如何在Unity3d平台下低延迟播放RTMP或RTSP流
随着VR类、工业仿真、智慧城市等场景的快速发展，开发者对Unity3d低延迟的直播需求量越来越大，前两年，大牛直播SDK发布了Windows平台、Android平台和iOS平台的Unity3d RTMP和RTSP的播放，好多公司用起来体验都非常好，以下介绍大概实现流程。
本文以Android平台为例，我们的实现：基于大牛直播SDK现有非常成熟的native RTMP和RTSP播放模块，回调解码后的原始数据，传递给Unity3d，实现相应的绘制即可，对应demo，可以参考 Github。
具体步骤如下：
1. Native RTSP或RTSP直播播放SDK回调RGB/YUV420/NV12等其中的一种未压缩的图像格式；
2. Unity3D创建相应的RGB/YUV420等Shader；
3.Unity3D从各个平台获取图像数据来填充纹理即可。
以Android平台为例，我们在原有接口基础上，做了桥接接口，供Unity平台使用：
///
/// Init
///
public int NT_U3D_Init()
{
return DANIULIVE_RETURN_OK;
}
///
/// 开始
/// 返回播放句柄
///
public long NT_U3D_Open()
{
if ( 0 != player_obj_.Call("Init", java_obj_cur_activity_) )
{
return 0;
}
return player_obj_.Call("Open");
}
///
/// Register Game Object,用于消息传递
///
public int NT_U3D_Set_Game_Object(long handle, string gameObjectName)
{
return player_obj_.Call("SetGameObject", handle, gameObjectName);
}
///
/// 设置H.264解码方式 false 软件解码 true 硬件解码 默认为false
///
///
public int NT_U3D_SetVideoDecoderMode(long handle, int isHwDecoder)
{
return player_obj_.Call("SetPlayerVideoHWDecoder", handle, isHwDecoder);
}
///
/// 设置H.265 解码方式 false 软件解码 true 硬件解码 默认为false
///
///
public int NT_U3D_SetVideoHevcDecoderMode(long handle, int isHevcHwDecoder)
{
return player_obj_.Call("SetPlayerVideoHevcHWDecoder", handle, isHevcHwDecoder);
}
///
/// 设置音频输出模式: if 0: 自动选择; if with 1: audiotrack模式
///
///
public int NT_U3D_SetAudioOutputType(long handle, int use_audiotrack)
{
return player_obj_.Call("SetAudioOutputType", handle, use_audiotrack);
}
///
/// 设置播放端缓存大小, 默认200毫秒
///
///
public int NT_U3D_SetBuffer(long handle, int buffer)
{
return player_obj_.Call("SetBuffer", handle, buffer);
}
///
/// 接口可实时调用：设置是否实时静音，1：静音; 0: 取消静音
///
///
public int NT_U3D_SetMute(long handle, int is_mute)
{
return player_obj_.Call("SetMute", handle, is_mute);
}
///
/// 设置RTSP TCP模式, 1: TCP; 0: UDP
///
///
public int NT_U3D_SetRTSPTcpMode(long handle, int is_using_tcp)
{
return player_obj_.Call("SetRTSPTcpMode", handle, is_using_tcp);
}
///
/// 设置RTSP超时时间, timeout单位为秒，必须大于0
///
///
public int NT_U3D_SetRTSPTimeout(long handle, int timeout)
{
return player_obj_.Call("SetRTSPTimeout", handle, timeout);
}
///
/// 设置RTSP TCP/UDP自动切换
/// NOTE: 对于RTSP来说，有些可能支持rtp over udp方式，有些可能支持使用rtp over tcp方式.
/// 为了方便使用，有些场景下可以开启自动尝试切换开关, 打开后如果udp无法播放，sdk会自动尝试tcp, 如果tcp方式播放不了,sdk会自动尝试udp.
