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Dolby Dolby Surround Surround Mixing Mixing Manual Manual Chapter Chapter 7 7 - - Video Video Games Games and and Multimedia Multimedia
7-3 7-3
Dolby Surround Game Mode is designed to assist computer game developers with Dolby Surround Game Mode is designed to assist computer game developers with creating sound creating sound
effects and elements that can be used effects and elements that can be used within the game and spatially placed within the game and spatially placed within the sound field within the sound field
by the game while being played. by the game while being played.
This is a mode of the This is a mode of the Dolby Surround encoder itself: A mono input signal, the Dolby Surround encoder itself: A mono input signal, the audio that will be audio that will be
positioned by the game, is processed by the game positioned by the game, is processed by the game mode encoder to produce a two-channel output mode encoder to produce a two-channel output
signal having the same F and S signal having the same F and S components as with the phase shifter just described. During game components as with the phase shifter just described. During game
play, this two-channel signal may be moved using the play, this two-channel signal may be moved using the positioner as described above. positioner as described above.
DOLBY DOLBY
GAME GAME
MODE
MODE
ENCODER ENCODER
2-CHANNEL 2-CHANNEL
MASTERING MASTERING
RECORDER RECORDER
F F
S S
F F
S S
GAME MODE GAME MODE
SOUND ELEMENT SOUND ELEMENT
DOLBY DOLBY
PRO LOGIC PRO LOGIC
SURROUND SURROUND
DECODER DECODER
L L
C C
R R
S S
MONITOR CHAIN MONITOR CHAIN
Lt Lt
Rt Rt
Lt Lt
Rt Rt
AMPS AMPS
AND AND
SPEAKERS SPEAKERS
PRODUCTION PRODUCTION
CHAIN CHAIN
MONO MONO
SPOT EFFECT SPOT EFFECT
DOLBY DOLBY
POSITIONER POSITIONER
L L/R /R F F/S /S
Figure 7-2 Signal Flow for Game Encoding Figure 7-2 Signal Flow for Game Encoding
The resulting signal has the same audio processing as other true The resulting signal has the same audio processing as other true Dolby Surround encoded Dolby Surround encoded
signals, and needs no extra phase shift processing during game play. The main disadvantage is signals, and needs no extra phase shift processing during game play. The main disadvantage is
that this mono element now occupies twice
that this mono element now occupies twice the audio storage space a the audio storage space a mono element would in the mono element would in the
delivered program. delivered program.
7.6 7.6 Modification Modification Principle Principle
Game mode encoding is accomplished by modifying a Dolby Surround encoder to Game mode encoding is accomplished by modifying a Dolby Surround encoder to remove the remove the
surround signal from the phase shift combine for the Left channel output surround signal from the phase shift combine for the Left channel output of the encoder. The of the encoder. The
input signal to be encoded is delivered input signal to be encoded is delivered to both the Left and S to both the Left and S urround channel inputs of the urround channel inputs of the
encoder. encoder.
-3 dB -3 dB
-3 dB -3 dB
BREAK BREAK
F COMPONENT F COMPONENT
S COMPONENT S COMPONENT
SOUND SOUND
Figure 7-3 Dolby Surround Game Encoding Figure 7-3 Dolby Surround Game Encoding
The left output (labeled Lt) of The left output (labeled Lt) of the encoder becomes the front information (F) and the encoder becomes the front information (F) and the right output the right output
(labeled Rt) of the encoder becomes the (labeled Rt) of the encoder becomes the rear (S) information. If you are using the rear (S) information. If you are using the Game Mode Game Mode
encoder in Dolby Surround Tools, these outputs are Left and Right, encoder in Dolby Surround Tools, these outputs are Left and Right, respectively. respectively.