Windows平台Unity Camera场景实现轻量级RTSP服务和RTMP推送

Posted 2023-03-01

技术背景

随着VR技术在医疗、军事、农业、学校、景区、消防、公共安全、研学机构、展厅展馆，商场等场所普及，开发者对Unity平台下的直播体验提出了更高的要求。

技术实现

Unity平台下的RTMP推流、RTMP、RTSP播放前几年已经覆盖了Windows、Linux、android、ios平台。本文主要介绍Windows平台Unity环境下的轻量级RTSP服务。通过对外提供RTSP拉流URL的形式，供内网其他终端调用。

RTMP的技术方案，我们之前有探讨过，这里先说轻量级RTSP服务，轻量级RTSP服务，我们的设计是，可以启动一个RTSP Service，然后发布多个RTSP流实例，这个在多实例的设计，非常有价值，简单来说，一个RTSP Service下面挂载多个RTSP Stream，对外提供RTSP拉流的URL，整体设计方案如下：

我们看看支持的音视频采集选项，其中视频这块，除了Unity下的Camera场景覆盖，还有Windows摄像头、屏幕数据，音频采集覆盖了Unity声音、扬声器、麦克风，还有混音数据。

音视频原始数据采集到后，编码注入RTSP服务和RTMP推送模块。二者可以单独使用，也可同时使用。其中轻量级RTSP服务，可实时查看链接的RTSP会话数。

首先看启动RTSP service封装:

/*
 * PublisherWrapper.cs
 * Author: daniusdk.com
 */
public bool StartRtspService()

    if (NTBaseCodeDefine.NT_ERC_OK != NTSmartPublisherSDK.NT_PB_OpenRtspServer(ref rtsp_handle_, 0))
    
        Debug.LogError("创建rtsp server实例失败! 请检查sdk有效性.");
        return false;
    

    if (IntPtr.Zero == rtsp_handle_)
    
        Debug.LogError("创建rtsp server实例失败! 请检查sdk有效性.");
        return false;
    

    int port = 28554;

    if (NTBaseCodeDefine.NT_ERC_OK != NTSmartPublisherSDK.NT_PB_SetRtspServerPort(rtsp_handle_, port))
    
        NTSmartPublisherSDK.NT_PB_CloseRtspServer(rtsp_handle_);
        rtsp_handle_ = IntPtr.Zero;
        Debug.LogError("设置rtsp server端口失败,请检查端口是否重复或者端口不在范围内!");
        return false;
    

    //String user_name = "admin";
    //String password = "123456";

    //NTSmartPublisherSDK.NT_PB_SetRtspServerUserNamePassword(rtsp_handle, user_name, password);

    if (NTBaseCodeDefine.NT_ERC_OK == NTSmartPublisherSDK.NT_PB_StartRtspServer(rtsp_handle_, 0))
    
        Debug.Log("StartRtspServer suc..");
    
    else
    
        NTSmartPublisherSDK.NT_PB_CloseRtspServer(rtsp_handle_);
        rtsp_handle_ = IntPtr.Zero;
        Debug.LogError("启动rtsp server失败, 请检查设置的端口是否被占用!");
        return false;
    

    is_rtsp_service_running_ = true;

    return true;

停止RTSP Service：

public void StopRtspService()

    if (is_rtsp_service_running_ == false) return;

    NTSmartPublisherSDK.NT_PB_StopRtspServer(rtsp_handle_);
    NTSmartPublisherSDK.NT_PB_CloseRtspServer(rtsp_handle_);
    rtsp_handle_ = IntPtr.Zero;

    is_rtsp_service_running_ = false;

服务启动后，可以发布或停止RTSP流：

public bool StartRtspStream()

    if (CheckPublisherHandleAvailable() == false) return false;

    if (publisher_handle_ == IntPtr.Zero)
    
        return false;
    

    if (publisher_handle_count_ < 1)
    
        SetCommonOptionToPublisherSDK();
    

    String rtsp_stream_name = "stream1";

    NTSmartPublisherSDK.NT_PB_SetRtspStreamName(publisher_handle_, rtsp_stream_name);

    NTSmartPublisherSDK.NT_PB_ClearRtspStreamServer(publisher_handle_);

    NTSmartPublisherSDK.NT_PB_AddRtspStreamServer(publisher_handle_, rtsp_handle_, 0);

    if (NTBaseCodeDefine.NT_ERC_OK != NTSmartPublisherSDK.NT_PB_StartRtspStream(publisher_handle_, 0))
    
        if (0 == publisher_handle_count_)
        
            NTSmartPublisherSDK.NT_PB_Close(publisher_handle_);
            publisher_handle_ = IntPtr.Zero;
        

        Debug.LogError("调用发布rtsp流接口失败");

        return false;
    

    publisher_handle_count_++;

    is_rtsp_publisher_running_ = true;

    return true;

