Merge pull request #113 from go-gst/webrtc_support

initial Webrtc(-bin) support

go.mod

@@ -4,6 +4,6 @@ go 1.22
 
 require github.com/mattn/go-pointer v0.0.1
 
-require github.com/go-gst/go-glib v1.1.0
+require github.com/go-gst/go-glib v1.2.0
 
 require golang.org/x/exp v0.0.0-20240416160154-fe59bbe5cc7f // indirect

go.sum

@@ -1,5 +1,7 @@
 github.com/go-gst/go-glib v1.1.0 h1:XTGhwk2BWYjW/UZ08y7ojf3iPPRiYtXL0W6vJkXNKFc=
 github.com/go-gst/go-glib v1.1.0/go.mod h1:JybIYeoHNwCkHGaBf1fHNIaM4sQTrJPkPLsi7dmPNOU=
+github.com/go-gst/go-glib v1.2.0 h1:IEi5Og63V8YHBprCFiLsesRKSKWuxY0nYOMgbm7P2NI=
+github.com/go-gst/go-glib v1.2.0/go.mod h1:JybIYeoHNwCkHGaBf1fHNIaM4sQTrJPkPLsi7dmPNOU=
 github.com/mattn/go-pointer v0.0.1 h1:n+XhsuGeVO6MEAp7xyEukFINEa+Quek5psIR/ylA6o0=
 github.com/mattn/go-pointer v0.0.1/go.mod h1:2zXcozF6qYGgmsG+SeTZz3oAbFLdD3OWqnUbNvJZAlc=
 golang.org/x/exp v0.0.0-20240416160154-fe59bbe5cc7f h1:99ci1mjWVBWwJiEKYY6jWa4d2nTQVIEhZIptnrVb1XY=

gst/gst_promise.go

@@ -198,5 +198,11 @@ func marshalPromise(p unsafe.Pointer) (interface{}, error) {
 		done: nil, // cannot be awaited if received from FFI
 	}
 
+	prom.Ref()
+
+	runtime.SetFinalizer(prom, func(p *Promise) {
+		p.Unref()
+	})
+
 	return prom, nil
 }

gst/gst_promise_test.go

@@ -4,10 +4,8 @@ import (
 	"context"
 	"errors"
 	"runtime"
-	"sync"
 	"testing"
 	"time"
-	"unsafe"
 )
 
 //go:noinline
@@ -35,9 +33,7 @@ func awaitGC() {
 }
 
 func TestPromise(t *testing.T) {
-	initOnce.Do(func() {
-		Init(nil)
-	})
+	Init(nil)
 
 	prom := NewPromise()
 	cprom := prom.Instance()
@@ -87,12 +83,8 @@ func TestPromise(t *testing.T) {
 	awaitGC()
 }
 
-var initOnce sync.Once
-
 func TestPromiseMarshal(t *testing.T) {
-	initOnce.Do(func() {
-		Init(nil)
-	})
+	Init(nil)
 
 	prom := NewPromise()
 
@@ -102,7 +94,7 @@ func TestPromiseMarshal(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	receivedPromI, err := marshalPromise(unsafe.Pointer(gv.GValue))
+	receivedPromI, err := gv.GoValue()
 
 	if err != nil {
 		t.Fatal(err)

gst/gstsdp/doc.go

@@ -0,0 +1,2 @@
+// gstsdp contains bindings for the gstreamer sdp library. See also https://gstreamer.freedesktop.org/documentation/sdp/index.html
+package gstsdp

gst/gstsdp/gst.go.h

@@ -0,0 +1,6 @@
+#ifndef __GST_WEBRTC_GO_H__
+#define __GST_WEBRTC_GO_H__
+
+#include <gst/sdp/sdp.h>
+
+#endif

gst/gstsdp/message.go

@@ -0,0 +1,94 @@
+package gstsdp
+
+// #include "gst.go.h"
+import "C"
+import (
+	"errors"
+	"runtime"
+	"unsafe"
+)
+
+type SDPResult C.GstSDPResult
+
+const (
+	SDPResultOk SDPResult = C.GST_SDP_OK
+	SDPEinval   SDPResult = C.GST_SDP_EINVAL
+)
+
+type Message struct {
+	ptr *C.GstSDPMessage
+}
+
+func wrapSDPMessageAndFinalize(sdp *C.GstSDPMessage) *Message {
+	msg := &Message{
+		ptr: sdp,
+	}
+
+	// this requires that we copy the SDP message before passing it to any transfer-ownership function
+	runtime.SetFinalizer(msg, func(msg *Message) {
+		msg.Free()
+	})
+
+	return msg
+}
+
+// NewMessageFromUnsafe creates a new SDP message from a pointer and does not finalize it
+func NewMessageFromUnsafe(ptr unsafe.Pointer) *Message {
+	return &Message{
+		ptr: (*C.GstSDPMessage)(ptr),
+	}
+}
+
+var ErrSDPInvalid = errors.New("invalid SDP")
+
+func ParseSDPMessage(sdp string) (*Message, error) {
+	cstr := C.CString(sdp)
+	defer C.free(unsafe.Pointer(cstr))
+
+	var msg *C.GstSDPMessage
+
+	res := SDPResult(C.gst_sdp_message_new_from_text(cstr, &msg))
+
+	if res != SDPResultOk || msg == nil {
+		return nil, ErrSDPInvalid
+	}
+
+	return wrapSDPMessageAndFinalize(msg), nil
+}
+
+func (msg *Message) String() string {
+	cstr := C.gst_sdp_message_as_text(msg.ptr)
+	defer C.free(unsafe.Pointer(cstr))
+
+	return C.GoString(cstr)
+}
+
+// UnownedCopy creates a new copy of the SDP message that will not be finalized
+//
+// this is needed to pass the message back to C where C takes ownership of the message
+//
+// the returned SDP message will leak memory if not freed manually
+func (msg *Message) UnownedCopy() *Message {
+	var newMsg *C.GstSDPMessage
+	res := C.gst_sdp_message_copy(msg.ptr, &newMsg)
+
+	if res != C.GST_SDP_OK || newMsg == nil {
+		return nil
+	}
+
+	return &Message{
+		ptr: newMsg,
+	}
+}
+
+// Free frees the SDP message.
+//
+// This is called automatically when the object is garbage collected.
+func (msg *Message) Free() {
+	C.gst_sdp_message_free(msg.ptr)
+	msg.ptr = nil
+}
+
+func (msg *Message) Instance() unsafe.Pointer {
+	return unsafe.Pointer(msg.ptr)
+}

