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res_tonedetect: Add call progress tone detection 

Makes basic call progress tone detection available
in a tech-agnostic manner with the addition of the
ToneScan application. This can determine if the channel
has encountered a busy signal, SIT tones, dial tone,
modem, fax machine, etc. A few basic async progress
tone detect options are also added to the TONE_DETECT
function.

ASTERISK-29720 #close

Change-Id: Ia02437e0450473031e294798b8cb421fb8f24e90
This commit is contained in:
Naveen Albert 2021-11-06 23:35:16 +00:00 committed by Friendly Automation
parent c37e1ceb5a
commit fbf03832da
2 changed files with 364 additions and 7 deletions
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6
doc/CHANGES-staging/tonescan.txt Normal file
View File

@ -0,0 +1,6 @@
Subject: ToneScan application
A new application, ToneScan, allows for
synchronous detection of call progress
signals such as dial tone, busy tone,
Special Information Tones, and modems.

365
res/res_tonedetect.c
View File

@ -93,13 +93,90 @@
<ref type="application">PlayTones</ref>
</see-also>
</application>
<application name="ToneScan" language="en_US">
<synopsis>
Wait for period of time while scanning for call progress tones
</synopsis>
<syntax>
<parameter name="zone" required="false">
<para>Call progress zone. Default is the system default.</para>
</parameter>
<parameter name="timeout" required="false">
<para>Maximum amount of time, in seconds, to wait for call progress
or signal tones. Default is forever.</para>
</parameter>
<parameter name="threshold" required="false">
<para>DSP threshold required for a match. A higher number will
require a longer match and may reduce false positives, at the
expense of false negatives. Default is 1.</para>
</parameter>
<parameter name="options" required="false">
<optionlist>
<option name="f">
<para>Enable fax machine detection. By default, this is disabled.</para>
</option>
<option name="v">
<para>Enable voice detection. By default, this is disabled.</para>
</option>
</optionlist>
</parameter>
</syntax>
<description>
<para>Waits for a a distinguishable call progress tone and then exits.
Unlike a conventional scanner, this is not currently capable of
scanning for modem carriers.</para>
<variablelist>
<variable name="TONESCANSTATUS">
This indicates the result of the scan.
<value name="RINGING">
Audible ringback tone
</value>
<value name="BUSY">
Busy tone
</value>
<value name="SIT">
Special Information Tones
</value>
<value name="VOICE">
Human voice detected
</value>
<value name="DTMF">
DTMF digit
</value>
<value name="FAX">
Fax (answering)
</value>
<value name="MODEM">
Modem (answering)
</value>
<value name="DIALTONE">
Dial tone
</value>
<value name="NUT">
UK Number Unobtainable tone
</value>
<value name="TIMEOUT">
Timeout reached before any positive detection
</value>
<value name="HANGUP">
Caller hung up before any positive detection
</value>
</variable>
</variablelist>
</description>
<see-also>
<ref type="application">WaitForTone</ref>
</see-also>
</application>
<function name="TONE_DETECT" language="en_US">
<synopsis>
Asynchronously detects a tone
</synopsis>
<syntax>
<parameter name="freq" required="true">
<para>Frequency of the tone to detect.</para>
<para>Frequency of the tone to detect. To disable frequency
detection completely (e.g. for signal detection only),
specify 0 for the frequency.</para>
</parameter>
<parameter name="duration_ms" required="false">
<para>Minimum duration of tone, in ms. Default is 500ms.