///
///
/// timeout：如果设置1的话, sdk将在tcp和udp之间尝试切换播放，如果设置为0，则不尝试切换.
public int NT_U3D_SetRTSPAutoSwitchTcpUdp(long handle, int is_auto_switch_tcp_udp)
{
return player_obj_.Call("SetRTSPAutoSwitchTcpUdp", handle, is_auto_switch_tcp_udp);
}
///
/// 设置快速启动该模式，
///
///
public int NT_U3D_SetFastStartup(long handle, int is_fast_startup)
{
return player_obj_.Call("SetFastStartup", handle, is_fast_startup);
}
///
/// 设置超低延迟模式 false不开启 true开启 默认false
///
///
public int NT_U3D_SetPlayerLowLatencyMode(long handle, int mode)
{
return player_obj_.Call("SetPlayerLowLatencyMode", handle, mode);
}
///
/// 设置视频垂直反转
/// is_flip： 0: 不反转, 1: 反转
///
///
public int NT_U3D_SetFlipVertical(long handle, int is_flip)
{
return player_obj_.Call("SetFlipVertical", handle, is_flip);
}
///
/// 设置视频水平反转
/// is_flip： 0: 不反转, 1: 反转
///
///
public int NT_U3D_SetFlipHorizontal(long handle, int is_flip)
{
return player_obj_.Call("SetFlipHorizontal", handle, is_flip);
}
///
/// 设置顺时针旋转, 注意除了0度之外， 其他角度都会额外消耗性能
/// degress： 当前支持 0度，90度, 180度, 270度 旋转
///
///
public int NT_U3D_SetRotation(long handle, int degress)
{
return player_obj_.Call("SetRotation", handle, degress);
}
///
/// 设置是否回调下载速度
/// is_report: if 1: 上报下载速度, 0: 不上报.
/// report_interval: 上报间隔，以秒为单位，>0.
///
///
///
public int NT_U3D_SetReportDownloadSpeed(long handle, int is_report, int report_interval)
{
return player_obj_.Call("SetReportDownloadSpeed", handle, is_report, report_interval);
}
///
/// 设置是否需要在播放或录像过程中快照
///
///
public int NT_U3D_SetSaveImageFlag(long handle, int is_save_image)
{
return player_obj_.Call("SetSaveImageFlag", handle, is_save_image);
}
///
/// 播放或录像过程中快照
///
///
public int NT_U3D_SaveCurImage(long handle, string imageName)
{
return player_obj_.Call("SaveCurImage", handle, imageName);
}
///
/// 播放或录像过程中，快速切换url
///
///
public int NT_U3D_SwitchPlaybackUrl(long handle, string uri)
{
return player_obj_.Call("SwitchPlaybackUrl", handle, uri);
}
///
/// 创建录像存储路径
///
///
public int NT_U3D_CreateFileDirectory(string path)
{
return player_obj_.Call("CreateFileDirectory", path);
}
///
/// 设置录像存储路径
///
///
public int NT_U3D_SetRecorderDirectory(long handle, string path)
{
return player_obj_.Call("SetRecorderDirectory", handle, path);
}
///
/// 设置单个录像文件大小
///
///
public int NT_U3D_SetRecorderFileMaxSize(long handle, int size)
{
return player_obj_.Call("SetRecorderFileMaxSize", handle, size);
}
///
/// 设置录像时音频转AAC编码的开关
/// aac比较通用，sdk增加其他音频编码(比如speex, pcmu, pcma等)转aac的功能.
/// 注意: 转码会增加性能消耗
///
///
/// is_transcode：设置为1的话，如果音频编码不是aac，则转成aac，如果是aac，则不做转换. 设置为0的话，则不做任何转换. 默认是0.
