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MillimeterAVCHD on the March
Jun 22, 2006 8:00 AM, By D.W. Leitner
Look up AVCHD in Wikipedia and you’ll learn that the Advanced Video Codec High Definition is a “new digital optical media format introduced by Sony and Panasonic… being positioned to compete with handheld video camera recording formats like MiniDV.”
No doubt HDV too. As the consumer love affair with optical media heats up, time is not on the side of tape formats. Indeed, in my NAB coverage this year, I called HDV the Last Mohican of tape-based video formats.
Wikipedia also informs us that AVCHD is 8cm in diameter, like MiniCD and MiniDVD, and uses a robust MPEG-2 Transport Stream for advanced MPEG-4 AVC compression. AVC is another name for H.264, popularized over the past year by Apple and often described as two times as efficient as MPEG-2 compression.
In other words, Sony and Panasonic awoke to the fact that the nascent but soon-to-balloon market for consumer HD camcorders is too important to risk on yet another confusing and alienating format war.
This week I’m in Rockport, Maine, leading a class in HDV production at the International Film and TV Workshops. My class is exploring HDV camcorders from Sony, Canon, and JVC, as well as Panasonic HDX200s (which use DVCPRO HD, a milder compression with four times the data rate of HDV). We’re also learning to use Focus Enhancements FireStore hard disk recorders adapted to the JVC, Canon, and Panasonic camcorders.
This is a lot of new technology to master in a short time. But if AVCHD arrives on the scene anytime soon, its many intrinsic advantages—being drop-out proof, nonlinear, mechanically minimal (no clockwork tape transports or whirling head drums)—will surely threaten the Last Mohican’s chances of survival. (Panasonic’s DVCPRO HD already brings these benefits.)
The only advantage HDV would have left—MiniDV cassettes that are common and cheap, leveraged by a decade’s worth of preexisting technology—would soon evaporate as discounted 8cm discs appeared at Walmart and across the Internet.
That’s why, although announced as a camcorder-only format scarcely a month ago, AVCHD already feels inevitable, like the conclusion of a story told many times. For instance, despite introduction as a consumer format, AVCHD combines attributes already found in Sony’s latest optical-disc XDCAM HD broadcast camcorders: compactness, next-generation compression, low maintenance, 1080p/24, 18Mbps variable bit rate.
OK, that last one I’m speculating about. Hard information on AVCHD is sketchy, but press releases did say “up to 18Mbps.” Funny, that’s the lower variable bit rate of XDCAM HD, which also uses MPEG-2 Transport Stream. Note that it’s more than double the bit rate of existing DVDs.
Here’s what else we think we know about a format whose actual rollout has yet to be announced:
- Red laser wavelength of 650nm. This is not Blu-ray.
- AVCHD discs will read on Blu-ray players.
- No advanced copyright protection.
- 1080i or 720p.
- 8-bit, 4:2:0.
- Full 1920x1080 pixels, compared to 1440x1080 of HDV.
- Uncompressed PCM or lossless Dolby Digital AC-3 audio for multi-channel surround.
Interestingly, co-developer Panasonic said it will write the new AVCHD codec to SD flash cards. Will consumers face a future camcorder media choice similar to today’s professional XDCAM HD vs. P2, enacted by the same proponents, Sony and Panasonic?
A Canon rep recently told me behind closed doors that DVD camcorders had already taken 30 percent of the consumer camcorder market. I found this hard to swallow and I don’t know the source or scope of this information, but whether accurate or not, as a perception it signals another watershed change in consumer video practices. Have you noticed the working VHS decks in roadside garbage piles lately?
Questions about AVCHD will hang in the air for some time. We’re told AVCHD will record both 4:3 and 16:9. Does this mean an AVCHD camcorder will also record standard definition, as HDV camcorders do now? How long would an AVCHD camcorder take to boot up and start recording? Could a version of the format be rewritable like XDCAM HD? Will discs have to be finalized before external playback, like some current SD camcorder disc formats? Will limited damage to data cause failure-to-read of the entire disc?
I haven’t discussed these thoughts, or the likelihood of a new prosumer HD format, with my diligent students in the HDV class at the Workshops in Maine. I haven’t had the heart.
