Four reasons for using FLACs, and one reason you shouldn't
September 17, 2013 in digital music by Dan Gravell
Regular readers will know I commonly advise use of FLAC as your music file format of choice; both for ripping from CD and as a preferred file format for music downloads. Why do I encourage use of FLAC over other formats?
Computer music is stored on your computer's hard drive in much the same way as your photos, documents and videos. The audio, and any accompanying metadata, are stored in files and organised into folders. The files themselves are internally organised such that the audio data is stored in a special way.
There are different ways of storing this data, and each approach is called a file format. There are many commonly accepted file formats, and you've probably heard of the most popular: MP3. There are others; MP4 (commonly used in iTunes), WMA (the default in Windows computers), Ogg Vorbis, and more. FLAC (Free Lossless Audio Codec) is another example.
So why would you pick FLAC when there are other formats available?
1. A high quality/space ratio
File formats differ by the audio quality they offer and also the storage space required by a file written by the corresponding codec (a codec is software that is capable of reading and writing audio in the file format). Generally speaking, higher quality means more storage space. But it's not all that simple...
File formats can also differ by whether they are lossy or lossless. Lossy means that, when the file is created from raw audio input, the codec is allowed to remove parts of the raw audio that it doesn't think is necessary. This makes for a smaller file size. Lossless files, in contrast, never remove any aspect of the audio.
Lossless files are generally larger than lossy files. But within the category of lossless formats there are some formats that further compress the data, and those that don't. The act of compression in this case does not remove any of the audio data so, theoretically, audio quality remains the same, but with the added benefit of reduced storage cost. FLAC is a lossless compressed codec. WAV, for instance, is lossless but uncompressed, and so for the same theoretical audio quality you have to consume more storage space.
2. Improved flexibility and longevity
Lossless doesn't just affect audio quality, or the quality of reproduction you perceive. The fact that there are no audio data removed means that you never lose data you may need in the future.
This sounds like an academic concern, but actually it's very useful. A common application of this strength is the fact that lossy files cannot really be converted to another format without significant loss of audio quality. That's because the lossy codec depends on as much audio data as possible to generate a corresponding data stream.
With lossless files you always have all the data, and re-converting from that source data leads to the same uncompromised result. It's a bit like having a digital copy of a CD on your hard drive - always high quality and always available for conversion to different file formats.
3. Good metadata support
Metadata is important because it dictates how you browse, search and view your music library. Traditionally, many lossless file formats, such as WAV, had poor metadata support. There are some ways of tagging WAVs, but these approaches aren't universally agreed and some music players may not support tagged WAVs.
FLAC fully supports tagging and even allows cover art to be embedded in the files themselves.
4. Openness
"Openness" sounds like one of those airy-fairy notions that people with beards and sandals espouse. It's true that the fact that FLAC is open source won't make much difference to you today. It's what it means down the road that counts...
"Open source" means that a permissive licence is attached to FLAC such that anyone may copy and modify the source code for the FLAC codec, potentially releasing new versions of the FLAC codec themselves. This is as opposed to proprietary codecs, where an organization owns the rights to the codec and derivative works are not permitted.
This means the owners of such codecs are allowed to change the codecs, potentially removing features, in the future. The rights owners could even potentially charge for its use! In the unlikely event of the writer of FLAC wanting to change it, someone could (and would, given the take-up of the codec) "fork" the code and maintain their own "branch" (basically this means copying a version of the code and making that available)
One reason you shouldn't use FLAC: software and hardware support
The big caveat with FLAC is that it is not supported in all music players, software and hardware. The principle "audiophile" and high-end players support it, but not everyone.
Perhaps the most glaring example of devices not supporting FLAC is the iTunes ecosystem. There are hacks to get FLAC playing on your iPhone, but they aren't supported and require technical expertise to install.
Keeping a FLAC "gold" copy of your library, and transcoding (converting from FLAC to another format) is an option. There are numerous pieces of software that do this.
FLAC's advantages make sense for me, and so I use it to store the "gold" copy of my family's music library. When it comes to it, I transcode to MP3 to save on storage space for listening on mobile players and other storage constrained devices. Software such as mp3fs makes this extremely easy.
If you're having trouble deciding which format to use maybe my music file format comparison might help?
Thanks to INPIVIC for the image above.
