The migration to tapeless acquisition media may be great for shooters, but it increases the challenges for editors. There are at least five competing professional tapeless formats, but most videographers have settled on Sony’s XDCAM or Panasonic’s P2. Each is a capture and transport technology that can record standard- and high-definition imagery using various codecs and frame rates. Tapeless camcorders offer the advantage of capturing film-style, native frame rates, including 24fps, plus in-camera time lapse, slo-mo and buffered pre-recording.

Edit systems face three challenges in integrating tapeless recordings: accessing the physical media, reading the format or codec on that media, and dealing with a mixture of frame rates. The Sony XDCAM system consists of a family of SD and HD camcorders, SD and HD studio-style decks and the media itself. Recordings are made onto Sony professional, rewritable, blue-laser optical discs, which are housed in a cartridge. It’s essentially the same media as Blu-ray DVDs, but you can’t simply pop an XDCAM disc into a Blu-ray DVD player. Playback requires a professional transport, like the one inside the camera itself, or in Sony’s PDW-F70 recording deck or PDW-F30 viewing deck.

Standard-definition XDCAM recordings are either 25Mb/s DVCAM or MPEG-2 IMX at 30, 40 or 50Mb/s. If you record XDCAM HD, then your files will be encoded as MPEG-2 at a variable (18 or 35Mb/s) or constant bit rate (25Mb/s). The best quality (35Mb/s) setting lets you fit about 68 minutes onto a 23.3GB disc. Later this year, Sony will release dual-layer discs and XDCAM HD products offering an even higher-quality MPEG-2 signal (50Mb/s 4:2:2) that will rival the quality of Sony’s established HDCAM tape format.

Interoperability

At last count, more than 30 NLE and server companies offer compatibility with XDCAM and XDCAM HD products. This means more than just accessing the files. XDCAM HD clips use the MXF media container standard, which is a file wrapper like QuickTime. MXF contains essence (audio and video media files) and metadata (information about the media). Although XDCAM HD video clips are encoded as MPEG-2, they are wrapped as MXF, so an NLE must be able to open the MXF files and decode the MPEG-2 media.

The MXF container specification uses different organizing schemes, called Operational Patterns. Sony uses the OP-1A method, where video and multiple audio tracks are interleaved into one common file. OP-Atom, an alternate method favored by Panasonic and Avid, keeps the audio and video files separate. As a result, Avid can natively open, read and write files on the P2 cards but must go through an import and file rewrapping step when using XDCAM HD. Although this may seem like an advantage for Panasonic, few people work directly with P2 cards. The capacity is so limited that users generally copy the files to a hard drive first. On the other hand, XDCAM HD can be played back from a Sony device as either a data file or as a video signal, just like playing a videotape.

I tested XDCAM HD with both Avid Media Composer and Apple Final Cut Pro software. The simplest method to integrate XDCAM HD into your edit bay is to add a PDW-F70 or PDW-F30 deck. Both decks play video out of the HD-SDI spigot and can be controlled via regular RS-422 VTR control. If you are used to the standard workflow of logging, capturing, offline editing and online finishing, then these decks let you plug right in.

The alternate approach lets you take full advantage of file-based media. The Sony decks and/or camcorders can be switched into File Access Mode (FAM) and connected to a computer using the i.LINK connection (FireWire 400). Files in their native format are then transferred at faster-than-real-time speeds to connected hard drives. Sony also stores corresponding draft-quality MPEG-4 proxy files on the same discs. These proxies are intended for in-camera review as well as logging and even simple editing using Sony’s free PDZ-1 software (PC only). Other free Sony applications allow users to view XDCAM HD clips on a PC and import and convert media on a Mac for Final Cut Pro.

Avid Media Composer and XDCAM HD

Avid offers one of the better XDCAM HD workflows. There’s a special subroutine for importing either proxies or full-resolution files or both. Avid is one of the few NLE-makers whose media management tools accommodate batch importing. You can offline edit XDCAM proxies and then re-capture just the portion of the native HD files that ended up in your show. In theory, then, there is no need to import all the full-resolution media that was shot. This function has been fully implemented for Macs and PCs in Avid Media Composer 2.7.

Unfortunately, my actual tests hit some snags. Editing 24p proxy files worked fine, but rendering any effects crashed my system. Secondly, the Avid software wouldn’t batch import any files that used off-speed effects, such as overcranked slo-mo shots. Lastly, the visual quality of the MPEG-4 proxy files is poor, even on a laptop screen, which is okay for producer review in the field but not for editing. So, even though Avid enables working with the proxies, it doesn’t seem to make much sense to do so.

