为了保证最佳体验效果，本场景需要集成火山引擎的 RTC SDK 以及 HIFIVE 音乐开放平台的SDK，您需要在 RTC、HIFIVE的控制台开通服务，相应开通指南如下：

1. RTC SDK总体接入流程，详细步骤请参看 RTC服务开通指南。

2. HIFIVE 音乐开放平台 SDK 接入流程，详细步骤请参看 HIFIVE 集成文档。

参看：下载歌词/歌曲iOS

/**
 * 加入RTC房间并初始化参数
 * @param token: RTC Token
 * @param roomID: RTC room id
 * @param uid: RTC user id
 * @param isHost: YES 业务上主播 ； NO 业务上观众
 **/
- (void)joinRTCRoomWithToken:(NSString *)token
                      roomID:(NSString *)roomID
                         uid:(NSString *)uid
                      isHost:(BOOL)isHost {
    // 初始化 ByteRTCVideo 对象
    self.rtcEngineKit = [ByteRTCVideo createRTCVideo:APPID
                                        delegate:self
                                      parameters:@{}];
    
    // 初始化 ByteRTCRoom 对象
    self.rtcRoom = [self.rtcEngineKit createRTCRoom:roomID];
    self.rtcRoom.delegate = self;
    
    // 设置音频场景类型 Music
    [self.rtcEngineKit setAudioScenario:ByteRTCAudioScenarioMusic];
    
    // 设置音频双声道音乐音质
    [self.rtcEngineKit setAudioProfile:ByteRTCAudioProfileHD];
    
    // 设置主播为可见，观众为隐身
    [self.rtcRoom setUserVisibility:isHost ? YES : NO];
    
    // 加入房间时主播需要开启麦克风，观众需要关闭麦克风
    if (isHost) {
        [self.rtcEngineKit startAudioCapture];
    } else {
        [self.rtcEngineKit stopAudioCapture];
    }
 
    // 设置音频路由模式
    [self.rtcEngineKit setDefaultAudioRoute:ByteRTCAudioRouteSpeakerphone];
 
    // 开启发言者音量监听
    ByteRTCAudioPropertiesConfig *audioPropertiesConfig = [[ByteRTCAudioPropertiesConfig alloc] init];
    audioPropertiesConfig.interval = 300;
    [self.rtcEngineKit enableAudioPropertiesReport:audioPropertiesConfig];
    
    // 加入房间，开始连麦，需要申请AppId和Token
    ByteRTCUserInfo *userInfo = [[ByteRTCUserInfo alloc] init];
    userInfo.userId = uid;
    ByteRTCRoomConfig *config = [[ByteRTCRoomConfig alloc] init];
    config.profile = ByteRTCRoomProfileKTV;
    config.isAutoPublish = YES;
    config.isAutoSubscribeAudio = YES;
    [self.rtcRoom joinRoom:token userInfo:userInfo roomConfig:config];
}
objectivec

- (void)rtcRoom:(ByteRTCRoom *)rtcRoom onRoomStateChanged:(NSString *)roomId
                                                  withUid:(NSString *)uid
                                                    state:(NSInteger)state
                                                extraInfo:(NSString *)extraInfo {
    // 收到 RTC 加入房间结果
}

- (void)rtcEngine:(ByteRTCVideo *)engine onLocalAudioPropertiesReport:(NSArray<ByteRTCLocalAudioPropertiesInfo *> *)audioPropertiesInfos {
    // 本地用户音量回调    
}

- (void)rtcEngine:(ByteRTCVideo *)engine onRemoteAudioPropertiesReport:(NSArray<ByteRTCRemoteAudioPropertiesInfo *> *)audioPropertiesInfos 
                                                     totalRemoteVolume:(NSInteger)totalRemoteVolume {
    // 远端用户音量回调
}
objectivec

/**
 * 开始演唱。在歌词/歌曲下载完成，收到开始演唱广播后执行。
 * @param filePath 歌曲的文件路径
 */
- (void)startStartSinging:(NSString *)filePath {
    ByteRTCAudioMixingManager *audioMixingManager = [self.rtcEngineKit getAudioMixingManager];
    ByteRTCAudioMixingConfig *config = [[ByteRTCAudioMixingConfig alloc] init];
    
    // 设置歌曲本地播放和推送到远端
    config.type = ByteRTCAudioMixingTypePlayoutAndPublish;
    
    // 设置歌曲播放一次
    config.playCount = 1;
    
    // 开始播放歌曲
    [audioMixingManager startAudioMixing:audioMixingID
                                filePath:filePath
                                  config:config];
    
    // 设置歌曲进度回调，100ms 间隔回调一次
    [audioMixingManager setAudioMixingProgressInterval:audioMixingID 
                                              interval:100];
}


/**
 * 收到本地歌曲播放进度回调
 * @param engine ByteRTCVideo 对象
 * @param mixId 混音ID
 * @param progress 歌曲播放进度,单位为毫秒
 */
- (void)rtcEngine:(ByteRTCVideo *)engine onAudioMixingPlayingProgress:(NSInteger)mixId 
                                                             progress:(int64_t)progress {
    // 如果是演唱者
    BOOL isSinger;
    if (isSinger) {
        NSString *millisecondStr = [NSString stringWithFormat:@"%ld", (long)(progress)];
        
