Flac is an efficient form of lossless compression which result in huge reductions in our sample library file sizes. The codec is truly lossless. Sound quality remains exactly the same as the library in uncompressed wave format, but the loading times and disk streaming needs are reduced. Most of all, the space needed for the library file is rather small for libraries containing thousands of samples. Sample libraries are usually large and take up your hard drive space quickly. Not VI Labs libraries.