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；
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。
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SDKAndroid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：
代码语言：javascript复制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
代码语言：javascript复制 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
代码语言：javascript复制 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url
string 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()
代码语言：javascript复制 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");
else
Debug.LogError("NT_PB_U3D_Open fail");
}InitAndSetConfig()
代码语言：javascript复制 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()
代码语言：javascript复制 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：
代码语言：javascript复制 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
代码语言：javascript复制 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。