        // 刷新本地歌词进度
        [self reloadLocalLyrics:millisecondStr];
        
        // 发送音频流同步信息
        NSData *data = [millisecondStr dataUsingEncoding:NSUTF8StringEncoding];
        ByteRTCStreamSycnInfoConfig *config = [[ByteRTCStreamSycnInfoConfig alloc] init];
        config.streamIndex = ByteRTCStreamIndexMain;
        config.repeatCount = 3;
        [self.rtcEngineKit sendStreamSyncInfo:data config:config];
    }
}

/**
 * 收到音频同步信息
 * @param remoteStreamKey 远端流信息
 * @param streamType 媒体流类型
 * @param data 消息内容
 */
- (void)rtcEngine:(ByteRTCVideo *)engine onStreamSyncInfoReceived:(ByteRTCRemoteStreamKey *)remoteStreamKey 
                                                       streamType:(ByteRTCSyncInfoStreamType)streamType 
                                                             data:(NSData *)data {
    NSString *millisecondStr = [[NSString alloc] initWithBytes:data.bytes 
                                                        length:data.length 
                                                      encoding:NSUTF8StringEncoding];
    // 观众刷新歌词进度
    [self reloadLocalLyrics:millisecondStr];
}
objectivec

/**
 * 音乐文件播放状态改变回调
 */
- (void)rtcEngine:(ByteRTCVideo *)engine onAudioMixingStateChanged:(NSInteger)mixId state:(ByteRTCAudioMixingState)state error:(ByteRTCAudioMixingError)error {
    if (state == ByteRTCAudioMixingStateFinished) {
        // 歌曲播放结束
    }
}
objectivec

/**
 * 原唱/伴奏切换，需要音乐素材支持右声道伴奏，左声道原唱
 * @param isAccompaniment 是否为伴奏，YES 为伴奏，NO 为原唱
 */
- (void)setIsAccompaniment:(BOOL)isAccompaniment {
    ByteRTCAudioMixingManager *audioMixingManager = [self.rtcEngineKit getAudioMixingManager];
    if (isAccompaniment) {
        [audioMixingManager setAudioMixingDualMonoMode:audioMixingID
                                                  mode:ByteRTCAudioMixingDualMonoModeR];
    } else {
        [audioMixingManager setAudioMixingDualMonoMode:audioMixingID
                                                  mode:ByteRTCAudioMixingDualMonoModeL];
    }
}

/**
 * 原唱/伴奏切换，需要音乐素材支持。通过切换音轨来实现切换原唱/伴奏
 * @param audioTrackIndex 指定的播放音轨。
 * 设置的参数值需要小于或等于 getAudioTrackCount: 的返回值
 */
- (void)setIsAccompaniment:(NSInteger)audioTrackIndex {
    ByteRTCAudioMixingManager *audioMixingManager = [self.rtcEngineKit getAudioMixingManager];
    [audioMixingManager selectAudioTrack:audioMixingID audioTrackIndex:(int)audioTrackIndex];
}

/**
 * 暂停混音播放
 */
- (void)pauseSinging {
    ByteRTCAudioMixingManager *audioMixingManager = [self.rtcEngineKit getAudioMixingManager];
    [audioMixingManager pauseAudioMixing:audioMixingID];
}
 
/**
 * 恢复混音播放
 */
- (void)resumeSinging {
    ByteRTCAudioMixingManager *audioMixingManager = [self.rtcEngineKit getAudioMixingManager];
    [audioMixingManager resumeAudioMixing:audioMixingID];
}

/**
 * 开启/关闭耳返
 * @param isEnable YES 为开启耳返，NO 为关闭耳返
 */
- (void)enableEarMonitor:(BOOL)isEnable {
    [self.rtcEngineKit setEarMonitorMode:isEnable ? ByteRTCEarMonitorModeOn : ByteRTCEarMonitorModeOff];
}

/**
 * 设置耳返的音量
 * @param volume 耳返音量
 */
- (void)setEarMonitorVolume:(NSInteger)volume {
    [self.rtcEngineKit setEarMonitorVolume:volume];
}

/**
 * 调节本地播放和远端混音的音量大小
 * @param volume 混音音量
 */
- (void)setMusicVolume:(NSInteger)volume {
    ByteRTCAudioMixingManager *audioMixingManager = [self.rtcEngineKit getAudioMixingManager];
    [audioMixingManager setAudioMixingVolume:audioMixingID volume:(int)volume type:ByteRTCAudioMixingTypePlayoutAndPublish];
}

/**
 * 调节麦克风采集音量
 * @param volume 麦克风采集音量
 */
- (void)setRecordingVolume:(NSInteger)volume {
    [self.rtcEngineKit setCaptureVolume:ByteRTCStreamIndexMain volume:(int)volume];
}

/**
 * 设置混响特效类型
 * @param reverbType 特效类型
 */
- (void)setVoiceReverbType:(ByteRTCVoiceReverbType)reverbType {
    [self.rtcEngineKit setVoiceReverbType:reverbType];
}
objectivec