The impact of BXF 2.0

New improvements to the format will enable BXF-MXF metadata mapping.
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Since SMPTE's Broadcast eXchange Format (BXF) was first released on 1 April 2008, we have witnessed a flurry of activity surrounding it! And that's just on the SMPTE side of things — not to mention what's been going on in the industry in general.

Following the initial standard's publication date, work immediately forged ahead on a BXF Recommended Practice, intended to assist users in creating interoperable BXF implementations. It was important to provide guidance, as simply dropping a 640-page behemoth that was the original SMPTE BXF Standard (2021:2008) on the industry and hoping for the best seemed like a recipe for disaster.

The BXF Working Group produced the BXF Recommended Practice (SMPTE RP2021-9:2009) in early 2009, and then immediately proceeded with the task of addressing a set of improvements collectively known as BXF 2.0. The main reason for this was due to the pace at which industry requirements evolve. Any software-related standard that remains static for a period of even a few years runs the risk of becoming obsolete. As you read this, work is progressing on a host of improvements and extensions to the original BXF work that should serve broadcasters well in coming years. The BXF Working Group gathered input from a wide range of participants regarding what the industry felt was needed to supplement the already-existing capabilities of BXF. This article details the recent improvements made to the BXF standard. (See Figure 1.)

A roadmap to go by

Before any work could really begin, something had to be done to address the problem of the monolithic original document; 640 pages is a lot to digest successfully! Work began on correcting this in mid-2009, and by the end of the year, the group produced four new documents (2021-1 through 2021-4), which replaced the original document — eliminating redundancy and compartmentalizing the relevant bits into reasonably sized, logically grouped sections.

In addition, the group produced SMPTE's first multipart roadmap document (2021-0), which presents a concise listing and description of all components of the BXF suite of documents, schema and related goodies. With a large and growing suite such as BXF, having a small roadmap document to help the uninitiated sort through all the materials available is critical. Documents 2021-0 through 2021-4 (as well as RP2021-9) can be downloaded at https://store.smpte.org.

International reach

A small subgroup was formed to review all of the BXF documents and schema from an international perspective. Representatives from Europe and AsiaPac are currently reviewing the materials and will recommend improvements to BXF for market-specific requirements. While work on BXF has involved expertise from around the world since day one (and there has been widespread adoption of BXF worldwide already), it's important not to miss any region-specific requirements to ensure that BXF is equally useful worldwide.

BXF-MXF metadata mapping

One of the most daunting items the group tackled was BXF-MXF metadata mapping. This is possibly the most important output of the entire BXF 2.0 effort.

BXF and MXF are two separate standards that both handle metadata at distinct but related points in the media workflow process. While MXF is used to wrap audiovisual essence files (including metadata) and transport them from source to destination in a consistent manner, BXF is primarily used by systems and products that never touch MXF or other essence files with embedded metadata. These products and systems are normally media management systems such as scheduling, traffic, sales, asset management and automation, which, while interested in the video, never directly touch it. However, the need for metadata to reside in either BXF or MXF and flow smoothly from one into the other in a standardized way certainly exists. As file-based workflows dominate the landscape, with more and more automated processes involved in their management, such a mapping becomes critical to this entire ecosystem.

The heavy lifting to this point on the BXF-MXF metadata mapping project has been undertaken under the auspices of the Advanced Media Workflow Association (AMWA). In January 2010, it made preliminary contributions to the SMPTE BXF Working Group. The groups plan to publish BXF-MXF metadata mapping standards in 2010. One benefit that will come out of this work is a BXF data model, which many have expressed an interest in having.

Schema improvements

The next phase of BXF 2.0 work will focus on schema improvements. Because it's been several years since the original BXF schema work was done, additional industry requirements have surfaced. The planned schema work includes:

  • Implementing recommendations from the SMPTE XML Best Practices Review.
  • Adding a ContentContract Node to Schema. This will allow for richer rights management data to be exchanged between BXF-compliant systems.
  • Adding a NonPrimaryEvent-ProgramEvent to Schema. This will enable scheduling of program events that aren't necessarily the primary audio/video being shown. For example, this could be a secondary program shown during a DVE squeeze.
  • Adding a new element called “duration of effectiveness of house #” into the schema for compatibility with ATSC A/57. This allows for the scenario in which in-house content identification numbers are reused.
  • Instituting Schema edit, which allows for multiple title names and descriptions under Schedule/ScheduledEvent/EventData, so that multiple languages can be permitted.
  • Setting up SCTE 104 and 130 support. This enables compatibility with these important targeted ad insertion standards.

We expect work on these items to initiate in the second quarter of 2010, with hopeful publication of the results later this year.

Lower priority items

Beyond the significant efforts under way and soon to begin on the items outlined above, there are plans for additional items to be addressed as part of BXF 2.0. Among the items already prioritized for work are:

  • AFD and aspect ratio conversion support;
  • Review of audio structure (including multiple language considerations);
  • Addition of a new portion of schema for communication of manual interventions;
  • Implementation of remaining PMCP items (Programming Metadata Communication Protocol specification ATSC: A/76A);
  • Improved nonlinear (non real-time) support;
  • Roll-up of recommended practice items into standard;<
  • Schema typo cleanup; and
  • Synchronous support.

Implications for broadcasters

What will all of this mean for you? Of course, the answer to this question depends on the nature of your BXF implementation. Hopefully, in reviewing the already complete, ongoing and future work under the BXF 2.0 umbrella, you have found items of interest and ones that impact your operations.

Clearly, shortening the original document into parts 1-4 should benefit everyone implementing BXF. Beyond that, the group expects the biggest benefit to the media community at large to come out of the BXF-MXF metadata mapping initiative. The bottom line here is smooth flow of data between standards and systems that in the past were either disconnected, or connected in a nonstandardized and likely suboptimal manner. Few in the industry would not benefit from this.

The other improvements — from schema edits, to enabling of targeted advertising, to better support of non real-time broadcast services — all show promise of great benefit to a wide audience.

If you would like to provide input to this process, it's simple. As a SMPTE member, you can simply log into the members' area on www.smpte.org and request to join 32NF-10 WG BXF. The group has a significant document repository, including minutes from its biweekly meetings to help catch you up.

Chris Lennon, CTO Group, Harris Broadcast Communications.