局域网内端到端的聊天项目(八)

效果图:

iPod.gif

iPone.gif

• 上一篇已实现语音的录制/传输/播放
• 接下来实现局域网内的视频通话
• webRTC官网
• 该音视频通话基于 webRTC 来实现

webRTC 通过 RTCPeerConnection 来建立连接高效,稳定的音视频流传输它依然还需要利用服务器来做一些准备工作。比如STUN服务器、TURN服务器、ICE（NAT和防火墙穿透）、信令传输，相互之间的信令交换完毕，就会发送实时音视频留给对方。

一.设置好 STUN 服务器

- (RTCICEServer *)defaultSTUNServer:(NSString *)stunURL {
    NSURL *defaultSTUNServerURL = [NSURL URLWithString:stunURL];
    return [[RTCICEServer alloc] initWithURI:defaultSTUNServerURL
                                    username:@""
                                    password:@""];
}

二.创建 RTCPeerConnection 并设置好 本地视频/对方视频位置

- (void)setUPinitRTC
{
    self.peerConnection = [self.peerConnectionFactory peerConnectionWithICEServers:_ICEServers constraints:self.pcConstraints delegate:self];
    
    //设置 local media stream
    RTCMediaStream *mediaStream = [self.peerConnectionFactory mediaStreamWithLabel:@"ARDAMS"];
    // 添加 local video track
    RTCAVFoundationVideoSource *source = [[RTCAVFoundationVideoSource alloc] initWithFactory:self.peerConnectionFactory constraints:self.videoConstraints];
    RTCVideoTrack *localVideoTrack = [[RTCVideoTrack alloc] initWithFactory:self.peerConnectionFactory source:source trackId:@"AVAMSv0"];
    [mediaStream addVideoTrack:localVideoTrack];
    self.localVideoTrack = localVideoTrack;
    
    // 添加 local audio track
    RTCAudioTrack *localAudioTrack = [self.peerConnectionFactory audioTrackWithID:@"ARDAMSa0"];
    [mediaStream addAudioTrack:localAudioTrack];
    // 添加 mediaStream
    [self.peerConnection addStream:mediaStream];
    
    RTCEAGLVideoView *localVideoView = [[RTCEAGLVideoView alloc] initWithFrame:self.callView.meVideoView.bounds];
    localVideoView.transform = CGAffineTransformMakeScale(-1, 1);
    localVideoView.delegate = self;
    [self.callView.meVideoView addSubview:localVideoView];
    self.localVideoView = localVideoView;
    
    [self.localVideoTrack addRenderer:self.localVideoView];
    
    RTCEAGLVideoView *remoteVideoView = [[RTCEAGLVideoView alloc] initWithFrame:self.callView.friendVideoView.bounds];
    remoteVideoView.transform = CGAffineTransformMakeScale(-1, 1);
    remoteVideoView.delegate = self;
    [self.callView.friendVideoView addSubview:remoteVideoView];
    self.remoteVideoView = remoteVideoView;
}

三.由视频发起方来触发信令的发送 ,

• 通过SocketManager来发送offer信令
• 发起方发送 offer 信令给接受方
• 接受方收到 offer 初始化自己的 RTCPeerConnection 发出自己的offer 并保存接收到的消息
• 接收方点击接听视频时 -> 遍历保存的信息 -> 有offer信息保存sdp 并创建 answer -> 有 answer 保存 sdp
• 发起方接收到 answer 时保存

3.1-弹出视频对话view

- (void)showRTCViewByRemoteName:(NSString *)remoteName isVideo:(BOOL)isVideo isCaller:(BOOL)isCaller
{
    // 1.显示视图
    WS(weakSelf);
    self.callView = [VideoOrAudioCallView callViewWithUserName:remoteName isVideo:isVideo role:isCaller ? RoleCaller : RoleCallee];
    self.callView.acceptHandle = ^{
        [weakSelf acceptAction];
    };
    self.callView.closeHandle = ^{
        [weakSelf hangupEvent];
    };
    
