Interoperable Master Format (IMF) is a SMPTE standard for providing a single, interchangeable master file format and structure for the distribution of content between businesses around the world. IMF provides a framework for creating a true file-based final master.
Description of IMF Components:
IMF is an evolution of the Digital Cinema Package (DCP) architecture, providing a complete file interchange unit to the distribution channel. While DCP is about theatrical content distribution, IMF is about providing businesses with a master format for creating multiple tailored versions of the same piece of content for different audiences. It allows distribution of unique versions from content owners to service providers, or distributors—and multiple final destinations such as Airlines, Broadcaster, OTT (e.g. Netflix), DVD authoring, and more.
For example, a widely distributed major motion picture may require dozens of different versions in order to support multiple market segments such as airlines, VOD providers, promo spots, or an edit for cable television. IMF eliminates the need to create a dozen plus master copies by separating each market requirement into individual ‘component formulas’ (Composition Play Lists or CPL) that reference the available essence components (namely MXF media files) included in an IMF package. Individual CPLs are used to create versions based on the master essence components for each of the differing market audiences.
IMF is not made up as a single file. It is a standard specifying individual components which together create a complete IMF package. An IMF package includes the following:
Essence wrapped into MXF track files
- Video essence (J2K up to UHD)
- Audio essence (24bit uncompressed, any number of channels)
- Data essence (subtitles & captioning using IMSC Timed Text)1
- Dynamic metadata (metadata changes over time)
Composition playlist (CPL) – human readable XML
- Similar to an Edit Decision List (EDL)
- References track files via UUID instead of directory paths
Packaging data XML (asset map, packing list and volume index)
IMF essences are defined by Application specifications that allow for different codec types, frame rates and resolution. Two application specifications, Application #2 and #2 Extended, are applicable to the broadcast media market. Application #2 supports SD/HD with JPEG-2000 Broadcast Profile; #2 Extended supports UHD (up to 4K) with JPEG-2000 Broadcast Profile media up to 10bit.
Telestream Vantage Support for IMF:
Vantage from Telestream can take an IMF CPL as a master source input to create all appropriate outputs, and can create single segment IMF Master Packages as an output. Vantage currently supports ingesting and outputting IMF Application #2, and Application #2 Extended IMF packages.
More information on IMF can be found at the SMPTE website, SMPTE Standards Development Update: IMF.
In our last blog about Ultra High Definition (UHD), we covered the spacial resolution of the human visual system, and how (horizontally) the highest frequency the average human with 20/20 vision can detect subtends an angle of approximately 1 arc minute (1/60th of a degree) at the retina. There’s another aspect we need to consider, though, and that’s the sensitivity of the eye to variations in brightness The human eye can resolve the wide range of colors and brightness found in the natural world, but our existing TV systems limit the amount of light that the display can produce to the range of 0.117 nits (a nit is a measurement of brightness) to 100 nits for full white. In comparison, the natural world can produce high brightness colors in excess of 1400 nits. So Cinematographers and Directors of Photography have to adjust aperture on their cameras to allow those bright colors to still fit within the available range of TV transmission. The same is true for the range of colors that can be reproduced (“color gamut”), which is again limited to what is referred to as “rec 709 colors”. This results in what is now termed “Standard Dynamic Range” (or SDR) images. It’s not perfect, but it’s the best we’ve had so far (and it was largely determined by the available CRT technology at the time the specs were written).
Technology advances, and we now have display technologies that can produce a significantly wider black-to-white range, along with being able to reproduce a much wider set of colors. The result of both of these is displays that are capable of producing images which are much more vivid and true-to-life (assuming they were shot with this display technology in mind, of course) – this is what is now referred to as “High Dynamic Range” (HDR) images. The displays themselves are only part of the story, however. Cinematographers/DPs must now set up their cameras to capture a much wider dynamic range, and the transmission and processing (not too much of a problem there!). The colorists need to work their magic in HDR color space (not too much of a problem there, either). But the processing equipment needs to be able to work on signals of 12 bits or larger, in order to process these images. Generally speaking, this means that these processing devices must have an internal video pipeline of 16 bits. If not, the resultant processing will “crush” the dynamic range of the image, which goes against the whole point of HDR – in the worst case, they may throw away bits, which will result in significant contouring.
But there’s a bigger problem than that: whilst you can already find TV sets which are labeled as being HDR capable, there are no standards as yet for the format to be used for delivery of HDR material – in fact, the CEA has only just announced the industry definition for HDR compatible displays themselves. We have to consider legacy support as part of the process– how should an SDR set display an HDR signal? There are several approaches, some of which separate the signal into SDR images with a sidecar transmission that provides the additional information needed to recreate the HDR signal in an HDR display. Others use metadata to tell the SDR set what to do with an HDR signal. HDR is unlikely to achieve widespread adoption until this standardization issue is resolved.
One thing that is certain, though, is that HDR is very much at the forefront of everybody’s mind when considering new television technologies. You only have to see the images produced by a properly sourced HDR display to understand the impact this technology is going to have on TV viewing. In fact, a well set up 1080p HDR image will blow away an SDR 4K image in almost every respect – we just need to standardize on the delivery format and EOTF/PQ (the HDR equivalent of Gamma) so manufacturers know what to design to.
At Telestream, we are always watching developments such as this, to ensure our customers have access to all the latest technologies. Vantage was engineered with a 16 bit (award-winning) video processing system and pipeline, so is perfectly poised to process HDR material – in fact, for certain input/output configurations, we already can!
A post from our friends at NewBlueFX
After months of hard work and a lot of input from professionals like you, it’s finally here.
Titler Pro Live 2 is the easiest and fastest way to raise the production value of your live streams. Leverage over 70 templates and the fully featured Title Designer to create animated titles and graphics in a fully integrated interface.
Why We Made It
You told us here at NewBlue you wanted a product that was faster and easier to use. And we didn’t disappoint.
We redesigned Titler Pro Live 2 from the ground up. We aligned our workflow with Wirecast’s by leveraging multiple sources to deliver a truly native experience. We then used technology from our latest titling tool, Titler Pro 4, to boost render speeds and video playback.
And we didn’t stop there. Read the rest of this entry →
Another great contribution from our very own Paul Turner!
One thing we know to be constant in our industry is that there is always going to be change. We’ve moved from black and white to color to digital to HD, in the constant desire to bring higher and higher fidelity images to the home. Now we’re hearing about 4K/UHDTV (these are not quite the same, but we’ve had that discussion) and beyond – the Japanese broadcasters – and specifically NHK – have announced that they intend to broad cast the 2020 Olympics in 8K resolution. Read the rest of this entry →