XBMC Rewrite Includes Dolby TrueHD and DTS-HD Master Audio

Fans of XBMC who've wanted their HTPCs to replace the higher end components of a home theater setup such as Blu-ray players and higher-end receivers are having their wishes fulfilled through a completely reworked sound system.

AudioEngine, as it's called, can process every stage of audio encoding and decoding, even with 7.1-channel formats like Dolby TrueHD and DTS-HD Master Audio. As the code uses more precise floating point math, the improvements can bolster heavily compressed audio and allow for upmixing from stereo to a native surround format. Sound should sync more closely to video and avoid any jarring interruptions from system sounds as wll.

Features of AudioEngine include:

- support for DTS-MA / Dolby TrueHD Bluray formats (OSX pending)
- support for 24-bit and floating-point audio at up to 384,000hz
- mixing of all streams including GUI sounds even when transcoding audio
- start-up enumeration of hardware audio devices and their capablities with log output
- bitstreaming support in PAPlayer (XBMC’s music player)
- upmixing of stereo to full channel layout
- tighter syncing of A/V streams
- floating-point processing of audio
- 24-bit and floating-point decoding/handling of mp3
- full support for ReplayGain
- built-in sample-rate conversion and transcoding

Planned Features for upcoming AudioEngine releases:

- rules-based decisions for output formats based on hardware capabilites
- a range of DSP’s (digital signal processors) including headphone head-related transfer function processing, DRC (dynamic range compression), low-pass filtering for subs and an equalizer function
- custom channel-mixing/mapping for up and downmixing

The AudioEngine update is still limited to experimental nightly builds of XBMC, so don't be surprised if something goes awry, but it's slated as part of the main development track and should be a boon for just about any XBMC media junkie before long.