By Oliver Peters, April 14, 2004
This industry loves acronyms and now it's more than tape formats. Here are some terms that will be heard all over the NAB floor.
First there are the new standards of AAF (Advanced Authoring Format) and MXF (Material eXchange Format). AAF is like a super-EDL, containing metadata about edits, effects and more, whereas MXF - a subset of the AAF standard - is a media wrapper that contains audio and video (called "essence") as well as metadata describing this essence. These file standards are destined to replace legacy formats, like Avid's OMF and 30-year-old CMX EDLs.
With the convergence of video and multimedia we've become used to codecs and formats like QuickTime, AVI and MPEG, but there are new options, such as MPEG4, Windows Media 9 and JPEG2000. The first two are generally viewed as distribution formats, but for instance, Windows Media can range from uncompressed to highly compressed. JPEG2000 is a production codec that is a rewrite of the older JPEG compression algorithm. It is gaining favor in the digital intermediate world because it greatly reduces file sizes and is visually lossless.
Speaking of DI, you hear a lot about 2K and 4K files. These designations are shorthand for the file sizes associated with scanned film frames. 2K files are 2048 x 1556 at 72dpi. 4K files are 4096 x 3048 at 72dpi. This is the full-frame resolution of a 35mm film frame when scanned by a device like the Grass Valley Spirit. Another film term is DPX (Digital Picture Exchange). DPX is the raw file format of scanned images and is an SMPTE-approved standard that stems from the Kodak Cineon file format. DPX files will play a greater role in editorial workflow, once nonlinear editors start to deal with actually editing and tracking film files instead of film that was first transferred to videotape.
Then there are other recording schemes giving videotape a run for its money: P2 and XDCAM. Last year Panasonic and Sony both introduced tapeless recording concepts. This year they're back with real product. XDCAM is Sony's branding for it's optical recording system that uses DVD media. P2 is the Panasonic solution based on solid-state memory cards that are mounted inside PCMCIA-style cartridges.
There are rapid changes in hard drive technology and the new terms to know are SATA, iSCSI, FireWire 400 and FireWire 800. All of these are new interfaces for the control of drives and have nothing to do with the performance or the mechanics of the drive itself
. SATA (Serial ATA) is a newer replacement for Parallel ATA and allows for easier user replacement of internally mounted drives due to a simplified control system and connections. iSCSI uses Ethernet connections and Internet protocol to control drives. When Gigabit Ethernet is used, the bandwidth compares favorably with Fiber Channel drives. Of course, you're probably familiar with FireWire as a connection for drives, VTRs, camcorders and other devices. Up until now FW400 has been the typical interface on Macs and some PCs. This passes 400Mbps of data, which is enough for DV and even uncompressed video using specialized devices like AJA's Io or Avid's DNA units; but, not enough for sustained drive speeds to pass uncompressed SD video to and from an external drive. Many newer Macs also include the faster FW800 standard, which passes 800Mbps. Some users report success with single FW800 drives when used with uncompressed SD video, so expect to see a number of solutions using FW800-based drive arrays for editing workstations.
Finally, what would an NAB Convention be without some new tape or video format. Last year Sony and JVC intro'ed products that represent both ends of the hi-def cost spectrum. JVC showed the first HDV product. HDV is a highly compressed version of hi-def video that uses essentially the same type of signal as broadcast HD television. 1080i video fits into a data rate of about 25Mbps and 720p into 19Mbps. HDV is backed by a consortium of several companies that include JVC, Sharp, Canon and Sony, so expect to see more products than just JVC's prosumer camcorder. At the other end, Sony showed its HDCAM-SR cameras and decks, which are George Lucas' new choice to lens "Star Wars, Episode III". HDCAM-SR features a higher bandwidth than the original HDCAM format, generating full RGB signals (4:4:4) from the camera. The dilemma is how to record this in the field. Camcorders aren't an option yet, but Sony is showing a portable field recorder capable of recording this signal. It can either record a full-bandwidth 4:4:4 signal using a dual-link cable or record a single 4:2:2 feed and apply mild MPEG4 compression. Dual-link is a way of splitting a wide bandwidth signal into two industry-standard interfaces, like SDI or HD-SDI, and sending them to a recording system.
Oliver Peters is a post-production consultant based in Orlando, Florida and specializes in editing, project management and DVD development. You may contact him at www.OliverPeters.com .
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