TT#122401 add option to bypass AMR SID

Change-Id: I0504d452737573f388941dcca507e3adfd5744c6

daemon/codec.c

@@ -2835,8 +2835,14 @@ static struct ssrc_entry *__ssrc_handler_transcode_new(void *p) {
 			&ch->encoder_format, &h->source_pt.format_parameters, &h->source_pt.codec_opts);
 	if (!ch->decoder)
 		goto err;
-	if (rtpe_config.dtx_cn_params.len)
-		decoder_set_cn_dtx(ch->decoder, &rtpe_config.dtx_cn_params);
+	if (rtpe_config.dtx_cn_params.len) {
+		if (ch->decoder->def->amr) {
+			if (rtpe_config.amr_cn_dtx)
+				decoder_set_cn_dtx(ch->decoder, &rtpe_config.dtx_cn_params);
+		}
+		else
+			decoder_set_cn_dtx(ch->decoder, &rtpe_config.dtx_cn_params);
+	}
 
 	ch->decoder->event_data = h->media;
 	ch->decoder->event_func = codec_decoder_event;

daemon/main.c

@@ -423,6 +423,7 @@ static void options(int *argc, char ***argv) {
 	AUTO_CLEANUP_GVBUF(cn_payload);
 	AUTO_CLEANUP_GVBUF(dtx_cn_params);
 	int debug_srtp = 0;
+	AUTO_CLEANUP_GBUF(amr_dtx);
 
 	rwlock_lock_w(&rtpe_config.config_lock);
 
@@ -522,6 +523,7 @@ static void options(int *argc, char ***argv) {
 		{ "dtx-lag",	0,0,	G_OPTION_ARG_INT,	&rtpe_config.dtx_lag,	"Maxmium time span in milliseconds held in DTX buffer",	"INT"},
 		{ "dtx-shift",	0,0,	G_OPTION_ARG_INT,	&rtpe_config.dtx_shift,	"Length of time (in ms) to shift DTX buffer after over/underflow",	"INT"},
 		{ "dtx-cn-params",0,0,	G_OPTION_ARG_STRING_ARRAY,&dtx_cn_params,	"Parameters for CN generated from DTX","INT INT INT ..."},
+		{ "amr-dtx", 0,0,	G_OPTION_ARG_STRING,	&amr_dtx,		"DTX mechanism to use for AMR and AMR-WB","native|CN"},
 		{ "silence-detect",0,0,	G_OPTION_ARG_DOUBLE,	&silence_detect,	"Audio level threshold in percent for silence detection","FLOAT"},
 		{ "cn-payload",0,0,	G_OPTION_ARG_STRING_ARRAY,&cn_payload,		"Comfort noise parameters to replace silence with","INT INT INT ..."},
 		{ "reorder-codecs",0,0,	G_OPTION_ARG_NONE,	&rtpe_config.reorder_codecs,"Reorder answer codecs based on sender preference",NULL},
@@ -768,6 +770,14 @@ static void options(int *argc, char ***argv) {
 	parse_cn_payload(&rtpe_config.cn_payload, cn_payload, "\x20", "cn-payload");
 	parse_cn_payload(&rtpe_config.dtx_cn_params, dtx_cn_params, NULL, "dtx-cn-params");
 
+	if (amr_dtx) {
+		if (!strcasecmp(amr_dtx, "native")) {}
+		else if (!strcasecmp(amr_dtx, "CN"))
+			rtpe_config.amr_cn_dtx = 1;
+		else
+			die("Invalid --amr-dtx ('%s')", amr_dtx);
+	}
+
 	if (!rtpe_config.software_id)
 		rtpe_config.software_id = g_strdup_printf("rtpengine-%s", RTPENGINE_VERSION);
 	g_strcanon(rtpe_config.software_id, "QWERTYUIOPASDFGHJKLZXCVBNMqwertyuiopasdfghjklzxcvbnm1234567890-", '-');

daemon/rtpengine.pod

@@ -833,6 +833,18 @@ If any CN parameters are configured, the parameters will be passed to an RFC
 3389 CN decoder, and the generated comfort noise will be used to fill in DTX
 gaps.
 
