SMPTE Sampling: File-Based Workflows
HOLLYWOOD: Optimal storage configurations, enterprise IP multicasting and
making more money with BFX were a few of the topics covered during the opening
day of the 2012 Society of Motion Picture and Television Engineers Technical Conference
in Hollywood last month. TV Technology provides
Performance Parameters for Storage
Karl Paulsen*, chief technologist of Diversified System talked storage and
what to consider when scaling it. A large, enterprise-level storage system is
much more than a bigger version of the average email server, he said, although many are being
built of similar components. Larger systems are more likely to have to bridge
other platforms, accommodate more peripherals and support multiple clients and
associated workflows. Size, itself, is another matter as well. Paulsen favors RAIDs versus larger capacity
drives. RAIDs-redundant arrays of independent disks—are scalable in smaller
steps and have higher fault tolerance. E.g., with a RAID of four 150 GB disks,
all is not lost when one fails, compared to the loss of a 1 TB disk.
When designing a storage system, Paulsen recommended doing so with long-term
uses in mind. Considerations should include overhead—things like RAID level,
compression format, and encoder type; performance, such as what processes
affect file-transfer speeds; the multiple workflow processes, core servers and
databases supported; and many others. All these factors need to be managed for the
greatest efficiency to assure peak performance. Paulsen suggested a
hierarchical storage management policy for moving aging files to other
platforms, and deduplicating data as much as possible.
Optimized IP Multicast
Thomas Kernen, a consulting systems engineer for Cisco, presented a case
for use of enterprise IP multicasting. He noted that services as diverse as
AT&T’s U-verse and high-frequency stock trading rely on IP multicasting.
The basic premise of multicasting is one copy for many receivers. Content is
replicated by network elements such as switches or routers. The payload is
irrelevant, Kernen said.
When multicasting was first designed, it used an any-source architecture that
required a shared tree set-up and a rendezvous point. The receiver sought out
the desired stream, rather than its source, which required mapping.
Source-specific multicasting, or SSM,
resolves this by pointing the receiver to the source. SSM was
standardized in 2006. Kernen said that
with SSM and other IP multicast improvements, 4K and even 8K workflows can be
accommodated over private networks.
BXF and Swapping Spots
Chris Lennon, chief technology officer of Harris Corp., said last-minute
scheduling changes used to be the exception rather than the rule at TV
stations. Now, he said, “people expect to be able to change things at the last
minute and do it in a fairly simple and automated way.”
Lennon used the last-minute spot swap to highlight applications of the
Broadcast Exchange Format, or BXF, developed under a SMPTE Working Group he
chaired. BXF is basically a file wrapper for video-related data sets, published
by SMPTE April 1, 2008, and now in use in several thousand operations. Lennon
summarized the impact of BXF implementation on ad scheduling at two TV
The first involved a public broadcaster, where the staff oversaw master
control, monitors, seven radio and five TV stations, three studio interconnects
and automation. The chief technology officer wanted a system where data was
entered one time only.
Before BXF, the programming department entered the data into a scheduling
system, while traffic and scheduling sent the record lists and dub lists to
automation. More data may have been added at automation and at ingest. Each
manual process introduced delay and cost, Lennon said. BXF allowed those
disparate entries to be consolidated.
The second operation, a commercial TV station group, replaced a Post-It note
system with BXF live update functionality. The transition took station
personnel “out of their comfort level,” because they were used to the
reliability of information they could lay their hands on. The smallest station
was outfitted first, to work the kinks out. Ultimately, the use of BXF allowed
the stations to change commercials on the fly and to reduced the turn-around
time to reschedule pre-empted spots.
The ability to make those changes so much faster allowed the stations to do it
for smaller incremental revenue gains than it would have considered previously
with the Post-It system. Revenue at the smaller station rose by $1,500 a week. The
largest station estimated its gain at $5,000 to $7,000 a week. In one log, the
station replaced $6,000 in spots with $14,000 in spots, Lennon said.
In addition to streamlining the traffic and scheduling operation, BXF has other
uses, Lennon said.
“Something unique about the BXF standard is that most standards are meant to be
consumed by machines, and so is BXF, but it’s also supposed to be readable by
humans,” he said. “BXF can hold the key to workflow obstructions and
BXF 2.0, published in July, is backward compatible with Vers. 1, and features
such a live window that can show what just aired, what’s about to air and
what’s on a the moment. It allows re-sued of house numbers, and programming of
secondary events. BXF 2.0 also adds support of multiple languages.
BXF 3.0 will add automated agency copy instructions, when and where secondary
events can be placed; active format description and audio information, he said.
~ Deborah D. McAdams
(*Karl Paulsen is a regular contributor
to TV Technology whose ongoing column
on media servers and storage is available here.)