Lossless Transform Audio Compression (LTAC) allows lossless compression of pulse-coded audio signals and error-free decoding into the original bitstream. There are several LTAC versions, which differ in improved compression, number of audio channels, user interface and performance increase due to a new adaptation algorithm.
LTAC compression has some disadvantages compared to Lossless Predictive Audio Compression( LPAC) in terms of encoding and decoding speed and is therefore not developed further. With LPAC compression there is a method that is based on the prediction of events. LPAC has been incorporated into the activities ofMPEG-4 as MPEG-4 Audio Lossless Coding( ALS).
Since there is no difference in sound quality with lossless compression, the focus of these audio codecs is on the codec speed for compression and decompression, as well as on the sampling rate and the resulting file size.