+=item B<--amr-dtx=>B<native>|B<CN>
+
+Select the DTX behaviour for AMR codecs. The default is use the codec's
+internal processing: during a DTX event, a "no data" frame is passed to the
+decoder and the output is used as audio data.
+
+If B<CN> is selected here, the same DTX mechanism as other codecs use is used
+for AMR, which is to fill in DTX gaps with either silence or RFC 3389 comfort
+noise (see B<dtx-cn-params>). This also affects processing of received SID
+frames: SID frames would not be passed to the codec but instead be replaced by
+generated silence or comfort noise.
+
 =item B<--silence-detect=>I<FLOAT>
 
 Enable silence detection and specify threshold in percent. This option is

include/main.h

@@ -117,6 +117,7 @@ struct rtpengine_config {
 	int			dtx_lag;
 	int			dtx_shift;
 	str			dtx_cn_params;
+	int			amr_cn_dtx;
 	double			silence_detect_double;
 	uint32_t		silence_detect_int;
 	str			cn_payload;

lib/codeclib.c

@@ -112,14 +112,17 @@ static const codec_type_t codec_type_cn = {
 };
 
 static const dtx_method_t dtx_method_silence = {
+	.method_id = DTX_SILENCE,
 	.do_dtx = generic_silence_dtx,
 };
 static const dtx_method_t dtx_method_cn = {
+	.method_id = DTX_CN,
 	.do_dtx = generic_cn_dtx,
 	.init = generic_cn_dtx_init,
 	.cleanup = generic_cn_dtx_cleanup,
 };
 static const dtx_method_t dtx_method_amr = {
+	.method_id = DTX_NATIVE,
 	.do_dtx = amr_dtx,
 };
 
@@ -472,6 +475,7 @@ static codec_def_t __codec_defs[] = {
 		.codec_type = &codec_type_amr,
 		.set_enc_options = amr_set_enc_options,
 		.set_dec_options = amr_set_dec_options,
+		.amr = 1,
 		.dtx_methods = {
 			[DTX_NATIVE] = &dtx_method_amr,
 			[DTX_SILENCE] = &dtx_method_silence,
@@ -494,6 +498,7 @@ static codec_def_t __codec_defs[] = {
 		.codec_type = &codec_type_amr,
 		.set_enc_options = amr_set_enc_options,
 		.set_dec_options = amr_set_dec_options,
+		.amr = 1,
 		.dtx_methods = {
 			[DTX_NATIVE] = &dtx_method_amr,
 			[DTX_SILENCE] = &dtx_method_silence,
@@ -2097,8 +2102,22 @@ static int amr_decoder_input(decoder_t *dec, const str *data, GQueue *out) {
 		}
 
 		err = "failed to decode AMR data";
-		if (avc_decoder_input(dec, &frame, out))
-			goto err;
+		if (bits == 40) {
+			// SID
+			if (dec->dtx.method_id == DTX_NATIVE) {
+				if (avc_decoder_input(dec, &frame, out))
+					goto err;
+			}
+			else {
+				// use the DTX generator to replace SID
+				if (dec->dtx.do_dtx(dec, out, 20))
+					goto err;
+			}
+		}
+		else {
+			if (avc_decoder_input(dec, &frame, out))
+				goto err;
+		}
 
 		amr_bitrate_tracker(dec, ft);
 	}

lib/codeclib.h

@@ -156,7 +156,8 @@ struct codec_def_s {
 
 	// flags
 	unsigned int supplemental:1,
-	             dtmf:1; // special case
+	             dtmf:1, // special case
+		     amr:1;
 
 	const codec_type_t *codec_type;
 
@@ -181,6 +182,8 @@ enum codec_event {
 };
 
 struct dtx_method_s {
+	enum dtx_method method_id;
+
 	int (*init)(decoder_t *);
 	void (*cleanup)(decoder_t *);
 	int (*do_dtx)(decoder_t *, GQueue *, int);