best compressed audio format

See also: Audio | Audio Formats | Lossless | Lossy

The "best" audio format depends on your needs. To balance download speed and hard drive space against quality, this page looks to chronicle some of the tests that have been done around the Internet. While not all are up-to-date, they do provide a good swath of audio formats available.

As a result of these tests, this document assumes that Ogg Vorbis is the best so-far in audio compression, based on tests listed. There are exceptions to OGG's superiority, including on portable devices where OGG is not commonly available. MP3 size-quality performance is among the worst but it's quality (when encoded with LAME) is still considered high and its compatibility is unmatched.

1. Variable Bitrate Compression: Whenever possible, it is better to encoded using this setting (usually noted as "VBR"). The only time Constant Bitrate Compression (CBR) should be used is when providing music that people can listen to while they download from you. This is called streaming media and it is usually only necessary when operating an Internet radio station.
2. Whether using CBR or VBR, both allow for some representation of quality. Unless otherwise noted, the general rule of thumb is a quality level between 96 and 192 bits per second.

Quality-Level Suggestions: General

Purpose	Suggested Format
Audio track collaborations with a remote musician	Need a format that is as close to the original as possible. Encoding in FLAC or WinRAR on the file has zero file degradation. The file will be absolutely identical to the original.
Adding files to your portable player	Most players currently support WMA format and MP3. Of the two, WMA has a much better quality-to-size ratio but there is some protest whether it can truly mimic CD-quality sound. Still, WMA also has a lossless. The most popular player, Apple's iPod is similar, using AAC for its high-compression format but MP3 in some tests showing better overall CD-mimiking. AAC has a lossless format as well.
For outstanding quality speaker system or headphones	FLAC or a high-bitrate (192-256) encoding format is again advised to utilize the full breadth of the sound.
Surround-Sound compatible audio	AAC, Ogg Vorbis, and WMA version 9+ all allow encoding 5.1 surround audio.
Your voice, or another's, recorded from low-quality microphone	WMA and Real Audio's basic encoders also have a history of being excellent for recording simple voice easily. 56-bit MP3 in mono format, 48 bit Ogg Vorbis format, or 32 bit WMA/RA. You may also try Speex, the free voice-compression encoder which has many more voice compression options but is a textmode tool. This is considered by iA to still be in development, even though it is currently in use in many VoIP services.

Quality-Level Suggestions: Often Heard

If saving space is important, sometimes you can gauge quality you use by how often you listen to a song.

Purpose	Suggested Format
Turning that once-in-a-while CD you listen to into MP3 format	You won't need top-quality sound; you can record it in MP3 128 bit, WMA 96, or Ogg Vorbis 96 with a clean conscience.
A CD you listen to once or twice a month	Variable bitrate compression using Ogg Vorbis is ideal, usually around a 96-bit median. This is still excellent quality at the right size.
A CD you listen to weekly	Variable bitrate compression using Ogg Vorbis is ideal, usually around 128-192 bit median. For most listeners, this will be indistiguishable from CD-qualtiy.
Your favorite album	FLAC is advised for top quality.

The Best?

While this question is always up for debate, there are several sources who have provided insight. Some of the tests also depend on which type of music you are encoding:

1. Rjamorim May, 2004 test. Winner: quality-centric Ogg Vorbis fork AoTuV
2. Modatic - Winner: Ogg Vorbis in most cases.
3. c't Winner: Ogg Vorbis in most cases. In German, translated using Altavista's Babelfish.
4. 7 Audio Experts sound off Winner (overall): Windows Media Audio - WMA in most cases - a beta version of Ogg Vorbis was used during this test)
5. The best low-bitrate audio compression algorithm
6. Test for various AAC encoders/players (there's more than just Apple) - Winner: Apple's Quicktime
7. 64kbps test - Ogg Vorbis was level with MP3Pro and HE-AAC codecs.

Lossless

1. A comparison of lossless compression systems (excluding FLAC)
2. FLAC's own comparison

Related

1. wiki.etree.org - Lossless Digital Audio wiki
2. Ogg Vorbis
3. MP3Pro
4. Variable Bitrate Compression
5. Fixed Bitrate Compression

This article is based on a public domain infoAnarchy article: Best_Compressed_Audio_Format

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