Changeset 2837

Timestamp:

02/15/07 16:34:24 (6 years ago)

Author:

jgaeddert

Message:

minor updates to documentation, code

Location:

components/CVSDEncoder/trunk/CVSDEncoder

Files:

• CVSDEncoder.cpp (modified) (1 diff)
• CVSDEncoder.h (modified) (1 diff)
• Doxyfile (modified) (1 diff)
• documentation.txt (modified) (4 diffs)

components/CVSDEncoder/trunk/CVSDEncoder/CVSDEncoder.cpp

@@ -61 +61 @@
          kr,
          min_gain,
-         max_gain,
-         0.1     // zeta (energy filter coefficient)
-    );
+         max_gain);
 
     //Create the thread for the writer's processing function 

components/CVSDEncoder/trunk/CVSDEncoder/CVSDEncoder.h

@@ -38 +38 @@
 #include "sigproc/SigProc.h"
 
+/// This is a description of the CVSD Encoder class...
 class CVSDEncoder_i : public virtual Resource_impl
 {

components/CVSDEncoder/trunk/CVSDEncoder/Doxyfile

@@ -234 +234 @@
 # will be included in the documentation.
 
-EXTRACT_PRIVATE        = NO
+EXTRACT_PRIVATE        = YES
 
 # If the EXTRACT_STATIC tag is set to YES all static members of a file 

components/CVSDEncoder/trunk/CVSDEncoder/documentation.txt

@@ -4 +4 @@
 Continuously variable slope delta (CVSD) source encoding is used for data compression
 of audio signals.  It is a form of delta modulation where the delta value
-(step size) is changed continuously to minimize slope-overload distortion [1].
+(step size) is changed continuously to minimize slope-overload distortion [1,
+p. 131].
 The output bit stream has a rate equal to that of the sampling frequency.
 CVSD is a lossy compression whose quality is directly related to the sampling
@@ -13 +14 @@
 \section properties Properties
 
-\subsection adjacent_bits adjacent_bits (DCE:ddfc035a-423c-499b-845d-075017002a69)
-The number of adjacent identical bits observed before the slope doubles.
+\subsection prop_adjacent_bits adjacent_bits (DCE:ddfc035a-423c-499b-845d-075017002a69)
+The number of adjacent identical bits observed before the slope is increased
+(doubles).  Generally \f$N\f$ is chosen to be 3 or 4.  The default value is 3.
 
-\subsection agc_strength agc_strength (DCE:xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx)
+\subsection prop_agc_strength agc_strength (DCE:xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx)
 The automatic gain control (AGC) within the CVSD Encoder conditions the input
 signal's energy to be within a certain range.  This improves the encoding
@@ -28 +30 @@
 property.  agc_strength can take on unsigned (short) integer values from zero
 to 100.  Typical values for are:
- - No AGC: 0
- - External PC microphone near user: 50
- - External PC microphone 20 ft. from user: 90
+ - 0 : no gain control
+ - 50 : external PC microphone near user
+ - 90 : external PC microphone greater than 10 ft. from user
 
 NOTE: this feature has not yet been implemented
 
-\subsection vox vox (DCE:xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx)
+\subsection prop_vox vox (DCE:xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx)
 The CVSD encoder implements a voice-operated switch (vox) which allows
-transmission to be contingent upon audio levels.
+transmission to be contingent upon audio levels.  
+The vox relies on the AGC
+for determining signal levels, so the \ref prop_agc_strength property must be
+greater than zero for the vox to be active.  The vox threshold is set
+automatically from the AGC gain level.
 
 NOTE: this feature has not yet been implemented
@@ -57 +63 @@
 
 \section algorithm Detailed Description of Algorithm
+...where \f$N\f$ is the number of adjacent bits... (see \ref prop_adjacent_bits)
+
 The error signal is defined as
 \f[