April 02, 2008
| by Dennis Burger
The Lows: Inefficient compared to other lossy codecs, and potentially a waste of disk space at the very highest bitrates, depending on the encoder you use. Even at those highest bitrates, MP3 has a hard time with certain sounds, like cymbals, drums, and applause. And at the lowest useable bitrates, MP3 performs significantly worse than AAC, Ogg Vorbis, and other, newer lossy codecs. Also, the loose specifications for MP3 encoders can lead to some confusion, as well as huge debates over minute differences in the quality of files generated by different encoders.
Ogg Vorbis: Designed as an open-source alternative to/replacement for MP3 and initially released in 2002, Ogg Vorbis has quickly become the audio codec equivalent of a cult classic. Unlike many lossy codecs, Vorbis offers only variable-bitrate encoding (VBR, an option with most MP3 and AAC encoders), meaning that users select a preferred quality setting instead of a bitrate, and the encoder constantly varies the bitrate in relation to the complexity of the audio signal.
The Highs: Major brownie points for being named after a character from Terry Pratchett’s Discworld series, as well as being completely DRM-free. Widely considered by many critical listeners to be the lossy codec with the best sound quality by a wide margin, especially at higher bitrates. Well supported on Linux. Widely used in the video game industry. Supported by ReQuest’s music servers, Sonos and SqueezeBox wireless music systems, and popular software players like MediaMonkey, AlbumPlayer, and WinAmp (after installing the appropriate plugin).
The Lows: Not supported by Escient audio servers and the vast majority of personal digital audio players, such as the iPod and Zune. Getting iTunes and Windows Media Player to recognize the format requires a bit of tinkering.
WMA (and WMA Pro, WMA Lossless): Windows Media Audio got off to a bit of a rocky start thanks to some spurious statements by Microsoft, who claimed that WMA generated CD-quality audio at a mere 64 kbit/s (a claim handily refuted by anyone with two ears and some without). In the intervening years, though, WMA has been widely embraced, and is nearly as widely supported as MP3 these days.
WMA comes in a few different varieties. In addition to the recent improvements of the original WMA codec, Microsoft has developed WMA Pro—which supports better-than-CD-quality audio—as well as their own lossless format dubbed, creatively enough, WMA Lossless. The only problem with this is that the three formats share little in common, other than their names and file extension. In fact, any real examination of the differences between them—from the way their work to the devices that support them—would require an article unto itself.
The Highs: High quality audio playback. Significant improvements over the years. Standard WMA files are nearly as universally supported as MP3, with playback available on many personal digital audio players, wireless music systems, and software players. May well be the perfect format for those who own the Zune and use entirely Microsoft-based music distribution systems. WMA Pro offers extremely high-quality surround sound playback, with sampling rates up to 96kHz (more than twice the sampling rate of CD audio). And WMA Lossless offers the same bit-for-bit recreation of the original file, while on average taking up less disc space.
The Lows: Unsupported by popular ReQuest music servers, as well as iTunes and iPod. Pro and Lossless aren’t nearly as widely supported as standard WMA, which can lead to confusion since all three formats use the same .wma file extension. Digital rights management can also lead to compatibility issues and playback problems, and certainly don’t do anything to ameliorate Microsoft’s Big Brother perception among some users.