gst/gstsdp/pkg_config.go

@@ -0,0 +1,7 @@
+package gstsdp
+
+/*
+#cgo pkg-config: gstreamer-sdp-1.0
+#cgo CFLAGS: -Wno-deprecated-declarations -g -Wall
+*/
+import "C"

gst/gstwebrtc/data_channel.go

@@ -0,0 +1,67 @@
+package gstwebrtc
+
+// #include "gst.go.h"
+import "C"
+import (
+	"errors"
+	"unsafe"
+
+	"github.com/go-gst/go-glib/glib"
+)
+
+func init() {
+
+	tm := []glib.TypeMarshaler{
+		{T: glib.Type(C.GST_TYPE_WEBRTC_DATA_CHANNEL), F: marshalDataChannel},
+	}
+
+	glib.RegisterGValueMarshalers(tm)
+}
+
+// DataChannel is a representation of GstWebRTCDataChannel. See https://gstreamer.freedesktop.org/documentation/webrtclib/gstwebrtc-datachannel.html?gi-language=c
+//
+// there is no constructor for DataChannel, you can get it from webrtcbin signals
+type DataChannel struct {
+	*glib.Object
+}
+
+func (dc *DataChannel) Close() {
+	C.gst_webrtc_data_channel_close((*C.GstWebRTCDataChannel)(dc.Native()))
+}
+
+func (dc *DataChannel) SendData(data []byte) error {
+	var gerr *C.GError
+
+	addr := unsafe.SliceData(data)
+
+	cbytes := C.g_bytes_new(C.gconstpointer(addr), C.gsize(len(data)))
+	defer C.g_bytes_unref(cbytes)
+
+	C.gst_webrtc_data_channel_send_data_full((*C.GstWebRTCDataChannel)(dc.Native()), cbytes, &gerr)
+
+	if gerr != nil {
+		defer C.g_error_free((*C.GError)(gerr))
+		errMsg := C.GoString(gerr.message)
+		return errors.New(errMsg)
+	}
+
+	return nil
+}
+
+// ToGValue implements glib.ValueTransformer
+func (dc *DataChannel) ToGValue() (*glib.Value, error) {
+	val, err := glib.ValueInit(glib.Type(C.GST_TYPE_WEBRTC_DATA_CHANNEL))
+	if err != nil {
+		return nil, err
+	}
+	val.SetInstance(unsafe.Pointer(dc.GObject))
+	return val, nil
+}
+
+func marshalDataChannel(p unsafe.Pointer) (interface{}, error) {
+	c := C.g_value_get_object((*C.GValue)(p))
+
+	return &DataChannel{
+		Object: glib.Take(unsafe.Pointer(c)),
+	}, nil
+}

gst/gstwebrtc/data_channel_test.go

@@ -0,0 +1,42 @@
+package gstwebrtc
+
+import (
+	"testing"
+
+	"github.com/go-gst/go-gst/gst"
+)
+
+func TestDataChannelMarshal(t *testing.T) {
+	gst.Init(nil)
+
+	// hack to get a valid glib.Object
+	el, err := gst.NewElement("webrtcbin")
+
+	if err != nil {
+		t.Error(err)
+	}
+
+	dc := &DataChannel{
+		Object: el.Object.Object,
+	}
+
+	gv, err := dc.ToGValue()
+
+	if err != nil {
+		t.Error(err)
+	}
+
+	dcI, err := gv.GoValue()
+
+	if err != nil {
+		t.Error(err)
+	}
+
+	dc, ok := dcI.(*DataChannel)
+
+	if !ok {
+		t.Error("Failed to convert to DataChannel")
+	}
+
+	_ = dc
+}

gst/gstwebrtc/doc.go

@@ -0,0 +1,2 @@
+// gstwebrtc contains bindings for the gstreamer webrtclib. See also https://gstreamer.freedesktop.org/documentation/webrtclib/index.html
+package gstwebrtc

