Expose functionality for client side applications

srtgo.go

@@ -277,27 +277,41 @@ func (s SrtSocket) Connect() error {
 	return nil
 }
 
-// Read data from the SRT socket
-func (s SrtSocket) Read(b []byte) (n int, err error) {
+// ReadMsg from the socket including SRT control data.
+func (s SrtSocket) ReadMsg(b []byte) (n int, ctrl SrtMsgCtrl, err error) {
 	if !s.blocking {
 		len := C.int(2)
 		timeoutMs := C.int64_t(s.pollTimeout)
 		ready := [2]C.int{SRT_INVALID_SOCK, SRT_INVALID_SOCK}
 
 		if C.srt_epoll_wait(s.epollIo, &ready[0], &len, nil, nil, timeoutMs, nil, nil, nil, nil) == SRT_ERROR {
 			if C.srt_getlasterror(nil) == C.SRT_ETIMEOUT {
-				return 0, nil
+				return
 			}
-			return 0, fmt.Errorf("error in read:epoll %s", C.GoString(C.srt_getlasterror_str()))
+			err = fmt.Errorf("error in read:epoll %s", C.GoString(C.srt_getlasterror_str()))
+			return
 		}
 	}
 
-	res := C.srt_recvmsg2(s.socket, (*C.char)(unsafe.Pointer(&b[0])), C.int(len(b)), nil)
+	var c C.SRT_MSGCTRL
+
+	res := C.srt_recvmsg2(s.socket, (*C.char)(unsafe.Pointer(&b[0])), C.int(len(b)), &c)
+
 	if res == SRT_ERROR {
-		return 0, fmt.Errorf("error in read::recv %s", C.GoString(C.srt_getlasterror_str()))
+		err = fmt.Errorf("error in read::recv %s", C.GoString(C.srt_getlasterror_str()))
+		return
 	}
 
-	return int(res), nil
+	n = int(res)
+	ctrl = newSrtMsgCtrl(&c)
+
+	return
+}
+
+// Read data from the SRT socket
+func (s SrtSocket) Read(b []byte) (n int, err error) {
+	n, _, err = s.ReadMsg(b)
+	return
 }
 
 // Write data to the SRT socket
@@ -621,3 +635,8 @@ func (s SrtSocket) postconfiguration(sck *SrtSocket) error {
 	err := setSocketOptions(sck.socket, bindingPost, s.options)
 	return err
 }
+
+// Now - Time in microseconds elapsed since epoch using SRT internal clock
+func Now() int64 {
+	return int64(C.srt_time_now())
+}

srtmsgctrl.go

@@ -0,0 +1,24 @@
+package srtgo
+
+// #cgo LDFLAGS: -lsrt
+// #include <srt/srt.h>
+import "C"
+
+type SrtMsgCtrl struct {
+	MsgTTL   int   // TTL for a message (millisec), default -1 (no TTL limitation)
+	InOrder  int   // Whether a message is allowed to supersede partially lost one. Unused in stream and live mode.
+	Boundary int   // 0:mid pkt, 1(01b):end of frame, 2(11b):complete frame, 3(10b): start of frame
+	SrcTime  int64 // source time since epoch (usec), 0: use internal time (sender)
+	PktSeq   int32 // sequence number of the first packet in received message (unused for sending)
+	MsgNo    int32 // message number (output value for both sending and receiving)
+}
+
+func newSrtMsgCtrl(ctrl *C.SRT_MSGCTRL) (res SrtMsgCtrl) {
+	res.MsgTTL = int(ctrl.msgttl)
+	res.InOrder = int(ctrl.inorder)
+	res.Boundary = int(ctrl.boundary)
+	res.SrcTime = int64(ctrl.srctime)
+	res.PktSeq = int32(ctrl.pktseq)
+	res.MsgNo = int32(ctrl.msgno)
+	return
+}