@ -108,6 +185,18 @@
</parameter>
<parameter name="options">
<optionlist>
<option name="a">
<para>Match immediately on Special Information Tones, instead of or in addition
to a particular frequency.</para>
</option>
<option name="b">
<para>Match immediately on a busy signal, instead of or in addition to
a particular frequency.</para>
</option>
<option name="c">
<para>Match immediately on a dial tone, instead of or in addition to
a particular frequency.</para>
</option>
<option name="d">
<para>Custom decibel threshold to use. Default is 16.</para>
</option>
@ -147,10 +236,18 @@
<literal>rx</literal> to get the number of times a tone has been detected in the
RX direction.</para>
<example title="intercept2600">
same => n,Set(TONE_DETECT(2600,1000,g(got-2600,s,1))=)
same => n,Set(TONE_DETECT(2600,1000,g(got-2600,s,1))=) ; detect 2600 Hz
same => n,Wait(15)
same => n,NoOp(${TONE_DETECT(rx)})
</example>
<example title="dropondialtone">
same => n,Set(TONE_DETECT(0,,bg(my-hangup,s,1))=) ; disconnect a call if we hear a busy signal
same => n,Goto(somewhere-else)
same => n(myhangup),Hangup()
</example>
<example title="removedetector">
same => n,Set(TONE_DETECT(0,,x)=) ; remove the detector from the channel
</example>
</description>
</function>
***/
@ -170,6 +267,7 @@ struct detect_information {
int txcount;
int rxcount;
int hitsrequired;
int signalfeatures;
};
enum td_opts {
@ -181,6 +279,9 @@ enum td_opts {
OPT_DECIBEL = (1 << 6),
OPT_SQUELCH = (1 << 7),
OPT_HITS_REQ = (1 << 8),
OPT_SIT = (1 << 9),
OPT_BUSY = (1 << 10),
OPT_DIALTONE = (1 << 11),
};
enum {
@ -193,6 +294,9 @@ enum {
};
AST_APP_OPTIONS(td_opts, {
AST_APP_OPTION('a', OPT_SIT),
AST_APP_OPTION('b', OPT_BUSY),
AST_APP_OPTION('c', OPT_DIALTONE),
AST_APP_OPTION_ARG('d', OPT_DECIBEL, OPT_ARG_DECIBEL),
AST_APP_OPTION_ARG('g', OPT_GOTO_RX, OPT_ARG_GOTO_RX),
AST_APP_OPTION_ARG('h', OPT_GOTO_TX, OPT_ARG_GOTO_TX),
@ -230,6 +334,7 @@ static int detect_callback(struct ast_audiohook *audiohook, struct ast_channel *
{
struct ast_datastore *datastore = NULL;
struct detect_information *di = NULL;
int match = 0;
/* If the audiohook is stopping it means the channel is shutting down.... but we let the datastore destroy take care of it */
if (audiohook->status == AST_AUDIOHOOK_STATUS_DONE) {
@ -258,6 +363,7 @@ static int detect_callback(struct ast_audiohook *audiohook, struct ast_channel *
char result = frame->subclass.integer;
if (result == 'q') {
int now;
match = 1;
if (direction == AST_AUDIOHOOK_DIRECTION_READ) {
di->rxcount = di->rxcount + 1;
now = di->rxcount;
@ -275,6 +381,42 @@ static int detect_callback(struct ast_audiohook *audiohook, struct ast_channel *
}
}
}
if (di->signalfeatures && !match) { /* skip unless there are call progress/signal options */
int tstate, tcount;
tcount = ast_dsp_get_tcount(di->dsp);
tstate = ast_dsp_get_tstate(di->dsp);
if (tstate > 0) {
ast_debug(3, "tcount: %d, tstate: %d\n", tcount, tstate);
switch (tstate) {
case DSP_TONE_STATE_DIALTONE:
if (di->signalfeatures & DSP_FEATURE_WAITDIALTONE) {
match = 1;
}
break;
case DSP_TONE_STATE_BUSY:
if (di->signalfeatures & DSP_PROGRESS_BUSY) {
