Off-topic - A brief introduction to several video formats,including ASF, style197 - Thu Apr 22, 2010 2:39 am Post subject: A brief introduction to several video formats,including ASF,
A brief introduction to several video formats,including ASF,MTS/M2TS,MOD/TOD,MKV,MPEG,DivX,etc.
Nowadays, more and more video formats have emerged; however, people sometimes feel confused with them, in purpose of letting people have brief understanding of these formats, this article will choose some to do simple explanations.
ASF
ASF is an acronym for Advanced Streaming format, and from the literal meaning (Advanced Streaming Format) that we should know its usage. To put it bluntly, ASF is a compression video format for online watching, which is developed by Microsoft to compete with Real player. Because of its use of MPEG4 compression algorithm, its compression ratio and image quality is very good.
ASF is a real-time online viewing video streaming format, so its image quality is inferior to VCD. But it is better than RAM which is the same video streaming format. However, if you do not consider spreading on-line, and choose the best quality to compress files, then, the generated video files would be better than VCD (MPEG1). But it will lose the original intension of developing ASF. In that case, you might as well directly use N AVI or DIVX. However, the "offspring” of Microsoft has its unique advantages. The most obvious thing is that various kinds of software are supporting it.
nAVI
nAVI is short for newAVI, it is a video format developed by an underground organization called ShadowRealm. It is from the changes of Microsoft ASF compression algorithm, not AVI in imagine. Video format is nothing more than the pursuit of compression ratio and image quality, so in pursuit of this goal, nAVI improved the shortcomings in ASF, and has a higher frame rate. Of course, this sacrifices the video streaming features of ASF as a price.
In summary, nAVI is the modified ASF format which has been removed the features of video streaming. More simply speaking, it is the non-network version of ASF.
AVI
AVI stands for Audio Video Interleave, and it seems to be no need for me to explain. This old video format, which was released in the age of WIN3.1 by Microsoft, has been in application for a number of years. Its advantages are good compatibility and image quality, as well as convenient transfer. But it has a well-known shortcoming: the large size. Because of this drawback, we can see the changes from the birth of MPEG1 to the development of MPEG-4.
MPEG
MPEG is short for Motion Picture Experts Group, which includes MPEG-1, MPEG-2 and MPEG-4 (note that there is no MPEG-3, MP3 that we are familiar with is MPEG Layeur 3).
MPEG-1 is widely used in the production of VCD and some online downloading applications of video clips. It can be said that 99% of the VCDs are compressed in MPEG1. Using MPEG-1 compression algorithm, a 120-minute film can be compressed to the size of about 1.2 GB.
MPEG-2 is used in DVD compression, and also has applications in the aspect of HDTV, and some videos that demand high editing and processing. With MPEG-2 compression algorithm, a 120-minute film can be compressed to 4 to 8 GB in size (of course, its image quality is much better than MPEG-1.)
MPEG-4 is a new compression algorithm, the ASF format in this algorithm can compress a 120-minute film to video streaming in about 300M for online watching. Other DIVX formats can be compressed to about 600M, but the image quality is much better than ASF.
DIVX
DIVX video encoding technology can be said to pose a threat to DVD (some people say it is DVD killer), it comes from Microsoft mpeg4v3 modifications, and use MPEG4 compression algorithm. Meanwhile, it can be also said developing in the purpose of breaking some protocols of ASF. Compress a DVD just need two pieces of CD ROMs. This means that you do not need to buy DVD ROMs any more, but you can get more or less the same video quality as it, what you need is just CD ROMs. In addition, its requirements of the machine are not high, CPU is more than 300MHZ, with a 64M memory card, and an 8M graphic card, and then it can be played smoothly.
QuickTime
QuickTime (MOV) is a video format created by Apple. In a very long period of time, it only exists on MAC. Later developed to support the WINDOWS platform, but to be fair, it is an excellent video encoding format no matter for local playing or online spreading.
REAL VIDEO
REAL VIDEO (RA, RAM) format is firstly defined to do video streaming applications, and it can be said to be the originators of video streaming technology. It can achieve uninterrupted video playback by 56K MODEM dial-up. Of course, its image quality is incomparable to MPEG-2 and DIVX. After all, continuous online transmission of videos requires a lot of bandwidth. In this case, ASF is its powerful competitor.
MKV
MKV is one of the file types of a container format called Matroska, which is similar to other containers like ASF, AVI, MP4, and 3GP in conception. Matroska is an open standard free container format, which can hold an unlimited number of subtitle tracks, pictures, audios, or videos within a single file. It contains three file types: MKV for video files (including audios and subtitles); MKS for subtitles (only subtitles); MKA for audio files only. To store HD video files is the most common use of MKV files.
MTS/M2TS
Before talk about MTS/M2TS, AVCHD have to be mentioned at first. AVCHD is a tapeless HD format developed by Sony and Panasonic in May, 2006. AVCHD video is compressed in MPEG-4 AVC/H.264 format, and it supports 720p, 1080i, 1080p, etc. At the same time, AVCHD audio is stored in compressed form Dolby AC-3. Well, what is the relationship between AVCHD and MTS/M2TS? If you are attentive enough, you will find AVCHD is with file extension .mts on camcorder and with .m2ts after importing to computer. Briefly speaking, MTS and M2TS are the formats that used by AVCHD camcorders to record footages. In addition, Blu-ray disc also reserve video files in format of M2TS.
MOD and TOD
Both MOD and TOD are the informal tapeless video formats produced by certain digital camcorders. And both of them have never been given to any meaning explanations or official names by their creators JVC or Panasonic. The differences between them lie in: MOD are used by JVC, Panasonic, and Canon in some models of camcorders, such as JVC GZ-MG130, GZ-MS100U, GZ-MG255, Panasonic SDR-SW20, SDR-SW21, SDR-S26, Canon FS100, FS200, FS21 and so on, while TOD is only used by JVC camcorders, like JVC GZ-HD7, GZ-HD5, GZ-HD6, GZ-HD30, and GZ-HD40; Moreover, MOD is only used for standard definition video files, while TOD is exclusively used for high definition video files.
Factually, all the above video formats can be played on your portable devices, or imported to editors to do further editing, etc. as long as you convert them to their workable formats with the proper converters. The recommendations:
If you are windows user, this would be adaptive to you: