FLAC is a lossless encoder and will encode audio perfectly without loss. The size of the encoded file can vary, depending on how much time you want FLAC to spend on compression. If you have a fast CPU, select Best to get the smallest possible files.

The flac tool is used for encoding, and is included in iRecordMusic.

The metaflac tool is used for adding comments to FLAC files, and is included in iRecordMusic.