像Unity3D下的RTMP或RTSP播放器一样，好多开发者苦于在Unity环境下，如何高效率低延迟的把数据采集并编码实时推送到流媒体服务器，实现Unity场景下的低延迟推拉流方案。

关于屏幕采集，有两种方案：

1. 直接封装Android原生的屏幕采集工程，在unity提供接口，拿到屏幕权限后，获取屏幕数据并推送；

具体可以参考 https://blog.csdn.net/renhui1112/article/details/106750891

2. 如果只需要拿到Unity的窗体或摄像机数据推出去，可在Unity下获取到需要推送的原始数据，然后封装原生的RTMP推流接口，调用原生SDK实现数据推送，这种做法的好处是，可以自定义需要采集的数据内容，只要按照原生SDK提供的接口，完成数据对接即可，具体实现参看本文。

Android平台Unity3D的RTSP或RTMP播放器，可以参考

https://blog.csdn.net/renhui1112/article/details/104154788

本文以Android平台为例，介绍下Unity环境下的Android平台RTMP推流，数据采集在Unity完成，数据编码推送，调用大牛直播SDK（官方）Android平台RTMP直播推送SDK原生库对外二次封装的接口，高效率的实现RTMP推送。废话多说，先上图看效果。

下图系Android平台Unity环境下采集屏幕，编码推送到RTMP服务器，然后Windows平台播放器拉取RTMP流播放，为了方便看到延迟效果，特地在Android端的Unity窗口显示了当前时间，可以看到，整体延迟在毫秒级：

数据采集推送

unity数据采集相对简单，可以很轻松的拿到RGB24的数据：

texture_ = new Texture2D(video_width_, video_height_, TextureFormat.RGB24, false);texture_.ReadPixels(new Rect(0, 0, video_width_, video_height_), 0, 0, false);texture_.Apply();

然后通过调用texture_.GetRawTextureData<sbyte>(); 获取到数据即可。

拿到数据后，调用原生SDK封装的NT_PB_U3D_OnCaptureVideoRGB24PtrData()接口，完成数据投递。

简单调用流程

    private void Start(){game_object_ = this.gameObject.name;AndroidJavaClass android_class = new AndroidJavaClass("com.unity3d.player.UnityPlayer");java_obj_cur_activity_ = android_class.GetStatic<AndroidJavaObject>("currentActivity");pusher_obj_ = new AndroidJavaObject("com.daniulive.smartpublisher.SmartPublisherUnity3d");NT_PB_U3D_Init();//NT_U3D_SetSDKClientKey("", "", 0);btn_encode_mode_.onClick.AddListener(OnEncodeModeBtnClicked);btn_pusher_.onClick.AddListener(OnPusherBtnClicked);btn_mute_.onClick.AddListener(OnMuteBtnClicked);}

完成接口初始化后，调用Push()接口

    public void Push(){if (is_running){Debug.Log("已推送..");   return;}if (texture_ != null){UnityEngine.Object.Destroy(texture_);texture_ = null;}video_width_ = Screen.width;video_height_ = Screen.height;scale_width_ = (video_width_ + 1) / 2;scale_height_ = (video_height_ + 1) / 2;if (scale_width_ % 2 != 0){scale_width_ = scale_width_ + 1;}if (scale_height_ % 2 != 0){scale_height_ = scale_height_ + 1;}texture_ = new Texture2D(video_width_, video_height_, TextureFormat.RGB24, false);//获取输入框的urlstring url = input_url_.text.Trim();if (!url.StartsWith("rtmp://")){push_url_ = "rtmp://192.168.0.199:1935/hls/stream1";}else{push_url_ = url;}OpenPusher();if (pusher_handle_ == 0)return;NT_PB_U3D_Set_Game_Object(pusher_handle_, game_object_);/* ++ 推送前参数配置可加在此处 ++ */InitAndSetConfig();NT_PB_U3D_SetPushUrl(pusher_handle_, push_url_);/* -- 推送前参数配置可加在此处 -- */int flag = NT_PB_U3D_StartPublisher(pusher_handle_);if (flag  == DANIULIVE_RETURN_OK){Debug.Log("推送成功..");}else{Debug.LogError("推送失败..");}is_running = true;}

调用OpenPusher()

    private void OpenPusher(){if ( java_obj_cur_activity_ == null ){Debug.LogError("getApplicationContext is null");return;}int audio_opt = 1;int video_opt = 1;pusher_handle_ = NT_PB_U3D_Open(audio_opt, video_opt, video_width_, video_height_);if (pusher_handle_ != 0)Debug.Log("NT_PB_U3D_Open success");elseDebug.LogError("NT_PB_U3D_Open fail");}

