AudioEngine

From Official Kodi Wiki
Revision as of 14:10, 19 January 2014 by UNiversal (talk | contribs) (Future additions)
Jump to: navigation, search
Home icon grey.png   ▶ Development ▶ AudioEngine

AudioEngine or (AE) refers to XBMC's new audio system. For more details about history see AudioEngine/History and Team.


 Audio: AudioEngine HOW-TO: Configure audio Windows Settings Intel Linux Modifications for HD Audio 

1 Features

AudioEngine replaces SDL and brings some of the external dependencies into XBMC, and wraps up all the different media types for mixing, samplerate conversion, format conversion, encoding, upmix, downmix, etc.

Features of AE include
  • Support for DTS-HD MA / Dolby TrueHD Bluray formats
  • 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 capabilities 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

It's still early days for AE. Bugs will be found, and new and exciting features added.

2 AudioEngine Settings

Audio settings can be found in the GUI at

Settings -> System -> Audio output

Refer to AudioEngine/HOW-TO: Configure audio for more detail.

3 Supported Audio Formats for Passthrough

A summary of some of the supported formats within the AudioEngine

Audio Codec Audio Source XBMC Passthrough Setting
HD DVD Blu-ray Disc DVD-Video DVD-Audio
Channels (max) Max bit rate Sample rate (max) Channels (max) Max bit rate Sample rate (max) Channels (max) Max bit rate Sample rate (max) Channels (max) Max bit rate Sample rate (max)
Dolby Digital (AC-3) 5.1 504 kbit/s 48 kHz / 16 bit 5.1 640 kbit/s 48 kHz / 16 bit 5.1 448 kbit/s 48 kHz / 16 bit 5.1 448 kbit/s 48 kHz / 16 bit Dolby Digital (AC3) capable receiver
Dolby Digital Plus (E-AC-3) 7.1 3 Mbit/s 48 kHz / 24 bit 7.1 1.7 Mbit/s 48 kHz / 24 bit N/A
DTS 5.1 (Core) 1536 kbit/s 48 kHz / 24 bit 5.1 (Core) 1536 kbit/s 48 kHz / 24 bit 6.1 768 kbit/s 48 kHz / 16 bit N/A DTS capable receiver
DTS 24/96 N/A 5.1 1536 kbit/s 96 kHz / 24-bit 5.1 1536 kbit/s 96 kHz / 24-bit
Linear PCM (LPCM) 7.1 27 Mbit/s 192 kHz / 24 bit 8.1 27 Mbit/s 192 kHz / 24 bit 5.1 6.1 Mbit/s 48 kHz / 16 bit 5.1 6.1 Mbit/s 96 kHz / 24 bit MultiChannel LPCM capable receiver
Dolby TrueHD 7.1 18 Mbit/s 192 kHz / 24 bit 7.1 18 Mbit/s 192 kHz / 24 bit N/A TrueHD capable receiver
DTS-HD High Resolution Audio (HRA) 7.1 6 Mbit/s 96 kHz / 24 bit 7.1 6 Mbit/s 96 kHz / 24 bit N/A DTS-HD capable receiver
DTS-HD Master Audio (MA) 5.1 18 Mbit/s 192 kHz / 24 bit 5.1 18 Mbit/s 192 kHz / 24 bit N/A
7.1 18 Mbit/s 96 kHz / 24 bit 7.1 18 Mbit/s 96 kHz / 24 bit N/A

3.1 Test audio files

Below You can find a excellent range of flac test audio files stereo/multichannel and varied sample/bit rates and quality.

Click here to to download flac test files

4 Hardware capabilities and reported to work

Legend - Templates - Formatting
Yes No N/A ? Code Name Plug Receiver
{{yes}} {{no}} {{NA}} {{?}} See: ATI | See: Nvidia '''HDMI''' '''Optical''' '''Analog''' '''TV/Receiver/Brand'''

Note: Dolby Digital Plus a.k.a. DD+ or E-AC-3 is supported in AE > ActiveAE (as of XBMC v13) and will not work properly in XBMC 12.3 or Older.

