跨房 PK 连麦方案

- (void)connectOtherRoom:(NSString *)roomId {
    NSMutableDictionary *jsonDict = [[NSMutableDictionary alloc] init];
    // 以字符串房间号为例，数字房间号 key:roomId
    [jsonDict setObject:roomId forKey:@"strRoomId"];
    [jsonDict setObject:self.userId forKey:@"userId"];
    NSData *jsonData = [NSJSONSerialization dataWithJSONObject:jsonDict options:NSJSONWritingPrettyPrinted error:nil];
    NSString *jsonString = [[NSString alloc] initWithData:jsonData encoding:NSUTF8StringEncoding];
    [self.trtcCloud connectOtherRoom:jsonString];
}

// 请求跨房连麦的结果回调
- (void)onConnectOtherRoom:(NSString *)userId errCode:(TXLiteAVError)errCode errMsg:(NSString *)errMsg {
    // userId:  要跨房连麦的另一个房间中的主播的用户 ID
    // errCode: 错误码，ERR_NULL 代表请求成功
    // errMsg:  错误信息
}

- (void)onUserAudioAvailable:(NSString *)userId available:(BOOL)available {
    // 某远端用户发布/取消了自己的音频
    // 在自动订阅模式下，您无需做任何操作，SDK 会自动播放远端用户音频
}

- (void)onUserVideoAvailable:(NSString *)userId available:(BOOL)available {
    // 某远端用户发布/取消了主路视频画面
    if (available) {
        // 订阅远端用户的视频流，并绑定视频渲染控件
        [self.trtcCloud startRemoteView:userId streamType:TRTCVideoStreamTypeBig view:self.remoteView];
    } else {
        // 停止订阅远端用户的视频流，并释放渲染控件
        [self.trtcCloud stopRemoteView:userId streamType:TRTCVideoStreamTypeBig];
    }
}

// 退出跨房连麦
[self.trtcCloud disconnectOtherRoom];

// 退出跨房连麦的结果回调
- (void)onDisconnectOtherRoom:(TXLiteAVError)errCode errMsg:(NSString *)errMsg {
}

{
  "SdkAppId": 1400000000,
  "RoomId": "B",
  "RoomIdType": 1,
  "AgentParams": {
    "UserId": "B_Agent",
    "UserSig": "eJwtjMEKgkAUAP9lz2Hv6b40oU...",
    "MaxIdleTime": 50
  },
  "WithTranscoding": 1,
  "AudioParams": {
    "AudioEncode": {
      "Codec": 0,
      "SampleRate": 48000,
      "Channel": 2,
      "BitRate": 64
    }
  },
  "FeedBackRoomParams": [
    {
      "RoomId": "A",
      "RoomIdType": 1,
      "UserId": "B_Feed",
      "UserSig": "eJwtzEELgkAUBOD-sldD3745..."
    },
    {
      "RoomId": "N",
      "RoomIdType": 1,
      "UserId": "B_Feed",
      "UserSig": "eJwtzEELgkAUBOD-sldD3745..."
    }
  ]
}

{
  "SdkAppId": 1400000000,
  "RoomId": "N",
  "RoomIdType": 1,
  "AgentParams": {
    "UserId": "N_Agent",
    "UserSig": "eJwtjMEKgkAUAP9lz2Hv6b40oU...",
    "MaxIdleTime": 50
  },
  "WithTranscoding": 1,
  "AudioParams": {
    "AudioEncode": {
      "Codec": 0,
      "SampleRate": 48000,
      "Channel": 2,
      "BitRate": 64
    }
  },
  "FeedBackRoomParams": [
    {
      "RoomId": "A",
      "RoomIdType": 1,
      "UserId": "N_Feed",
      "UserSig": "eJwtzEELgkAUBOD-sldD3745..."
    },
    {
      "RoomId": "B",
      "RoomIdType": 1,
      "UserId": "N_Feed",
      "UserSig": "eJwtzEELgkAUBOD-sldD3745..."
    }
  ]
}

// 初始化 TRTC 主实例
TRTCCloud *mainCloud = [TRTCCloud sharedInstance];
// 创建 TRTC 子实例
TRTCCloud *subCloud = [mainCloud createSubCloud];
// 添加子实例事件监听
subCloud.delegate = self;

// 子实例进入 PK 房间
TRTCParams *params = [[TRTCParams alloc] init];
params.sdkAppId = self.SDKAppId;
params.userId = [NSString stringWithFormat:@"Sub_%@", self.UserId];
params.userSig = self.UserSig;
params.role = TRTCRoleAnchor;
params.strRoomId = self.PK_RoomId;
[subCloud enterRoom:params appScene:TRTCAppSceneLIVE];

// 子实例开启本地音频采集和发布
[subCloud startLocalAudio:TRTCAudioQualityDefault];
// 子实例开启本地视频预览和发布
[subCloud startLocalPreview:self.isFrontCamera view:self.anchorPreviewView];