InitAndSetConfig()

    private void InitAndSetConfig(){if (is_hw_encode_){int h264HWKbps = setHardwareEncoderKbps(true, video_width_, video_height_);Debug.Log("h264HWKbps: " + h264HWKbps);int isSupportH264HWEncoder = NT_PB_U3D_SetVideoHWEncoder(pusher_handle_, h264HWKbps);if (isSupportH264HWEncoder == 0){Debug.Log("Great, it supports h.264 hardware encoder!");}}else {if (is_sw_vbr_mode_) //H.264 software encoder{int is_enable_vbr = 1;int video_quality = CalVideoQuality(video_width_, video_height_, true);int vbr_max_bitrate = CalVbrMaxKBitRate(video_width_, video_height_);NT_PB_U3D_SetSwVBRMode(pusher_handle_, is_enable_vbr, video_quality, vbr_max_bitrate);//NT_PB_U3D_SetSWVideoEncoderSpeed(pusher_handle_, 2);}}NT_PB_U3D_SetAudioCodecType(pusher_handle_, 1);NT_PB_U3D_SetFPS(pusher_handle_, 25);NT_PB_U3D_SetGopInterval(pusher_handle_, 25*2);//NT_PB_U3D_SetSWVideoBitRate(pusher_handle_, 600, 1200);}

ClosePusher()

    private void ClosePusher(){if (texture_ != null){UnityEngine.Object.Destroy(texture_);texture_ = null;}int flag = NT_PB_U3D_StopPublisher(pusher_handle_);if (flag == DANIULIVE_RETURN_OK){Debug.Log("停止成功..");}else{Debug.LogError("停止失败..");}flag = NT_PB_U3D_Close(pusher_handle_);if (flag == DANIULIVE_RETURN_OK){Debug.Log("关闭成功..");}else{Debug.LogError("关闭失败..");}pusher_handle_ = 0;NT_PB_U3D_UnInit();is_running = false;}

为了便于测试，Update()刷新下当前时间：

    private void Update(){//获取当前时间hour = DateTime.Now.Hour;minute = DateTime.Now.Minute;millisecond = DateTime.Now.Millisecond;second = DateTime.Now.Second;year = DateTime.Now.Year;month = DateTime.Now.Month;day = DateTime.Now.Day;GameObject.Find("Canvas/Panel/LableText").GetComponent<Text>().text = string.Format("{0:D2}:{1:D2}:{2:D2}:{3:D2} " + "{4:D4}/{5:D2}/{6:D2}", hour, minute, second, millisecond, year, month, day);}

相关Event处理

 public void onNTSmartEvent(string param){if (!param.Contains(",")){Debug.Log("[onNTSmartEvent] android传递参数错误");return;}string[] strs = param.Split(',');string player_handle =strs[0];string code = strs[1];string param1 = strs[2];string param2 = strs[3];string param3 = strs[4];string param4 = strs[5];Debug.Log("[onNTSmartEvent] code: 0x" + Convert.ToString(Convert.ToInt32(code), 16));String publisher_event = "";switch (Convert.ToInt32(code)){case EVENTID.EVENT_DANIULIVE_ERC_PUBLISHER_STARTED:publisher_event = "开始..";break;case EVENTID.EVENT_DANIULIVE_ERC_PUBLISHER_CONNECTING:publisher_event = "连接中..";break;case EVENTID.EVENT_DANIULIVE_ERC_PUBLISHER_CONNECTION_FAILED:publisher_event = "连接失败..";break;case EVENTID.EVENT_DANIULIVE_ERC_PUBLISHER_CONNECTED:publisher_event = "连接成功..";break;case EVENTID.EVENT_DANIULIVE_ERC_PUBLISHER_DISCONNECTED:publisher_event = "连接断开..";break;case EVENTID.EVENT_DANIULIVE_ERC_PUBLISHER_STOP:publisher_event = "关闭..";break;case EVENTID.EVENT_DANIULIVE_ERC_PUBLISHER_RECORDER_START_NEW_FILE:publisher_event = "开始一个新的录像文件 : " + param3;break;case EVENTID.EVENT_DANIULIVE_ERC_PUBLISHER_ONE_RECORDER_FILE_FINISHED:publisher_event = "已生成一个录像文件 : " + param3;break;case EVENTID.EVENT_DANIULIVE_ERC_PUBLISHER_SEND_DELAY:publisher_event = "发送时延: " + param1 + " 帧数:" + param2;break;case EVENTID.EVENT_DANIULIVE_ERC_PUBLISHER_CAPTURE_IMAGE:publisher_event = "快照: " + param1 + " 路径：" + param3;if (Convert.ToInt32(param1) == 0){publisher_event = publisher_event + "截取快照成功..";}else{publisher_event = publisher_event + "截取快照失败..";}break;case EVENTID.EVENT_DANIULIVE_ERC_PUBLISHER_RTSP_URL:publisher_event = "RTSP服务URL: " + param3;break;case EVENTID.EVENT_DANIULIVE_ERC_PUSH_RTSP_SERVER_RESPONSE_STATUS_CODE:publisher_event = "RTSP status code received, codeID: " + param1 + ", RTSP URL: " + param3;break;case EVENTID.EVENT_DANIULIVE_ERC_PUSH_RTSP_SERVER_NOT_SUPPORT:publisher_event = "服务器不支持RTSP推送, 推送的RTSP URL: " + param3;break;}Debug.Log(publisher_event);}

总结

通过以上流程，可以实现Unity环境下屏幕或摄像机数据，毫秒级体验的RTMP推送和播放，感兴趣的开发者可酌情参考。