| Compression Standards | | | | MPEG-21 |
| MPEG stands for the Motion Picture Experts Group | | | | Work on this standard, also called the Multimedia |
| MPEG is an ISO/IEC working group, established in 1988 | | | | Framework, has just begun. MPEG-21 will attempt to |
| to develop standards for digital audio and video | | | | describe the elements needed to build an infrastructure |
| formats. There are five MPEG standards being used | | | | for the delivery and consumption of multimedia content. |
| or in development. Each compression standard was | | | | JPEG stands for Joint Photographic Experts Group. |
| designed with a specific application and bit rate in mind, | | | | JPEG is a lossy compression technique used for |
| although MPEG compression scales well with | | | | full-color or gray-scale images, by exploiting the fact |
| increased bit rates. They include: | | | | that the human eye will not notice small color changes. |
| | | | DV is a high-resolution digital video format used with |
| Designed for up to 1.5 Mbit/sec | | | | video cameras and camcorders. The standard uses |
| Standard for the compression of moving pictures and | | | | DCT to compress the pixel data and is a form of |
| audio. This was based on CD-ROM video applications, | | | | lossy compression. The resulting video stream is |
| and is a popular standard for video on the Internet, | | | | transferred from the recording device via FireWire |
| transmitted as .mpg files. In addition, level 3 of MPEG-1 | | | | (IEEE 1394), a high-speed serial bus capable of |
| is the most popular standard for digital compression of | | | | transferring data up to 50 MB/sec. |
| audio--known as MP3. | | | | Pay Attention Here Folks |
| MPEG-2 | | | | DivX Compression |
| Designed for between 1.5 and 15 Mbit/sec | | | | DivX is a software application that uses the MPEG-4 |
| Standard on which Digital Television set top boxes and | | | | standard to compress digital video, so it can be |
| DVD compression is based. It is based on MPEG-1, but | | | | downloaded over a DSL/cable modem connection in a |
| designed for the compression and transmission of | | | | relatively short time with no reduced visual quality. The |
| digital broadcast television. The most significant | | | | latest version of the codec, DivX 4.0, is being |
| enhancement from MPEG-1 is its ability to efficiently | | | | developed jointly by DivXNetworks and the open |
| compress interlaced video. | | | | source community. DivX works on Windows 98, ME, |
| MPEG-4 | | | | 2000, CE, Mac and Linux. |
| Standard for multimedia and Web compression. | | | | Terms |
| MPEG-4 is based on object-based compression, | | | | Lossy compression - reduces a file by permanently |
| similar in nature to the Virtual Reality Modeling | | | | eliminating certain redundant information, so that even |
| Language. Individual objects within a scene are tracked | | | | when the file is uncompressed, only a part of the |
| separately and compressed together to create an | | | | original information is still there. |
| MPEG4 file. This results in very efficient compression | | | | Codec - A video codec is software that can |
| that is very scalable, from low bit rates to very high. | | | | compress a video source (encoding) as well as play |
| MPEG -7 | | | | compressed video (decompress). |
| This standard, currently under development, is also | | | | The best compression software I've used is that |
| called the Multimedia Content Description Interface. | | | | produced by It's very inexpensive and without it, you |
| When released, this standard will provide a framework | | | | will NEVER upload a single video. Ever. The files are |
| for multimedia content that will include information on | | | | simply too big pre-compression. Without compression, it |
| content manipulation, filtering and personalization, as | | | | would be like trying to shove a football through a |
| well as the integrity and security of the content. | | | | garden hose. |