Lossy files sacrifice data for brevity. Lossy files can be very small relative to their original versions and they get smaller by throwing away musical data. The smaller they get, the more data is lost. They hope you won’t notice what’s missing, like the grocer who puts his thumb on the scale.
The most famous of the lossy files, MP3, allows data storage and transfer of music files with relatively low space and bandwidth. Without MP3 the entire iPod and portable music player phenomena would likely never had existed.
It’s perhaps accurate to suggest 99% of all music enjoyed by billions of people around the world is heard through the lens of an MP3 (or similar) lossy container. Uncompressed files, even losslessly compressed files, are not the norm. Not even close.
What’s the point of accepting loss of data in your files, and who cares?
The answer to the first question gets fuzzier nearly every day. Originally, the point was storage and bandwidth restrictions. There simply wasn’t enough storage and streaming/download bandwidth to go around. Now that has changed, at least in first and second world countries, with third worlds catching up quickly. So, why are we still so concerned with compressing data? Cost is one answer. Regardless of what’s available, it still costs money to store and send data around the world. That’s likely to always be true.
And as to the second question, who cares. I can tell you without reservation billions of music lovers around the world don’t care about loss of some fidelity, and likely they’re unaware there was anything to lose in the first place. The small handful of folks like you and me that do care appear as anomalies to those in charge of data storage and transmission. It’s likely we don’t even make a blip on the radar.
Except… and that’s what we’ll cover tomorrow.
In yesterday’s post I had mentioned that I get questions on the two compression types, lossy and lossless. Some have questioned the term compression and wonder, if it’s compressed how can it be lossless? Is it a marketing scam or is it real? Probably worth spending a few minutes on this subject.
Lossless is indeed lossless. This means an identical copy can be extracted once uncompressed.
If you’ve ever gotten a ZIP file you’re already familiar with compressing data. You would never expect to unpack a ZIP file and have your picture, text or document anything less than perfect. Audio compression of the lossless nature is the same.
The best known lossless compression schemes, FLAC (Free Lossless Audio Codec) and ALAC (Apple Lossless Audio Codec), are both able to compress a music file into about half the space of the original. Uncompress it and the bits are identical. There are other lesser known schemes just as accurate too, like MLP (Meridian Lossless Packing), WavPack, TAK, Monkey’s, WMA, OptimFROG, TTA, among others. The list is long.
There is a lot of talk amongst Audiophiles that despite the fact lossless files are unquestionably bit perfect, they don’t sound the same. How could that be? Well, for one thing, the amount of processing resources required to unpack a lossless file are far greater than those playing the original WAV file. If for no other reason, the extra number crunching impacts noise, jitter and increases power supply demands. So while the bits are identical, the payback demands are not.
If you download a compressed lossless file, uncompress it, and place it on your hard drive, that file will now sound identical to the same file on the same hard drive that had never been compressed. In other words, compressed or uncompressed the bits are the same.
Playback of compressed bits has different demands than playback of uncompressed bits. Hence, sound quality varies depending on the hardware reproducing it.
But that should be no surprise.