gst/gstwebrtc/enums.go

@@ -0,0 +1,507 @@
+package gstwebrtc
+
+// #include "gst.go.h"
+import "C"
+
+type BundlePolicy C.GstWebRTCBundlePolicy
+
+const (
+	BUNDLE_POLICY_NONE       BundlePolicy = C.GST_WEBRTC_BUNDLE_POLICY_NONE       // none
+	BUNDLE_POLICY_BALANCED   BundlePolicy = C.GST_WEBRTC_BUNDLE_POLICY_BALANCED   // balanced
+	BUNDLE_POLICY_MAX_COMPAT BundlePolicy = C.GST_WEBRTC_BUNDLE_POLICY_MAX_COMPAT // max-compat
+	BUNDLE_POLICY_MAX_BUNDLE BundlePolicy = C.GST_WEBRTC_BUNDLE_POLICY_MAX_BUNDLE // max-bundle
+)
+
+func (e BundlePolicy) String() string {
+	switch e {
+	case C.GST_WEBRTC_BUNDLE_POLICY_NONE:
+		return "none"
+	case C.GST_WEBRTC_BUNDLE_POLICY_BALANCED:
+		return "balanced"
+	case C.GST_WEBRTC_BUNDLE_POLICY_MAX_COMPAT:
+		return "max-compat"
+	case C.GST_WEBRTC_BUNDLE_POLICY_MAX_BUNDLE:
+		return "max-bundle"
+	}
+	return "unknown"
+}
+
+type DTLSSetup C.GstWebRTCDTLSSetup
+
+const (
+	DTLS_SETUP_NONE    DTLSSetup = C.GST_WEBRTC_DTLS_SETUP_NONE    // none
+	DTLS_SETUP_ACTPASS DTLSSetup = C.GST_WEBRTC_DTLS_SETUP_ACTPASS // actpass
+	DTLS_SETUP_ACTIVE  DTLSSetup = C.GST_WEBRTC_DTLS_SETUP_ACTIVE  // sendonly
+	DTLS_SETUP_PASSIVE DTLSSetup = C.GST_WEBRTC_DTLS_SETUP_PASSIVE // recvonly
+)
+
+func (e DTLSSetup) String() string {
+	switch e {
+	case C.GST_WEBRTC_DTLS_SETUP_NONE:
+		return "none"
+	case C.GST_WEBRTC_DTLS_SETUP_ACTPASS:
+		return "actpass"
+	case C.GST_WEBRTC_DTLS_SETUP_ACTIVE:
+		return "sendonly"
+	case C.GST_WEBRTC_DTLS_SETUP_PASSIVE:
+		return "recvonly"
+	}
+	return "unknown"
+}
+
+type DTLSTransportState C.GstWebRTCDTLSTransportState
+
+const (
+	DTLS_TRANSPORT_STATE_NEW        DTLSTransportState = C.GST_WEBRTC_DTLS_TRANSPORT_STATE_NEW        // new
+	DTLS_TRANSPORT_STATE_CLOSED     DTLSTransportState = C.GST_WEBRTC_DTLS_TRANSPORT_STATE_CLOSED     // closed
+	DTLS_TRANSPORT_STATE_FAILED     DTLSTransportState = C.GST_WEBRTC_DTLS_TRANSPORT_STATE_FAILED     // failed
+	DTLS_TRANSPORT_STATE_CONNECTING DTLSTransportState = C.GST_WEBRTC_DTLS_TRANSPORT_STATE_CONNECTING // connecting
+	DTLS_TRANSPORT_STATE_CONNECTED  DTLSTransportState = C.GST_WEBRTC_DTLS_TRANSPORT_STATE_CONNECTED  // connected
+)
+
+func (e DTLSTransportState) String() string {
+	switch e {
+	case C.GST_WEBRTC_DTLS_TRANSPORT_STATE_NEW:
+		return "new"
+	case C.GST_WEBRTC_DTLS_TRANSPORT_STATE_CLOSED:
+		return "closed"
+	case C.GST_WEBRTC_DTLS_TRANSPORT_STATE_FAILED:
+		return "failed"
+	case C.GST_WEBRTC_DTLS_TRANSPORT_STATE_CONNECTING:
+		return "connecting"
+	case C.GST_WEBRTC_DTLS_TRANSPORT_STATE_CONNECTED:
+		return "connected"
+	}
+	return "unknown"
+}
+
+type DataChannelState C.GstWebRTCDataChannelState
+
+const (
+	DATA_CHANNEL_STATE_CONNECTING DataChannelState = C.GST_WEBRTC_DATA_CHANNEL_STATE_CONNECTING // connecting
+	DATA_CHANNEL_STATE_OPEN       DataChannelState = C.GST_WEBRTC_DATA_CHANNEL_STATE_OPEN       // open
+	DATA_CHANNEL_STATE_CLOSING    DataChannelState = C.GST_WEBRTC_DATA_CHANNEL_STATE_CLOSING    // closing
+	DATA_CHANNEL_STATE_CLOSED     DataChannelState = C.GST_WEBRTC_DATA_CHANNEL_STATE_CLOSED     // closed
+)
+
+func (e DataChannelState) String() string {
+	switch e {
+	case C.GST_WEBRTC_DATA_CHANNEL_STATE_CONNECTING:
+		return "connecting"
+	case C.GST_WEBRTC_DATA_CHANNEL_STATE_OPEN:
+		return "open"
+	case C.GST_WEBRTC_DATA_CHANNEL_STATE_CLOSING:
+		return "closing"
+	case C.GST_WEBRTC_DATA_CHANNEL_STATE_CLOSED:
+		return "closed"
+	}
+	return "unknown"
+}
+
+type Error C.GstWebRTCError
+
+const (
+	ERROR_DATA_CHANNEL_FAILURE           Error = C.GST_WEBRTC_ERROR_DATA_CHANNEL_FAILURE           // data-channel-failure
+	ERROR_DTLS_FAILURE                   Error = C.GST_WEBRTC_ERROR_DTLS_FAILURE                   // dtls-failure
+	ERROR_FINGERPRINT_FAILURE            Error = C.GST_WEBRTC_ERROR_FINGERPRINT_FAILURE            // fingerprint-failure
+	ERROR_SCTP_FAILURE                   Error = C.GST_WEBRTC_ERROR_SCTP_FAILURE                   // sctp-failure
+	ERROR_SDP_SYNTAX_ERROR               Error = C.GST_WEBRTC_ERROR_SDP_SYNTAX_ERROR               // sdp-syntax-error
+	ERROR_HARDWARE_ENCODER_NOT_AVAILABLE Error = C.GST_WEBRTC_ERROR_HARDWARE_ENCODER_NOT_AVAILABLE // hardware-encoder-not-available
+	ERROR_ENCODER_ERROR                  Error = C.GST_WEBRTC_ERROR_ENCODER_ERROR                  // encoder-error
+	ERROR_INVALID_STATE                  Error = C.GST_WEBRTC_ERROR_INVALID_STATE                  // invalid-state
+	ERROR_INTERNAL_FAILURE               Error = C.GST_WEBRTC_ERROR_INTERNAL_FAILURE               // internal-failure
+	ERROR_INVALID_MODIFICATION           Error = C.GST_WEBRTC_ERROR_INVALID_MODIFICATION           // invalid-modification
+	ERROR_TYPE_ERROR                     Error = C.GST_WEBRTC_ERROR_TYPE_ERROR                     // type-error