match = 1;
}
break;
case DSP_TONE_STATE_SPECIAL3:
if (di->signalfeatures & DSP_PROGRESS_CONGESTION) {
match = 1;
}
break;
default: /* ignore */
break;
}
if (match) {
if (direction == AST_AUDIOHOOK_DIRECTION_READ && di->gotorx) {
ast_async_parseable_goto(chan, di->gotorx);
} else if (di->gototx) {
ast_async_parseable_goto(chan, di->gototx);
} else {
ast_debug(3, "Detected call progress signal, but don't know where to go\n");
}
}
}
}
/* this could be the duplicated frame or a new one, doesn't matter */
ast_frfree(frame);
return 0;
@ -326,8 +468,8 @@ static int freq_parser(char *freqs, int *freq1, int *freq2) {
ast_log(LOG_WARNING, "Frequency must be an integer: %s\n", f1);
return -1;
}
if (*freq1 < 1) {
ast_log(LOG_WARNING, "Sorry, positive frequencies only: %d\n", *freq1);
if (*freq1 < 0) {
ast_log(LOG_WARNING, "Sorry, no negative frequencies: %d\n", *freq1);
return -1;
}
if (!ast_strlen_zero(f2)) {
@ -413,6 +555,23 @@ static int detect_read(struct ast_channel *chan, const char *cmd, char *data, ch
return 0;
}
static int parse_signal_features(struct ast_flags *flags)
{
int features = 0;
if (ast_test_flag(flags, OPT_SIT)) {
features |= DSP_PROGRESS_CONGESTION;
}
if (ast_test_flag(flags, OPT_BUSY)) {
features |= DSP_PROGRESS_BUSY;
}
if (ast_test_flag(flags, OPT_DIALTONE)) {
features |= DSP_FEATURE_WAITDIALTONE;
}
return features;
}
static int detect_write(struct ast_channel *chan, const char *cmd, char *data, const char *value)
{
char *parse;
@ -422,6 +581,7 @@ static int detect_write(struct ast_channel *chan, const char *cmd, char *data, c
char *opt_args[OPT_ARG_ARRAY_SIZE];
struct ast_dsp *dsp;
int freq1 = 0, freq2 = 0, duration = 500, db = 16, squelch = 0, hitsrequired = 1;
int signalfeatures = 0;
AST_DECLARE_APP_ARGS(args,
AST_APP_ARG(freqs);
@ -461,6 +621,7 @@ static int detect_write(struct ast_channel *chan, const char *cmd, char *data, c
return -1;
}
}
signalfeatures = parse_signal_features(&flags);
ast_channel_lock(chan);
if (!(datastore = ast_channel_datastore_find(chan, &detect_datastore, NULL))) {
@ -481,8 +642,12 @@ static int detect_write(struct ast_channel *chan, const char *cmd, char *data, c
ast_log(LOG_WARNING, "Unable to allocate DSP!\n");
return -1;
}
ast_dsp_set_features(dsp, DSP_FEATURE_FREQ_DETECT);
ast_dsp_set_freqmode(dsp, freq1, duration, db, squelch);
di->signalfeatures = signalfeatures; /* we're not including freq detect */
if (freq1 > 0) {
signalfeatures |= DSP_FEATURE_FREQ_DETECT;
ast_dsp_set_freqmode(dsp, freq1, duration, db, squelch);
}
ast_dsp_set_features(dsp, signalfeatures);
di->dsp = dsp;
di->txcount = 0;
di->rxcount = 0;
@ -493,7 +658,12 @@ static int detect_write(struct ast_channel *chan, const char *cmd, char *data, c
} else {
di = datastore->data;
dsp = di->dsp;
ast_dsp_set_freqmode(dsp, freq1, duration, db, squelch);
di->signalfeatures = signalfeatures; /* we're not including freq detect */
if (freq1 > 0) {
signalfeatures |= DSP_FEATURE_FREQ_DETECT;
ast_dsp_set_freqmode(dsp, freq1, duration, db, squelch);
}
ast_dsp_set_features(dsp, signalfeatures);
}
di->duration = duration;
