Dolby has expanded the Dolby TrueHD format to allow the format to support Dolby Atmos content on Blu-ray and ultra high definition Blu-ray Disc. Prior to Dolby Atmos, Dolby TrueHD provided lossless support for channel-based audio, such as 5.1 and 7.1. Now we have added a fourth substream for Dolby Atmos sound in Dolby TrueHD codec to enable a support for a losslessly encoded object-based sound mix.
Dolby Atmos in Dolby TrueHD is transmitted from a Blu-ray player or Ultra HD Blu-ray player to your AVR via an HDMI connection. If your AVR supports Dolby Atmos, the Dolby TrueHD object-based audio and related metadata will be decoded, processed, scaled, and rendered to your specific speaker configuration. Dolby Atmos audio can be encoded with Dolby TrueHD at multiple sampling rates (including 48 and 96 kHz) and bit depths (16- and 24-bit).
Dolby Atmos enabled receivers will also support legacy Dolby TrueHD bitstreams at multiple sampling rates (including 48, 96, and 192 kHz) and bit depths (16-, 20-, and 24-bit) to provide full backward compatibility with legacy Blu-ray Disc media and Dolby TrueHD music files.