The use of lossy compression is designed to greatly reduce the amount of data required to represent the audio recording and still sound like a faithful reproduction of the original uncompressed audio. In a comparison of compressed audio formats, FFmpeg's FLAC implementation was noted to have the fastest and most efficient embedded decoder of any modern lossless audio format. The technical strengths of FLAC compared to other lossless formats lie in its ability to be streamed and decoded quickly, independent of compression level.

It is a common audio format for consumer audio streaming or storage, as well as a de facto standard of digital audio compression for the transfer and playback of music on most digital audio players. MPEG-1 or MPEG-2 Audio Layer III, more commonly referred to as MP3, is an audio coding format for digital audio which uses a form of lossy data compression.

Digital audio compressed by FLAC's algorithm can typically be reduced to 50-60% of its original size and decompress to an identical copy of the original audio data. FLAC (Free Lossless Audio Codec) is an audio coding format for lossless compression of digital audio, and is also the name of the reference codec implementation.

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