di->gotorx = NULL;
@ -641,6 +811,185 @@ static int wait_exec(struct ast_channel *chan, const char *data)
}
static char *waitapp = "WaitForTone";
static char *scanapp = "ToneScan";
static int scan_exec(struct ast_channel *chan, const char *data)
{
char *appdata;
double timeoutf = 0;
int timeout = 0;
struct ast_frame *frame = NULL, *frame2 = NULL;
struct ast_dsp *dsp = NULL, *dsp2 = NULL;
struct timeval start;
int remaining_time = 0;
int features, match = 0, fax = 0, voice = 0, threshold = 1;
AST_DECLARE_APP_ARGS(args,
AST_APP_ARG(zone);
AST_APP_ARG(timeout);
AST_APP_ARG(threshold);
AST_APP_ARG(options);
);
appdata = ast_strdupa(data);
AST_STANDARD_APP_ARGS(args, appdata);
if (!ast_strlen_zero(args.timeout) && (sscanf(args.timeout, "%30lf", &timeoutf) != 1 || timeout < 0)) {
ast_log(LOG_WARNING, "Invalid timeout: %s\n", args.timeout);
pbx_builtin_setvar_helper(chan, "TONESCANSTATUS", "ERROR");
return -1;
}
if (!ast_strlen_zero(args.threshold) && (ast_str_to_int(args.threshold, &threshold) || threshold < 1)) {
ast_log(LOG_WARNING, "Invalid threshold: %s\n", args.threshold);
pbx_builtin_setvar_helper(chan, "TONESCANSTATUS", "ERROR");
return -1;
}
timeout = 1000 * timeoutf;
if (!ast_strlen_zero(args.options) && strchr(args.options, 'f')) {
fax = 1;
}
if (!ast_strlen_zero(args.options) && strchr(args.options, 'v')) {
voice = 1;
}
if (!(dsp = ast_dsp_new())) {
ast_log(LOG_WARNING, "Unable to allocate DSP!\n");
pbx_builtin_setvar_helper(chan, "TONESCANSTATUS", "ERROR");
return -1;
}
if (!ast_strlen_zero(args.zone)) {
if (ast_dsp_set_call_progress_zone(dsp, args.zone)) {
ast_log(LOG_WARNING, "Invalid call progress zone: %s\n", args.zone);
pbx_builtin_setvar_helper(chan, "TONESCANSTATUS", "ERROR");
ast_dsp_free(dsp);
return -1;
}
}
if (fax) {
if (!(dsp2 = ast_dsp_new())) {
ast_dsp_free(dsp);
ast_log(LOG_WARNING, "Unable to allocate DSP!\n");
pbx_builtin_setvar_helper(chan, "TONESCANSTATUS", "ERROR");
return -1;
}
}
features = DSP_PROGRESS_RINGING; /* audible ringback tone */
features |= DSP_PROGRESS_BUSY; /* busy signal */
features |= DSP_PROGRESS_CONGESTION; /* SIT tones (not reorder!) */
features |= DSP_PROGRESS_TALK; /* voice. */
features |= DSP_FEATURE_WAITDIALTONE; /* dial tone */
features |= DSP_FEATURE_FREQ_DETECT; /* modem answer */
if (voice) {
features |= DSP_TONE_STATE_TALKING; /* voice */
}
ast_dsp_set_features(dsp, features);
/* all modems begin negotiating with Bell 103. An answering modem just sends mark tone, or 2225 Hz */
ast_dsp_set_freqmode(dsp, 2225, 400, 16, 0); /* this needs to be pretty short, or the progress tones code will thing this is voice */
if (fax) { /* fax detect uses same tone detect internals as modem and causes things to not work as intended, so use a separate DSP if needed. */
ast_dsp_set_features(dsp2, DSP_FEATURE_FAX_DETECT); /* fax tone */
ast_dsp_set_faxmode(dsp2, DSP_FAXMODE_DETECT_CED); /* we only care about the answering side (CED), not originating (CNG) */
}
ast_debug(1, "Starting tone scan, timeout: %d ms, threshold: %d\n", timeout, threshold);
start = ast_tvnow();
do {
if (timeout > 0) {
