter operable Mastering Format) - SMPTE ST 2067-2.

So what is IMF?

• Built upon the proven success of formats such as DCP (Digital Cinema Packages), IMF is a true production master, a media packaging format that streamlines the assembly of multiple versions of a title for any downstream distribution.
• Instead of a single master file – like a quicktime or xdcam file, all IMF audio, video and text components are contained within the file as individual assets.
• IMF components are individually referenced by an editorial Composition Playlist (CPL). As an analogy, the assets are the ingredients and the CPL is the recipe.
• An IMF can contain unlimited CPLs, each representing a unique combination of the files contained in the package - think of these as each disparate edit or cut of a programme.
• Instead of hundreds of separate versions of a master, you can create one IMP (Interoperable Master Package) with all the various media elements (soundtracks, subtitles, graphics, technical metadata etc.) and endless variations described by the CPLs.
• The IMF format also includes an Output Playlist (OPL). The OPL is the IMF package’s technical instructions and it can incorporate additional modifications like sizing, audio, channel mixing and transcoding profiles. Additional OPL functionality for broadcast is still in development, with a range of companies, including Prime Focus Technologies (PFT), working to create the specification and tools.

IMF’s combined functionality greatly reduces the need to create hundreds of standalone high res versions of a title. This simplifies distribution workflows, and lowers costs and time-to-market.

How is Prime Focus Technologies developing its IMF tools?

This year, in partnership with SMPTE, NABA and the EBU, the DPP has been working towards fast-tracking a constrained version of IMF for Broadcast & Online; with the final specification due to be published by NAB 2018. PFT has been an integral part of the DPP group helping to create the IMF for Broadcast and Online specification.

PFT’s CLEAR team has been hard at work during the past year to create the first of many developments in the exciting new world of IMF mastering and delivery. The company’s flagship product, CLEAR™ Media ERP includes an IMF proxy player that enables the viewing of files and their various CPLs. Currently UHD IMF files are difficult to play back due to the huge file sizes. This normally requires an extremely powerful workstation and significant investment.

CLEAR’s IMF player solves this challenge by creating proxy files of all the component elements of the IMP and conforms the elements into a virtual CPL. This can be viewed from any computer or mobile device with internet access. CLEAR’s MAM functionality enables content managers to easily view and deliver IMF content in a cloud environment.