What are the major video formats?

1. MPEG format
This type of format is a large family, which we usually have seen the most common video format. Multi-format derived from it, including mpg, mpe, mpa, m15, m1v, mp2, etc. MPEG format, including MPEG video, MPEG audio and MPEG systems (video, audio synchronization), MP3 (MPEG-3) audio files is a typical application of MPEG audio; video include MPEG-1, MPEG-2 and MPEG4.
MPEG-1 is widely used in the VCD production and some video clips to be downloaded, the largest of which is the VCD - VCD is almost all used Mpge-1 compression format (*. dat files). MPEG-1 compression algorithm can be a 120-minute film (the original video files) compressed to about 1.2GB size.
MPEG-2 is applied in the production of DVD (*. vob files), but also in some of the HDTV high definition television) and some demanding video editing, processing has considerable application. Using MPEG-2 compression algorithm produced a 120-minute film (the original video files) about the size of 4GB to 8GB, of course, image quality indicator is the MPEG-1 can not match.
MPEG-4 is a new compression algorithm, using this algorithm ASF format files (next to be introduced) can make a 120 minute film (the original video file) "downsizing" to 300MB or so, because of its small easy to spread, it becomes one of the main online video. This algorithm is said to be banned the export of coding technology by the United States, In addition, the use of the DivX format can compress the source files to 600MB or so, but its image quality is much higher than the ASF. Because of its efficiency, there are rumors that the U.S. government banned the export of this technology.
Here also the way explain the DivX format, the most brilliant general in the DivX format, a word is: DVD killer. DivX video encoding technology can be produced for the DVD, and it is bound to break all the ASF and developed. As mentioned above, as it uses MPEG-4 algorithm, this has been compressed a DVD requires only 2 VCD! This not only means that you do not need to buy a DVD-ROM and it can get similar video quality and playback of this code, the requirements of the machine is not high: CPU as long as more than 300MHZ, 64MB of RAM and 4MB of video memory (I believe the vast majority of machines are now eligible), you can smooth playback.
In addition, it is worth mentioning that, when the MPEG-1 and MPEG-2 were made into VCD and DVD, due for in different formats, each of which has its special resolution of the standard, VCD NTSC format to use, it's MPEG -1 compressed image resolution of 352 × 240, which uses the PAL format, is 352 × 288, DVD using NTSC format, MPEG-2 compressed image resolution of 720 × 480, using the PAL format, it is 720 × 576. If you intend to make the DVD / VCD playback on CD-ROM, then the image file in the production of a variety of recorders require special attention when using the standard.

2. AVI format
AVI is not so complex compared to MPEG, from WIN3.1 era, it has been published. The most immediate advantage is that it is compatible with good image quality, convenient and good call, so often compared with the DVD and said. But its drawback is also very clear: bulky. Also because of this, we see that the MPEG-1 and MPEG-4 was born. 2 hours AVI video file size with no difference between MPEG-2 count, but this is only for the purposes of the standard resolution: according to different application requirements, AVI's resolution can be arbitrarily adjusted. Resolution larger, the greater the amount of data files. Lower resolution can substantially reduce its size, but image quality will inevitably suffer. MPEG-2 format with the file size is almost the case, AVI format video quality is poor relative to many, but making it less demanding on the computer's configuration, has often been a good first recorded video in AVI format, then converted to other formats.

3. RM format
It is Real's multimedia world, a major contribution to the online video promotion. Its birth, also makes the stream file for more people to know. Such files can achieve real-time playback, that start with the server to download some video files, streaming video form after the real-time playback buffer, while continuing to download, ready for the next play. This "side edge of playback transmission" approach to avoid the user must wait for the entire file downloaded from the Internet to view, and thus particularly suitable for viewing online video. RM is mainly used in low rate of online real-time transmission of video compression format, it also has a small size, but fairly clear characteristics. RM file size depends entirely on making the selection of compression rate, which is why sometimes we see the one-hour video only 200MB, sometimes 500MB.

4. ASF and WMV format
The *. asf and *. wmv video file for RM came into being, but also is WindowsMedia core. Their common feature is the use of MPEG-4 compression algorithm, so the compression ratio and image quality is very good (almost point than the VCD only, better than the RM format). Like with most video formats, the picture quality with file size is inversely proportional relationship. That is, the better quality, larger files; the contrary, the smaller the file, the worse the quality. In the production of ASF file, recommended 320 × 240 resolution and 30 frames / second frame rate, you can take into account the clarity and file size, then the image is about 2 hours about 1GB.

5. MOV format
Among all the video formats, MOV format is perhaps the most unknown. You might have heard of QuickTime, MOV file format to play it by its. Almost in the PC world domination today, ported from the Apple MOV format naturally marginalized. It has a cross-platform, small storage space requirements of the technical characteristics, and uses a lossy compression method, MOV format, the picture is slightly better than the AVI format. So far, a total of four versions of it, of which 4.0 version of the best compression ratio.

refer : http://www.ultramediasoft.com/multimedia-glossary/multimedia-glossary.html