    // 拨打时，禁止黑屏
    [UIApplication sharedApplication].idleTimerDisabled = YES;

    // 做RTC必要设置
    if (isCaller) {
        [self setUPinitRTC];
        // 如果是发起者，创建一个offer信令
        [self.peerConnection createOfferWithDelegate:self constraints:self.sdpConstraints];
    } 
}

3.2-收到消息的处理

- (void)hangupEvent
{
    NSDictionary *dict = @{@"type":@"bye"};
    [self processMessageDict:dict];
}

- (void)receiveSignalingMessage:(NSNotification *)notification
{
    NSDictionary *dict = notification.userInfo;
    NSString *type = dict[@"type"];
    if ([type isEqualToString:@"offer"]) {
        [self showRTCViewByRemoteName:CURRENT_FRIENDNAME isVideo:YES isCaller:NO];
        
        [self.messages insertObject:dict atIndex:0];
    } else if ([type isEqualToString:@"answer"]) {
        RTCSessionDescription *sdp = [[RTCSessionDescription alloc] initWithType:type sdp:dict[@"sdp"]];
        [self.peerConnection setRemoteDescriptionWithDelegate:self sessionDescription:sdp];
    } else if ([type isEqualToString:@"candidate"]) {
        
        [self.messages addObject:dict];
    } else if ([type isEqualToString:@"bye"]) {
        [self processMessageDict:dict];
    }
}

- (void)acceptAction
{
    [self initRTCSetting];
    for (NSDictionary *dict in self.messages) {
        [self processMessageDict:dict];
    }
    [self.messages removeAllObjects];
}

- (void)processMessageDict:(NSDictionary *)dict
{
    NSString *type = dict[@"type"];
    if ([type isEqualToString:@"offer"]) {
        RTCSessionDescription *remoteSdp = [[RTCSessionDescription alloc] initWithType:type sdp:dict[@"sdp"]];
        [self.peerConnection setRemoteDescriptionWithDelegate:self sessionDescription:remoteSdp];
        
        [self.peerConnection createAnswerWithDelegate:self constraints:self.sdpConstraints];
    } else if ([type isEqualToString:@"answer"]) {
        RTCSessionDescription *remoteSdp = [[RTCSessionDescription alloc] initWithType:type sdp:dict[@"sdp"]];
        [self.peerConnection setRemoteDescriptionWithDelegate:self sessionDescription:remoteSdp];
        
    } else if ([type isEqualToString:@"candidate"]) {
        NSString *mid = [dict objectForKey:@"id"];
        NSNumber *sdpLineIndex = [dict objectForKey:@"label"];
        NSString *sdp = [dict objectForKey:@"sdp"];
        RTCICECandidate *candidate = [[RTCICECandidate alloc] initWithMid:mid index:sdpLineIndex.intValue sdp:sdp];

        [self.peerConnection addICECandidate:candidate];
    } else if ([type isEqualToString:@"bye"]) {

        if (self.callView) {
            NSData *jsonData = [NSJSONSerialization dataWithJSONObject:dict options:0 error:nil];
            NSString *jsonStr = [[NSString alloc] initWithData:jsonData encoding:NSUTF8StringEncoding];
            if (jsonStr.length > 0) {
                [[SocketManager shareSockManager] RTCMessageSendWithData:jsonData withTag:-100];
            }
            WS(weakSelf);
            [self.callView closeWithCompletion:^(BOOL finished) {
                weakSelf.callView = nil;
            }];
            
            [self cleanCache];
        }
    }
}

3.3-创建信令的delegate回调 并发送 offer 信令 及sdp

#pragma mark - RTCSessionDescriptionDelegate
// Called when creating a session.
- (void)peerConnection:(RTCPeerConnection *)peerConnection
didCreateSessionDescription:(RTCSessionDescription *)sdp
                 error:(NSError *)error
{
    if (error) {
        NSLog(@"创建SessionDescription 失败");
    } else {
        [self.peerConnection setLocalDescriptionWithDelegate:self sessionDescription:sdp];
        NSDictionary *jsonDict = @{ @"type" : sdp.type, @"sdp" : sdp.description};
        NSData *jsonData = [NSJSONSerialization dataWithJSONObject:jsonDict options:0 error:nil];
        [[SocketManager shareSockManager] RTCMessageSendWithData:jsonData withTag:-100];
    }
}

