Professional media continues its inexorable march towards component-based workflows, where the elements of a presentation - audio, video, timed text - are stored and processed individually, to be assembled just in time to meet the specific needs of each distribution channel, writes IMF User Group chair and partner at Sandflow Consulting Pierre-Anthony Lemieux.
Component-based workflows are designed to tackle the explosion in the number of content versions resulting from proliferation of localised versions due to worldwide distribution and acquisition, multiplication of viewing experiences as well as the expanding repertoire of audio-visual essence, such as access services, immersive sound, HDR, 4K.
The Interoperable Master Format (IMF) family of standards, managed by SMPTE and in active use, is designed for the interchange of component-based audio-visual masters – from movies to adverts.
At the heart of IMF is the Composition Playlist (CPL), which is an XML document that defines the timeline for one version of the master. The essence and metadata associated with the timeline are usually stored in separate MXF files called Track Files.
An IMF Composition is the combination of a Composition Playlist and all the Track Files it references. The same portion of a Track File can be referenced by any number of Composition Playlists, allowing multiple content versions to reuse the same essence. This approach dramatically:
• reduces duplication of assets during interchange and storage
• encourages reuse of assets
• reduces times when creating new content versions
• preserves the relationship between content versions.
A single standard (SMPTE ST 2067-2) defines the core of IMF, while additional Application standards tailor IMF to specific domains (see box out ‘IMF Applications’).
Coinciding with the shift to component-based workflows, professional media is also being transformed by the adoption of cloud-based solutions.
These solutions are particularly relevant to IMF since content masters are increasingly processed in the cloud, and IMF is ideally suited to facilitate interchange of content between processing nodes.
In fact, a number of IMF implementers offer cloud-based solutions with many present at IBC, including Dalet, Fraunhofer Alliance Digital Media, Interra Systems, Ownzones, Prime Focus Technologies, Tedial, TransMedia Dynamics, Venera Technologies and Videomenthe.
Inconceivable just a few years ago, the adoption of cloud-based solutions is being driven by the following factors:
• Scalability: Scale to business demand without requiring additional on-premises resources, and makes possible previously unattainable peak performance.
• Ease of use: Remove the need to install and maintain hardware or software on premises, simplifying operations and lowering the barrier to adoption.
• Rapid deployment: Allows feature and bug updates to be deployed immediately.
• Accessibility: Accessible on any connected device, even mobile phones, and anywhere in the world.
• Security: Decreases the attack surface by reducing the number of entities handling cloud content – in contrast to manually moving files from workstation to workstation, over networks or hard drives or tape, – and also benefits from the specialised security expertise of cloud platform providers.
While adopting new technologies always requires time and education, cloud-based solutions face a number of unique challenges. One of these is interactivity; due to network latency and web-platform limitations, some specialised tools, for example colour grading, remain off-limits for now.
There are also technical bottlenecks, and standards need to be revised to make optimal use of cloud parallel processing, for example, hashing of Track Files.
There are also challenges to business models. Subscription or compute cycles pricing models are a stark departure from traditional costs measured in workstation or jobs.
The IMF User Group (IMF UG) was formed to be an open forum for the community of IMF users and implementers. It is organised under the Hollywood Professional Association (HPA) umbrella and currently has 87 members, from large multinationals to individuals.
The IMF UG offers a unique opportunity for IMF users and implementers to communicate directly with each other, and to co-ordinate best practices based on operational experience. Recent examples include best practices for the use of EIDR and ISAN identifiers to enable workflow automation.
As more of professional media moves beyond traditional HD workflows, the demand for component-based and cloud-based workflows, enabled by technologies such as IMF, will grow. Join us in the IMF UG to be at the forefront of these developments.