app_amd: Correct maximum_number_of_words functionality & documentation

- The maximum_number_of_words was previously documented as being
the number of words that when exceeded, would result in the AMD
application returning that the audio represents a machine.

This was inconsistent with its actual functionality - it was
a number of words that when REACHED, would result in determination
as a machine.

This update corrects the functionality to match the previously
documented functionality.  This is a backwards incompatible change
in configuration file, and has been added to UPGRADE.txt as a result.

The sample configuration file and application defaults have been updated
so that the default value is now 2, which reflects the same default
functionality as previous versions.

- Update documentation for silence_threshold, which previously implied
that it was measuring time, rather than noise averages in the sample.

- Update the comments in amd.conf.sample.

ASTERISK-25639 #close
Change-Id: I4b1451e5dc9cb3cb06d59b6ab872f5275ba79093

1 files changed, 17 insertions, 9 deletions

diff --git a/configs/samples/amd.conf.sample b/configs/samples/amd.conf.sample
index d7323ecf2..d1764b50c 100644
--- a/configs/samples/amd.conf.sample
+++ b/configs/samples/amd.conf.sample
@@ -3,17 +3,25 @@
 ;
 
 [general]
+total_analysis_time = 5000	; Maximum time allowed for the algorithm to decide
+				; on whether the audio represents a HUMAN, or a MACHINE
+silence_threshold = 256		; If the average level of noise in a sample does not reach
+				; this value, from a scale of 0 to 32767, then we will consider
+				; it to be silence.
+
+; Greeting ;
 initial_silence = 2500		; Maximum silence duration before the greeting.
-				; If exceeded then MACHINE.
-greeting = 1500			; Maximum length of a greeting. If exceeded then MACHINE.
+				; If exceeded, then the result is detection as a MACHINE.
 after_greeting_silence = 800	; Silence after detecting a greeting.
-				; If exceeded then HUMAN
-total_analysis_time = 5000	; Maximum time allowed for the algorithm to decide
-				; on a HUMAN or MACHINE
+				; If exceeded, then the result is detection as a HUMAN
+greeting = 1500			; Maximum length of a greeting. If exceeded, then the
+				; result is detection as a MACHINE.
+
+; Word detection ;
 min_word_length = 100		; Minimum duration of Voice to considered as a word
+maximum_word_length = 5000  	; Maximum duration of a single Voice utterance allowed.
 between_words_silence = 50	; Minimum duration of silence after a word to consider
 				; the audio what follows as a new word
-maximum_number_of_words = 3	; Maximum number of words in the greeting.
-				; If exceeded then MACHINE
-maximum_word_length = 5000      ; Maximum duration of a single Voice utterance allowed.
-silence_threshold = 256
+
+maximum_number_of_words = 2	; Maximum number of words in the greeting
+				; If exceeded, then the result is detection as a MACHINE