+)
+
+func (e Error) String() string {
+	switch e {
+	case C.GST_WEBRTC_ERROR_DATA_CHANNEL_FAILURE:
+		return "data-channel-failure"
+	case C.GST_WEBRTC_ERROR_DTLS_FAILURE:
+		return "dtls-failure"
+	case C.GST_WEBRTC_ERROR_FINGERPRINT_FAILURE:
+		return "fingerprint-failure"
+	case C.GST_WEBRTC_ERROR_SCTP_FAILURE:
+		return "sctp-failure"
+	case C.GST_WEBRTC_ERROR_SDP_SYNTAX_ERROR:
+		return "sdp-syntax-error"
+	case C.GST_WEBRTC_ERROR_HARDWARE_ENCODER_NOT_AVAILABLE:
+		return "hardware-encoder-not-available"
+	case C.GST_WEBRTC_ERROR_ENCODER_ERROR:
+		return "encoder-error"
+	case C.GST_WEBRTC_ERROR_INVALID_STATE:
+		return "invalid-state"
+	case C.GST_WEBRTC_ERROR_INTERNAL_FAILURE:
+		return "internal-failure"
+	case C.GST_WEBRTC_ERROR_INVALID_MODIFICATION:
+		return "invalid-modification"
+	case C.GST_WEBRTC_ERROR_TYPE_ERROR:
+		return "type-error"
+	}
+	return "unknown"
+}
+
+type FECType C.GstWebRTCFECType
+
+const (
+	FEC_TYPE_NONE    FECType = C.GST_WEBRTC_FEC_TYPE_NONE    // none
+	FEC_TYPE_ULP_RED FECType = C.GST_WEBRTC_FEC_TYPE_ULP_RED // ulpfec + red
+)
+
+func (e FECType) String() string {
+	switch e {
+	case C.GST_WEBRTC_FEC_TYPE_NONE:
+		return "none"
+	case C.GST_WEBRTC_FEC_TYPE_ULP_RED:
+		return "ulpfec + red"
+	}
+	return "unknown"
+}
+
+type ICEComponent C.GstWebRTCICEComponent
+
+//  GST_WEBRTC_ICE_COMPONENT_RTP (0)RTP component
+// GST_WEBRTC_ICE_COMPONENT_RTCP (1)RTCP component
+
+const (
+	ICE_COMPONENT_RTP  ICEComponent = C.GST_WEBRTC_ICE_COMPONENT_RTP  // RTP component
+	ICE_COMPONENT_RTCP ICEComponent = C.GST_WEBRTC_ICE_COMPONENT_RTCP // RTCP component
+)
+
+func (e ICEComponent) String() string {
+	switch e {
+	case C.GST_WEBRTC_ICE_COMPONENT_RTP:
+		return "RTP component"
+	case C.GST_WEBRTC_ICE_COMPONENT_RTCP:
+		return "RTCP component"
+	}
+	return "unknown"
+}
+
+type ICEConnectionState C.GstWebRTCICEConnectionState
+
+const (
+	ICE_CONNECTION_STATE_NEW          ICEConnectionState = C.GST_WEBRTC_ICE_CONNECTION_STATE_NEW          // new
+	ICE_CONNECTION_STATE_CHECKING     ICEConnectionState = C.GST_WEBRTC_ICE_CONNECTION_STATE_CHECKING     // checking
+	ICE_CONNECTION_STATE_CONNECTED    ICEConnectionState = C.GST_WEBRTC_ICE_CONNECTION_STATE_CONNECTED    // connected
+	ICE_CONNECTION_STATE_COMPLETED    ICEConnectionState = C.GST_WEBRTC_ICE_CONNECTION_STATE_COMPLETED    // completed
+	ICE_CONNECTION_STATE_FAILED       ICEConnectionState = C.GST_WEBRTC_ICE_CONNECTION_STATE_FAILED       // failed
+	ICE_CONNECTION_STATE_DISCONNECTED ICEConnectionState = C.GST_WEBRTC_ICE_CONNECTION_STATE_DISCONNECTED // disconnected
+	ICE_CONNECTION_STATE_CLOSED       ICEConnectionState = C.GST_WEBRTC_ICE_CONNECTION_STATE_CLOSED       // closed
+)
+
+func (e ICEConnectionState) String() string {
+	switch e {
+	case C.GST_WEBRTC_ICE_CONNECTION_STATE_NEW:
+		return "new"
+	case C.GST_WEBRTC_ICE_CONNECTION_STATE_CHECKING:
+		return "checking"
+	case C.GST_WEBRTC_ICE_CONNECTION_STATE_CONNECTED:
+		return "connected"
+	case C.GST_WEBRTC_ICE_CONNECTION_STATE_COMPLETED:
+		return "completed"
+	case C.GST_WEBRTC_ICE_CONNECTION_STATE_FAILED:
+		return "failed"
+	case C.GST_WEBRTC_ICE_CONNECTION_STATE_DISCONNECTED:
+		return "disconnected"
+	case C.GST_WEBRTC_ICE_CONNECTION_STATE_CLOSED:
+		return "closed"
+	}
+	return "unknown"
+}
+
+type ICEGatheringState C.GstWebRTCICEGatheringState
+
+const (
+	ICE_GATHERING_STATE_NEW       ICEGatheringState = C.GST_WEBRTC_ICE_GATHERING_STATE_NEW       // new
+	ICE_GATHERING_STATE_GATHERING ICEGatheringState = C.GST_WEBRTC_ICE_GATHERING_STATE_GATHERING // gathering
+	ICE_GATHERING_STATE_COMPLETE  ICEGatheringState = C.GST_WEBRTC_ICE_GATHERING_STATE_COMPLETE  // complete
+)
+
+func (e ICEGatheringState) String() string {
+	switch e {
+	case C.GST_WEBRTC_ICE_GATHERING_STATE_NEW:
+		return "new"
+	case C.GST_WEBRTC_ICE_GATHERING_STATE_GATHERING:
+		return "gathering"
+	case C.GST_WEBRTC_ICE_GATHERING_STATE_COMPLETE:
+		return "complete"
+	}
+	return "unknown"
+}
+
+type ICERole C.GstWebRTCICERole
+
+const (
+	ICE_ROLE_CONTROLLED  ICERole = C.GST_WEBRTC_ICE_ROLE_CONTROLLED  // controlled
+	ICE_ROLE_CONTROLLING ICERole = C.GST_WEBRTC_ICE_ROLE_CONTROLLING // controlling
+)
+
+func (e ICERole) String() string {
+	switch e {
+	case C.GST_WEBRTC_ICE_ROLE_CONTROLLED:
+		return "controlled"
+	case C.GST_WEBRTC_ICE_ROLE_CONTROLLING:
+		return "controlling"
+	}
+	return "unknown"
+}
+
+type ICETransportPolicy C.GstWebRTCICETransportPolicy
+
+const (
+	ICE_TRANSPORT_POLICY_ALL   ICETransportPolicy = C.GST_WEBRTC_ICE_TRANSPORT_POLICY_ALL   // all
+	ICE_TRANSPORT_POLICY_RELAY ICETransportPolicy = C.GST_WEBRTC_ICE_TRANSPORT_POLICY_RELAY // relay
+)
+
+func (e ICETransportPolicy) String() string {
+	switch e {
+	case C.GST_WEBRTC_ICE_TRANSPORT_POLICY_ALL:
