[asterisk-commits] irroot: branch irroot/t38gateway-1.8 r329327 - in /team/irroot/t38gateway-1.8...
SVN commits to the Asterisk project
asterisk-commits at lists.digium.com
Fri Jul 22 14:57:04 CDT 2011
Author: irroot
Date: Fri Jul 22 14:57:00 2011
New Revision: 329327
URL: http://svnview.digium.com/svn/asterisk?view=rev&rev=329327
Log:
V.21 1850hz Detector instead of CED
Modified:
team/irroot/t38gateway-1.8/include/asterisk/dsp.h
team/irroot/t38gateway-1.8/main/dsp.c
team/irroot/t38gateway-1.8/res/res_fax.c
Modified: team/irroot/t38gateway-1.8/include/asterisk/dsp.h
URL: http://svnview.digium.com/svn/asterisk/team/irroot/t38gateway-1.8/include/asterisk/dsp.h?view=diff&rev=329327&r1=329326&r2=329327
==============================================================================
--- team/irroot/t38gateway-1.8/include/asterisk/dsp.h (original)
+++ team/irroot/t38gateway-1.8/include/asterisk/dsp.h Fri Jul 22 14:57:00 2011
@@ -46,7 +46,8 @@
#define DSP_FAXMODE_DETECT_CNG (1 << 0)
#define DSP_FAXMODE_DETECT_CED (1 << 1)
#define DSP_FAXMODE_DETECT_SQUELCH (1 << 2)
-#define DSP_FAXMODE_DETECT_ALL (DSP_FAXMODE_DETECT_CNG | DSP_FAXMODE_DETECT_CED)
+#define DSP_FAXMODE_DETECT_V21 (1 << 3)
+#define DSP_FAXMODE_DETECT_ALL (DSP_FAXMODE_DETECT_CNG | DSP_FAXMODE_DETECT_CED | DSP_FAXMODE_DETECT_V21)
#define DSP_TONE_STATE_SILENCE 0
#define DSP_TONE_STATE_RINGING 1
Modified: team/irroot/t38gateway-1.8/main/dsp.c
URL: http://svnview.digium.com/svn/asterisk/team/irroot/t38gateway-1.8/main/dsp.c?view=diff&rev=329327&r1=329326&r2=329327
==============================================================================
--- team/irroot/t38gateway-1.8/main/dsp.c (original)
+++ team/irroot/t38gateway-1.8/main/dsp.c Fri Jul 22 14:57:00 2011
@@ -251,6 +251,20 @@
int last_hit; /* Indicates if the last processed block was a hit */
} tone_detect_state_t;
+
+typedef struct
+{
+ int block_size;
+ goertzel_state_t tone;
+ float energy; /* Accumulated energy of the current block */
+ int samples_pending; /* Samples remain to complete the current block */
+
+ float threshold; /* Energy of the tone relative to energy from all other signals to consider a hit */
+
+ int hit_count;
+ int miss_count;
+
+} v21_detect_state_t;
typedef struct
{
@@ -399,6 +413,7 @@
digit_detect_state_t digit_state;
tone_detect_state_t cng_tone_state;
tone_detect_state_t ced_tone_state;
+ v21_detect_state_t v21_state;
};
static void mute_fragment(struct ast_dsp *dsp, fragment_t *fragment)
@@ -471,10 +486,55 @@
ast_debug(1, "Setup tone %d Hz, %d ms, block_size=%d, hits_required=%d\n", freq, duration, s->block_size, s->hits_required);
}
+static void ast_v21_detect_init(v21_detect_state_t *s)
+{
+ float x;
+ int periods_in_block;
+
+ /* If we want to remove tone, it is important to have block size not
+ to exceed frame size. Otherwise by the moment tone is detected it is too late
+ to squelch it from previous frames. Block size is 20ms at the given sample rate.*/
+ s->block_size = SAMPLES_IN_FRAME;
+
+ periods_in_block = s->block_size * 1850 / SAMPLE_RATE;
+
+ /* Make sure we will have at least 5 periods at target frequency for analisys.
