Acronym on AbbreviationFinder.org for Moving Picture Experts Group and pronounced m-peg, MPEG is a group of the ISO and the family of compression standards and file formats of Video Digital developed by the group. It generally produces better quality video than other formats, such as Video for Windows, Indeo, and QuickTime.
MPG or MPGE is basically a container format, since it can contain several audio and video tracks, or even optional subtitle tracks. Depending on the properties of the audio and video (resolution, bitrate, FPS, etc.), the MPG file will conform to a certain standard. The following table shows the most popular MPG formats with their respective properties. There are other less popular formats that are not included in the table. For CD support, the most popular MPEG-1 formats are VCD and CVCD; for MPEG-2, SVCD.
Regions
The MPG format is dependent on the geographical area in which it is used. Therefore, the PAL format is the one used in Europe, while NTSC is the American format. However, there are multi-zone devices that are compatible with both PAL and NTSC. If the MPG video you will use is in 25 FPS, you must convert it to PAL format, and if it is in 23.976 or 29.976FPS, you must use the NTSC format. Converting to the wrong format may cause audio / video desynchronization or other inconveniences. The converted MPG video can be burned like a normal data CD, but in order to view it on a desktop DVD or portable device, it must be burned with one of the VCD standards listed in the table. The structure of a VCD is very different from that of a common data CD, so special programs must be used to burn VCDs, such as Nero.
Compression process
MPEG algorithms compress information into small packets that can be easily transmitted and then decompressed. MPEG achieves its high compression rate by only storing changes from one frame to the next, instead of storing the entire frame. The video information is then encoded using a technique called Discrete Cosine Transform (DCT).
Functioning
MPEG uses Codec (codecs) with low loss compression audio codecs using transformation.
In low-loss transformation codecs, the samples taken of image and sound are divided into small fragments and only the differences with these reconstructed images and some extra necessary to carry out the prediction are stored.
MPEG only normalizes the format of the bit stream and the decoder. The encoder is not standardized in any sense, but there are reference implementations, for members, that produce valid binary streams.
MPEG: VCD, MPEG2: DVD, MPEG3: HDTV, MPEG4: DIVX, XVID
Main compression formats
- MPEG -1: is the initial audio and video compression standard. Provides video with a resolution of 352×240 at 30 frames per second (fps). This produces a video quality slightly lower than the quality of conventional VCR videos. Includes Layer 3 (MP3) audio compression format.
- MPEG -2: standard for audio and video for broadcast quality television. It offers resolutions of 720×480 and 1280×720 at 60 fps, with audio CD quality. This is sufficient for most TV standards, including NTSC, and even HDTV. MPEG-2 is used for you, satellite TV services and digital cable TV signals. MPEG-2 can compress a 2 hour video into a few gigabytes. Although decompressing a stream of Mpeg-2 data does not require a lot of computer resources, encoding to the Mpeg-2 format requires considerably more power to process.
- MPEG -3: It was designed for HDTV but was abandoned in favor of MPG-2.
- MPEG -4: Standard video and graphics compression algorithm based on Mpeg-1 and Mpeg-2 technology and Apple QuickTime. Mpeg-4 files are smaller than JPEG or QuickTime files, so they are designed to transmit video and images over a narrow bandwidth and can mix video with text, graphics, and 2D and 3D animation layers.
- MPEG -7: formally called Multimedia Content Description Interface, MPEG -7 provides a set of tools for multimedia content. Mpeg-7 is designed to be generic and is not intended for a specific use.
- MPEG -21: Includes a Rights Expression Language (REL) and a Rights Data Dictionary. Unlike other MPEG standards that describe compression and encoding methods, Mpeg-21 describes a standard that defines the description of content and also the processes for accessing, searching, storing, and copyrighting
Beyond the table presented, it is important to note that currently there are three MPEG formats that are most used by users, due to the possibilities they offer.
On the one hand, we find the MPEG-1 that is usually used for the creation of videos in VCD and CVCD, while the MPEG-2 is used for DVD, SVCD, CVD and within the parameters of digital television. Finally, MPEG-4, which is generally used in videos found in DivX and Xvid containers, also applies.