public int NT_U3D_SetRecorderAudioTranscodeAAC(long handle, int is_transcode)
{
return player_obj_.Call("SetRecorderAudioTranscodeAAC", handle, is_transcode);
}
///
/// 设置播放路径
///
public int NT_U3D_SetUrl(long handle, string url)
{
return player_obj_.Call("SetUrl", handle, url);
}
///
/// 开始播放
///
public int NT_U3D_StartPlay(long handle)
{
return player_obj_.Call("StartPlay", handle);
}
///
/// 获取YUV数据
///
public AndroidJavaObject NT_U3D_GetVideoFrame(long handle)
{
return player_obj_.Call("GetVideoFrame", handle);
}
///
/// 停止播放
///
public int NT_U3D_StopPlay(long handle)
{
return player_obj_.Call("StopPlay", handle);
}
///
/// 开始录像
///
public int NT_U3D_StartRecorder(long handle)
{
return player_obj_.Call("StartRecorder", handle);
}
///
/// 停止录像
///
public int NT_U3D_StopRecorder(long handle)
{
return player_obj_.Call("StopRecorder", handle);
}
///
/// 关闭播放
///
public int NT_U3D_Close(long handle)
{
return player_obj_.Call("Close", handle);
}
///
/// UnInit Player
///
public int NT_U3D_UnInit()
{
return DANIULIVE_RETURN_OK;
}
Event传递，我们在unity3d里面解析相应的字串即可：
///
/// android 传递过来 code
///
///
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));
switch (Convert.ToInt32(code))
{
case EVENTID.EVENT_DANIULIVE_ERC_PLAYER_STARTED:
Debug.Log("开始。。");
break;
case EVENTID.EVENT_DANIULIVE_ERC_PLAYER_CONNECTING:
Debug.Log("连接中。。");
break;
case EVENTID.EVENT_DANIULIVE_ERC_PLAYER_CONNECTION_FAILED:
Debug.Log("连接失败。。");
break;
case EVENTID.EVENT_DANIULIVE_ERC_PLAYER_CONNECTED:
Debug.Log("连接成功。。");
break;
case EVENTID.EVENT_DANIULIVE_ERC_PLAYER_DISCONNECTED:
Debug.Log("连接断开。。");
break;
case EVENTID.EVENT_DANIULIVE_ERC_PLAYER_STOP:
Debug.Log("停止播放。。");
break;
case EVENTID.EVENT_DANIULIVE_ERC_PLAYER_RESOLUTION_INFO:
Debug.Log("分辨率信息: width: " + Convert.ToInt32(param1) + ", height: " + Convert.ToInt32(param2));
break;
case EVENTID.EVENT_DANIULIVE_ERC_PLAYER_NO_MEDIADATA_RECEIVED:
Debug.Log("收不到媒体数据，可能是url错误。。");
break;
case EVENTID.EVENT_DANIULIVE_ERC_PLAYER_SWITCH_URL:
Debug.Log("切换播放URL。。");
break;
case EVENTID.EVENT_DANIULIVE_ERC_PLAYER_CAPTURE_IMAGE:
Debug.Log("快照: " + param1 + " 路径：" + param3);
if (Convert.ToInt32(param1) == 0)
{
Debug.Log("截取快照成功。.");
}
else
{
Debug.Log("截取快照失败。.");
}
break;
case EVENTID.EVENT_DANIULIVE_ERC_PLAYER_RECORDER_START_NEW_FILE:
Debug.Log("[record]开始一个新的录像文件 : " + param3);
break;
case EVENTID.EVENT_DANIULIVE_ERC_PLAYER_ONE_RECORDER_FILE_FINISHED:
Debug.Log("[record]已生成一个录像文件 : " + param3);
break;
case EVENTID.EVENT_DANIULIVE_ERC_PLAYER_START_BUFFERING:
Debug.Log("Start_Buffering");
break;
case EVENTID.EVENT_DANIULIVE_ERC_PLAYER_BUFFERING:
Debug.Log("Buffering: " + Convert.ToInt32(param1));
break;
case EVENTID.EVENT_DANIULIVE_ERC_PLAYER_STOP_BUFFERING:
Debug.Log("Stop_Buffering");
break;
case EVENTID.EVENT_DANIULIVE_ERC_PLAYER_DOWNLOAD_SPEED:
Debug.Log("download_speed:" + param1 + "Byte/s" + ", "
+ (Convert.ToInt32(param1) * 8 / 1000) + "kbps" + ", " + (Convert.ToInt32(param1) / 1024)
+ "KB/s");