+ This may make block larger than expected packet and will make squelching impossible
+ but at least we will be detecting the tone */
+ if (periods_in_block < 5)
+ periods_in_block = 5;
+
+ /* Now calculate final block size. It will contain integer number of periods */
+ s->block_size = periods_in_block * SAMPLE_RATE / 1850;
+
+ goertzel_init(&s->tone, 1850.0, s->block_size);
+
+ s->samples_pending = s->block_size;
+ s->hit_count = 0;
+ s->miss_count = 0;
+ s->energy = 0.0;
+
+ /* We want tone energy to be amp decibels above the rest of the signal (the noise).
+ According to Parseval's theorem the energy computed in time domain equals to energy
+ computed in frequency domain. So subtracting energy in the frequency domain (Goertzel result)
+ from the energy in the time domain we will get energy of the remaining signal (without the tone
+ we are detecting). We will be checking that
+ 10*log(Ew / (Et - Ew)) > amp
+ Calculate threshold so that we will be actually checking
+ Ew > Et * threshold
+ */
+
+ x = pow(10.0, 16 / 10.0);
+ s->threshold = x / (x + 1);
+
+ ast_debug(1, "Setup v21 detector, block_size=%d\n", s->block_size);
+}
+
static void ast_fax_detect_init(struct ast_dsp *s)
{
ast_tone_detect_init(&s->cng_tone_state, FAX_TONE_CNG_FREQ, FAX_TONE_CNG_DURATION, FAX_TONE_CNG_DB);
ast_tone_detect_init(&s->ced_tone_state, FAX_TONE_CED_FREQ, FAX_TONE_CED_DURATION, FAX_TONE_CED_DB);
+ ast_v21_detect_init(&s->v21_state);
if (s->faxmode & DSP_FAXMODE_DETECT_SQUELCH) {
s->cng_tone_state.squelch = 1;
s->ced_tone_state.squelch = 1;
@@ -523,6 +583,89 @@
} else {
ast_dtmf_detect_init(&s->td.dtmf);
}
+}
+
+/*! \brief Detect a v21 preamble.
+ * This code is derived from the tone_detect code and detects a pattern of 1850
+ * Hz tone found in a v21 preamble.
+ */
+static int v21_detect(struct ast_dsp *dsp, v21_detect_state_t *s, int16_t *amp, int samples)
+{
+ float tone_energy;
+ int i;
+ int hit = 0;
+ int limit;
+ int res = 0;
+ int16_t *ptr;
+ int start, end;
+
+ for (start = 0; start < samples; start = end) {
+ /* Process in blocks. */
+ limit = samples - start;
+ if (limit > s->samples_pending) {
+ limit = s->samples_pending;
+ }
+ end = start + limit;
+
+ for (i = limit, ptr = amp ; i > 0; i--, ptr++) {
+ /* signed 32 bit int should be enough to suqare any possible signed 16 bit value */
+ s->energy += (int32_t) *ptr * (int32_t) *ptr;
+
+ goertzel_sample(&s->tone, *ptr);
+ }
+
+ s->samples_pending -= limit;
+
+ if (s->samples_pending) {
+ /* Finished incomplete (last) block */
+ break;
+ }
+
+ tone_energy = goertzel_result(&s->tone);
+
+ /* Scale to make comparable */
+ tone_energy *= 2.0;
+ s->energy *= s->block_size;
+
+ ast_debug(10, "v21 1850 Ew=%.2E, Et=%.2E, s/n=%10.2f\n", tone_energy, s->energy, tone_energy / (s->energy - tone_energy));
+
+ hit = 0;
+ if (tone_energy > s->energy * s->threshold) {
+ ast_debug(10, "Hit! count=%d; miss_count=%d\n", s->hit_count, s->miss_count);
+ hit = 1;
+ }
+
+ if (hit) {
+ if (s->hit_count == 0 || s->miss_count == 3) {
+ s->hit_count++;
+ } else {
+ s->hit_count = 0;
+ }
+
+ s->miss_count = 0;
+ } else {
