AVCHD (Advanced Video Codec High Definition)

Advanced Video Codec High Definition is a high-definition recording format introduced by sony and panasonic. It can use numerus storage media, including 8 cm recordable DVD discs, a hard disk. The format is to compatible with other handheld video camera recording formats, particularly HDV and MiniDV.
AVCHD uses an MPEG-4 AVC (H.264) video codec. AVC's better compression (compared to the older MPEG-2 codec of HDV) lets it record video of the same quality of MPEG-2 but in less space. The audio track can be stored as uncompressed 7.1 linear PCM or compressed AC-3 5.1. The compressed audio and video data are encapsulated in an MPEG-2 Transport stream called BDAV. This stream format and most of the structure of AVCHD are derived from the Blu-ray Disc BDMV format. Consequently, AVCHD recordings can be played without modification in most set-top Blu-ray Disc players, such as the Sony BDP-S1, Panasonic DMP-BD10, and the PlayStation 3.
AVCHD supports a variety of resolutions and aspect ratios, all the way from 480/60i to 1080/24p "Full HD" with 1920x1080 pixels in 16:9 aspect ratio. The typical maximum bit rate for HD recordings is ~24Mbps when recording to hard disk or flash memory and ~18Mbps for when recording to DVD. This results in 3MB or 2.25MB used per second respectively. (which is about 6 minutes of recording for every GB of storage
Sony claims the format has a total storage time on a MiniDVD of about 20 minutes of high-definition video using "average" bitrates. By comparison, today's 8 cm discs can store 30 minutes of standard-definition MPEG-2 video, and MiniDV tapes can store a full 60 minutes of either standard-definition DV or high-definition (HDV) video. At the maximum resolution, a standard 8cm DVD will hold just 15 minutes of material. The newer dual layer disks will hold 27 minutes. AVCHD camcorders using hard disks or flash memory such as SD or MemoryStick overcome this constraint and typically offer USB connections to access their content
Among the touted advantages of AVCHD over MiniDV tapes is random access, since AVCHD does not need to be fast-forwarded or rewound as on tape formats such as MiniDV. For advanced users, however, digital video-footage is rarely edited in-camera anyway; instead, it is transferred entirely to a computer, where the operator uses video editing software. So random access is less important to some professional users but may prove valuable to professionals in electronic news gathering.
The biggest problem with editing and converting these files is the sheer amount of resources they require—decoding and re-encoding AVC is much more intensive than, say, MPEG-2. Furthermore, AVCHD employs long-GOP frame storage, which while space-efficient, introduces problems into editing and decoding of material. Even so, just as MPEG-2 was originally taxing to home PCs, even needing special PCI decoder cards, AVC's challenges will be overcome with time, especially on multi-core CPUs