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Now WAV has become a standard format of PC. Whereas due to great demand of large storage
capacity (size of music files per minute is 10M), in most circumstances people choose to convert it
to compression formats (MP3, WMA etc.). If the original sound quality of the music is required,
you should choose lossless Audio Codec.
MP3
MPEG-1 Audio Layer 3, normally named as MP3, was developed by Moving Picture Experts
Group (MPEG). It is a popular digital audio coding and lossy compression format. It is designed
to greatly reduce the audio data. To most users there is no apparent decline of the sound quality
compared with the original uncompressed audio. It was created and standardized by an
engineering group from Germany Erlangen Research Organization Fraunhofer-Gesellschaft in
1991.
MP3 is a compression format. It removes unimportant audio component to human in PCM
digital audio, therefore it yields a much smaller file size.
Many techniques are applied in MP3 including audio psychology to confirm which part of audio
could be removed. MP3 audio can be compressed according to bit rate. It provides a middle
solution both considering data size and sound quality.
WMA
WMA (Windows Media Audio) is a kind of digital audio compression format opened by Microsoft.
Some pure audio ASF, which adopts Windows Media Audio coding format to code its whole
content also use WMA as its extended name.
WMA format is primarily privately owned by Microsoft. However, with Apple iTunes’ surport,
this format is becoming a competitor to MP3 format. It is compatible to the ID3 tag and supports
extra tag at the same time.
In addition, generally for WMA and MP3 audios with the same sound quality, the former has
smaller sizes (in conditions of sound quality less than 192kbps). Windows Media Audio is a kind
of audio coding format similar to MP3 and AAC, is a lossy audio format.
AAC
AAC is the abbreviation of Advanced Audio Coding, also named as MPEG-2 AAC or MPEG-2
NBC. AAC is a kind of audio format developed together by Fraunhofer IIS-A
、
Dolby and AT&T.
It is a part of MPEG-2 standard. AAC adopts a different algorithm compared with MP3. AAC
raises the coding efficiency by combining other functions. In its compression capability, the
audio algorithm is much superior to former compression algorithm (such as MP3 etc.). It at the
same time supports up to 48 tracks and 15 low frequency tone tracks, more varieties of Sampling
Rate and Bit Rate, Multi-language Compatibility, and more efficient decoding capability. In all,
AAC can provide higher sound quality on the premise that it is 30% smaller than MP3 files.
After Apple declared to take AAC as the main format of the downloading digital music sold in its
