Friday, February 29, 2008

IP video compression standards

MPEG means Moving Picture Experts Group. This group of experts was established in 1988 in order to develop standars for digital audio and video formats. The following MPEG standards are available:

MPEG-1: up to 1,5 Mbit/sec.. It is a compression for audio and video, this standard is known from videos on the internet (.mpeg files). The 3rd level of MPEG-1 is for audio compression and is commonly known as MP3.

MPEG-2: up to 1,5 and 15 Mbit/sec. On this standard digital TV set top boxes and DVD compression are based. MPEG-2 is based on MPEG-1, but dedicated to transmit digital broadcast TV.

MPEG-4: This standard is used for multimedia applications or web compression. It is based on object-based compression, like VR modelling languages. Índividual objects are tracked seperately and compressed together to create the compressed file. It is a very efficient compression, which is scalable in a wide range of bit rates. This is a very interactive compression, because objects can be controlled independently in a scene.

MPEG-7: A standard under development at the moment, it is also known as Multimedia Content Description Interface. The main difference to the other standards is that it will provide a framework for multimedia content including information on content manipulation, filtering, personalisation, integrity and security of the content. Also information about the content will be displayed.

MPEG-21: Also under development, known as Multimedia Framework.

JPEG means Joint Photographic Experts Group, a work group of experts to develop standards for continuous tone image coding.

M-JPEG: Motion JPEG, multimedia formats where each video frame or interlaced field of a digital video sequence is separately compressed as a JPEG image. M-JPEG is also commonly used by IP based video cameras via HTTP streams.


H.261: Is a video coding standard originally designed for transmission over ISDN lines on which data rates are multiples of 64 kbit/s. It is part of the H.26x family of video coding standards in the domain of the ITU-T Video Coding Experts Group (VCEG). The coding algorithm was designed to be able to operate at video bit rates between 40 kbit/s and 2 Mbit/s. The standard supports two video frame sizes: CIF (352x288 luma with 176x144 chroma) and QCIF (176x144 with 88x72 chroma) using a 4:2:0 sampling scheme.

H.263: Is a video codec standard originally designed with a low-bitrate compressed format for videoconferencing. It is one member of the H.26x family of video coding standards in the domain of the ITU-T Video Coding Experts Group (VCEG). It is based on the H.261 and the MPEG-1 and MPEG-2standards.

H.264/MPEG-4 AVC: standard for video compression which is also known as MPEG-4 Part 10, or MPEG-4 AVC (for Advanced Video Coding). It was written by the ITU-T Video Coding Experts Group (VCEG) in collaboration with the ISO/IEC Moving Picture Experts Group (MPEG). The ITU-T H.264 standard and the ISO/IEC MPEG-4 Part 10 standard (formally, ISO/IEC 14496-10) are both maintained in order to have identical technical content.

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