Minor Thoughts from me to you

The new HD camcorders are different from traditional camcorders in several ways. The most obvious is the stunning picture quality. Never have your most banal home videos looked so good! But I'm most concerned about the technical differences. Here are a few of my notes.

Tape or Tapeless?

Many of the newest HD camcorders leave out the DV tapes in favor of flash memory. Most record to either Secure Digital or Secure Digital High Capacity memory cards. SD cards range 8MiB to 4GiB and SDHC cards range from 1GiB to 32GiB. 4GiB SDHC cards are currently selling for $15-20 and 16GiB SDHC cards are currently selling for $50-60.

How much recording time is that? Well, it depends on the exact resolution of the camera and the exact format being used to store the video. Depending on the exact quality of the video, AVCHD can store 60 minutes of video in about 4-8GiB of memory.

Some HD camcorders still use reliable old DV tapes and the HDV format. With HDV, each tape can store 80 minutes of video. Once downloaded, HDV will require about 8-12GiB of storage per hour of video.

Formats

AVCHD is a popular format for tapeless camcorders.

AVCHD (AVC-HD, AVC HD) video is recorded using the MPEG-4 AVC/H.264 video compression codec. Audio is stored in either compressed form (Dolby AC-3), or uncompressed form (multichannel PCM). Aside from recorded audio and video, AVCHD includes features to improve media presentation: menu navigation, slide shows and subtitles. The menu navigation system is similar to DVD-video, allowing access to individual videos from a common intro screen. Slide shows are prepared from a sequence of AVC still frames, and can be accompanied by a background audio track. Subtitles are used in some camcorders to timestamp the recordings.

Just as HDV-editing once demanded an expensive high-end PC, the system requirements for AVCHD editing software currently limits it to powerful desktops. Compared to HDV, AVCHD video compression requires 2-4x the processing power, placing a greater burden on the computer memory and CPU. Older computers, even those that are capable of handling HDV, are often unacceptably slow for editing AVCHD, and can even struggle with smooth playback of AVCHD recordings. Improvements in multi-core computing and graphics processor acceleration is bringing AVCHD playback to mainstream desktops and laptops.

The implementation of H.264/AVC codec varies from manufacturer to manufacturer. Canon and Panasonic camcorders use High-Profile@Level-4.1, up to the AVCHD format's maximum bitrate of 24 Mbit/s. To date, Sony camcorders have only used Main-Profile@Level-4.0, at a maximum bitrate of 17 Mbit/s. The High-Profile mode of H264 is more difficult to create and playback than main-profile. Consequently, recordings made by one vendor's camcorder or editing software may be unplayable on another vendor's equipment, leading to a frustrating user experience.

HDV is the preferred format for tape-based camcorders.

HDV was designed to offer a cost-conscious upgrade path from standard-definition (SD) to high-definition (HD) video. As such, HDV uses the same DVC cassette as MiniDV. Recording time for HDV is identical to MiniDV SP. As of yet, no HDV cameras can record HDV at LP speed, so the maximum record time on one tape is 80 minutes, as opposed to 120 with an 80 minute tape at LP. Although wanted by the consumer market, it is not likely that there will be an HDV camcorder that records HDV in LP mode because of the higher risk of video drop-outs at faster transport speeds.

HDV cameras are offered in both consumer and professional designs. Consumer models are sold to the mass consumer market, competing with other camcorders used for home, travel and vacation video. Professional models have better lenses and other advanced features for those doing paid video production, and are used for a wide variety of projects including some popular TV shows (e.g. "Deadliest Catch"). HDV can be captured and edited in most modern NLEs on personal computers, then output to either Blu-ray or computer delivery formats.

Compatibility

Since I'm a Mac user, I'm mostly concerned about Mac compatibility. Apple's various video editing software do not directly support AVCHD video. Instead, they automatically convert the video into the Apple Intermediate Codec format. This conversion dramatically slows down the import process.

HDV is supported by all of Apple's video editing software. Because it is read directly from the tape, it will import in real-time. Of course, before buying any video camera it would be a good idea to check the iMovie 08 Camcorder Support page.

Bottom Line

It looks like shooting video in a tapeless camcorder with AVCHD would be significantly more expensive than shooting with a more traditional tape-based camcorder. With MiniDV tapes selling for about $3 each, I can cheaply shoot hours of video on vacation without needing to download everything to my computer. Assuming the highest quality video, AVCHD would cost me about $25 in flash memory for every hour I tape. If I waited until I got home to download my video, I'd need to take a lot of expensive memory on my trips.

Right now, it's also easier for me to edit MiniDV on my computers. iMovie HD and iMovie 08 support MiniDV natively, but I'd only be able to edit AVCHD after a lengthy conversion process.

If I had to buy an HD camcorder today, I'd buy a MiniDV HDV camcorder.

(UPDATE: camcorderinfo.com has a nice overview of HD camcorders and popular models.)