multiple assets in a single logical storage location.
The assets don’t need to be only audio or video files, although an IMF can
just as easily contain multiple camera
angles and multiple language audio
files, but can also be subtitles or timed-text files. The beauty of a single format container holding many complementary files is that these assets can
be bound together in one of multiple
permutations at the time of delivery—
called late binding—that are supported by multiple streaming technologies
such as MPEG-DASH or Apple’s HTTP
Live Streaming (HLS).
Late binding from a grouping of
complementary assets within the IMF
container means that IMF is as beneficial for delivery as it is for storage.
But editing IMF content can be tricky.
Why? Well, it turns out that IMF
packages are active document containers similar to the Microsoft Binder
concept in early versions of Microsoft
Office. While IMF is made up of modern video and web technologies likes MXF and
XML, it turns out that the IMF package essentially works the same way as Binder, which housed
all the PowerPoint slide decks, Word documents,
and Excel sheets for a given project.
Binder allowed Excel sheets that were dynamically linked into a PowerPoint slide deck
to be always available when the PowerPoint
slides were edited or delivered. It’s true that
Binder added to the size of a typical PowerPoint
deck, but only by a negligible amount, since the
Excel sheet was a much smaller file size, and
the convenience of having the Excel and PowerPoint files together in one container format
outweighed the show-stopping inconvenience
of having a broken link to an Excel table embedded in the PowerPoint presentation.
One problem with the Microsoft Binder ap-
proach, and perhaps a major reason that it was
discontinued around the time of Office 2007,
was the problem of editing. While the Microsoft
Office suite of products could easily edit Binder
documents, other editing tools that were Excel-
or Word-compatible were often unable to un-
derstand the same document types integrated
into the Binder format. Even those that did un-
derstand the Binder format often could not ex-
tract or edit either the internal Excel or Word
documents without damaging the document’s
relationship with the Binder or other files with-
in the Binder.
Editing Within IMF
As mentioned earlier, the idea of using IMF
as a container format for acquisition or post-production processes is not the initial intent
It’s true that IMF is based partly on MXF,
which itself is a video and audio container format used in acquisition, but IMF’s additional
payload options make it more suited for delivery than a production workflow.
“Although IMF uses ‘simple’ MXF variants
for the storage/transport of the actual media
“We do not currently
see IMF as a format
in the production
“but rather as a
deliverable for the