+ s->miss_count++;
+ if (s->miss_count > 3) {
+ s->hit_count = 0;
+ }
+ }
+
+ if (s->hit_count == 4) {
+ ast_debug(1, "v21 preamble detected\n");
+ res = 1;
+ }
+
+ /* Reinitialise the detector for the next block */
+ goertzel_reset(&s->tone);
+
+ /* Advance to the next block */
+ s->energy = 0.0;
+ s->samples_pending = s->block_size;
+
+ amp += limit;
+ }
+
+ return res;
}
static int tone_detect(struct ast_dsp *dsp, tone_detect_state_t *s, int16_t *amp, int samples)
@@ -1389,6 +1532,10 @@
if ((dsp->faxmode & DSP_FAXMODE_DETECT_CED) && tone_detect(dsp, &dsp->ced_tone_state, shortdata, len)) {
fax_digit = 'e';
}
+
+ if ((dsp->faxmode & DSP_FAXMODE_DETECT_V21) && v21_detect(dsp, &dsp->v21_state, shortdata, len)) {
+ fax_digit = 'g';
+ }
}
if (dsp->features & (DSP_FEATURE_DIGIT_DETECT | DSP_FEATURE_BUSY_DETECT)) {
Modified: team/irroot/t38gateway-1.8/res/res_fax.c
URL: http://svnview.digium.com/svn/asterisk/team/irroot/t38gateway-1.8/res/res_fax.c?view=diff&rev=329327&r1=329326&r2=329327
==============================================================================
--- team/irroot/t38gateway-1.8/res/res_fax.c (original)
+++ team/irroot/t38gateway-1.8/res/res_fax.c Fri Jul 22 14:57:00 2011
@@ -274,6 +274,8 @@
int framehook;
/*! \brief bridged */
int bridged:1;
+ /*! \brief 1 if a v21 preamble has been detected */
+ int detected_v21:1;
/*! \brief a flag to track the state of our negotiation */
enum ast_t38_state t38_state;
/*! \brief Original audio formats */
@@ -2499,10 +2501,10 @@
gateway->framehook = -1;
ast_dsp_set_features(gateway->chan_dsp, DSP_FEATURE_FAX_DETECT);
- ast_dsp_set_faxmode(gateway->chan_dsp, DSP_FAXMODE_DETECT_CED);
+ ast_dsp_set_faxmode(gateway->chan_dsp, DSP_FAXMODE_DETECT_V21);
ast_dsp_set_features(gateway->peer_dsp, DSP_FEATURE_FAX_DETECT);
- ast_dsp_set_faxmode(gateway->peer_dsp, DSP_FAXMODE_DETECT_CED);
+ ast_dsp_set_faxmode(gateway->peer_dsp, DSP_FAXMODE_DETECT_V21);
details->caps = AST_FAX_TECH_GATEWAY;
if (!(gateway->s = fax_session_reserve(details, &gateway->token))) {
@@ -2557,12 +2559,53 @@
return 0;
}
-static struct ast_frame *fax_gateway_detect_ced(struct fax_gateway *gateway, struct ast_channel *chan, struct ast_channel *peer, struct ast_channel *active, struct ast_frame *f)
+static struct ast_frame *fax_gateway_request_t38(struct fax_gateway *gateway, struct ast_channel *chan, struct ast_frame *f)
+{
+ struct ast_frame *fp;
+ struct ast_control_t38_parameters t38_parameters = {
+ .request_response = AST_T38_REQUEST_NEGOTIATE,
+ };
+ struct ast_frame control_frame = {
+ .src = "res_fax",
+ .frametype = AST_FRAME_CONTROL,
+ .datalen = sizeof(t38_parameters),
+ .subclass.integer = AST_CONTROL_T38_PARAMETERS,
+ .data.ptr = &t38_parameters,
+ };
+
+ struct ast_fax_session_details *details = find_details(chan);
+
+ if (!details) {
+ ast_log(LOG_ERROR, "no FAX session details found on chan %s for T.38 gateway session, odd\n", chan->name);
+ ast_framehook_detach(chan, gateway->framehook);
+ return f;
+ }
+
+ t38_parameters_fax_to_ast(&t38_parameters, &details->our_t38_parameters);
+ ao2_ref(details, -1);
+
