Common audio compression formats

The current audio market, audio formats are mainly divided into two: lossless compression and lossy compression. Listen to different formats of audio, sound quality will also be relatively large differences. Lossless audio compression can save 100% of the data of the source file on the basis of compressing the volume of the audio file is smaller, and then the compressed audio file can be restored to achieve the same size and the same bit rate as the source file. Lossy compression of audio, which reduces the audio sampling rate and bit rate so that the output audio file is smaller than the source file.

MP3

MP3, short for MPEG Audio Layer3, is a lossy compression encoding format that was developed successfully in the 1990s and is often used in players. It is the use of the masking effect of the human ear to compress the sound, so that the file at a lower bit rate, as far as possible to maintain the original sound quality, is currently the most popular compression method, is now the most important format of online music, MP3 audio coding with 10:1~12:1 high compression rate at the same time, basically keep the low audio part without distortion. However, the quality of the 12KHz to 16KHz high audio part of the sound file is lost in exchange for the size of the file, and the original sound quality is basically maintained under the transmission rate of no less than 128kbps. It is this feature that makes MP3 related products maintain a long life.

CD

Laser turntable CD storage takes the form of an audio track, which records a waveform stream and is an approximately lossless format. Windows comes with a CD player, and most sound cards come with software that allows you to play CD, which is one of the most commonly used audio formats. CD uses a sampling frequency of 44.1K, a rate of 1411K/ s, and 16 quantization bits.

WAV

WAV is a sound file format jointly developed by Microsoft Windows and IBM in the early stage. It is used to save the audio information resources of Windows platform, and is supported by Windows platform and its applications. WAV format supports many compression algorithms, supports a variety of audio bits, sampling frequencies and channels, using 44.1kHz sampling frequency, 16 quantization bits, so the sound quality of WAV is almost the same as that of CD, and it is also a popular sound file format on the computer, almost all audio editing software can recognize WAV format.

MPEG

MPEG stands for Dynamic Picture Experts Group. This group of experts was created in 1988 to develop video and audio compression standards for CDS. MPEG audio file refers to the sound part of the MPEG standard called MPEG audio layer. MP3 is the most common music format on the INTERNET. Although it is a lossy compression, it trades very little sound distortion for high compression ratio. MPEG includes: MPEG-1, MPEG-2, MPEG-Layer3, MPEG-4

AIFF

Audio Interchange File Format (AIFF) is a standard audio file format developed by Apple Computer Company. It is a part of Quick-Time technology. The characteristic of this format is that the format itself has nothing to do with the meaning of the data, so it was favored by Microsoft, and made WAV format accordingly. AIFF is an excellent file format, but it hasn’t gained much popularity on the PC platform because it’s a Macintosh format. However, since Apple computers are mostly used in the multimedia production and publishing industry, almost all audio editing software and playback software support the AIFF format more or less. As long as Apple is around, AIFF will have a place. Due to its subsumption nature, AIFF supports many compression techniques.

WMA

WMA format is a digital music format promoted by Microsoft, and the sound quality is stronger than MP3 format and better than RA format. It is the same as the VQF format developed by YAMAHA Company in Japan, and it achieves a higher compression rate than MP3 by reducing data traffic but maintaining sound quality. The compression rate of WMA can generally reach 1: Around 18, another advantage of WMA is that content providers can add anti-copy protection through Data Rights Management (DRM) schemes, which has quite strong copyright protection capabilities.

MIDI

The Musical Instrument Digital Interface (MIDI) format is used by people who play music a lot, and MIDI allows digital synthesizers to exchange data with other devices. The MID file format is inherited from MIDI. A MID file is not a recorded sound, but a set of instructions that record information about the sound and then tell the sound card how to reproduce the music. Such a MID file only uses about 5 to 10KB per minute of music. MID files are mainly used for original instrumental compositions, amateur performances of popular songs, game tracks, and electronic greeting cards. *The performance of *.mid file replay depends entirely on the level of the sound card. The biggest use of the *.mid format is in computer composition. *.mid files can be written by music composition software, or by inputting the music played by the external sequencer into the computer through the MIDI port of the sound card.

FLAC

FLAC and MP3 are similar, are audio compression coding, but FLAC is lossless compression, that is to say audio FLAC encoding compression will not lose any information, FLAC file restored to WAV file, and the WAV file content before compression is the same. The compression method of FLAC is similar to that of ZIP, but the compression ratio of FLAC is higher than that of ZIP and RAR, because FLAC is specially designed for PCM audio compression. And you can use the player to play FLAC compressed files directly, just as you would normally play your MP3 files. FLAC file is also about equal to the volume of ordinary audio CD, and can be freely converted to each other, so it is also one of the best choices for music CD storage on the computer, it will completely retain the original information of the audio, the user can transfer it back to the CD at any time, the music quality will not have any change, and in the playback, Each data frame of FLAC file contains all the information needed for decoding, and the errors in the middle will not affect the normal playback of other frames, which ensures its practical validity and minimum network time delay. FLAC is one of the two most commonly used lossless audio formats along with APE in the domestic market, and its coding technology makes it have a huge development space beyond APE in the future.

APE

APE is one of the popular digital music file formats. Unlike MP3 and other lossy compression methods, APE is a lossless compression audio technology, audio data files read from audio CD compressed into APE format, you can also restore the APE format file, and the restored audio file is exactly the same as before compression, without any loss. The file size of APE is about half of CD. With the popularization of broadband, APE format has been loved by many music lovers, especially for friends who want to transmit audio CDS through the network, APE can help them save a lot of resources. Of course, only tracks on music CDS and uncompressed WAV files can be converted to APE; MP3 files cannot be converted to APE. In fact, APE compression rate is not high, although the sound quality is well maintained, but the compressed capacity is not much smaller. A 34MB WAV file compressed to APE format is still around 17MB. RealAudio

RealAudio file is a streaming Media format audio file developed by Real Networks company, also known as network audio format. It is included in the audio and video compression specification Real Media formulated by Real Networks company. It is mainly used for real-time transmission of audio information on low transmission rate WAN. Depending on the network link rate, different sound quality will be obtained. There are three formats: RA, RM and RAM.

AAC

AAC is an audio format developed jointly by Fraunhofer IIS-A, Dolby, and AT&T as part of the MPEG-2 specification. The algorithm used by AAC is different from that of MP3. AAC combines other functions to improve the coding efficiency. The compression capability of AAC is much better than that of previous audio compression algorithms (such as MP3). It also supports up to 48 tracks, 15 low frequency tracks, more sampling and bit rates, multiple language compatibility, and higher decoding efficiency. In summary, AAC can provide better sound quality with 30% smaller file size than MP3.

Your task

Choose an audio compression format that interests you and talk about your understanding of it.

Share your thoughts and ideas in the comments below.