Extra Information
Software Compression
Software Compression is based on CPU technology concentrating on the power of the processor to control video/audio data recording. This compression method does however put the CPU under a lot of pressure especially with 16 channel systems, causing large amounts of heat to be generating resulting in a slower CPU speed and shortening the lifespan of the computer system considerably.
Software Compression DVR Boards are much better suited to smaller size systems 1 to 8 cameras ideally.Hardware Compression
Hardware Compression is based on memory RAM usage not just the CPU, this memory can be both DDR from the main board and also the graphics card installed, and with the new windows vista ‘Ready Boost’ system there is no shortage for additional memory add-ons.
Hardware Compression method greatly increases the Computer system lifespan by putting less stress on the CPU and distributing percentage usage throughout the whole system, then include the use of specialist SATA Hard Drives the heat generated is far less than any Software Compression system, even running the maximum 32 cameras.Ogg Vorbis
Vorbis is a free and open source, lossy audio codec project headed by the Xiph.Org Foundation and intended to serve as a replacement for MP3. It is most commonly used in conjunction with the Ogg container and is therefore called Ogg Vorbis.
Vorbis development began following a September 1998 letter from Fraunhofer Gesellschaft announcing plans to charge licensing fees for the MP3 audio format. Soon after, founder Christopher "Monty" Montgomery commenced work on the project and was assisted by a growing number of other developers. They continued refining the source code until a stable version 1.0 of the codec was released on July 19, 2002.
The latest official version is 1.2.0 released on 2007-07-25, but there are some fine-tuned forks, most notably aoTuV, that offer better audio quality, particularly at low bitrates. Work is in progress to merge back those improvements.MPEG4
MPEG-4 Part 14, formally ISO/IEC 14496-14:2003, is a multimedia container format standard specified as a part of MPEG-4. It is most commonly used to store digital audio and digital video streams, especially those defined by MPEG, but can also be used to store other data such as subtitles and still images. Like most modern container formats, MPEG-4 Part 14 allows streaming over the Internet. The official filename extension for MPEG-4 Part 14 files is .mp4, thus the container format is often referred to simply as MP4.
Note that many devices advertised as "MP4 players" are simply AMV video capable MP3 players, and do not play MPEG-4 part 14 or any other MPEG-4 format.RS-485
RS-485 can be used to communicate with remote devices (PTZ Cameras)at distances up to 4000 ft (1200 m) at speeds of up to 100 kbit/s at this distance. Converters between RS232 and RS485, USB and RS485, Ethernet and RS485 are available to allow your PC to communicate with remote devices. By using "Repeaters" and "Multi-Repeaters" very large RS485 networks can be formed.WAN
Wide Area Network (WAN) is a computer network that covers a broad area (i.e., any network whose communications links cross metropolitan, regional, or national boundaries [1]). Or, less formally, a network that uses routers and public communications links [1]. Contrast with personal area networks (PANs), local area networks (LANs), campus area networks (CANs), or metropolitan area networks (MANs) which are usually limited to a room, building, campus or specific metropolitan area (e.g., a city) respectively. The largest and most well-known example of a WAN is the Internet.