Feel free to update this list accordingly and add fields to table for other Audio types your hardware can or cant do. Please add your experience

ATI / AMD
Hardware and audio playback compatibility
HTPC Hardware External Equipment Audio Capabilities
Operative
System
Driver XBMC
Version
Model GPU - VPU type Audio device Code Name Limitation Plug Receiver Television AC3 LPCM DTS DTS-HD MA DTS-HD TrueHD DD+/E-AC3 Version Limitation
AMD A4-2800K APU Radeon HD 6450M Caicos Yes Yes Yes Yes Yes Yes ? 12.1 No No HDMI Denon Windows 7 x64 Pro
ASRock E350M1 Radeon HD 6310 Wrestler Yes ? Yes Yes Yes Yes ? 13.2 Beta6 No No HDMI Onkyo HT-R380 Windows 8 Pro, x64
ASRock E350M1 Radeon HD 6310 Wrestler Yes ? Yes No No No ? 12.10 Yes No HDMI Onkyo HT-R380 OpenELEC 3.0 RC4 (2.99.4)
AMD A4-3400 APU Radeon HD 6410D WinterPark Yes Yes Yes ? ? Yes ? 5.12.0.13 No No ? ? Windows 8 RTM
AMD A8-3870K APU Radeon HD 6550D BeaverCreek Yes No Yes No No No ? 12.1 Yes No ? ? Ubuntu 12.04 LTS
AMD A8-3870K APU Radeon HD 6550D BeaverCreek ? Yes ? Yes ? Yes ? 12.4 No No ? ? Windows 7 x64 Pro
Asus E45M1-I Deluxe Radeon HD 6320 Zacate Yes Yes Yes No No No ? 12.10 Yes No HDMI Denon AVR-3312 OpenELEC 3.0 (RC 1)
ZOTAC ZBOX AD04 PLUS Radeon HD 6320 Zacate Yes Yes Yes No No No ? ? Yes No HDMI Denon AVR-1713 XBMCbuntu 12.0 "FRODO"
Zotac ZBOX AD06 Radeon HD 7340 Zacate Yes Yes Yes No No No ? 12.10? Yes No HDMI Samsung AV-R720 OpenELEC 3.0.0
NVIDIA
Hardware and audio playback compatibility
HTPC Hardware External Equipment Audio Capabilities
Operative
System
Driver XBMC
Version
Model GPU - VPU type Audio device Code Name Limitation Plug Receiver Television AC3 LPCM DTS DTS-HD MA DTS-HD TrueHD DD+/E-AC3 Version Limitation
Gigabyte GV-N560OC-1GI GeForce GTX 560 GF110/GF114 Yes Yes Yes Yes ? Yes ? 313.09 No No ? ? OpenELEC 3.0
Asus EN210 GeForce 210 GT218 Yes Yes Yes Yes No Yes ? 302.17 No Yes ? ? Ubuntu 12.04 LTS
Gigabyte GT210 GeForce 210 GT218 Yes Yes Yes Yes ? Yes ? 310.19 No Yes ? ? Debian Wheezy
Asus ENGT430 DC SL DI GeForce GT 430 GF108 Yes Yes Yes Yes Yes Yes ? 295.59 No No ? ? Ubuntu 12.04 LTS
Asus ENGT520 GeForce GT 520 GF119 Yes Yes Yes Yes Yes Yes ? 310.19 No No HDMI Yamaha/HTR-4063 Debian Wheezy
EVGA GTX550 GeForce GTX 550 ti GF116 Yes Yes Yes Yes Yes Yes ? 304.43 No No HDMI Sony/STR-DN610 Ubuntu 12.10
Asus ENGTX560 GTX 560 TI GF110/GF114 Yes Yes Yes Yes Yes Yes ? 304.43 No No ? ? Ubuntu 12.04 LTS
Palit GT640 GeForce GT 640 GK107 Yes Yes Yes Yes Yes Yes ? 304.43 No No ? ? Ubuntu 12.04 LTS
Asus GT610-SL-1GD3-L Geforce GT610 GF119 Yes Yes Yes Yes Yes Yes ? 310.19 No No HDMI Onkyo TX-NR807 Slackware 13.37
Zotac GT430 Zone Edition GeForce GT 430 GF108 Yes Yes Yes Yes ? Yes ? 306.97 No No ? ? Windows 7 x64 Pro
Asrock ION 330HT GeForce 9400M G G96a/G96b Yes Yes Yes No No No Yes 304.64 No Yes HDMI TV/OTHER Ubuntu 12.04 LTS
ZOTAC GT 610 ZONE Ed. Geforce GT610 GF119 Yes Yes Yes Yes Yes Yes ? 331.65 No No HDMI Onkyo TX-SR608 Win8 64bit + XBMCbuntu

5 History and Team

AudioEngine, AE for short was two-year project spear-headed by Gnif which was released in v12 (Frodo), and was first merged with master for user testing as of May 15th, 2012.

