
FLAC
FLAC stands for Free Lossless Audio Codec, an audio format similar to MP3, but lossless, meaning that audio is compressed in FLAC without any loss in quality. This is similar to how Zip works, except with FLAC you will get much better compression because it is designed specifically for audio.
Compression Level
Higher compression levels will result in smaler file sizes but longer encode times. Lower compression levels result in larger file sizes but encode faster. The compression level does not effect the sound quality of the file.
Sample Rate
Sample rate is the number of samples of audio carried per second, measured in Hz or kHz (1000 Hz). 44.1 kHz is the sampling rate of audio CDs and 48.0 kHz is commonly used for professional video. Higher sample rates result in higher quality audio with larger file sizes. Setting this to Auto will create an output file with the same sample rate as the input file.
Bit Depth
Bit Depth defines the numer of bits (1's and 0's) used to represent each sample.
By increasing the bit depth, quantization noise is reduced improving the signal to noise ratio. For each 1-bit increment in bit depth, the S/N will increase by 6dB. 24-bit digital audio has a theoretical maximum S/N of 144 dB, compared to 96 dB for 16-bit. Audio CDs use a bit depth of 16 bits. 24-bit is common in professional audio and video environments.
Verify Encoding
With this option, a decoder is run in parallel to the encoder and its output is compared against the original input. If a difference is found flac will stop with an error.