+		return "all"
+	case C.GST_WEBRTC_ICE_TRANSPORT_POLICY_RELAY:
+		return "relay"
+	}
+	return "unknown"
+}
+
+type Kind C.GstWebRTCKind
+
+const (
+	UNKNOWN Kind = C.GST_WEBRTC_KIND_UNKNOWN // unknown
+	AUDIO   Kind = C.GST_WEBRTC_KIND_AUDIO   // audio
+	VIDEO   Kind = C.GST_WEBRTC_KIND_VIDEO   // video
+)
+
+func (e Kind) String() string {
+	switch e {
+	case C.GST_WEBRTC_KIND_UNKNOWN:
+		return "unknown"
+	case C.GST_WEBRTC_KIND_AUDIO:
+		return "audio"
+	case C.GST_WEBRTC_KIND_VIDEO:
+		return "video"
+	}
+	return "unknown"
+}
+
+type PeerConnectionState C.GstWebRTCPeerConnectionState
+
+//  GST_WEBRTC_PEER_CONNECTION_STATE_NEW (0)new
+// GST_WEBRTC_PEER_CONNECTION_STATE_CONNECTING (1)connecting
+// GST_WEBRTC_PEER_CONNECTION_STATE_CONNECTED (2)connected
+// GST_WEBRTC_PEER_CONNECTION_STATE_DISCONNECTED (3)disconnected
+// GST_WEBRTC_PEER_CONNECTION_STATE_FAILED (4)failed
+// GST_WEBRTC_PEER_CONNECTION_STATE_CLOSED (5)closed
+
+const (
+	PEER_CONNECTION_STATE_NEW          PeerConnectionState = C.GST_WEBRTC_PEER_CONNECTION_STATE_NEW          // new
+	PEER_CONNECTION_STATE_CONNECTING   PeerConnectionState = C.GST_WEBRTC_PEER_CONNECTION_STATE_CONNECTING   // connecting
+	PEER_CONNECTION_STATE_CONNECTED    PeerConnectionState = C.GST_WEBRTC_PEER_CONNECTION_STATE_CONNECTED    // connected
+	PEER_CONNECTION_STATE_DISCONNECTED PeerConnectionState = C.GST_WEBRTC_PEER_CONNECTION_STATE_DISCONNECTED // disconnected
+	PEER_CONNECTION_STATE_FAILED       PeerConnectionState = C.GST_WEBRTC_PEER_CONNECTION_STATE_FAILED       // failed
+	PEER_CONNECTION_STATE_CLOSED       PeerConnectionState = C.GST_WEBRTC_PEER_CONNECTION_STATE_CLOSED       // closed
+)
+
+func (e PeerConnectionState) String() string {
+	switch e {
+	case C.GST_WEBRTC_PEER_CONNECTION_STATE_NEW:
+		return "new"
+	case C.GST_WEBRTC_PEER_CONNECTION_STATE_CONNECTING:
+		return "connecting"
+	case C.GST_WEBRTC_PEER_CONNECTION_STATE_CONNECTED:
+		return "connected"
+	case C.GST_WEBRTC_PEER_CONNECTION_STATE_DISCONNECTED:
+		return "disconnected"
+	case C.GST_WEBRTC_PEER_CONNECTION_STATE_FAILED:
+		return "failed"
+	case C.GST_WEBRTC_PEER_CONNECTION_STATE_CLOSED:
+		return "closed"
+	}
+	return "unknown"
+}
+
+type PriorityType C.GstWebRTCPriorityType
+
+const (
+	PRIORITY_TYPE_VERY_LOW PriorityType = C.GST_WEBRTC_PRIORITY_TYPE_VERY_LOW // very-low
+	PRIORITY_TYPE_LOW      PriorityType = C.GST_WEBRTC_PRIORITY_TYPE_LOW      // low
+	PRIORITY_TYPE_MEDIUM   PriorityType = C.GST_WEBRTC_PRIORITY_TYPE_MEDIUM   // medium
+	PRIORITY_TYPE_HIGH     PriorityType = C.GST_WEBRTC_PRIORITY_TYPE_HIGH     // high
+)
+
+func (e PriorityType) String() string {
+	switch e {
+	case C.GST_WEBRTC_PRIORITY_TYPE_VERY_LOW:
+		return "very-low"
+	case C.GST_WEBRTC_PRIORITY_TYPE_LOW:
+		return "low"
+	case C.GST_WEBRTC_PRIORITY_TYPE_MEDIUM:
+		return "medium"
+	case C.GST_WEBRTC_PRIORITY_TYPE_HIGH:
+		return "high"
+	}
+	return "unknown"
+}
+
+type RTPTransceiverDirection C.GstWebRTCRTPTransceiverDirection
+
+const (
+	RTP_TRANSCEIVER_DIRECTION_NONE     RTPTransceiverDirection = C.GST_WEBRTC_RTP_TRANSCEIVER_DIRECTION_NONE     // none
+	RTP_TRANSCEIVER_DIRECTION_INACTIVE RTPTransceiverDirection = C.GST_WEBRTC_RTP_TRANSCEIVER_DIRECTION_INACTIVE // inactive
+	RTP_TRANSCEIVER_DIRECTION_SENDONLY RTPTransceiverDirection = C.GST_WEBRTC_RTP_TRANSCEIVER_DIRECTION_SENDONLY // sendonly
+	RTP_TRANSCEIVER_DIRECTION_RECVONLY RTPTransceiverDirection = C.GST_WEBRTC_RTP_TRANSCEIVER_DIRECTION_RECVONLY // recvonly
+	RTP_TRANSCEIVER_DIRECTION_SENDRECV RTPTransceiverDirection = C.GST_WEBRTC_RTP_TRANSCEIVER_DIRECTION_SENDRECV // sendrecv
+)
+
+func (e RTPTransceiverDirection) String() string {
+	switch e {
+	case C.GST_WEBRTC_RTP_TRANSCEIVER_DIRECTION_NONE:
+		return "none"
+	case C.GST_WEBRTC_RTP_TRANSCEIVER_DIRECTION_INACTIVE:
+		return "inactive"
+	case C.GST_WEBRTC_RTP_TRANSCEIVER_DIRECTION_SENDONLY:
+		return "sendonly"
+	case C.GST_WEBRTC_RTP_TRANSCEIVER_DIRECTION_RECVONLY:
+		return "recvonly"
+	case C.GST_WEBRTC_RTP_TRANSCEIVER_DIRECTION_SENDRECV:
+		return "sendrecv"
+	}
+	return "unknown"
+}
+
+type SCTPTransportState C.GstWebRTCSCTPTransportState
+
+const (
+	SCTP_TRANSPORT_STATE_NEW        SCTPTransportState = C.GST_WEBRTC_SCTP_TRANSPORT_STATE_NEW        // new
+	SCTP_TRANSPORT_STATE_CONNECTING SCTPTransportState = C.GST_WEBRTC_SCTP_TRANSPORT_STATE_CONNECTING // connecting
+	SCTP_TRANSPORT_STATE_CONNECTED  SCTPTransportState = C.GST_WEBRTC_SCTP_TRANSPORT_STATE_CONNECTED  // connected
+	SCTP_TRANSPORT_STATE_CLOSED     SCTPTransportState = C.GST_WEBRTC_SCTP_TRANSPORT_STATE_CLOSED     // closed
+)
+
+func (e SCTPTransportState) String() string {
+	switch e {
+	case C.GST_WEBRTC_SCTP_TRANSPORT_STATE_NEW:
+		return "new"
+	case C.GST_WEBRTC_SCTP_TRANSPORT_STATE_CONNECTING:
