AFsetSpeaker


Routine:

int AFsetSpeaker (const char String[])

Purpose:

Set loudspeaker spatial positions

Description:

This routine sets the mapping of output channels to speaker positions. The spatial positions of the loudspeakers are specified as a list of comma and/or white-space separated locations from the list below.

          Name                    IEC 62574  AES 22.2 WAVE Ext
  "FL"    - Front Left                x        1/1       x
  "FR"    - Front Right               x        1/2       x
  "FC"    - Front Center              x        2/1       x
  "LFE1"  - Low Frequency Effects-1   x        2/2       x
  "BL"    - Back Left                 x        3/1       x
  "BR"    - Back Right                x        3/2       x
  "FLc"   - Front Left center         x        4/1       x
  "FRc"   - Front Right center        x        4/2       x
  "BC"    - Back Center               x        5/1       x
  "LFE2"  - Low Frequency Effects-2   x        5/2
  "SiL"   - Side Left                 x        6/1       x
  "SiR"   - Side Right                x        6/2       x
  "TpFL"  - Top Front Left            x        7/1       x
  "TpFR"  - Top Front Right           x        7/2       x
  "TpFC"  - Top Front Centre          x        8/1       x
  "TpC"   - Top Centre                x        8/2       x
  "TpBL"  - Top Back Left             x        9/1       x
  "TpBR"  - Top Back Right            x        9/2       x
  "TpSiL" - Top Side Left             x       10/1
  "TpSiR" - Top Side Right            x       10/2
  "TpBC"  - Top Back Centre           x       11/1       x
  "BtFC"  - Bottom Front Centre       x       11/2
  "BtFL"  - Bottom Front Left         x       12/1
  "BtFR"  - Bottom Front Right        x       12/2
  "FLw"   - Front Left wide           x
  "FRw"   - Front Right wide          x
  "LS"    - Left Surround             x
  "RS"    - Right Surround            x
  "LSd"   - Left Surround direct      x
  "RSd"   - Right Surround direct     x
  "TpLS"  - Top Left Surround         x
  "TpRS"  - Top Right Surround        x
  "-"     - No speaker assigned

A speaker position can be associated with only one channel. For compatibility with previous usage, some synonyms are applicable. For instance

  "LF"   -> "LFE1"
  "SL"   -> "SiL", ...
  "TpFL" -> "TFL", ...
Configuration Names:

The following names can be used to set a speaker location configuration.

  "Stereo" : "FL FR"
  "Quad"   : "FL, FR, BL BR"
  "5.1"    : "FL, FR, FC, LFE1, BR, BL"
  "7.1"    : "FL, FC, FR, LFE1, BR, BL, SiL, SiR"
WAVE extensible files:

These files can store the speaker locations in the file header if certain constraints are in place.

- The list of available speaker locations are:
FL, FR, FC, LFE1, BL, BR FLc, FRc, BC, SiL, SiR, TpC, TpFL, TpFC, TpFR, TpBR, TpBC, TpBR
- Assume M speaker locations are specified. These must be associated with the
first M audio channels.
- The speaker locations must be in the same order as the list, but specific
locations can be skipped.
- As an example, the order "FL FR TpC" is valid, but "FL FC FR" is not.
AIFF-C files:

Speaker locations are implicit in AIFC-C audio files.

- Stereo: "FL FR"
- 3 channel: "FL FR FC"
- Quadraphonic" "FR FR BL BR"
- 4 channel surround: "FL FC FR BC"
- 6 channel surround: "FL FLc FC FRc FR BC"
AU, AIFF, AIFF-C, and WAVE (non-extensible):

Speaker locations appear as an information record of the form,

  "loudspeakers: FL FR LFE1"

This speaker location record is one of the standard information records which appear in the file header.

Parameters:

<- int AFsetSpeaker
Error flag, zero for no error
-> const char String[]
String containing the comma and/or white-space separated list of speaker positions

Author / revision:

P. Kabal / Revision 1.18 2017-06-12

See Also

AFopnWrite


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