1 Ambisonic decoder configuration presets are provided here for common surround
2 sound speaker layouts. The presets are prepared to work with OpenAL Soft's high
3 quality decoder. By default all of the speaker distances within a preset are
4 set to the same value, which results in no effect from distance compensation.
5 If this doesn't match your physical speaker setup, it may be worth copying the
6 preset and modifying the distance values to match (note that modifying the
7 azimuth and elevation values in the presets will not have any effect; the
8 specified angles do not change the decoder behavior).
10 Details of the individual presets are as follows.
13 Specifies a basic square speaker setup for Quadraphonic output, with identical
14 width and depth. Front speakers are placed at +45 and -45 degrees, and back
15 speakers are placed at +135 and -135 degrees.
18 Specifies a narrower speaker setup for Quadraphonic output, with a little less
19 width but a little more depth over a basic square setup. Front speakers are
20 placed at +30 and -30 degrees, providing a bit more compatibility for existing
21 stereo content, with back speakers at +150 and -150 degrees.
24 Specifies a standard ITU 5.0/5.1 setup for 5.1 Surround output. The front-
25 center speaker is placed directly in front at 0 degrees, with the front-left
26 and front-right at +30 and -30 degrees, and the surround speakers (side or
27 back) at +110 and -110 degrees.
30 Specifies a flat-front hexagonal speaker setup for 7.1 Surround output. The
31 front left and right speakers are placed at +30 and -30 degrees, the side
32 speakers are placed at +90 and -90 degrees, and the back speakers are placed at
33 +150 and -150 degrees. Although this is for 7.1 output, no front-center speaker
34 is defined for the decoder, meaning that speaker will be silent for 3D sound
35 (however it may still be used with AL_SOFT_direct_channels or ALC_EXT_DEDICATED
36 output). A "proper" 7.1 decoder may be provided in the future, but due to the
37 nature of the speaker configuration will have trade-offs.
40 Specifies a flat-front hexagonal speaker setup, plus an elevated quad speaker
41 setup, for 7.1.4 Surround output. The front left and right speakers are placed
42 at +30 and -30 degrees, the side speakers are placed at +90 and -90 degrees,
43 and the back speakers are placed at +150 and -150 degrees. The elevated
44 speakers are placed at an elevation of +35 degrees, with the top front left and
45 right speakers placed at +45 and -45 degrees, and the top back left and right
46 speakers placed at +135 and -135 degrees. Similar to 7.1, the front-center
47 speaker is not used for 3D sound, but will be used as appropriate with
48 AL_SOFT_direct_channels or ALC_EXT_DEDICATED.
51 Specifies a 3D7.1 speaker setup for 3D7.1 Surround output. Please see
52 docs/3D7.1.txt for information about speaker placement. Similar to 7.1, the
53 front-center speaker is not used for 3D sound, but will be used as appropriate
54 with AL_SOFT_direct_channels or ALC_EXT_DEDICATED.