+ if (!(fp = ast_frisolate(&control_frame))) {
+ ast_log(LOG_ERROR, "error generating T.38 request control frame on chan %s for T.38 gateway session\n", chan->name);
+ return f;
+ }
+
+ gateway->t38_state = T38_STATE_NEGOTIATING;
+ gateway->timeout_start = ast_tvnow();
+
+ ast_debug(1, "requesting T.38 for gateway session for %s\n", chan->name);
+ return fp;
+}
+
+static struct ast_frame *fax_gateway_detect_v21(struct fax_gateway *gateway, struct ast_channel *chan, struct ast_channel *peer, struct ast_channel *active, struct ast_frame *f)
{
struct ast_frame *dfr = ast_frdup(f);
struct ast_dsp *active_dsp = (active == chan) ? gateway->chan_dsp : gateway->peer_dsp;
struct ast_channel *other = (active == chan) ? peer : chan;
+ if (gateway->detected_v21) {
+ return f;
+ }
+
if (!dfr) {
return f;
}
@@ -2571,43 +2614,13 @@
return f;
}
- if (dfr->frametype == AST_FRAME_DTMF && dfr->subclass.integer == 'e') {
+ if (dfr->frametype == AST_FRAME_DTMF && dfr->subclass.integer == 'g') {
+ gateway->detected_v21 = 1;
if (ast_channel_get_t38_state(other) == T38_STATE_UNKNOWN) {
- struct ast_control_t38_parameters t38_parameters = {
- .request_response = AST_T38_REQUEST_NEGOTIATE,
- };
- struct ast_frame control_frame = {
- .src = "res_fax",
- .frametype = AST_FRAME_CONTROL,
- .datalen = sizeof(t38_parameters),
- .subclass.integer = AST_CONTROL_T38_PARAMETERS,
- .data.ptr = &t38_parameters,
- };
-
- struct ast_fax_session_details *details = find_details(chan);
- ast_frfree(dfr);
-
- if (!details) {
- ast_log(LOG_ERROR, "no FAX session details found on chan %s for T.38 gateway session, odd\n", chan->name);
- ast_framehook_detach(chan, gateway->framehook);
- return f;
- }
-
- t38_parameters_fax_to_ast(&t38_parameters, &details->our_t38_parameters);
- ao2_ref(details, -1);
-
- if (!(dfr = ast_frisolate(&control_frame))) {
- ast_log(LOG_ERROR, "error generating T.38 request control frame on chan %s for T.38 gateway session\n", chan->name);
- return f;
- }
-
- gateway->t38_state = T38_STATE_NEGOTIATING;
- gateway->timeout_start = ast_tvnow();
-
- ast_debug(1, "detected CED tone on %s, requesting T.38 on %s for T.38 gateway session\n", active->name, other->name);
- return dfr;
+ ast_debug(1, "detected v21 preamble from %s\n", active->name);
+ return fax_gateway_request_t38(gateway, chan, f);
} else {
- ast_debug(1, "detected CED tone on %s, but %s does not support T.38 for T.38 gateway session\n", active->name, other->name);
+ ast_debug(1, "detected v21 preamble on %s, but %s does not support T.38 for T.38 gateway session\n", active->name, other->name);
}
}
@@ -2660,6 +2673,7 @@
if (control_params->request_response == AST_T38_REQUEST_NEGOTIATE) {
enum ast_t38_state state = ast_channel_get_t38_state(other);
+
if (state == T38_STATE_UNKNOWN) {
/* we detected a request to negotiate T.38 and the
* other channel appears to support T.38, we'll pass
@@ -2699,7 +2713,7 @@
return &ast_null_frame;
} else if (gateway->t38_state == T38_STATE_NEGOTIATING) {
/* we got a request to negotiate T.38 after we already
- * sent one to the other party based on CED tone
