Digital Video Recorder

H.264 ?
A New Standard for Digital Video
DivX® 7 is based on the H.264 standard, the state-of-the-art digital encoding format for high definition video. Why is H.264 so great? Well, to make a long story short, H.264 provides powerful compression technology that delivers a superior video experience at a low bit rate.
If you want to get more detailed, we should tell you that the standard's flexible bit stream control enables H.264 to deliver high-quality video to a variety of devices ranging from low-powered cell phones to high-powered Blu-ray devices. That's why the H.264 standard is set to supersede some of the formats that are commonplace today such as DV, the standard used by many consumer video cameras, and MPEG-2, the standard for DVD video and some types of cable TV and digital broadcast. In a nutshell, H.264 is suited to any platform — handheld to high def.

MPEG-4 ?
MPEG-4 provides a series of technologies for developers, for various service-providers and for end users:
- MPEG-4 enables different software and hardware developers to create multimedia objects possessing better abilities of adaptability and flexibility to improve the quality of such services and technologies as digital television, animation graphics, the World Wide Web and their extensions.
- Data network providers can use MPEG-4 for data transparency. With the help of standard procedures, MPEG-4 data can be interpreted and transformed into other signal types compatible with any available network.
- The MPEG-4 format provides end users with a wide range of interaction with various animated objects.
- Standardized Digital Rights Management signaling, otherwise known in the MPEG community as Intellectual Property Management and Protection (IPMP).
The MPEG-4 format can perform various functions, among which might be the following:
- Multiplexes and synchronizes data, associated with media objects, in such a way that they can be efficiently transported further via network channels.
- Interaction with the audio-visual scene, which is formed on the side of the receiver.
MPEG (pronounced M-peg), which stands for Moving Picture Experts Group, is the name of a family of standards used for coding audio-visual information (e.g., movies, video, music) in a digital compressed format. The major advantage of MPEG compared to other video and audio coding formats is that MPEG files are much smaller for the same quality. This is because MPEG uses very sophisticated compression techniques.

H.264 can compress files into smaller pieces than MPEG-4, allowing for more video storage ability using H.264 without increased hard drive space.
H.264 gives you about a 50% improvement in compression which means what used to take 1 TB of HD space can now be stored on 500 GB or you can record 2 times longer video. This advantage translates into lower cost for the same storage capacity.

Perform 5 operations simultaneously, without degrading each other operation performance: recording, live monitoring, playback, archiving and networking.

Perform 3 operations simultaneously, without degrading each other operation performance: recording, live monitoring and playback.

The phrase PTZ Camera has two uses within the video security and surveillance products industries.
First, PTZ is an acronym for Pan, Tilt, and Zoom and may refer merely to features of specific surveillance cameras. Second, PTZ Cameras may also be used to describe an entire category of cameras where a combination of sound and/or motion and/or change in heat signature may enable the camera to activate, focus and track suspected changes in the video field.
By activating only during times of change, systems can notify human monitors and minimize storage requirements.
In the March 2009 edition of "Security Products" magazine, Keith Jentoft notes the continuing problems organizations have with outdoor PTZ cameras during thunderstorms. Despite continuing improvements in PTZ software, problems with continual activation during thunderstorms have led some organizations to completely disable these types of cameras during the duration of thunderstorms. This translates to continuing challenges in trying to monitor and protect facilities from crime and terrorism during inclement weather.

IP65 OR IP66 ?
The IP Code (or International Protection Rating, sometimes also interpreted as Ingress Protection Rating) consists of the letters IP followed by two digits and an optional letter. It classifies the degrees of protection provided against the intrusion of solid objects (including body parts like hands and fingers), dust, accidental contact, and water in electrical enclosures. The standard aims to provide users more detailed information than vague marketing terms such as waterproof. The rating is also known as ingress protection.
The digits (characteristic numerals) indicate conformity with the conditions summarized in the tables below. Where there is no protection rating with regard to one of the criteria, the digit is replaced with the letter X. For example, an electrical socket rated IP22 is protected against insertion of fingers and will not be damaged or become unsafe during a specified test in which it is exposed to vertically or nearly vertically dripping water. IP22 or IP2X are typical minimum requirements for the design of electrical accessories for indoor use.
The first digit indicates the level of protection that the enclosure provides against access to hazardous parts (e.g., electrical conductors, moving parts) and the ingress of solid foreign objects.
6 means no ingress of dust; complete protection against contact.

The second digit indicates the level of protection of the equipment inside the enclosure against harmful ingress of water. 5 means that water projected by a nozzle against enclosure from any direction shall have no harmful effects.
6 means that water projected in powerful jets against the enclosure from any direction shall have no harmful effects.

In conclusion, both IP65 and IP66 are weatherproof but IP66 is more resistant. For a full explanation, refer to Wikipedia