What's the best lossless format?Most of us know that generally lossless is better than lossy because it retains all of the audio and therefore sound better, and you can also convert form one lossless format to another without losing any sound quality. Lossless does require significantly more disk space but his doesn’t mean you have to reduce the amount of music stored on your iPod, iPhone or mobile device. For example iTunes allows users to convert higher data rate music files to 128kbps AAC on the fly as the music is synced to the mobile device in question.
But what Lossless format should you choose ?
Currently there are four widely available choices:
- Apple Lossless
WavWAV is a music file format developed by Microsoft and IBM capable of storing Linear PCM audio (the digital encoding format used on compact discs) in completely uncompressed form. Ripping a CD and storing it as an uncompressed WAV results in “bit perfect” storage; the ripped music file is identical to the original CD data package. WAV files can also store high-resolution music files at greater bit depths and sampling rates than CD’s 16-bit/44.1kHz resolution. Uncompressed WAV files can be ripped and played back in iTunes and are very high quality. However, they do take up more hard drive storage space then lossless compressed formats such as Flac or Apple Lossless
WAV files originally did not support metadata, there is now defacto support using ID3v2 - the same format that is used by Mp3s. However not all players and tools currently recognize ID3v2 metadata in Wavs.
AiffAIFF was developed by Apple and is very similar to WAV. Again it is capable of storing uncompressed Linear PCM audio. Ripping a CD and storing it as uncompressed AIFF results in “bit perfect” storage with the ripped music file identical to the original data on the CD. Like WAV files, AIFF files can also store high-resolution music files at high bit depths and sampling rates.
AIFF uses ID3v2 like Wavs and Mp3s. ID3v2 metadata is within Aiff is much more widely recognized - notably it is properly supported in iTunes.
Apple LosslessThis is a newer Apple file format option that employs lossless compression, which reduces the stored data to as little as half of the original music file’s size but restores bit-for-bit identical to the original music file on playback. The process is not unlike a zip file in which a large amount of data is “zipped” down to a smaller file size for storage and “unzipped” to its full size when opened.
There is discussion about whether uncompressed music files such as WAV or AIFF can sound better than lossless compression formats like Apple Lossless or FLAC because they don’t require the additional step of being “unzipped” and restored to their original PCM data package during real-time during playback, but this difference should only be noticeable in older and slower hardware.
Apple Lossless offers full metadata support using its own metadata format, this metadata format is also used by Apples lossy Advanced Audio Coding format. Both formats can be found using the .mp4 or or .m4a format which can be confusing
FLAC (Free Lossless Audio Codec)FLAC is an open source lossless compression format similar to Apple Lossless Compression, this reduces the stored music file’s size, but then restores the data package bit-for-bit identical to the original music file on playback. It supports high-resolution audio with greater bit depths and sample rates and also supports metadata tagging using Vorbis Comments.
The main problem with FLAC is that although it is an extremely common and accepted format, it is not supported by iTunes and Apple hardware such as the iPod.
ConclusionsI would love to recommend the open source FLAC format but because of its poor support in the Apple ecosphere I don't think it is currently the best choice, particularly since Apple punches above its weight when it comes to digital music.
Although Wav audio format is well supported, support for its metadata is poor so again I would not recommend Wav.
So we are left with two Apple formats. With Apple Lossless we get a smaller filesize and good metadata support, with Aiff we get a larger filesize but even better metadata. Both are well supported on Apple and non Apple hardware and software. The ID3v2 format used by Aiff format has been around a long time (because used by Mp3 as well) and although it is a little unwieldy it is well understood and very powerful, the metadata format used by Apple Lossless is not as well understood or flexible.
Everybody circumstances differ but for me the current best choice is Aiff