This was encoded with the libopus encoder in VBR mode, giving the encoder plenty of headroom to allocate additional bits to complex audio passages when needed, using the highest-quality sources available for these editions (Dolby EAC-3 files at 762 kbps). The original surround sound layout was preserved by encoding the audio as 5.1-channel Opus, retaining the surround effects and spatial audio experience of the source. The final files average around 112 kbps. This is thanks to Opus’s high efficiency compared with codecs such as AAC and EAC-3, allowing it to maintain almost the same audio quality at a significantly lower average bitrate.