[Freeswitch-svn] [commit] r10720 - freeswitch/trunk/src/mod/applications/mod_vmd
FreeSWITCH SVN
ericdc at freeswitch.org
Thu Dec 11 14:13:21 PST 2008
Author: ericdc
Date: Thu Dec 11 17:13:20 2008
New Revision: 10720
Log:
Added useful comments.
Eric
Modified:
freeswitch/trunk/src/mod/applications/mod_vmd/mod_vmd.c
Modified: freeswitch/trunk/src/mod/applications/mod_vmd/mod_vmd.c
==============================================================================
--- freeswitch/trunk/src/mod/applications/mod_vmd/mod_vmd.c (original)
+++ freeswitch/trunk/src/mod/applications/mod_vmd/mod_vmd.c Thu Dec 11 17:13:20 2008
@@ -50,35 +50,40 @@
#define ISNAN(x) ((x)== NAN)
#endif
-/* Number of points for beep detection */
+/*! Number of points for beep detection */
#define POINTS 32
-/* Number of valid points required for beep detection */
+/*! Number of valid points required for beep detection */
#define VALID 22
-/* Maximum number of invalid points
- * to declare beep has stopped */
+/*! Maximum number of invalid points to declare beep has stopped */
#define MAX_CHIRP 22
-/* Minimum time for a beep */
+/*! Minimum time for a beep */
#define MIN_TIME 8000
-/* Minimum amplitude of the signal */
+/*! Minimum amplitude of the signal */
#define MIN_AMPL 0.10
-/* Minimum beep frequency */
+/*! Minimum beep frequency */
#define MIN_FREQ (600)
-/* Maximum beep frequency */
+/*! Maximum beep frequency */
#define MAX_FREQ (1100)
-/* PSI function for amplitude calculation*/
+/*! \brief \f$\psi{(x)}\f$ function for amplitude calculation
+ *
+ * \f$\psi{(x)} = {x^2_1} - {x_2} {x_0}\f$
+ */
#define PSI(x) (x[1]*x[1]-x[2]*x[0])
-/* Sample rate */
+/*! Sample rate NOTE: this should be dynamic in the future */
#define F (8000)
-/* Conversion of frequency to Hz */
+/*! \brief Conversion of frequency to Hz
+ *
+ * \f$F = \frac{f}{{2}{\pi}}\f$
+ */
#define TO_HZ(f) ((F * f) / (2.0 * M_PI))
/* Number of points in discreet energy separation */
@@ -91,22 +96,22 @@
* DEPRECATED */
#define ADJUST_MAX (65536)
-/* Discreet energy separation tolerance to error */
+/*! Discreet energy separation tolerance to error */
#define TOLERANCE (0.20)
-/* Maximum value within tolerance */
+/*! Maximum value within tolerance */
#define TOLERANCE_T(m) (m + (m * TOLERANCE))
-/* Minimum value within tolerance */
+/*! Minimum value within tolerance */
#define TOLERANCE_B(m) (m - (m * TOLERANCE))
-/* Syntax of the API call */
+/*! Syntax of the API call */
#define VMD_SYNTAX "<uuid> <command>"
-/* Number of expected parameters in api call */
+/*! Number of expected parameters in api call */
#define VMD_PARAMS 2
-/* FreeSWITCH CUSTOM event type */
+/*! FreeSWITCH CUSTOM event type */
#define VMD_EVENT_BEEP "vmd::beep"
/* Prototypes */
@@ -117,39 +122,39 @@
SWITCH_MODULE_DEFINITION(mod_vmd, mod_vmd_load, NULL, NULL);
SWITCH_STANDARD_APP(vmd_start_function);
-/* Type that holds state information about the beep */
+/*! Type that holds state information about the beep */
typedef enum vmd_state {
BEEP_DETECTED, BEEP_NOT_DETECTED
} vmd_state_t;
-/* Type that holds data for 5 points of discreet energy separation */
+/*! Type that holds data for 5 points of discreet energy separation */
typedef struct vmd_point {
double freq;
double ampl;
} vmd_point_t;
-/* Type that holds codec information */
+/*! Type that holds codec information */
typedef struct vmd_codec_info {
int rate;
int channels;
} vmd_codec_info_t;
-/* Type that holds session information pertinent to the vmd module */
