Updated Sony and Matsushita today launched a would-be standard for HD camcorders that used DVDs as their storage media. The two companies said they would promote the AVCHD specification on their own products - Matsushita doing so through its Panasonic brand - and encourage other camcorder vendors to do the same.

The AVCHD specification supports both 4:3 and 16:9 aspect-ratio images recorded at a range of resolutions from 576i - equivalent to the PAL TV standard - through to 1080p, each with the requisite number of pixels - 720 x 576 up to 1,920 x 1,080.

The video signals, both HD and SD, are encoded on the DVD using the H.264 MPEG 4 codec. The system supports Linear PCM and Dolby Digital (aka AC-3) for sound encoding with, respectively, SD and HD pictures. Multi-speaker set-ups are supported: up to 7.1 for SD and up to 5.1 for HD.

The discs use an MPEG 2 transport stream, which suggests while they won't be playable on a regular DVD player, they can be used in a standard DVD drive to extract, edit and transcode the pictures and sound. However, neither Sony nor Matsushita have confirmed this.

Matsushita separately said it would work to allow the same spec to cover the storage of HD video on SD memory cards.

Neither company said when they themselves will ship AVCHD-branded equipment, but they are preparing to license the format to fellow consumer electronics manufacturers. They said they will "extensively promote the format throughout the industry". ®