停止RTSP流：

public void StopRtspStream()

    publisher_handle_count_--;

    NTSmartPublisherSDK.NT_PB_StopRtspStream(publisher_handle_);

    if (0 == publisher_handle_count_)
    
        NTSmartPublisherSDK.NT_PB_Close(publisher_handle_);
        publisher_handle_ = IntPtr.Zero;
    

    is_rtsp_publisher_running_ = false;

获取RTSP session连接数：

public int GetRtspSessionNumbers()

    int num = 0;
    if (rtsp_handle_!=IntPtr.Zero)
    
        if (NTBaseCodeDefine.NT_ERC_OK != NTSmartPublisherSDK.NT_PB_GetRtspServerClientSessionNumbers(rtsp_handle_, ref num))
        
            Debug.LogError("Call NT_PB_GetRtspServerClientSessionNumbers failed..");
        
    

    return num;

封装部分看过后，我们看看我们Unity下调用示例：

启动、停止RTSP服务：

public void btn_rtsp_service_Click()

    if (publisher_wrapper_.IsRtspServiceRunning())
    
        publisher_wrapper_.StopRtspService();
        btn_rtsp_service_.GetComponentInChildren<Text>().text = "启动RTSP服务";

        btn_rtsp_publisher_.interactable = false;
        return;
    

    if (!publisher_wrapper_.StartRtspService())
    
        Debug.LogError("调用StartRtspService失败..");
        return;
    

    btn_rtsp_publisher_.interactable = true;

    btn_rtsp_service_.GetComponentInChildren<Text>().text = "停止RTSP服务";

发布、停止RTSP流：

public void btn_rtsp_publisher_Click()

    if (publisher_wrapper_.IsRtspPublisherRunning())
    
        publisher_wrapper_.StopRtspStream();

        if (!publisher_wrapper_.IsPreviewing() && !publisher_wrapper_.IsPushingRtmp())
        
            StopCaptureAvData();

            if (coroutine_ != null)
            
                StopCoroutine(coroutine_);
                coroutine_ = null;
            
        

        btn_rtsp_service_.interactable = true;

        btn_rtsp_publisher_.GetComponentInChildren<Text>().text = "发布RTSP";
    
    else
    
        if (!publisher_wrapper_.IsRtspServiceRunning())
        
            Debug.LogError("RTSP service is not running..");
            return;
        


        if (!publisher_wrapper_.IsPreviewing() && !publisher_wrapper_.IsPushingRtmp())
        
            publisher_wrapper_.SetVideoPushType(video_push_type_);
            publisher_wrapper_.SetAudioPushType(audio_push_type_);
        

        publisher_wrapper_.StartRtspStream();

        if (!publisher_wrapper_.IsPreviewing() && !publisher_wrapper_.IsPushingRtmp())
        
            StartCaptureAvData();
            coroutine_ = StartCoroutine(OnPostVideo());
        

        btn_rtsp_publisher_.GetComponentInChildren<Text>().text = "停止RTSP";

        btn_rtsp_service_.interactable = false;
    

获取RTSP Session链接数：

public void btn_get_rtsp_session_numbers_Click()

    if (publisher_wrapper_.IsRtspServiceRunning())
    
        btn_get_rtsp_session_numbers_.GetComponentInChildren<Text>().text = "RTSP会话数:" + publisher_wrapper_.GetRtspSessionNumbers();
    

RTMP推送、停止推送：

public void btn_start_rtmp_pusher_Click()

    if (publisher_wrapper_.IsPushingRtmp())
    
        StopPushRTMP();
        btn_rtmp_pusher_.GetComponentInChildren<Text>().text = "推送RTMP";

        return;
    

    String url = rtmp_pusher_url_.text;

    if (url.Length < 8)
    
        publisher_wrapper_.Close();

        Debug.LogError("请输入RTMP推送地址");
        return;
    

    if (!publisher_wrapper_.IsPreviewing() && !publisher_wrapper_.IsRtspPublisherRunning())
    
        publisher_wrapper_.SetVideoPushType(video_push_type_);
        publisher_wrapper_.SetAudioPushType(audio_push_type_);
    

    if (!publisher_wrapper_.StartRtmpPusher(url))
    
        Debug.LogError("调用StartPublisher失败..");
        return;
    

    btn_rtmp_pusher_.GetComponentInChildren<Text>().text = "停止推送";

    if (!publisher_wrapper_.IsPreviewing() && !publisher_wrapper_.IsRtspPublisherRunning())
    
        StartCaptureAvData();
        coroutine_ = StartCoroutine(OnPostVideo());
    

总结

轻量级RTSP服务和RTMP推送的区别在于，轻量级RTSP服务不需要单独部署流媒体服务器（类似于网络摄像头），在内网小并发场景下，使用起来非常方便，如果需要上公网，还是需要用RTMP推送，感兴趣的开发者可酌情参考。