Audio Format

Audio files come in three flavors.

• uncompressed
• lossless compression
• lossy compression

Uncompromising Uncompressed

Well-known examples are  WAV (Waveform audio format, developed by Microsoft and IBM) and AIFF (Audio Interchange File Format, a format was co-developed by Apple Computer in 1988).
They contain uncompressed audio in the pulse-code modulation (PCM) format. PCM audio is the standard audio format for CDs.
There is no loss of quality using any of these formats as lossless=lossless.

The only difference is the sequence of the bits, WAV is in little-endian, AIFF in big-endian ( most-significant byte first) and this corresponds with the processor architecture used by Windows (Intel X86=little-endian) and Apple (Power PC=big-endian)
The only criteria I can conjecture up is that if you have Windows as an operating system WAV might be a more convenient choice. Likewise AIFF if you have a MAC.

 

Pro:

• no loss of quality. If you rip a CD straight to WAV, you rip 16 bit/44.1 kHz PCM Red book audio format to 16 bit/44.1 kHz PCM in WAV format, this is as close as you can get to the original source.

Cons:

• Uses a lot of disk space.
  In case of Redbook audio:
  bits * sample rate * chanels = 16 * 41000 * 2=1411200 Bits/sec ≈ 172 Kb per second.
• Tagging in WAV might be a problem.

  Due to a lack of standardization portability of the tags is poor. Best practice is probably to act as if tags in WAV are not supported at all.

Uncompromising compressed

The data is compressed without any loss of information. This is similar to how WinZip works, except you will get a better compression because the software  is designed specifically for audio. Examples are:

FLAC  (Free lossless Audio Codec) Monkey's Audio (APE), WavPack (WV), Tom's lossless Audio Kompressor (TAK), Apple Lossless (ALAC) and Windows Media Audio Lossless (WMA).

 

Pro:

• No loss of quality.
• Reduces file size 40 to 60% depending on the kind of music.

Cons:

• Limited support. Apple and Microsoft support support their own proprietary lossless formats only.
• Not as frugal on disk space as MP3.

Compromising compression

MPEG-1 Audio Layer 3, more commonly referred to as MP3, is a popular digital audio encoding, lossy compression format, an algorithm designed to greatly reduce the amount of data required to represent audio, yet still sound like a faithful reproduction of the original uncompressed audio to most listeners. It was invented by a team of European engineers of Philips, CCETT (Centre commun d'études de télévision et télécommunications), IRT and Fraunhofer Society, who worked in the framework of the EUREKA 147 DAB digital radio research program, and it became an ISO/IEC standard in 1991.

 

Pro:

• high compression so frugal on disk space.
• can be used on any MP3 player.

Cons:

• the stronger the compression the higher the loss of quality.
• you can’t convert back to a lossless format (it is technically possible, but what is lost in converting to MP3, is lost forever) .

What to choose?

I consider MP3 a solution for a problem I don’t have.
Having a DSL internet connection and a 1Tb NAS, bandwidth nor disk space is a problem. So why temper with sound quality?

 

You choose a lossless format only to find out that your MP3 player accepts MP3 files only. The answer is transcoding. A lot of players support conversion to another format on the fly. This is a scenario used quit often. You have your collection in a lossless format and you use transcoding to load the music on a portable device.

 

If you have the same audiophile neurosis as I have, the idea only that there is some information removed (that’s what MP3 does in a very clever way) spoils your listening pleasure.
All of a sudden you see on Amazon the track you wanted to have for years.

Wow! Eureka!

Oh no, it is only available in MP3. Shit!!!!

 

Amazon MP3s are made with LAME at 256 kbps.
Lots of people can’t hear the difference between the original CD and a 192 kbps MP3. Even a lower rate like 128 kbps is often hard to discern from the original.
So don’t worry, get it and enjoy. MP3 is not that bad.

How to test

If you want to hear the differences between file formats and especially between lossless and lossy you must use music putting the compression to test.

Small settings are recommended, there ain’t much to mask in it.

Harpsichord is often motioned, its generates a lot of high pitch harmonics. Like wise cymbals. Instruments requiring high rise times, so percussion.

SQAM=Sound Quality Assessment Material

A couple of samples from the EBU (European Broadcasting Union) can be found here.

How to set up the listening conditions can be found here.