San Francisco -Dolby has developed
a way to improve the sound quality of lossless Blu-ray soundtracks played back
through home theater systems.
The company is incorporating
Meridian-developed 96kHz upsampling technology into Dolby Media Producer, a
post-production product that encodes Dolby TrueHD bitstreams for use on Blu-ray
discs. The technology creates 96kHz Dolby TrueHD soundtracks from the 48kHz-PCM
mixes that the movie industry creates for movie theaters, which use 48kHz
playback equipment.
The technology, called Advanced
96k Upsampling, delivers more natural sound through home theater audio systems,
Dolby said. The soundtracks are
backward-compatible with any home theater system and Blu-ray player, Dolby
added.
The technology, which is available
as a software upgrade to Dolby’s post-production equipment, uses an advanced
upsampling algorithm developed by high-end audio supplier
Meridian, whose technology is also the foundation for Dolby TrueHD, Dolby said.
Although many home theater audio
components upsample audio to 96kHz, most lack the processing power to deliver
the performance that the Meridian technology does when applied during the
content-creation process, Dolby said. Delivering native 96kHz bitstreams to the
AV receiver also ensures a clearer pathway for DSP processing and D-to-A
conversion in the receiver, Dolby said.
Advanced 96k Upsampling technology
also uses what Dolby calls an apodising filter to identify and mask digital
artifacts — referred to as “pre-ringing” — introduced upstream in the analog-to-digital
conversion process during content creation. The result is a smoother, more
detailed listing experience with rich reverb and more spaciousness, Dolby explained.
The improvements provided by Advanced 96k
Upsampling can be subtle or immediately evident, depending upon content, the
company said.
Dolby foresees the technology
being applied to catalog titles as well as to new releases. The discs would
bear an advanced 96k upsampling designation. This technology is exclusive to
Dolby TrueHD
The Blu-ray format supports
uncompressed 7.1-channel PCM soundtracks with sampling rates up to 96kHz with
resolutions up to 24 bits per channel. The format also supports 5.1 channels of
PCM up to 192kHz with 24-bit resolution. For Dolby TrueHD and dts-HD Master
Audio soundtracks, which are losslessly compressed, Blu-ray supports the same
sampling rates and resolutions.
