Atrac 3

We believe that Atrac 3 uses principles like Hybrid-Filter bank, Gain Control, Huffman-Coding and Rate Loop, which means that at least a license under the following patents of Fraunhofer or Thomson is needed:

ep0287578b1 (OCF Basis: Rate Loop)
ep0612156b1 (OCF Supplement: ESC)
ep0193143b1 (Grouping of values, suppression of signal compression below thresshold)
ep0251028b1 (Masking threshold covering more than one group)
ep0277613b1 (Masking threshold in adjacent groups)

Note: This list is not exhaustive; other patents of Fraunhofer and Thomson might be used.

We have not yet determined our licensing policy for this format nor do we have details of the licensing program of Sony.