5.1 Why write a new audio subsystem?

It's been an accepted fact that the existing audio code was little-touched since the early days of XBMC, and was limited by the 16-bit architecture of the original Xbox and codecs available at the time. Dolby AC3 and mp3 (or earlier formats!) ruled the media codec world. Over time HTPC's became more mainstream, more powerful and better connected. Analog gave way to optical SPDIF connections, in turn replaced with HDMI. Processors, GPU's and media formats evolved at a steady pace.

With the growth of the HTPC and new formats like those made available with Bluray technology, the audio subsystem was under scrutiny as an area for improvement. Higher definition audio like multichannel FLAC was becoming a preferred standard for those demanding higher quality audio media. It was time for an update, and what an update!

Early efforts at patching fixes and even an initial attempt at a completely new system fell by the wayside. The scope of the required changes and the complexity of the API made it a daunting task, especially for volunteer programmers working in their spare time. This was compounded by the fact that XBMC runs on a wide range of hardware and operating systems. Most of the developers focus on specific platforms or subsystems within the whole of XBMC. Any new system had to be platform-agnostic, cohesive and flexible.

In time, it became obvious the project was going to require a full re-write and replacement of the audio engine. Furthermore, XBMC's base of hardware and OS platforms continued to grow. The detailed specifications for the new audio formats were unknown, and of course the master code for XBMC was ever-changing.

5.2 Progress

In November of 2009 Gnif decided to bite the proverbial bullet, and after extensive consultation with the team finalized the API or structure which was to become AE. Drawing in other developers as required, the massive project slowly took shape, and reached the ready-point for user tests a year later. The forum thread for those hardy beta-testers (thank you!) reached over 1,200 posts, and slowly but surely features were added and debugged, and system stability grew.

Over the next two years, thanks to the determination of Gnif the core engines, decoders, encoders and utilities that make up AudioEngine became a reality, and other developers began to contribute to the core and especially the platform-specific sinks or output stages. Among those contributing were Gimli, Fneufneu, Memphiz, Dddamian, Anssi and others.

There was a goal to have the new audio system ready for Eden 11.0, but there was just too much left to do. Many users were eagerly looking forward to it's inclusion, but stable releases must continue, and AE wasn't ready when the Eden feature-freeze went into effect. During this time the AE code-base was solidified, bugs tracked and squashed, features added and testing increased.

Finally, on May 15th 2012, AudioEngine was merged to master. Weighing in at over 22,000 lines of code, it represents one of the single biggest code-merges ever for XBMC. Now for the first time it is readily accessible for all the development team (and users!) to see, test and improve within the greater context of XBMC's master branch.

5.2.1 ActiveAE

ActiveAE was a large rewrite of SoftAE and combined all platforms to one engine. Sinks are available for all platforms. ActiveAE uses an active state machine pattern, with a separate high priority sink thread, that cares for underruns. ActiveAE is completely build upon ffmpeg. It is used for resampling, channel mapping and decoding. High performance SSE algorithms do the final conversion into formats the sinks can accept. It uses float format internal and is working bit exact. A new feature is the upmix via AC3 transcoding support. On optical devices where only 2 pcm channels are available, we can now upmix to 5.1 by transcoding to ac3.

ActiveAE has three build-in profiles: Best Match, Optimized and Fixed.

  • Fixed takes care that all audio you will play is play in the very same data format. Your receiver does not need to switch modes.
  • Best Match is what previously existed as the "audiophile" mode. Whenever a new video or music playback starts, the audio engine will select the best sink for that stream.
  • Optimized is something special, as it tries to reduce the reopening of sinks a lot. One example is live-TV where it switches between 5.1 to 2.0 during commercials. In order to not open the device anew and loosing some (milliseconds of) audio, the 2.0 commercials are played with the already open 5.1 sink by muting the non existent channels.

The main developers of ActiveAE are Fernetmenta and Fritsch.

5.2.2 Current Developemnt

A PulseAudio sink for ActiveAE Called AESinkPULSE Was merged into XBMC mailine on the 9th January 2014. This enables Linux desktop users to use the PulseAudio system instead of ALSA. See Pulseaduio