Resources: Digital Audio on Mac


About Audio Formats

In the beginning of the digital music age, there wasn’t much confusion about audio music formats, because there was limited choice. Music was stored on the Audio CD. Today there growing number of audio formats available. But while the number of formats may seem confusing, there are two primary factors driving the use and popularity of a format – whether or not it uses compression, and whether or not it using it involves royalties.

In the beginning, there was just the digital audio format used for Audio CDs.  It is uncompressed and royalty free.  So, when a company produces software or hardware to play this format, the company doesn’t have to pay a royalty.  This makes supporting this format very popular with manufacturers, since it can be done without incurring royalty payments.

But because this format is uncompressed, music files stored in this format are very large – too large to be of use on the internet.  For this reason, compressed digital audio formats were developed to store and transfer music in digital format.  The most well known of these formats is MP3, widely adopted by hardware and software manufacturers because it was both a compressed format and was royalty free.  Since it is no longer royalty-free, the market has been quick to step in with new compressed formats that are royalty-free, formats such as Ogg (Ogg Vorbis).  It will be up to the market to decide which of these formats withstand the test of time.

If you’re wondering why some audio formats need a codec and some don’t, the answer is simple – all audio formats need a codec (also known as an encoder, a decoder, a component, or even a library.) All audio formats need a decoder to decode (i.e. to play) and an encoder to encode (i.e. to convert to), hence the term codec – “co” for encoder and “dec” for decoder. But your computer manufacturer has already paid the licensing fee to include some codecs on your computer. If you want to use an audio format for which the codec is not already included on your computer, you’ll have to download and install it. Many, but not all codecs are available free of charge.

For further information about audio formats, see the links below.

All about AAC on Mac

AAC, short for Advanced Audio Coding, is the audio encoding format used by the MPEG-4 Standard. While AAC must be licensed on a per application basis on the Windows operating system, there are no license requirements for using AAC in applications on Mac OS X. There are file extensions used – M4A, M4P and M4B. Unprotected AAC uses the extensions .m4a and .m4b, protected AAC uses the extensions .m4p and .m4b.

  • Unprotected AAC (M4A, unprotected M4B) can be played on your computer using music player software such as Music Man. Unprotected AAC (M4A, unprotected M4B) can be converted to other formats.
  • DRM Protected AAC (M4P, protected M4B) can be played on your computer using music player software such as Music Man. DRM Protected AAC (M4P, protected M4B) CANNOT be converted to other formats. For more information about DRM, go to “All about DRM Protected music on Mac
  • AAC (M4A, M4B, M4P) can be played on your Mac using music player software such as Music Man. AAC (M4A) can also be played on an iPod
  • For more information about AAC, go to the MPEG Site

 

Other Music Formats