remaining_time = ast_remaining_ms(start, timeout);
if (remaining_time <= 0) {
pbx_builtin_setvar_helper(chan, "TONESCANSTATUS", "TIMEOUT");
break;
}
}
if (ast_waitfor(chan, 1000) > 0) {
if (!(frame = ast_read(chan))) {
ast_debug(1, "Channel '%s' did not return a frame; probably hung up.\n", ast_channel_name(chan));
pbx_builtin_setvar_helper(chan, "TONESCANSTATUS", "HANGUP");
break;
} else if (frame->frametype == AST_FRAME_VOICE) {
if (fax) {
frame2 = ast_frdup(frame);
}
frame = ast_dsp_process(chan, dsp, frame);
if (frame->frametype == AST_FRAME_DTMF) {
char result = frame->subclass.integer;
match = 1;
if (result == 'q') {
pbx_builtin_setvar_helper(chan, "TONESCANSTATUS", "MODEM");
} else {
pbx_builtin_setvar_helper(chan, "TONESCANSTATUS", "DTMF");
}
} else if (fax) {
char result;
frame2 = ast_dsp_process(chan, dsp2, frame2);
result = frame->subclass.integer;
if (result == AST_FRAME_DTMF) {
if (result == 'e') {
pbx_builtin_setvar_helper(chan, "TONESCANSTATUS", "FAX");
match = 1;
} else {
ast_debug(1, "Ignoring inactionable event\n"); /* shouldn't happen */
}
}
ast_frfree(frame2);
}
if (!match) {
int tstate, tcount;
tcount = ast_dsp_get_tcount(dsp);
tstate = ast_dsp_get_tstate(dsp);
if (tstate > 0) {
ast_debug(3, "tcount: %d, tstate: %d\n", tcount, tstate);
if (tcount >= threshold) {
match = 1;
switch (tstate) {
case DSP_TONE_STATE_RINGING:
pbx_builtin_setvar_helper(chan, "TONESCANSTATUS", "RINGING");
break;
case DSP_TONE_STATE_DIALTONE:
pbx_builtin_setvar_helper(chan, "TONESCANSTATUS", "DIALTONE");
break;
case DSP_TONE_STATE_TALKING:
/* even if we don't specify this feature, it's still checked, so we always need to handle it.
Even if we are looking for it, we need to wait a while or tones will be interpreted
as voice, because this will match first (and this should match last). */
if (voice && tcount > 15 && tcount >= threshold) {
pbx_builtin_setvar_helper(chan, "TONESCANSTATUS", "VOICE");
} else {
match = 0;
}
break;
case DSP_TONE_STATE_BUSY:
pbx_builtin_setvar_helper(chan, "TONESCANSTATUS", "BUSY");
break;
case DSP_TONE_STATE_SPECIAL3:
pbx_builtin_setvar_helper(chan, "TONESCANSTATUS", "SIT");
break;
case DSP_TONE_STATE_HUNGUP: /* UK only */
pbx_builtin_setvar_helper(chan, "TONESCANSTATUS", "NUT");
break;
default:
match = 0;
ast_debug(1, "Something else we weren't expecting? tstate: %d, #%d\n", tstate, tcount);
}
}
}
}
}
ast_frfree(frame);
} else {
pbx_builtin_setvar_helper(chan, "TONESCANSTATUS", "HANGUP");
}
} while (!match && (timeout == 0 || remaining_time > 0));
ast_dsp_free(dsp);
if (dsp2) {
ast_dsp_free(dsp2);
}
return 0;
}
static struct ast_custom_function detect_function = {
.name = "TONE_DETECT",
@ -653,6 +1002,7 @@ static int unload_module(void)
int res;
res = ast_unregister_application(waitapp);
res |= ast_unregister_application(scanapp);
res |= ast_custom_function_unregister(&detect_function);
return res;
@ -663,6 +1013,7 @@ static int load_module(void)
int res;
res = ast_register_application_xml(waitapp, wait_exec);
res |= ast_register_application_xml(scanapp, scan_exec);
res |= ast_custom_function_register(&detect_function);
return res;