TNL's Guide to The Music File Formats: Part Four
Part 4 – OGG, AAC, and a Preliminary Verdict
OGG
OGG is a patent free, open source format for streaming and compressing audio and video files. The audio portion is more properly referred to as Ogg Vorbis. In other words, they are the Linux of the digital musical file world, and are supported by the Xiph.org foundation. The first codec was released in 2002.
Of note, the Ogg Vorbis format is inherently variable bit rate. This is probably why it is generally felt to have a higher audio quality than other formats ripped at equivalent bit rates. Another nuance of Ogg Vorbis is that when ripping the tracks, you don’t specify a bit rate. Rather, you specify a quality setting from zero to ten. A q4 is equal to about 128 kbps, a q5 about 160 kbps, and a q6 about 192 kbps which are the most common settings that the majority of users should use. There is also a lossless variation of Ogg Vorbis, otherwise known as FLAC.
The biggest obstacle to using Ogg Vorbis is again a lack of mainstream support. Portable devices from Samsung, iRiver, and Cowon support it. Apple does not officially support it, but apparently an iPod can be hacked using iPodLinux to support Ogg Vorbis, which also voids your warranty (in other words, you’ve been warned, proceed at your own risk, and don’t blame us when that shiny iPod you received this Christmas only displays “error”). In my opinion, the jury is still out for this format, and I’d watch it from a distance before committing a collection to Ogg.
AAC
This is the Advanced Audio Codec, not the “Apple Associated Codec” as it’s sometimes called because of its close association to iPods and iTunes. While MP3’s were built out of the MPEG-1 video standard, AAC is built on the newer MPEG-2 and MPEG-4 video standards. With a larger sample frequency range of 8 Hz to 96 kHz, this codec was designed from the ground up to be superior to the MP3 format.
Any music purchased at Apple’s iTunes store is in this AAC format. It incorporates digital rights management into the tracks to prevent unregulated usage of the music. In typical Apple fashion, in the Windows version of iTunes 6, the default setting for ripping in AAC is a 128 kbps CBR. Going through the preferences, users will be rewarded to find that the AAC can be created from 16 to 320 kbps, in CBR, or VBR settings. There is also an option for an Apple Lossless file setting to preserve the tracks using a compression scheme without eliminating any audio information.
iPods are, by far, the predominate players for this standard of audio file. A few cell phones, including the Motorola ROKR will play back tracks of this AAC standard. To say that only iPods play back this audio standard is hardly a major shortcoming currently, as they dominate the personal audio player marketplace, now and in the foreseeable future. At least for now, if you want a portable player to work with your AAC files, it will have an Apple logo somewhere on it. I’m sure this is part of Apple’s long term marketing strategy to force their customer database to continue buying their iPod line of players; it will likely work. For now, I don’t own an iPod, and don’t rip AAC files, although I’m clearly in the minority.
Conclusion
After delving into the four major standards for digital audio files, and their various VBR, and lossless variants, we’re back to the original and humble MP3. While it may not have the latest theoretical underpinnings, it still is easy to argue for it. Especially using the newer VBR algorithms, file sizes are still manageable, and they produce excellent audio on playback. The MP3 can be played back on the widest variety of devices including all portable music players, your favorite computer software, a growing number of car stereos, and almost any DVD player. I’m quite confident that the MP3 will continue to be the dominant music format for the foreseeable future, and that’s why it is my pick.
Part One: An Introduction
Part Two: MP3's
Part Three: Windows Media Audio
Part Four: OGG, AAC, and a Preliminary Verdict
Part Five: Popular Software
Part Six: Conclusion & Links To Software
OGG
OGG is a patent free, open source format for streaming and compressing audio and video files. The audio portion is more properly referred to as Ogg Vorbis. In other words, they are the Linux of the digital musical file world, and are supported by the Xiph.org foundation. The first codec was released in 2002.
Of note, the Ogg Vorbis format is inherently variable bit rate. This is probably why it is generally felt to have a higher audio quality than other formats ripped at equivalent bit rates. Another nuance of Ogg Vorbis is that when ripping the tracks, you don’t specify a bit rate. Rather, you specify a quality setting from zero to ten. A q4 is equal to about 128 kbps, a q5 about 160 kbps, and a q6 about 192 kbps which are the most common settings that the majority of users should use. There is also a lossless variation of Ogg Vorbis, otherwise known as FLAC.
The biggest obstacle to using Ogg Vorbis is again a lack of mainstream support. Portable devices from Samsung, iRiver, and Cowon support it. Apple does not officially support it, but apparently an iPod can be hacked using iPodLinux to support Ogg Vorbis, which also voids your warranty (in other words, you’ve been warned, proceed at your own risk, and don’t blame us when that shiny iPod you received this Christmas only displays “error”). In my opinion, the jury is still out for this format, and I’d watch it from a distance before committing a collection to Ogg.
AAC
This is the Advanced Audio Codec, not the “Apple Associated Codec” as it’s sometimes called because of its close association to iPods and iTunes. While MP3’s were built out of the MPEG-1 video standard, AAC is built on the newer MPEG-2 and MPEG-4 video standards. With a larger sample frequency range of 8 Hz to 96 kHz, this codec was designed from the ground up to be superior to the MP3 format.
Any music purchased at Apple’s iTunes store is in this AAC format. It incorporates digital rights management into the tracks to prevent unregulated usage of the music. In typical Apple fashion, in the Windows version of iTunes 6, the default setting for ripping in AAC is a 128 kbps CBR. Going through the preferences, users will be rewarded to find that the AAC can be created from 16 to 320 kbps, in CBR, or VBR settings. There is also an option for an Apple Lossless file setting to preserve the tracks using a compression scheme without eliminating any audio information.
iPods are, by far, the predominate players for this standard of audio file. A few cell phones, including the Motorola ROKR will play back tracks of this AAC standard. To say that only iPods play back this audio standard is hardly a major shortcoming currently, as they dominate the personal audio player marketplace, now and in the foreseeable future. At least for now, if you want a portable player to work with your AAC files, it will have an Apple logo somewhere on it. I’m sure this is part of Apple’s long term marketing strategy to force their customer database to continue buying their iPod line of players; it will likely work. For now, I don’t own an iPod, and don’t rip AAC files, although I’m clearly in the minority.
Conclusion
After delving into the four major standards for digital audio files, and their various VBR, and lossless variants, we’re back to the original and humble MP3. While it may not have the latest theoretical underpinnings, it still is easy to argue for it. Especially using the newer VBR algorithms, file sizes are still manageable, and they produce excellent audio on playback. The MP3 can be played back on the widest variety of devices including all portable music players, your favorite computer software, a growing number of car stereos, and almost any DVD player. I’m quite confident that the MP3 will continue to be the dominant music format for the foreseeable future, and that’s why it is my pick.
Part One: An Introduction
Part Two: MP3's
Part Three: Windows Media Audio
Part Four: OGG, AAC, and a Preliminary Verdict
Part Five: Popular Software
Part Six: Conclusion & Links To Software
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