From Wikipedia, the free encyclopedia
AVCHD specification allows for standard definition recording and cameras now allow recording in high definition as well as standard definition.
720p
As of September 2008, the Panasonic AG-HMC150 is the only AVCHD camcorder to support 720p progressive recording, in addition to 1080i and 1080p recording modes.
1080i
Deinterlacing allows getting rid of combing artifacts, but may reduce vertical resolution. Interlaced video can be deinterlaced in post-production and delivered as progressive, or it can be deinterlaced on playback. All modern flat-panel televisions have a built-in deinterlacing engine, so deinterlacing is not required if video is distributed on DVD or Blu-ray Disc. Watching interlaced video on a computer can be more complicated, but some codecs provide different deinterlacing schemes that can be manually chosen by a viewer.[11]
Some 1080i AVCHD camcorders offer capturing and recording of progressive video, borrowing techniques from television industry. There are two major methods of packaging progressive video into interlaced carrier signal depending on whether a particular video system utilizes 50 Hz or 60 Hz scanning.
50 Hz systems commonly use Progressive segmented frame (PsF) recording scheme, which originates from 2-2 pulldown technique. This scheme is utilized in Canon camcorders for 50 Hz market ("PF25" mode, 25 frame/s) and in some newer Canon camcorders for 60 Hz market ("PF30" mode, 30 frame/s). Such a video can be processed with standard interlaced hardware and software. When handled properly, it retains full vertical resolution.
Another approach has been borrowed from the 60 Hz television system, which uses 2-3 pulldown to broadcast movies. This recording scheme was originally meant to add cinematic feel to interlaced video, but newer editing systems are capable of recognizing the pulldown pattern and recover the original frames. This process is known as inverse telecine or film-mode deinterlacing. Select camcorders from Canon and Panasonic are capable of recording 24 frame/s progressive video using this scheme.
The major downside of recording progressive video within an interlaced stream is that technically video remains interlaced and is detected as interlaced by most editing tools. A videographer has to remember how a particular video was shot, or has to visually check video frames and make a correct decision.
Another disadvantage is that frame rate cannot be higher than half of field rate, this means that shooting 1080p50 or 1080p60 video is not possible with this technique.
1080p
Select Panasonic camcorders are able to record native 1080p video. The most notable model is the AG-HMC150, which is capable of recording in all three high definition formats: 1080i, 1080p and 720p. Of the consumer models, the HDC-SD9, HDC-HS100 and HDC-SD100 are capable of recording native 1080p24/1080p25 video. This means that no film-mode deinterlacing is required to edit such a video in a progressive timeline.
.jpg){kind=link}