An alternate approach is to import all of the full-resolution MXF clips and transcode them into another format for offline editing. Avid’s version 2.7 software introduces the DNxHD 36 offline editing codec for HD progressive formats, such as 24p. I found these transcoded files to convert quickly, look as good as the original on my screen and edit very easily. Avid allows you to re-link based on resolution, so you might import your files to a set of drives, park those on a shelf and edit a rough cut on a laptop with the transcoded DNxHD 36 files. During finishing, you simply re-link to the original, native files, render and master to tape.

Apple Final Cut Pro and XDCAM HD

Apple doesn’t offer batch import, so the standard offline/online editing model doesn’t work for file-based projects. Instead of directly importing XDCAM HD files, Apple uses the Sony XDCAM Transfer software as a conduit. When you select “Import XDCAM” in Final Cut, the Sony transfer software is launched, enabling you to browse the proxy files and subclip shots, and import complete files or subclipped segments of files. Once you’ve made your selection, full-resolution files are imported in the background and rewrapped as QuickTime media. These files are then available for native editing inside Final Cut Pro. This all worked well, and in fact the native 35Mb/s HD files seemed more responsive to me in Final Cut Pro than the same files did on the same machine using Avid Media Composer.

Again, I had issues with the overcranked files. In Media Composer, I could see the files to scrub, mark and edit them, but not in Final Cut on this machine until I dropped them onto the timeline. Apple apparently does an on-the-fly conversion to make these files play correctly, and they must be rendered for final output. This conversion, dependent on the graphics display card and the RAM in the computer, worked fine on a different Mac Pro with the ATI Radeon X1900 XT and 8GB of RAM. If you have trouble, my recommended workaround is to use FCP’s Media Manager to re-compress the files to Apple’s new ProRes 422 intermediate codec (available with Final Cut Studio 2) before you start to edit. Final Cut also permits re-linking. If you don’t want to edit full-resolution HD files, you can also re-compress to a lower-bandwidth format for offline editing and later re-link to the imported HD files for final mastering.

Reality Television and XDCAM

XDCAM and XDCAM HD are popular with reality television producers. I asked Mark Raudonis, vice president of postproduction at Bunim-Murray Productions, to share one of his rather unique experiences in posting MTV’s Road Rules 2007: Viewers’ Revenge. Raudonis explains, “We were facing an incredibly tight post schedule due to the fact that there was an interactive ‘Internet component’ planned for the show. Viewers were invited to vote on who they wanted to kick off the show each week. This meant we had only one week from shoot to broadcast, but it really meant we had to post in less than three days. This would have normally been a six-week schedule.”

The secret to their success was the use of XDCAM and Sony’s PDW-D1 portable disc drive. As Raudonis points out, “This small, battery-operated unit inspired a ‘light bulb moment.’ Why not take advantage of the travel time between the production location and our postproduction offices?”

Raudonis decided to set up mobile production teams that would digitize during the drive back to their Los Angeles offices, which can take hours in heavy traffic. Each team of digitizers took a couple of MacBook Pros, a couple of Sony PDW-D1s and a pile of batteries and digitized in the car returning from the location. Using the XDCAM file access mode, they were able to transfer the material faster than real time to the laptops in the back seat as they were driven back to the offices. On average, they were able to ingest five to eight hours of production media on the way to the office.”

Raudonis continues, “Once they arrived in the office, they would connect their MacBook Pros to our Xsan via Ethernet and upload their media to our shared storage pool. From that point on, the group-based workflow proceeded much like any of Bunim-Murray’s other shows—just faster. We produced 15 episodes of Road Rules 2007: Viewers’ Revenge, and I can honestly say that using XDCAM enabled us to accelerate the post schedule by nearly a day due to the ability to digitize in the car.”

XDCAM HD offers a bridge between the tape- and file-based worlds. The compression artifacts are less obvious in the 35Mb/s setting, so shooting XDCAM HD versus HDCAM isn’t as big a compromise as some might think. Many major networks have approved it for HD acquisition. It’s a near-perfect media for reality, news and documentaries in this transition to high definition, but it’s not only an acquisition format. Some NLEs include export functions to write back to the discs. There’s a General folder in the file hierarchy for all-purpose computing use. Even if you don’t master in MPEG-2, you can still export a self-contained file and archive it on the same XDCAM HD disc as your source media. Since XDCAM media is competitively priced versus tape, you get the best of both worlds. This makes XDCAM the only file-based format that functions as a direct replacement for videotape—from acquisition to archive.