Difference between revisions of "User:Jeff Kelley/Multichannel Audio"

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</div>
 
</div>
  
== Introduction ==
+
==Introduction==
  
 
Since QuickTime 7, it is possible to deliver multichannel audio. Second Life streamed audio relies on QuickTime and inherits this capability without further work.
 
Since QuickTime 7, it is possible to deliver multichannel audio. Second Life streamed audio relies on QuickTime and inherits this capability without further work.
  
== Producing a multichannel audio movie ==
+
==Producing a multichannel audio movie==
  
'''Step 1: Produce an interleaved multichannel WAV file'''
+
===Step 1: Produce an interleaved multichannel WAV file===
  
 
We are using ProTools. Bounce a multichannel session to Stereo interleaved format:
 
We are using ProTools. Bounce a multichannel session to Stereo interleaved format:
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[[Image:PT Multichannel Track.png]]
 
[[Image:PT Multichannel Track.png]]
  
'''Step 2: Open with QuickTime Pro'''
+
===Step 2: Open with QuickTime Pro===
  
 
Choose menu 'Show Movie Properties', select 'Sound Track', select 'Audio Settings' tab:
 
Choose menu 'Show Movie Properties', select 'Sound Track', select 'Audio Settings' tab:
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[[Image:QT Audio Tracks Assign.png]]
 
[[Image:QT Audio Tracks Assign.png]]
  
'''Step 3: Export to QuickTime Movie'''
+
===Step 3: Export to QuickTime Movie===
  
 
Choose 'Export', 'Movie to QuickTime Movie', 'Options', 'Sound Settings', 'Channels'.
 
Choose 'Export', 'Movie to QuickTime Movie', 'Options', 'Sound Settings', 'Channels'.
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[[Image:QT_Audio_Tracks_Export.png]]
 
[[Image:QT_Audio_Tracks_Export.png]]
  
==== Channels Assignements ====
+
===Step 4: Stream the usual way===
 +
 
 +
Using an HTTP server and Second Life's 'About Land > Media'.
 +
 
 +
 
 +
==Playing multichannel audio==
 +
 
 +
 
 +
==QuickTime multichannel audio support==
 +
 
 +
===Channels Assignements===
 +
 
 
{|{{Prettytable}}
 
{|{{Prettytable}}
| Left
 
 
| L
 
| L
 +
| Left
 
|-  
 
|-  
| Right
 
 
| R
 
| R
 +
| Right
 
|-
 
|-
| Center
 
 
| C
 
| C
 +
| Center
 
|-
 
|-
| LFE Screen
 
 
| LFE
 
| LFE
 +
| LFE Screen
 
|-
 
|-
 +
| Ls
 
| Left Surround
 
| Left Surround
| Ls
 
 
|-  
 
|-  
| Right Surround
 
 
| Rs
 
| Rs
 +
| Right Surround
 
|-  
 
|-  
| Left Center
 
 
| Lc
 
| Lc
 +
| Left Center
 
|-  
 
|-  
 +
| Rc
 
| Right Center
 
| Right Center
| Rc
 
 
|-
 
|-
| Center Surround
 
 
| Cs
 
| Cs
 +
| Center Surround
 
|-  
 
|-  
| Rear Surround Left
 
 
| Rls
 
| Rls
 +
| Rear Surround Left
 
|-  
 
|-  
| Rear Surround Right
 
 
| Rrs
 
| Rrs
 +
| Rear Surround Right
 
|}
 
|}
 +
 +
Note: For a full-reference, see
 +
http://developer.apple.com/documentation/MusicAudio/Reference/CACoreAudioReference/CoreAudioTypes/CompositePage.html
 +
  
  
 +
Note: QuickTime also support the following recording formats: XY Stereo, MS Stereo, WXYZ Ambisonic (B-Format). The latter is especially interesting for immersive 3D with soundfield recordings. Although consumer multichannel audio supports only surround formats, some succes has been achieved matrixing ambisonics to surround. See Robert Miller, AES 2003 http://www.ambiophonics.org/AESJune2003/AES_June_2003_1.htm 
  
 
==== Multichannel Mixing and Surround Formats ====
 
==== Multichannel Mixing and Surround Formats ====

Revision as of 03:47, 25 December 2007

   WORK IN PROGRESS

Introduction

Since QuickTime 7, it is possible to deliver multichannel audio. Second Life streamed audio relies on QuickTime and inherits this capability without further work.

Producing a multichannel audio movie

Step 1: Produce an interleaved multichannel WAV file

We are using ProTools. Bounce a multichannel session to Stereo interleaved format:

PT Multichannel Track.png

Step 2: Open with QuickTime Pro

Choose menu 'Show Movie Properties', select 'Sound Track', select 'Audio Settings' tab:

QT Audio Tracks Assign.png

Step 3: Export to QuickTime Movie

Choose 'Export', 'Movie to QuickTime Movie', 'Options', 'Sound Settings', 'Channels'.

QT Audio Tracks Export.png

Step 4: Stream the usual way

Using an HTTP server and Second Life's 'About Land > Media'.


Playing multichannel audio

QuickTime multichannel audio support

Channels Assignements

L Left
R Right
C Center
LFE LFE Screen
Ls Left Surround
Rs Right Surround
Lc Left Center
Rc Right Center
Cs Center Surround
Rls Rear Surround Left
Rrs Rear Surround Right

Note: For a full-reference, see http://developer.apple.com/documentation/MusicAudio/Reference/CACoreAudioReference/CoreAudioTypes/CompositePage.html


Note: QuickTime also support the following recording formats: XY Stereo, MS Stereo, WXYZ Ambisonic (B-Format). The latter is especially interesting for immersive 3D with soundfield recordings. Although consumer multichannel audio supports only surround formats, some succes has been achieved matrixing ambisonics to surround. See Robert Miller, AES 2003 http://www.ambiophonics.org/AESJune2003/AES_June_2003_1.htm

Multichannel Mixing and Surround Formats

Format Channels Layout
Mono 1 C
Stereo 2 L R
Cinema Stereo 3 L C R
Quadraphonic 4 L R Lr Rr
Dolby ProLogic 4 L C R S
Film (Dolby Digital) 6 L C R Ls Rs LFE
SMPTE/ITU 6 L R C LFE Ls Rs
DTS 6 L R Ls Rs C LFE
Dolby Surround EX 7 L C R Ls Cs Rs LFE
SDDS 8 L Lc C Rc R Ls Rs LFE



NOTE: delete Image:Jef Kelley Images QT Audio Tracks Assign.png (stupid one)