ealthTV, a high-definition network, uses Apple Final Cut Pro editing with Apple Xserve Raids. Photo courtesy A. F. Associates. Photo by Carmen Shettino.
My how things have changed. Imagine what this column would be about if it had been written just a decade ago. How might one have described a TV studio in a box? The box could have been a remote truck or a bunch of travel cases, loaded with cameras, character generators, tape decks and other production components needed to produce a television program. For those applications needing only minimal audio and video mixing capabilities, you might even have found an all-in-one box that could get the job done. One thing that you would not have seen was a claim that a personal computer could be configured as a studio-in-a-box.
By the early ‘90s, PCs were making major inroads into audio production, and beginning to compete with dedicated systems for video paint and character generation applications. Nonlinear editing was beginning to emerge, as an offline process to create edit decision lists. The ability to use a computer to produce a complete television program was predicted, but broadcasters and traditional video equipment suppliers were, shall we say, skeptical.
Some things have not changed as dramatically as some predicted. Broadcast-quality cameras and video recording systems are still big-ticket items from the handful of companies that remain standing. The introduction of DV camcorders has helped to democratize video production. However, until recently, those without the money to buy an expensive deck to play the tapes weren't able to capture clips for use as compressed video files. Composite, S-video, analog component video and SDI (SMPTE 259M/292M) still served as the interconnections for a professional video production system. This was true even in a one-man professional project studio — the equivalent of a studio-in-a-box.
Broadcast station infrastructures evolved down a uniquely broadcast-centric path, even as facilities upgraded from analog to digital. Crosspoint-oriented routing switchers emerged as the primary means of signal interconnection, with separate physical layers for switching audio and video streams. The notion of moving files between processing systems was for all intents and purposes meaningless. Broadcasters have built their digital infrastructures to mirror the analog infrastructures they were upgrading. The assumption behind this decision was that the purpose of a TV station was to deliver a single program stream to the transmitter.
The philosophy behind this traditional view of television as a bunch of video streams was not fundamentally flawed. The fatal flaw was the notion that data networking and video networking would remain separate and unique.
The requirement to produce live broadcasts has driven the design of signal routing infrastructures for broadcast. Unfortunately, broadcasters have applied this philosophy to areas where switching and mixing baseband video/audio signals is not required. DTV master control is an excellent example. The rapid migration to video servers built from commodity IT components has helped to reveal the fundamental flaws in the traditional view of video system design.
Open Studio, or closed?
A decade later, broadcasters and traditional equipment vendors are beginning finally to acknowledge the role of packet-based IT infrastructure in both traditional broadcast facilities and in new IT-based video production facilities.
In the mid-90s, a new movement emerged called Open Studio. The initiative has had a profound impact on the evolution of video production. A series of open conference forums encouraged vendors of computer-based tools and traditional video production tools to work together to help facilitate the digital revolution. In the early years, these forums were quite entertaining as the two factions tore into one another, each claiming that the predicted convergence of video and computing would never happen.
But it did happen. By 1995 the first nonlinear editing system with online-quality output reached the market. Due to increases in CPU speed, memory and storage, these systems soon evolved to handle uncompressed video streams and, more recently, both compressed and uncompressed HD production. In just a few years, online nonlinear editing has largely replaced tape-based online editing systems.
Rather than encouraging this convergence, however, most of the traditional video equipment vendors turned to a proprietary view of the future of television studio design.
In December of 1996 the first Open Studio Conference was held, with the goal of helping all parties work together to create the appropriate infrastructure for convergence of video and computing technologies. The conference succeeded in creating some lasting partnerships between traditional video equipment and computer technology vendors. Over the years, these partnerships have made advances that demonstrate the power of using commodity IT components to deliver digital, even HD, streams to end users in a variety of applications.
Several days after the 1996 Open Studio Conference, a meeting of the Society of Motion Picture and Television Engineers set the stage for the formation of the SMPTE/EBU Task Force for Harmonized Standards for the Exchange of Program Material as Bit Streams. Their first report outlined five areas of investigation: compression, physical link and transport layers for networks, wrappers and file formats, metadata, and file transfer protocols. (See Web links for a PDF version of the report.)
The final report of the task force was issued in 1998 (see Web links for URL). At this year's NAB, the SMPTE and Pro MPEG Forum celebrated the completion of some of the work called for in the SMPTE/EBU task force report. This includes the Media Exchange Format (MXF) and the Advanced Authoring Format (AAF). These new SMPTE standards tie together with the development of a Metadata Dictionary and SMPTE registry for metadata terms. Along the way the SMPTE also developed the SDDI standard, which allows the transport of packet data over a SMPTE 259M SDI link.
During the seven years that the SMPTE worked on these standards, the world did not stand still. While the Pro MPEG Forum held numerous interoperability demonstrations, the traditional video equipment vendors did little to make their products interoperate. Meanwhile, IT-based solutions have come to dominate the infrastructure used in many non-broadcast video production facilities. Standardized IT solutions including the various flavors of Ethernet (10/100/1000BaseT), IEEE 1394 and Fibre Channel provide the interconnection infrastructure used for PCs and packet data routing systems. DVI provides the display interconnect needed to deliver uncompressed HDTV rasters to computer (and consumer) HD-capable displays. In the place of tape and optical-disk-based video recording systems, many programs are now recorded directly to magnetic hard disk arrays.
The Open Studio initiative was quietly retired by the dawn of the new millennium. Not because of the quality of work done by SMPTE or any other standards group. The simple truth is that it was no longer needed. Computer-based video production systems have won the day — all that is left is for the technology to trickle down to the holdouts, those who bought into the video-centric view of studio infrastructures. Open Studio has given way to OpenDTV, where there is still much work to be done. Does anyone really know when the analog TV transmitters will finally be turned off?
Thus the following announcement (as reported by Broadcast Engineering) at the recent IBC Exhibition and Conference comes as no surprise. It came in the context of a SMPTE IBC tutorial on the standards they have spent the past seven years developing.
Given the rapid uptake of IT technology by the television industry, the adoption of digital content delivery and the associated desire to protect content through encryption schemes, the need has never been greater for standards and procedures to assist in the transition from a linear world to an IT-centric environment.
Speaking during IBC2004, SMPTE President Gavin Schutz emphasized that the society and other organizations must address networking technology and its ramifications on workflow. Those working in the industry increasingly must re-educate and re-train to transition from the old to the new, he said.
Maybe we are finally beginning to make some progress in the real DTV transition.
Craig Birkmaier is a technology consultant at Pcube labs, and he hosts and moderates the OpenDTV Forum.
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SMPTE/EBU task force user requirements: www.smpte.org/engineering_committees/pdf/tfhs_out.pdf
SMPTE/EBU task force final report: www.smpte.org/engineering_committees/pdf/tfrpt2w6.pdf
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