+/*! Type that holds session information pertinent to the vmd module */
typedef struct vmd_session_info {
- /* State of the session */
+ /*! State of the session */
vmd_state_t state;
- /* Snapshot of DESA samples */
+ /*! Snapshot of DESA samples */
vmd_point_t points[POINTS];
- /* Internal FreeSWITCH session */
+ /*! Internal FreeSWITCH session */
switch_core_session_t *session;
- /* Codec information for the session */
+ /*! Codec information for the session */
vmd_codec_info_t vmd_codec;
- /* Current position in the snapshot */
+ /*! Current position in the snapshot */
unsigned int pos;
- /* Frequency aproximation of a detected beep */
+ /*! Frequency aproximation of a detected beep */
double beep_freq;
- /* A count of how long a distinct beep was detected by
- * by the discreet energy separation algorithm */
+ /*! A count of how long a distinct beep was detected by
+ * by the discreet energy separation algorithm */
switch_size_t timestamp;
} vmd_session_info_t;
@@ -202,6 +207,7 @@
return SWITCH_TRUE;
}
+/*! Process and convert data to be used by the find_beep() function */
static switch_bool_t process_data(vmd_session_info_t * vmd_info, switch_frame_t * frame)
{
uint32_t i;
@@ -253,6 +259,7 @@
return SWITCH_TRUE;
}
+/*! Find voicemail beep in the audio stream */
static void find_beep(vmd_session_info_t * vmd_info, switch_frame_t * frame)
{
int i;
@@ -347,7 +354,7 @@
}
}
-/* Find the median of an array of doubles */
+/*! Find the median of an array of doubles */
static double median(double *m, int n)
{
int i;
@@ -411,17 +418,20 @@
return mingtguess;
}
-/* Convert many points for Signed L16 to relative floating point */
+/*! Convert many points for Signed L16 to relative floating point */
static void convert_pts(int16_t * i_pts, double *d_pts, int16_t max)
{
int i;
for (i = 0; i < P; i++) {
- /* Signed L16 to relative floating point conversion */
+ /*! Signed L16 to relative floating point conversion */
d_pts[i] = ((((double) (i_pts[i]) + (double) max) / (double) (2 * max)) - 0.5) * 2.0;
}
}
-/* Amplitude estimator for DESA-2 */
+/*! \brief Amplitude estimator for DESA-2
+ *
+ * \f$A = \sqrt{\frac{\psi{(x)}}{\sin{\Omega^2}}}\f$
+ */
double ampl_estimator(double *x)
{
double freq_sq;
@@ -432,7 +442,15 @@
return sqrt(PSI(x) / sin(freq_sq));
}
-/* The DESA-2 algorithm */
+/*! \brief The DESA-2 algorithm
+ *
+ * \f$\frac{1}{2}\arccos{\frac{{{x^2_2} -
+ * {x_0}{x_4}} - {{x^2_1} -
+ * {x_0}{x_2}} - {{x^2_3} -
+ * {x_2}{x_4}}}
+ * {{2}({x^2_2} - {x_1}{x_3})}}\f$
+ *
+ */
double freq_estimator(double *x)
{
return 0.5 * acos((((x[2] * x[2]) - (x[0] * x[4]))
@@ -443,7 +461,7 @@
);
}
-
+/*! FreeSWITCH module loading function */
SWITCH_MODULE_LOAD_FUNCTION(mod_vmd_load)
{
switch_application_interface_t *app_interface;
@@ -461,7 +479,7 @@
return SWITCH_STATUS_SUCCESS;
}
-/* Same as api function see it for comments */
+/*! FreeSWITCH application handler function */
SWITCH_STANDARD_APP(vmd_start_function)
{
switch_media_bug_t *bug;
@@ -518,7 +536,7 @@
}
-/* Called when the system shuts down */
+/*! Called when the system shuts down */
SWITCH_MODULE_SHUTDOWN_FUNCTION(mod_vmd_shutdown)
{
switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_NOTICE, "Voicemail detection disabled\n");
@@ -526,6 +544,7 @@
return SWITCH_STATUS_SUCCESS;
}
+/*! FreeSWITCH API handler function */
SWITCH_STANDARD_API(vmd_api_main)
{
switch_core_session_t *vmd_session;
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