Rodriguez Redux

Continued from "Approximating Rodriguez"….

I've customized my high-def video rig in a couple of areas. I beefed up its audio capture capabilities by mounting my Audio-Technica AT825 dual-channel cardioid microphone to the top of it; a Beachtek DXA-6 phantom-powers the mic and converts its dual XLR outputs into the mini-jack plug the camcorder is expecting. I also used a filter thread adapter to mount the 0.7x wide-angle converter lens from my Kodak DX6490 digital still camera to the front of the GR-HD1's fixed-mount lens, thereby extending its zoom range. Since the wide-angle converter uses a 55mm filter size, whereas the GR-HD1's built-in lens has a 52mm filter ring, there's no potential for vignetting.

Once the video is captured, of course, you need to edit it. Regardless of its format, HDV is a challenge to edit in a frame-accurate manner because of its long-GOP (group of picture) structure. Only 1 out of every 6 frames (for 720p) or 15 frames (for 1080i) is a complete image; the others are uni- or bi-directional references to preceding and following frames.

Apple's iMovie HD and Final Cut Express HD sidestep this inter-frame-compression challenge by converting the HDV stream to the intra-frame-compressed Apple Intermediate Codec during import. If you use Final Cut Pro v4, you can also transcode HDV to DVCPRO HD in conjunction with HDVxDV or LumiereHD, Similarly, CineForm's Aspect HD and Connect HD, along with the CineForm-developed HDV plug-ins for Adobe's Premiere Pro and Sony's Vegas Video, translate the HDV video into CineForm's proprietary wavelet codec.

Conversely, Apple's upcoming Final Cut Pro v5 for Mac, and Ulead System's MediaStudio Pro v7 (in conjunction with the company's HDV plug-in) enable native editing of HDV content, thereby eliminating transcoding's inevitable generational loss of image quality. Canopus's EDIUS Pro v3 either edits HDV in its native MPEG-2 Transport Stream format or translates it to a proprietary HQ AVI file, depending on your system's performance and storage capabilities.

Transcoded or not, editing HDV is one application where the sometimes-nebulous strengths of a dual-core CPU will definitely be evident! It's also another area where 30 frame-per-second 720p, due both to its progressive-scan nature and its comparatively lower bitrate, has an advantage over either 60 frame-per-second 720p or 60-field-per-second 1080i video. If you don't believe me, check out another Steve Mullen article, "The HDV Sweet Spot", in VideoSystem's September 2004 issue.