+ * sent one to the other party based on v21 preamble
* detection. We'll just pretend we passed this request
* through in the first place. */
@@ -2707,12 +2721,12 @@
gateway->t38_state = T38_STATE_UNKNOWN;
gateway->timeout_start = ast_tvnow();
- ast_debug(1, "%s is attempting to negotiate T.38 after we already sent a negotiation request based on CED detection\n", active->name);
+ ast_debug(1, "%s is attempting to negotiate T.38 after we already sent a negotiation request based on v21 preamble detection\n", active->name);
ao2_ref(details, -1);
return &ast_null_frame;
} else if (gateway->t38_state == T38_STATE_NEGOTIATED) {
/* we got a request to negotiate T.38 after we already
- * sent one to the other party based on CED tone
+ * sent one to the other party based on v21 preamble
* detection and received a response. We need to
* respond to this and shut down the gateway. */
@@ -2933,7 +2947,8 @@
gateway->timeout_start = ast_tvnow();
- /* we are bridged, change r/w formats to SLIN for CED detection and T.30 */
+ /* we are bridged, change r/w formats to SLIN for v21 preamble
+ * detection and T.30 */
gateway->chan_read_format = chan->readformat;
gateway->chan_write_format = chan->readformat;
@@ -3008,16 +3023,16 @@
return fax_gateway_detect_t38(gateway, chan, peer, active, f);
}
- /* not in gateway mode yet, listen for CED */
- /* XXX this should detect a v21 preamble instead of CED */
- if (gateway->t38_state == T38_STATE_UNAVAILABLE && f->frametype == AST_FRAME_VOICE) {
- return fax_gateway_detect_ced(gateway, chan, peer, active, f);
+ if (!gateway->detected_v21 && gateway->t38_state == T38_STATE_UNAVAILABLE && f->frametype == AST_FRAME_VOICE) {
+ /* not in gateway mode and have not detected v21 yet, listen
+ * for v21 */
+ return fax_gateway_detect_v21(gateway, chan, peer, active, f);
}
/* in gateway mode, gateway some packets */
if (gateway->t38_state == T38_STATE_NEGOTIATED) {
/* framehooks are called in __ast_read() before frame format
- * translation is does, so we need to translate here */
+ * translation is done, so we need to translate here */
if ((f->frametype == AST_FRAME_VOICE) && (f->subclass.codec != AST_FORMAT_SLINEAR)) {
if (active->readtrans && (f = ast_translate(active->readtrans, f, 1)) == NULL) {
f = &ast_null_frame;
@@ -3032,6 +3047,25 @@
gateway->s->tech->write(gateway->s, f);
f = &ast_null_frame;
return f;
+ }
+
+ /* force silence on the line if T.38 negotiation might be taking place */
+ if (gateway->t38_state != T38_STATE_UNAVAILABLE && gateway->t38_state != T38_STATE_REJECTED) {
+ if (f->frametype == AST_FRAME_VOICE && f->subclass.format.id == AST_FORMAT_SLINEAR) {
+ short silence_buf[f->samples];
+ struct ast_frame silence_frame = {
+ .frametype = AST_FRAME_VOICE,
+ .data.ptr = silence_buf,
+ .samples = f->samples,
+ .datalen = sizeof(silence_buf),
+ };
+ ast_format_set(&silence_frame.subclass.format, AST_FORMAT_SLINEAR, 0);
+ memset(silence_buf, 0, sizeof(silence_buf));
+
+ return ast_frisolate(&silence_frame);
+ } else {
+ return &ast_null_frame;
+ }
}
return f;
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