+		return "connecting"
+	case C.GST_WEBRTC_SCTP_TRANSPORT_STATE_CONNECTED:
+		return "connected"
+	case C.GST_WEBRTC_SCTP_TRANSPORT_STATE_CLOSED:
+		return "closed"
+	}
+	return "unknown"
+}
+
+type SDPType C.GstWebRTCSDPType
+
+const (
+	SDP_TYPE_OFFER    SDPType = C.GST_WEBRTC_SDP_TYPE_OFFER    // offer
+	SDP_TYPE_PRANSWER SDPType = C.GST_WEBRTC_SDP_TYPE_PRANSWER // pranswer
+	SDP_TYPE_ANSWER   SDPType = C.GST_WEBRTC_SDP_TYPE_ANSWER   // answer
+	SDP_TYPE_ROLLBACK SDPType = C.GST_WEBRTC_SDP_TYPE_ROLLBACK // rollback
+)
+
+func (e SDPType) String() string {
+	// returned string is const gchar* and must not be freed
+	cstring := C.gst_webrtc_sdp_type_to_string(C.GstWebRTCSDPType(e))
+
+	return C.GoString(cstring)
+}
+
+func SDPTypeFromString(s string) SDPType {
+	switch s {
+	case "offer":
+		return SDP_TYPE_OFFER
+	case "pranswer":
+		return SDP_TYPE_PRANSWER
+	case "answer":
+		return SDP_TYPE_ANSWER
+	case "rollback":
+		return SDP_TYPE_ROLLBACK
+	default:
+		panic("Unknown SDPType")
+	}
+}
+
+type SignalingState C.GstWebRTCSignalingState
+
+const (
+	SIGNALING_STATE_STABLE               SignalingState = C.GST_WEBRTC_SIGNALING_STATE_STABLE               // stable
+	SIGNALING_STATE_CLOSED               SignalingState = C.GST_WEBRTC_SIGNALING_STATE_CLOSED               // closed
+	SIGNALING_STATE_HAVE_LOCAL_OFFER     SignalingState = C.GST_WEBRTC_SIGNALING_STATE_HAVE_LOCAL_OFFER     // have-local-offer
+	SIGNALING_STATE_HAVE_REMOTE_OFFER    SignalingState = C.GST_WEBRTC_SIGNALING_STATE_HAVE_REMOTE_OFFER    // have-remote-offer
+	SIGNALING_STATE_HAVE_LOCAL_PRANSWER  SignalingState = C.GST_WEBRTC_SIGNALING_STATE_HAVE_LOCAL_PRANSWER  // have-local-pranswer
+	SIGNALING_STATE_HAVE_REMOTE_PRANSWER SignalingState = C.GST_WEBRTC_SIGNALING_STATE_HAVE_REMOTE_PRANSWER // have-remote-pranswer
+)
+
+func (e SignalingState) String() string {
+	switch e {
+	case C.GST_WEBRTC_SIGNALING_STATE_STABLE:
+		return "stable"
+	case C.GST_WEBRTC_SIGNALING_STATE_CLOSED:
+		return "closed"
+	case C.GST_WEBRTC_SIGNALING_STATE_HAVE_LOCAL_OFFER:
+		return "have-local-offer"
+	case C.GST_WEBRTC_SIGNALING_STATE_HAVE_REMOTE_OFFER:
+		return "have-remote-offer"
+	case C.GST_WEBRTC_SIGNALING_STATE_HAVE_LOCAL_PRANSWER:
+		return "have-local-pranswer"
+	case C.GST_WEBRTC_SIGNALING_STATE_HAVE_REMOTE_PRANSWER:
+		return "have-remote-pranswer"
+	}
+	return "unknown"
+}
+
+type StatsType C.GstWebRTCStatsType
+
+const (
+	STATS_CODEC               StatsType = C.GST_WEBRTC_STATS_CODEC               // codec
+	STATS_INBOUND_RTP         StatsType = C.GST_WEBRTC_STATS_INBOUND_RTP         // inbound-rtp
+	STATS_OUTBOUND_RTP        StatsType = C.GST_WEBRTC_STATS_OUTBOUND_RTP        // outbound-rtp
+	STATS_REMOTE_INBOUND_RTP  StatsType = C.GST_WEBRTC_STATS_REMOTE_INBOUND_RTP  // remote-inbound-rtp
+	STATS_REMOTE_OUTBOUND_RTP StatsType = C.GST_WEBRTC_STATS_REMOTE_OUTBOUND_RTP // remote-outbound-rtp
+	STATS_CSRC                StatsType = C.GST_WEBRTC_STATS_CSRC                // csrc
+	STATS_PEER_CONNECTION     StatsType = C.GST_WEBRTC_STATS_PEER_CONNECTION     // peer-connection
+	STATS_DATA_CHANNEL        StatsType = C.GST_WEBRTC_STATS_DATA_CHANNEL        // data-channel
+	STATS_STREAM              StatsType = C.GST_WEBRTC_STATS_STREAM              // stream
+	STATS_TRANSPORT           StatsType = C.GST_WEBRTC_STATS_TRANSPORT           // transport
+	STATS_CANDIDATE_PAIR      StatsType = C.GST_WEBRTC_STATS_CANDIDATE_PAIR      // candidate-pair
+	STATS_LOCAL_CANDIDATE     StatsType = C.GST_WEBRTC_STATS_LOCAL_CANDIDATE     // local-candidate
+	STATS_REMOTE_CANDIDATE    StatsType = C.GST_WEBRTC_STATS_REMOTE_CANDIDATE    // remote-candidate
+	STATS_CERTIFICATE         StatsType = C.GST_WEBRTC_STATS_CERTIFICATE         // certificate
+)
+
+func (e StatsType) String() string {
+	switch e {
+	case C.GST_WEBRTC_STATS_CODEC:
+		return "codec"
+	case C.GST_WEBRTC_STATS_INBOUND_RTP:
+		return "inbound-rtp"
+	case C.GST_WEBRTC_STATS_OUTBOUND_RTP:
+		return "outbound-rtp"
+	case C.GST_WEBRTC_STATS_REMOTE_INBOUND_RTP:
+		return "remote-inbound-rtp"
+	case C.GST_WEBRTC_STATS_REMOTE_OUTBOUND_RTP:
+		return "remote-outbound-rtp"
+	case C.GST_WEBRTC_STATS_CSRC:
+		return "csrc"
+	case C.GST_WEBRTC_STATS_PEER_CONNECTION:
+		return "peer-connection"
+	case C.GST_WEBRTC_STATS_DATA_CHANNEL:
+		return "data-channel"
+	case C.GST_WEBRTC_STATS_STREAM:
+		return "stream"
+	case C.GST_WEBRTC_STATS_TRANSPORT:
+		return "transport"
+	case C.GST_WEBRTC_STATS_CANDIDATE_PAIR:
+		return "candidate-pair"
+	case C.GST_WEBRTC_STATS_LOCAL_CANDIDATE:
+		return "local-candidate"
+	case C.GST_WEBRTC_STATS_REMOTE_CANDIDATE:
+		return "remote-candidate"
+	case C.GST_WEBRTC_STATS_CERTIFICATE:
+		return "certificate"
+	}
+	return "unknown"
+}