// Called when setting a local or remote description.
- (void)peerConnection:(RTCPeerConnection *)peerConnection
didSetSessionDescriptionWithError:(NSError *)error
{
    NSLog(@"%s",__func__);    
}

3.4- RTCPeerConnectionDelegate 添加视频流 新的 Ice candidate 被发现 及发送

#pragma mark - RTCPeerConnectionDelegate
// Triggered when the SignalingState changed.
- (void)peerConnection:(RTCPeerConnection *)peerConnection
 signalingStateChanged:(RTCSignalingState)stateChanged
{
    NSLog(@"信令状态改变");
}

// Triggered when media is received on a new stream from remote peer.
- (void)peerConnection:(RTCPeerConnection *)peerConnection
           addedStream:(RTCMediaStream *)stream
{
    dispatch_async(dispatch_get_main_queue(), ^{
        if ([stream.videoTracks count]) {
            self.remoteVideoTrack = nil;
            [self.remoteVideoView renderFrame:nil];
            self.remoteVideoTrack = stream.videoTracks[0];
            [self.remoteVideoTrack addRenderer:self.remoteVideoView];
            // 连接成功后的UI操作
            [self.callView connectFinshHandle];
        }
        
        [self videoView:self.remoteVideoView didChangeVideoSize:self.callView.friendVideoView.bounds.size];
        [self videoView:self.localVideoView didChangeVideoSize:self.callView.meVideoView.bounds.size];
        
    });
}

// Triggered when a remote peer close a stream.
- (void)peerConnection:(RTCPeerConnection *)peerConnection
         removedStream:(RTCMediaStream *)stream
{
    NSLog(@"%s",__func__);
}

// Triggered when renegotiation is needed, for example the ICE has restarted.
- (void)peerConnectionOnRenegotiationNeeded:(RTCPeerConnection *)peerConnection
{
     NSLog(@"%s",__func__);
}

// Called any time the ICEConnectionState changes.
- (void)peerConnection:(RTCPeerConnection *)peerConnection
  iceConnectionChanged:(RTCICEConnectionState)newState
{
    NSLog(@"%s",__func__);
}

// Called any time the ICEGatheringState changes.
- (void)peerConnection:(RTCPeerConnection *)peerConnection
   iceGatheringChanged:(RTCICEGatheringState)newState
{
    NSLog(@"%s",__func__);
    switch (newState) {
        case RTCICEGatheringNew:
        {
            NSLog(@"newState = RTCICEGatheringNew");
        }
            break;
        case RTCICEGatheringGathering:
        {
            NSLog(@"newState = RTCICEGatheringGathering");
        }
            break;
        case RTCICEGatheringComplete:
        {
            NSLog(@"newState = RTCICEGatheringComplete");
        }
            break;
    }

}

// New Ice candidate have been found.
- (void)peerConnection:(RTCPeerConnection *)peerConnection
       gotICECandidate:(RTCICECandidate *)candidate
{
    if (self.HaveSentCandidate) {
        return;
    }
    NSDictionary *jsonDict = @{@"type":@"candidate",
                               @"label":[NSNumber numberWithInteger:candidate.sdpMLineIndex],
                               @"id":candidate.sdpMid,
                               @"sdp":candidate.sdp
                               };
    NSData *jsonData = [NSJSONSerialization dataWithJSONObject:jsonDict options:0 error:nil];
    if (jsonData.length > 0) {
        [[SocketManager shareSockManager] RTCMessageSendWithData:jsonData withTag:-100];
        self.HaveSentCandidate = YES;
    }
}

// New data channel has been opened.
- (void)peerConnection:(RTCPeerConnection*)peerConnection
    didOpenDataChannel:(RTCDataChannel*)dataChannel
{
    NSLog(@"%s",__func__);
}