FLAC facts for kids

FLAC (pronounced "flack") stands for Free Lossless Audio Codec. It's a special way to store digital music. Think of it like a super-smart way to pack your favorite songs. When you compress music with FLAC, it becomes smaller. But here's the cool part: when you play it back, it sounds exactly like the original. Nothing is lost!

FLAC was created by the Xiph.Org Foundation. It's an "open format," which means anyone can use it without paying fees. It's also "free software," so the tools to use it are available to everyone. FLAC files can also store extra info like song titles, artist names, and even album pictures.

How FLAC Started

A person named Josh Coalson began working on FLAC in 2000. The first official version, 1.0, came out on July 20, 2001.

In 2003, FLAC joined the Xiph.Org Foundation. This group also supports other free audio and video formats. These include Vorbis and Opus.

Later, in 2013, the development of FLAC moved to a new online home. In 2019, people even suggested FLAC become an official internet standard.

How FLAC Works

FLAC takes your digital music and makes it smaller without losing any sound quality. It's like folding a big blanket very neatly so it fits in a smaller box. When you unfold it, it's still the same blanket.

Inside a FLAC File

Every FLAC file starts with a special code: "fLaC". After that, it has some information about the music. This includes things like the song title or artist.

The actual music data is split into small parts called "frames." Each frame has a header, which is like a label. This label tells the player important details. It might say how many sound bits are in that part. It also tells where the frame is in the song.

The header can also include the sample rate. This is how many times per second the sound was measured. It also tells the bit depth, which is how much detail each sound measurement has. After the header comes the actual music data.

Making and Playing FLAC Files

When you make a FLAC file, the program first splits the music into small sections. If the music has two channels (like for stereo sound), each channel is handled separately. The program then tries to find a simple mathematical way to describe each section.

It writes down this simple description. Then, it figures out the small differences between the simple description and the actual music. These differences are called the "residual." The program then packs these differences very efficiently. Often, this packed information takes up much less space than the original music.

When you play a FLAC file, the process is reversed. The player first unpacks the differences. Then, it uses the simple mathematical description to rebuild the sound. When it adds the differences back, you get the exact original sound. Because FLAC is "lossless," the sound you hear is perfect. It's exactly what was recorded.

Sometimes, for stereo music, FLAC can combine the two channels. It might create a "mid" channel (sum of both) and a "side" channel (difference between them). This can sometimes make the file even smaller.

Making Files Smaller

How much smaller a FLAC file gets depends on a few settings. But no matter what, you can always get the original sound back perfectly.

The FLAC tools offer different "compression levels," from 0 to 8. Higher numbers mean smaller files. But they also mean it takes longer to create the FLAC file. Playing the file, however, is always fast, no matter the compression level. This is because FLAC is designed to be quick to decode.

How FLAC Compares to Others

FLAC is special because it's made just for audio. Other general compression tools, like those used for ZIP files, can make audio smaller. But FLAC is much better at it. It can reduce audio size by 40-50%. ZIP files might only reduce it by 10-20%.

FLAC is great for keeping your music collection safe. If you have music CDs, you can turn them into FLAC files. This creates a perfect digital copy. If your original CD gets lost or damaged, you can always get an exact copy of the music back.

This is different from formats like MP3. MP3 files are "lossy." They throw away some sound information to make files very small. You can't get the original sound back from an MP3. Because FLAC is lossless, you can convert FLAC files to other formats, like MP3, without losing quality from the original.

You can also create a "CUE file" when you convert a CD to FLAC. This file helps you burn a new CD later. The new CD will be exactly like the original, including the song order.

Where FLAC is Used

Many different devices and programs support FLAC. The main FLAC software is called libFLAC. It helps programs create and play FLAC files. This software works on many computer systems. These include Linux, Microsoft Windows, and macOS.

While not as common as MP3, FLAC support is growing. Windows 10 and Android (since version 3.1) now support FLAC files. macOS High Sierra and iOS 11 also added FLAC playback.

Some car audio systems also support FLAC. The European Broadcasting Union (EBU) uses FLAC for sending high-quality audio. Music websites like Bandcamp let artists upload music in lossless formats like FLAC.

Many other programs can play FLAC files, no matter what operating system you use.

See also

In Spanish: FLAC para niños

• Comparison of audio coding formats