gst/gstwebrtc/gst.go.h

@@ -0,0 +1,8 @@
+#ifndef __GST_WEBRTC_GO_H__
+#define __GST_WEBRTC_GO_H__
+
+#define GST_USE_UNSTABLE_API // webrtc is unstable
+
+#include <gst/webrtc/webrtc.h>
+
+#endif

gst/gstwebrtc/pkg_config.go

@@ -0,0 +1,7 @@
+package gstwebrtc
+
+/*
+#cgo pkg-config: gstreamer-webrtc-1.0
+#cgo CFLAGS: -Wno-deprecated-declarations -g -Wall
+*/
+import "C"

gst/gstwebrtc/rtp_transceiver.go

@@ -0,0 +1,45 @@
+package gstwebrtc
+
+// #include "gst.go.h"
+import "C"
+import (
+	"unsafe"
+
+	"github.com/go-gst/go-glib/glib"
+	"github.com/go-gst/go-gst/gst"
+)
+
+func init() {
+
+	tm := []glib.TypeMarshaler{
+		{T: glib.Type(C.GST_TYPE_WEBRTC_RTP_TRANSCEIVER), F: marshalRTPTransceiver},
+	}
+
+	glib.RegisterGValueMarshalers(tm)
+}
+
+type RTPTransceiver struct {
+	*gst.Object
+}
+
+// ToGValue implements glib.ValueTransformer
+func (tc *RTPTransceiver) ToGValue() (*glib.Value, error) {
+	val, err := glib.ValueInit(glib.Type(C.GST_TYPE_WEBRTC_RTP_TRANSCEIVER))
+	if err != nil {
+		return nil, err
+	}
+	val.SetInstance(unsafe.Pointer(tc.Instance()))
+	return val, nil
+}
+
+func wrapRTPTransceiver(p unsafe.Pointer) *RTPTransceiver {
+	return &RTPTransceiver{
+		Object: gst.FromGstObjectUnsafeNone(p),
+	}
+}
+
+func marshalRTPTransceiver(p unsafe.Pointer) (interface{}, error) {
+	c := C.g_value_get_object((*C.GValue)(p))
+
+	return wrapRTPTransceiver(unsafe.Pointer(c)), nil
+}

gst/gstwebrtc/rtp_transceiver_test.go

@@ -0,0 +1,9 @@
+package gstwebrtc_test
+
+import (
+	"testing"
+)
+
+func TestRTPTransceiverGValueMarshal(t *testing.T) {
+	t.Skip("Not implemented, because we don't have a constructor for RTPTransceiver")
+}