// 来自 TRTC SDK 的各类事件通知
- (void)onEnterRoom:(NSInteger)result {
    if (result > 0) {
        // result 代表加入房间所消耗的时间(毫秒)
        [self toastTip:@"Enter room succeed!"];
    } else {
        // result 代表进房失败的错误码
        [self toastTip:@"Enter room failed!"];
    }
}

- (void)onUserAudioAvailable:(NSString *)userId available:(BOOL)available {
    // 某远端用户发布/取消了自己的音频
    // 在自动订阅模式下，您无需做任何操作，SDK 会自动播放远端用户音频
}

- (void)onUserVideoAvailable:(NSString *)userId available:(BOOL)available {
    // 某远端用户发布/取消了主路视频画面
    if (available) {
        // 订阅远端用户的视频流，并绑定视频渲染控件
        [subCloud startRemoteView:userId streamType:TRTCVideoStreamTypeBig view:self.remoteView];
    } else {
        // 停止订阅远端用户的视频流，并释放渲染控件
        [subCloud stopRemoteView:userId streamType:TRTCVideoStreamTypeBig];
    }
}

// 开始发布混合媒体流到 TRTC 房间
- (void)startPublishMediaToRoom {
    // 媒体流发布的目标地址
    TRTCPublishTarget* target = [[TRTCPublishTarget alloc] init];
    // 目标地址设定为混流回推到房间
    target.mode = TRTCPublishMixStreamToRoom;
    TRTCUser *mixStreamIdentity = [[TRTCUser alloc] init];
    mixStreamIdentity.strRoomId = self.RoomId;
    // 混流机器人用户名不能与房间内其他用户重复
    mixStreamIdentity.userId = [self.UserId stringByAppendingString:@"_robot"];
    target.mixStreamIdentity = mixStreamIdentity;
    
    // 设置媒体流编码输出参数
    TRTCStreamEncoderParam* encoderParam = [[TRTCStreamEncoderParam alloc] init];
    encoderParam.audioEncodedSampleRate = 48000;
    encoderParam.audioEncodedChannelNum = 1;
    encoderParam.audioEncodedKbps = 50;
    encoderParam.audioEncodedCodecType = 0;
    encoderParam.videoEncodedWidth = 540;
    encoderParam.videoEncodedHeight = 960;
    encoderParam.videoEncodedFPS = 15;
    encoderParam.videoEncodedGOP = 2;
    encoderParam.videoEncodedKbps = 1300;
    
    TRTCStreamMixingConfig *config = [[TRTCStreamMixingConfig alloc] init];
    if (self.mixUserList.count) {
        NSMutableArray<TRTCUser *> *userList = [NSMutableArray array];
        NSMutableArray<TRTCVideoLayout *> *layoutList = [NSMutableArray array];
        for (int i = 1; i < MIN(self.mixUserList.count, 16); i++) {
            TRTCUser *user = [[TRTCUser alloc] init];
            user.strRoomId = self.PK_RoomId;
            user.userId = self.mixUserList[i];
            [userList addObject:user];
            
            TRTCVideoLayout *layout = [[TRTCVideoLayout alloc] init];
            if ([self.mixUserList[i] isEqualToString:[NSString stringWithFormat:@"Sub_%@", self.UserId]]) {
                // 本地主播画面布局
                layout.rect = CGRectMake(0, 0, 540, 960);
                layout.zOrder = 0;
            } else {
                // PK 主播画面布局
                layout.rect = CGRectMake(400, 5 + i * 245, 135, 240);
                layout.zOrder = 1;
            }
            layout.fixedVideoUser = user;
            layout.fixedVideoStreamType = TRTCVideoStreamTypeBig;
            [layoutList addObject:layout];
        }
        // 指定转码流中的每一路输入音频的信息
        config.audioMixUserList = [userList copy];
        // 指定混合画面的中每一路视频画面的位置、大小、图层以及流类型等信息
        config.videoLayoutList = [layoutList copy];
    }
    // 开始发布媒体流
    [self.mainCloud startPublishMediaStream:target encoderParam:encoderParam mixingConfig:config];
}

// 开始发布媒体流的事件回调
- (void)onStartPublishMediaStream:(NSString *)taskId code:(int)code message:(NSString *)message extraInfo:(NSDictionary *)extraInfo {
    // taskId: 当请求成功时，TRTC 后台会在回调中提供给您这项任务的 taskId，后续您可以通过该 taskId 结合 updatePublishMediaStream 和 stopPublishMediaStream 进行更新和停止
    // code: 回调结果，0 表示成功，其余值表示失败
    if (code == 0) {
        // 主实例停止推流
        [self.mainCloud stopLocalAudio];
        [self.mainCloud stopLocalPreview];
    }
}