Add a speaker-dist config option

This can be used to specify an average speaker distance without having the
modify the decoder config files. This also sets a default value of 1, letting
near-field effects work (if imprecisely) without an explicitly-configured
distance.

1 files changed, 14 insertions, 14 deletions

diff --git a/alsoftrc.sample b/alsoftrc.sample
index f2b17982..4ea548ce 100644
--- a/alsoftrc.sample
+++ b/alsoftrc.sample
@@ -305,22 +305,22 @@
 ## nfc:
 #  Enables near-field control filters. This simulates and compensates for low-
 #  frequency effects caused by the curvature of nearby sound-waves, which
-#  creates a more realistic perception of sound distance. Note that the effect
-#  may be stronger or weaker than intended if the application doesn't use or
-#  specify an appropriate unit scale, or if incorrect speaker distances are set
-#  in the decoder configuration file.
+#  creates a more realistic perception of sound distance with surround sound
+#  output. Note that the effect may be stronger or weaker than intended if the
+#  application doesn't use or specify an appropriate unit scale, or if
+#  incorrect speaker distances are set. For HRTF output, hrtf-mode must be set
+#  to one of the ambi* values for this to function.
 #nfc = false
 
-## nfc-ref-delay
-#  Specifies the reference delay value for ambisonic output when NFC filters
-#  are enabled. If channels is set to one of the ambi* formats, this option
-#  enables NFC-HOA output with the specified Reference Delay parameter. The
-#  specified value can then be shared with an appropriate NFC-HOA decoder to
-#  reproduce correct near-field effects. Keep in mind that despite being
-#  designed for higher-order ambisonics, this also applies to first-order
-#  output. When left unset, normal output is created with no near-field
-#  simulation. Requires the nfc option to also be enabled.
-#nfc-ref-delay =
+## speaker-dist:
+#  Specifies the speaker distance in meters, used by the near-field control
+#  filters with surround sound output. For ambisonic output modes, this value
+#  is the basis for the NFC-HOA Reference Delay parameter (calculated as
+#  delay_seconds = speaker_dist/343.3). This value is not used when a decoder
+#  configuration is set for the output mode (since they specify the per-speaker
+#  distances, overriding this setting), or when the NFC filters are off. Valid
+#  values range from 0.1 to 10.
+#speaker-dist = 1
 
 ## quad:
 #  Decoder configuration file for Quadraphonic channel output. See