gst/gstwebrtc/session_description.go

@@ -0,0 +1,120 @@
+package gstwebrtc
+
+// #include "gst.go.h"
+import "C"
+import (
+	"runtime"
+	"unsafe"
+
+	"github.com/go-gst/go-glib/glib"
+	"github.com/go-gst/go-gst/gst/gstsdp"
+)
+
+func init() {
+
+	tm := []glib.TypeMarshaler{
+		{T: glib.Type(C.GST_TYPE_WEBRTC_SESSION_DESCRIPTION), F: marshalSessionDescription},
+	}
+
+	glib.RegisterGValueMarshalers(tm)
+}
+
+type SessionDescription struct {
+	ptr *C.GstWebRTCSessionDescription
+}
+
+func NewSessionDescription(t SDPType, sdp *gstsdp.Message) *SessionDescription {
+	sd := C.gst_webrtc_session_description_new(
+		C.GstWebRTCSDPType(t),
+		(*C.GstSDPMessage)(sdp.UnownedCopy().Instance()),
+	)
+
+	return wrapSessionDescriptionAndFinalize(sd)
+}
+
+func wrapSessionDescriptionAndFinalize(sdp *C.GstWebRTCSessionDescription) *SessionDescription {
+	sd := &SessionDescription{
+		ptr: sdp,
+	}
+
+	// this requires that we copy the SDP message before passing it to any transfer-ownership function
+	runtime.SetFinalizer(sd, func(sd *SessionDescription) {
+		sd.Free()
+	})
+
+	return sd
+}
+
+// W3RTCSessionDescription is used to marshal/unmarshal SessionDescription to/from JSON.
+//
+// We cannot implement the json.(Un-)Marshaler interfaces on SessionDescription directly because
+// the finalizer would run and free the memory, because the value would have to be copied.
+//
+// it complies with the WebRTC spec for SessionDescription, see https://www.w3.org/TR/webrtc/#rtcsessiondescription-class
+type W3RTCSessionDescription struct {
+	Type string `json:"type"`
+	Sdp  string `json:"sdp"`
+}
+
+// ToGstSDP converts a W3RTCSessionDescription to a SessionDescription
+func (w3SDP *W3RTCSessionDescription) ToGstSDP() (*SessionDescription, error) {
+	sdp, err := gstsdp.ParseSDPMessage(w3SDP.Sdp)
+	if err != nil {
+		return nil, err
+	}
+
+	return NewSessionDescription(SDPTypeFromString(w3SDP.Type), sdp), nil
+}
+
+// ToW3SDP returns a W3RTCSessionDescription that can be marshaled to JSON
+func (sd *SessionDescription) ToW3SDP() W3RTCSessionDescription {
+	jsonSDP := W3RTCSessionDescription{
+		Type: SDPType(sd.ptr._type).String(),
+		Sdp:  gstsdp.NewMessageFromUnsafe(unsafe.Pointer(sd.ptr.sdp)).String(),
+	}
+
+	return jsonSDP
+}
+
+func (sd *SessionDescription) Free() {
+	C.gst_webrtc_session_description_free(sd.ptr)
+}
+
+// UnownedCopy creates a new copy of the SessionDescription that will not be finalized
+//
+// this is needed for passing the SessionDescription to other functions that will take ownership of it.
+//
+// used in the bindings, should not be called by application code
+func (sd *SessionDescription) UnownedCopy() *SessionDescription {
+	newSD := C.gst_webrtc_session_description_copy(sd.ptr)
+
+	return &SessionDescription{
+		ptr: newSD,
+	}
+}
+
+// Copy creates a new copy of the SessionDescription
+func (sd *SessionDescription) Copy() *SessionDescription {
+	return wrapSessionDescriptionAndFinalize(sd.UnownedCopy().ptr)
+}
+
+// ToGValue implements glib.ValueTransformer
+func (sd *SessionDescription) ToGValue() (*glib.Value, error) {
+	val, err := glib.ValueInit(glib.Type(C.GST_TYPE_WEBRTC_SESSION_DESCRIPTION))
+	if err != nil {
+		return nil, err
+	}
+	val.SetBoxed(unsafe.Pointer(sd.ptr))
+	return val, nil
+}
+
+func marshalSessionDescription(p unsafe.Pointer) (interface{}, error) {
+	c := C.g_value_get_boxed((*C.GValue)(p))
+
+	// we don't own this memory, so we need to copy it to prevent other code from freeing it
+	ref := &SessionDescription{
+		ptr: (*C.GstWebRTCSessionDescription)(c),
+	}
+
+	return ref.Copy(), nil
+}

gst/gstwebrtc/session_description_test.go

@@ -0,0 +1,58 @@
+package gstwebrtc_test
+
+import (
+	"testing"
+
+	"github.com/go-gst/go-gst/gst/gstsdp"
+	"github.com/go-gst/go-gst/gst/gstwebrtc"
+)
+
+func TestSessionDescriptionGValueMarshal(t *testing.T) {
+	sdp, err := gstsdp.ParseSDPMessage("v=0\nm=audio 4000 RTP/AVP 111\na=rtpmap:111 OPUS/48000/2\nm=video 4000 RTP/AVP 96\na=rtpmap:96 VP8/90000\na=my-sdp-value")
+
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	sd := gstwebrtc.NewSessionDescription(gstwebrtc.SDP_TYPE_OFFER, sdp)
+
+	gv, err := sd.ToGValue()
+
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	sdI, err := gv.GoValue()
+
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	sd, ok := sdI.(*gstwebrtc.SessionDescription)
+
+	if !ok {
+		t.Fatal("Failed to convert to SessionDescription")
+	}
+
+	_ = sd
+}
+
+func TestSessionDescriptionJSONMarshal(t *testing.T) {
+	sdp, err := gstsdp.ParseSDPMessage("v=0\nm=audio 4000 RTP/AVP 111\na=rtpmap:111 OPUS/48000/2\nm=video 4000 RTP/AVP 96\na=rtpmap:96 VP8/90000\na=my-sdp-value")
+
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	sd := gstwebrtc.NewSessionDescription(gstwebrtc.SDP_TYPE_OFFER, sdp)
+
+	w3 := sd.ToW3SDP()
+
+	sd, err = w3.ToGstSDP()
+
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	_ = sd
+}