break;
}
}开始播放：
public void Play()
{
if (is_running)
{
Debug.Log("已经在播放。。");
return;
}
//获取输入框的url
string url = input_url_.text.Trim();
if (!url.StartsWith("rtmp://") && !url.StartsWith("rtsp://"))
{
videoUrl = "rtmp://202.69.69.180:443/webcast/bshdlive-pc";
}
else
{
videoUrl = url;
}
OpenPlayer();
if ( player_handle_ == 0 )
return;
NT_U3D_Set_Game_Object(player_handle_, game_object_);
NT_U3D_SetUrl(player_handle_, videoUrl);
/* ++ 播放前参数配置可加在此处 ++ */
int is_using_tcp = 0; //TCP/UDP模式设置
NT_U3D_SetRTSPTcpMode(player_handle_, is_using_tcp);
int is_report = 0;
int report_interval = 1;
NT_U3D_SetReportDownloadSpeed(player_handle_, is_report, report_interval); //下载速度回调
NT_U3D_SetBuffer(player_handle_, play_buffer_time_); //设置buffer time
NT_U3D_SetPlayerLowLatencyMode(player_handle_, is_low_latency_ ? 1 : 0); //设置是否启用低延迟模式
NT_U3D_SetMute(player_handle_, is_mute_ ? 1 : 0); //是否启动播放的时候静音
NT_U3D_SetVideoDecoderMode(player_handle_, is_hw_decode_ ? 1 : 0); //设置H.264软硬解模式
NT_U3D_SetVideoHevcDecoderMode(player_handle_, is_hw_decode_ ? 1 : 0); //设置H.265软硬解模式
int is_fast_startup = 1;
NT_U3D_SetFastStartup(player_handle_, is_fast_startup); //设置快速启动模式
int rtsp_timeout = 10;
NT_U3D_SetRTSPTimeout(player_handle_, rtsp_timeout); //设置RTSP超时时间
int is_auto_switch_tcp_udp = 1;
NT_U3D_SetRTSPAutoSwitchTcpUdp(player_handle_, is_auto_switch_tcp_udp); //设置TCP/UDP模式自动切换
/* -- 播放前参数配置可加在此处 -- */
int flag = NT_U3D_StartPlay(player_handle_);
if (flag == DANIULIVE_RETURN_OK)
{
is_need_get_frame_ = true;
Debug.Log("播放成功");
}
else
{
is_need_get_frame_ = false;
Debug.LogError("播放失败");
}
is_running = true;
}开始播放后，native模块，回调yuv/rgb数据，unity3d模块，做相应的绘制处理即可。
private void Update()
{
if (!is_need_get_frame_)
return;
if (player_handle_ == 0)
return;
AndroidJavaObject u3d_video_frame_obj = NT_U3D_GetVideoFrame(player_handle_);
if (u3d_video_frame_obj == null)
return;
VideoFrame converted_video_frame = ConvertToVideoFrame(u3d_video_frame_obj);
if (converted_video_frame == null)
return;
if ( !is_need_init_texture_)
{
if (converted_video_frame.width_ != video_width_
|| converted_video_frame.height_ != video_height_
|| converted_video_frame.y_stride_ != y_row_bytes_
|| converted_video_frame.u_stride_ != u_row_bytes_
|| converted_video_frame.v_stride_ != v_row_bytes_)
{
is_need_init_texture_ = true;
}
}
if (is_need_init_texture_)
{
if (InitYUVTexture(converted_video_frame))
{
is_need_init_texture_ = false;
}
}
UpdateYUVTexture(converted_video_frame);
converted_video_frame = null;
}关闭播放：
private void ClosePlayer()
{
is_need_get_frame_ = false;
is_need_init_texture_ = false;
int flag = NT_U3D_StopPlay(player_handle_);
if (flag == DANIULIVE_RETURN_OK)
{
Debug.Log("停止成功");
}
else
{
Debug.LogError("停止失败");
}
flag = NT_U3D_Close(player_handle_);
if (flag == DANIULIVE_RETURN_OK)
{
Debug.Log("关闭成功");
}
else
{
Debug.LogError("关闭失败");
}
player_handle_ = 0;
NT_U3D_UnInit();
is_running = false;
}以上是大概的实现流程，Unity环境下，实际测试时延，和 native直播模块相差无几，都是毫秒级延迟。Windows平台和iOS平台也是如此。