WAV is an audio format provided by Microsoft Windows itself. Due to the influence of Windows itself, this format has become a de facto universal audio format. To put it bluntly, it is actually a clone version of the Apple computer in AIFF format. Usually we use WAV format to save some uncompressed audio, but in fact the design of WAV format is very flexible (very complicated), and the format itself does not conflict with any media data. In other words, with software support, you can even store pictures in WAV format. The reason for this is that each piece of data stored in the WAV file has its own independent identifier, which can tell users what data it is. On the WINDOWS platform, more than 20 compression formats, such as ADPCM, GSM, CCITT G.7 1 1, G.723, can be stored in WAV files through ACM(Audio Compression Manager) structure and corresponding drivers (commonly referred to as codecs and encoders/decoders here). And, of course, MP3 format.

Although WAV file can store compressed audio or even mp3, its purpose is to store audio data and use it for further processing, instead of listening like mp3. At present, all audio playing software and editing software support this format, and take this format as one of the default file saving formats. These softwares include: Sound Forge, Cool Edit Pro, WaveLab and so on. Because the support of WAV is so extensive, it can be said that even if Windows quits the historical stage, WAV format will not die out.

Old and strong-

The second one is mp3 that changed the world. I believe everyone will agree with this metaphor. Mp3 is a Xing encoder developed by Fraunhofer-IIS Research Institute (many computers used this company's Xing player to watch VCD and listen to mp3).

Because mp3 is the first coding scheme with lossy compression in the world, it can be said that all playback software supports it, otherwise it will have no vitality. In terms of production, many third-party coding tools have also been produced. However, after Fraunhofer-IIS announced that it would levy royalties on encoders, many of them disappeared. At present, the encoder which belongs to open source code and is free is invented by Lame (LAME is not an Mp3 encoder). Its characteristic is that it can provide users with good enough sound quality for online listening at a very low bandwidth (as low as 28.8kbps). This function was simply the gospel of the majority of netizens in the early days of the Internet. That is, after the emergence of real media, related applications such as online broadcasting, online teaching and online on-demand surfaced, forming a new industry.

In fact, the principle of network streaming media is very simple. Simply put, it is to divide the original continuous audio into small packets with sequence tags, transmit these small packets through the network, and then reassemble these packets in order when receiving them. If the network quality is too poor and some packets are not received or delayed, it will skip these packets and not play them to ensure that the content that users are listening to is basically continuous. It is such a simple truth, but it has contributed to another legend on the Internet.

Because the real media is developed in an extremely harsh network environment, the sound quality of the real media is not so good, including at high bit rate, even worse than mp3. Especially for a long time, the real network only focused on adding various new functions to the real media, such as advertising spots, ignoring that with the improvement of network speed and the popularity of broadband networks, users' requirements for quality are also constantly improving. Later, through cooperation with Sony, Real Networks used Sony's ATRAC technology (/windows/windowsmedia), which is also a network streaming media technology, which is essentially the same as Real Media. However, Real Media is a limited and open technology, and rtsp (Real-time Streaming Protocol) and other network transmission protocols are submitted to the Network Working Group (NoRFC2326), while Windows Media has not disclosed any technical details, allegedly in order to better protect copyright, so it should be completely closed, and a transmission protocol called mms(Multi-Media Stream Multimedia Stream) has been created. Together, we can see Microsoft's ambition to unify the rivers and lakes.

The original version of Windows Media didn't get much praise, especially in terms of sound quality, which was despised by those "golden ears" netizens on the Internet. However, after several versions of updates, the latest Windows Media 9 technology carries many new features, and the cooperation with Windows Media Player is not the same. Especially in audio, Microsoft is the only solution that can provide various audio compression technologies (no distortion, no distortion, no voice), and it has a great momentum covering everything. This is also the consistent feature of Microsoft: although the quality of my products is not the best, it is definitely the most convenient and integrated. At present, Windows Media is still in the promotion period, players and encoders can be downloaded for free, and servers are bundled in the Windows server version without additional charges. These means are constantly increasing their market share. And because of the influence of Microsoft, there are many softwares supporting Windows Media. Although it is also used for listening and cannot be edited, almost all audio editing tools on the Windows platform provide read/write support for it, even third-party players support it. Simple direct editing can be achieved through the Windows Media file editor introduced by Microsoft itself. Recently, Microsoft also launched a version of Windows XP Media Center, which strengthened the role of Windows as a home entertainment center by bundling Windows Media 9 technology and related entertainment media software in Windows XP. If Microsoft continues to maintain its monopoly position in the operating system, especially the desktop operating system, the future of Windows Media will be brilliant.

Midi—— The Bridge between Computer and Electronic Musical Instrument

MIDI technology was not originally invented for computers. This technology was originally applied to electronic musical instruments to record musicians' performances for later replay. However, with the introduction of sound cards supporting MIDI synthesis in computers, MIDI has officially become an audio format. Many people mistakenly think that MIDI is used to record music, which is wrong. The content of MIDI not only records the music score, but also records the playing method of each note, so some MIDI files are not pleasant to play, while others are good. There are two versions of MIDI itself, Universal MIDI and Universal MIDI 2. Many third-party nonstandard technologies are also derived from MIDI, such as the famous X-MIDI (or XG), which was invented by Yamaha Corporation of Japan. Based on the original MIDI with 128 musical instruments, it has been expanded to 5 12 musical instruments, adding more playing controls, which can be restored by Yamaha's own wave table playing software or hardware supporting X-MIDI. In addition, in order to make up for the shortcoming that the sound synthesized by MIDI is always inferior to the real sound, the General MIDI Association (the international organization of MIDI specification) cooperated to add DirectMusic to DirectX, and then the soft wave table became the standard configuration of Windows system. It should be noted that for the X-MIDI format, you must use Yamaha's own player to get a good playback effect. For example, the sound card with Yamaha YMF724/740 as the chip used to sell well, and the player with X-MIDI was S-ysg 100.

If you want to edit MIDI files, you can use the famous software Cake Walk Pro and sonar (); X-MIDI can use Yamaha XGWorks. There are also some music software, such as Sibelius (). But these softwares are very expensive. There are also some related software supporting notation in China, such as TT composition ().

Lossless audio compression–-ape

APE is a lossless compressed audio format. Huge WAV audio files can be "slimmed down" by the monkey's audio and compressed into APE. Similarly, APE can also be restored to WAV through monkey's audio, and then burned to CD. Sometimes it is used for network audio file transmission, because the compressed APE file capacity is less than half of the WAV source file, which can save transmission time. More importantly, the WAV file obtained after decompression and restoration of monkey's audio can be exactly the same as the source file before compression. Therefore, APE is called "lossless audio compression format" and Monkey's audio is called "lossless audio compression software". Unlike using professional data compression software such as WinZip or WinRAR to compress audio files, compressed APE audio files can be played directly.

There are many others, see the links below.