MT#55283 Force transcoding

Closes #1912

Change-Id: I2ac29b8cf97f20637f693589dcf82fdba5b60026

daemon/call_interfaces.c

@@ -1060,6 +1060,10 @@ void call_ng_flags_flags(str *s, unsigned int idx, helper_arg arg) {
 		case CSH_LOOKUP("allow transcoding"):
 			out->allow_transcoding = true;
 			break;
+		case CSH_LOOKUP("force-transcoding"):
+		case CSH_LOOKUP("force transcoding"):
+			out->force_transcoding = true;
+			break;
 		case CSH_LOOKUP("always-transcode"):
 		case CSH_LOOKUP("always transcode"):;
 			static const str str_all = STR_CONST("all");

daemon/codec.c

@@ -1175,6 +1175,11 @@ void __codec_handlers_update(struct call_media *receiver, struct call_media *sin
 
 	// do we have to force everything through the transcoding engine even if codecs match?
 	bool force_transcoding = do_pcm_dtmf_blocking || do_dtmf_blocking || use_audio_player;
+	if ( (a.flags && a.flags->force_transcoding) || ML_ISSET(other_monologue, FORCE_TRANSCODING)) {
+		ilogs(codec, LOG_DEBUG, "Flag force-transcoding exist");
+		force_transcoding = true;
+		ML_SET(other_monologue, FORCE_TRANSCODING);
+	}
 
 	for (__auto_type l = receiver->codecs.codec_prefs.head; l; ) {
 		rtp_payload_type *pt = l->data;

docs/ng_control_protocol.md

@@ -920,6 +920,12 @@ Spaces in each string may be replaced by hyphens.
 	given, the answer will be accepted even if some codecs were rejected, and codecs will be
 	transcoded as required.
 
+* `force transcoding`
+
+	This flag will force transcoding between channels. This provides a loss measurement
+	between the A-leg and B-leg. If this flag appears in the NG protocol, it will always be 
+	transcoded (for example, between codecs G722 and G722). 
+
 * `always transcode`
 
 	Legacy flag, synonymous to `codec-accept=all`.

include/call.h

@@ -231,6 +231,7 @@ enum {
 #define ML_FLAG_SILENCE_MEDIA			0x01000000
 #define ML_FLAG_MOH_SENDRECV			0x02000000
 #define ML_FLAG_MOH_ZEROCONN			0x04000000
+#define ML_FLAG_FORCE_TRANSCODING              0x08000000
 
 /* call_t */
 #define CALL_FLAG_IPV4_OFFER			0x00010000

include/call_interfaces.h

@@ -219,6 +219,7 @@ RTPE_NG_FLAGS_STR_CASE_HT_PARAMS
 		     static_codecs:1,
 		     allow_no_codec_media:1,
 		     allow_transcoding:1,
+		     force_transcoding:1,
 		     allow_asymmetric_codecs:1,
 		     early_media:1,
 		     accept_any:1,

utils/rtpengine-ng-client

@@ -41,6 +41,7 @@ my @flags = qw(
 	pierce-NAT
 	SIP-source-address
 	allow-transcoding
+	force-transcoding
 	trickle-ICE
 	reject-ICE
 	egress