Music formats mainly include WMA, WAV, MP3Pro, ASF, AAC and VQF, etc.
Video formats mainly include AVI format: its full English name is Audio Video Interleaved, that is, audio video Interleaved format. It was launched by Microsoft in 1992 and became known and well-known together with Windows 3.1. The so-called "audio video interleaving" means that video and audio can be intertwined for synchronous playback. The advantage of this video format is that it has good image quality and can be used across multiple platforms. Its disadvantage is that it is too large in size, and what is even worse is that the compression standards are not unified. The most common phenomenon is that higher versions of Windows Media Player cannot play it when using early adopters. AVI format videos encoded and edited, and lower versions of Windows Media Player cannot play AVI format videos edited with the latest encoding, so when we play some AVI format videos, we often encounter video encoding problems that cause the video to not play or Even if it can be played, there are some inexplicable problems such as the inability to adjust the playback progress and only sound but no image during playback. If users encounter these problems when playing AVI format videos, they can solve them by downloading the corresponding decoder.
●nAVI format: nAVI is the abbreviation of newAVI, which is a new video format developed by an underground organization called ShadowRealm (it has little connection with the AVI format we mentioned above). It is modified from the Microsoft ASF compression algorithm, but it is different from the ASF video format in the online imaging video introduced below. It increases the number of frames at the expense of the original ASF video file's video "streaming" characteristics. rate to greatly improve the clarity of ASF video files.
●DV-AVI format: The full English name of DV is Digital Video Format, which is a home digital video format jointly proposed by Sony, Panasonic, JVC and other manufacturers. Currently very popular digital cameras use this format to record video data. It can transmit video data to the computer through the computer's IEEE 1394 port, and can also record video data edited in the computer back to the digital camera. The file extension of this video format is generally .avi, so it is also called DV-AVI format.
●MPEG format: Its full name in English is Moving Picture Expert Group, which is the format of the Moving Picture Expert Group. The VCD, SVCD, and DVD that are often seen at home are this format. The MPEG file format is an international standard for moving image compression algorithms. It uses a lossy compression method to reduce redundant information in moving images. To put it more clearly, the MPEG compression method is based on the fact that the vast majority of two adjacent pictures are the same. , remove the redundant parts of the subsequent image and the previous image to achieve the purpose of compression (the maximum compression ratio can reach 200:1). Currently, the MPEG format has three compression standards, namely MPEG-1, MPEG-2, and MPEG-4. In addition, MPEG-7 and MPEG-21 are still in the research and development stage.
MPEG-1: Established in 1992, it is an international standard designed for digital storage media moving images and their accompanying audio coding with a data transmission rate below 1.5Mbps. That is the VCD production format we usually see. Using the MPEG-1 compression algorithm, a 120-minute movie can be compressed to about 1.2GB in size. The file extensions of this video format include .mpg, .mlv, .mpe, .mpeg and .dat files in VCD discs, etc.
MPEG-2: Developed in 1994, the design goals are advanced industry standard image quality and higher transmission rates.
This format is mainly used in DVD/SVCD production (compression). It is also widely used in some HDTV (high-definition television broadcasts) and some high-demand video editing and processing. Using the MPEG-2 compression algorithm, a 120-minute movie can be compressed to a size of 4 to 8GB. File extensions for this video format include .mpg, .mpe, .mpeg, .m2v and .vob files on DVD discs.
MPEG-4: Developed in 1998, MPEG-4 is specially designed to play high-quality videos of streaming media. It can use very narrow bandwidth, through frame reconstruction technology, compression and Transfer data to achieve the best image quality using the least amount of data. The most attractive aspect of MPEG-4 at present is that it can save small video files close to DVD quality. In addition, this file format also includes some special features such as bit rate scalability, animation sprites, interactivity and even copyright protection that were not available in the previous MPEG compression standard. File extensions for this video format include .asf, .mov, and DivX AVI, among others.
Tips: Careful users must have noticed, why is there no MPEG-3 encoding? In fact, the MP3 that everyone is familiar with uses MPEG-3 (MPEG Layeur3) encoding.
●DivX format: This is another video coding (compression) standard derived from MPEG-4, which is what we usually call the DVDrip format. It uses the MPEG4 compression algorithm and integrates It understands all aspects of MPEG-4 and MP3 technologies. To put it bluntly, it uses DivX compression technology to compress the video images of DVD discs with high quality, while using MP3 or AC3 to compress the audio, and then synthesizes the video and audio and adds The video format formed by the corresponding external subtitle file. Its picture quality is close to that of DVD and its size is only a fraction of that of DVD. This kind of encoding does not have high requirements on machines, so DivX video encoding technology can be said to be a new video compression format that poses the greatest threat to DVD. It is known as the DVD killer or DVD terminator.
●MOV format: a video format developed by Apple in the United States. The default player is Apple's QuickTime Player. It has the characteristics of higher compression ratio and perfect video definition, but its biggest feature is cross-platform, that is, it can not only support MacOS, but also the Windows series.
2. Online imaging and video
●ASF format: Its English full name is Advanced Streaming format. It is a video format launched by Microsoft to compete with the current Real Player. Users can directly use Windows Media Player that comes with Windows to play it. Because it uses the MPEG-4 compression algorithm, the compression rate and image quality are very good (high compression rate is conducive to the transmission of video streams, but the image quality will definitely be lost, so sometimes the picture quality of the ASF format is not as good as VCD is normal).
●WMV format: Its full English name is Windows Media Video. It is also a file compression format introduced by Microsoft that uses an independent encoding method and can directly watch video programs in real time on the Internet. The main advantages of the WMV format include: local or network playback, scalable media types, component downloads, scalable media types, stream prioritization, multi-language support, environment independence, rich inter-stream relationships, and scalability. .
●RM format: The audio and video compression specification formulated by Real Networks is called Real Media. Users can use RealPlayer or RealOne Player to perform live broadcast of network audio/video resources that comply with RealMedia technical specifications and RealMedia can Different compression ratios are formulated according to different network transmission rates, thereby enabling real-time transmission and playback of image data on low-speed networks. Another feature of this format is that users can use RealPlayer or RealOne Player to play online without downloading audio/video content. In addition, as the current mainstream network video format, RM can also convert videos in other formats into RM videos through its Real Server server, and the Real Server server is responsible for external publishing and playback. It can be said that the RM and ASF formats have their own merits. Usually RM videos are softer, while ASF videos are relatively clear.
●RMVB format: This is a new video format extended from the RM video format upgrade. Its advancement is that the RMVB video format breaks the average compression sampling method of the original RM format. Reasonable use of bit rate resources while ensuring the average compression ratio means that scenes with still and few action scenes use a lower encoding rate, which can leave more bandwidth space, and these bandwidths will be used when fast-moving scenes appear used in the scene. This greatly improves the quality of moving images while ensuring the quality of still images, thus achieving a delicate balance between image quality and file size. In addition, compared to the DVDrip format, RMVB video also has obvious advantages. If a DVD movie with a size of about 700MB is transcribed into the RMVB format with the same audio-visual quality, its size will only be about 400MB at most. Not only that, this video format also has unique advantages such as built-in subtitles and no need for plug-in support. To play this video format, you can use RealOne Player2.0 or RealPlayer8.0 plus RealVideo9.0 or above version of the decoder to play.