Analog Camcorders
The first camcorders recorded to analog Videotape, and supported either VHS or BetaMax, the two competing consumer formats at the time. Later, the compact VHS-C and 8mm (Video8) formats dominated the market, and were eventually supplemented with the higher quality S-VHS-C and Hi8 formats. With the development of affordable digital Camcorders, even the highest quality analog models eventually disappeared.
SD Camcorders
When it comes to Standard Definition (SD) video, the vast majority of Camcorders use DV encoding for the video on either a minDV or Hi8 (analog 8mm) Videotape cassette. Audio for DV camcorders is typically uncompressed (LPCM) with 16 bit samples taken at 48kHz, making the audio compatible with DVD-Video. A smaller number of SD camcorders actually produce DVDs directly, bypassing the DV requirement to transcode the video to MPEG-2 and author. These models record to 8cm recordable disks, rather than the standard 12cm media used for commercial DVD releases.
HDV
Although the name suggests that this HD camcorder format is related to the SD DV format, in reality HDV uses MPEG-2 encoding to fit HD video on miniDV tapes. The result is much higher Compression than DV. Although this is generally accepted as a neccessary compromise for delivering a low cost HD companion to SD DV video encoding, this HDV's use of Delta Frames (P and B) makes it less suitable for lossless editing, and more prone to encoding artifacts.
HDV uses a number of different Resolutions and Framerates. Unlike DV, which because of being developed around analog TV standards (PAL and NTSC) is almost always interlaced, it's fairly common to find HDV camcorders capable of creating Progressive video at a variety of Framerates, including 24fps, 25fps, 30fps, and sometimes even 60fps. Since HDV uses the MPEG-2 HL@H-14 Profile, although 1080i frames are supported, the Resolution only goes up to 1440x1080, compared to the typical 1080i HDTV which has a Native Resolution of 1920x1080, with 1440x1080 being the resolution of the 4:3 AR center portion of the screen.
AVCHD
AVCHD is an alternative to HDV that replaces MPEG-2 encoding with Advanced Video Coding (AVC), also known as MPEG-4 Part 10 or H.264. There are clear technical advantages to using AVC, both in terms of visual quality at low bitrates and reduced Blocking due to AVC's advanced features. However, like HDV, AVCHD isn't particularly suitable for even basic editing, with only a small percentage of all frames being readable without also decoding the surrounding frames. Unlike HDV, AVCHD Camcorders use either 8cm DVD media or a computer hard disk drive for storage. However, the storage
AVCHD was developed in part as a companion to Blu-ray's BDMV format, which is used for commercially authored Blu-ray titles. AVCHD uses the same file/folder structure and Container (BD-AV), which is essentially a MPEG-2 Transport Stream (MPEG-2 TS). Unlike BDMV, however, BD-Java isn't supported, meaning only simple menus and playlists can be used, rather than the nearly limitless possibilities for BDMV menus.
Analog Connections
Both analog and digital Camcorders may still have analog inputs and outputs. For digital SD Camcorders it's common to see both Composite Video and S-Video support, while analog SD typically only includes Composite Video. HD Camcorders may include analog Component Video connections, but may not include any analog video connections. Nearly all Camcorders, whether analog or digital, SD or HD, include an analog audio input for attaching an external microphone. Most also include some sort of analog audio output. For digital Camcorders this is often in the form of a 1/8" jack that may include options for a standard line level or headphone signal.
Digital Connections
With analog camcorders its necessary to use some sort of Video Capture device to turn it into digital video. Digital Camcorders, on the other hand, are designed to get video and audio from the recording media, whether that be a Videotape cassette, optical disc, or hard drive, to a computer with literally no loss. If the video is stored on DVD this simply requires removing the disc from the camcorder and reading it with a computer. For most other camcorders a FireWire (IEEE 1394) port is typically used for data transfer. USB connections are also often found on digital Camcorders, but they generally don't transfer the original video stream the same way a Firewire connection does, and are to be avoided in most cases.
UDF 2.50
Since AVCHD is an extension of Blu-ray's design, it's authored to a UDF 2.5 file system. Unfortunately no operating system provides built-in support for this file system, so you'll need a third party driver to read them, although they can be written by software like Nero without being able to read them. You should receive a suitable driver along with your Camcorder.
Camcorders and Film Capture
Although not specifically designed for it, digital Camcorders can be used to capture from film sources. There are a number of different methods for this type of Capture, ranging from professional rigs that use a workprinter to advance a single frame and send a signal to a camera to take a single picture, to taking a Camcorder into a movie theater and simply pointing it at the screen when the movie comes on. Cam captures are generally made for distribution on the internet or through another unauthorized channel, such as on a pirated DVD or SVCD.
Cam-Related News
Police arrest and charge "maVen" of piracy scene
MPAA unveils new anti-camcording posters for US theaters
Canada introduces anti-piracy legislation
MPAA makes report about camcorded films
Study: Most movies leaked to Net by insiders
Related Guides
Digital Video Fundamentals - Frames & Framerates
Digital Video Fundamentals - Resolution and Aspect Ratio
Digital Video Fundamentals - Color Formats
Digital Video Fundamentals - Lossy Compression
| Digital Camcorders | |||
|---|---|---|---|
| |||
| All Camcorders |
