麒麟操作系统|Linux下低延时RTMP|RTSP直播播放实现

背景

国产操作系统多为以Linux为基础二次开发的操作系统。2014年4月8日起，美国微软公司停止了对Windows XP SP3操作系统提供服务支持，这引起了社会和广大用户的广泛关注和对信息安全的担忧。而2020年对Windows7服务支持的终止再一次推动了国产系统的发展。
工信部对此表示，将继续加大力度，支持Linux的国产操作系统的研发和应用，并希望用户可以使用国产操作系统。随着信息技术和互联网的快速发展普及，电子商务已经成为不可抗拒的现代商业潮流，云计算、大数据应用日趋成熟，但随之带来了许多问题和挑战。为全面响应国家“互联网+”战略的提出和深入贯彻落实国家“十二五”规划纲要，帮助传统企业开展“商务智慧转型”，加强电子商务深入应用，特别是移动电子商务发展中的环境保障建设，促进电子商务行业健康有序发展，使电子商务相关的技术和经济、法律和规则、诚信和信誉及如何建立一个安全、可靠、可信的电子商务环境，保障电子商务活动中系统、交易的安全性，信息的保密性，已经成为当前亟待需要探讨和解决的重要课题。

国产操作系统|Linux下RTMP|RTSP直播播放

在发布国产操作系统|Linux平台的RTMP|RTSP直播播放SDK之前，大牛直播SDK（官方）的直播播放SDK无需赘述，采用自研内核框架，功能齐全、高稳定、超低延迟、超低资源占用，覆盖Windows、Android和iOS平台。

本次发布的可用于国产操作系统和Linux上的的RTMP|RTSP直播播放SDK, 视频绘制使用XLib相关库实现, 音频输出使用PulseAudio和Alsa Lib实现，除了常规功能如实时静音、快照、buffer time设定、网络自动重连等，RTMP支持扩展H265播放, RTSP也支持H265播放。

播放器接口和调用都比较简单，集成复杂度低，且不依赖于QT。

相关DEMO

大牛直播SDK发布的Linux平台播放器SDK支持多实例播放，以单个窗体播放为例，相关代码如下：

const char* player_url_ = "rtsp://admin:daniulive12345@192.168.0.120:554/h264/ch1/main/av_stream";int main(int argc, char *argv[])
{XInitThreads(); // X支持多线程, 必须调用NT_SDKLogInit();// SDK初始化SmartPlayerSDKAPI player_api;if (!NT_PlayerSDKInit(player_api)){fprintf(stderr, "SDK init failed.\n");return 0;}auto display = XOpenDisplay(nullptr);if (!display){fprintf(stderr, "Cannot connect to X server\n");player_api.UnInit();return 0;}display_ = display;auto screen = DefaultScreen(display);auto root = XRootWindow(display, screen);XWindowAttributes root_win_att;if (!XGetWindowAttributes(display, root, &root_win_att)){fprintf(stderr, "Get Root window attri failed\n");player_api.UnInit();XCloseDisplay(display);return 0;}if (root_win_att.width < 100 || root_win_att.height < 100){fprintf(stderr, "Root window size error.\n");player_api.UnInit();XCloseDisplay(display);return 0;}fprintf(stdout, "Root Window Size:%d*%d\n", root_win_att.width, root_win_att.height);int main_w = root_win_att.width / 2, main_h = root_win_att.height / 2;auto black_pixel = BlackPixel(display, screen);auto white_pixel = WhitePixel(display, screen);main_wid_ = XCreateSimpleWindow(display, root, 0, 0, main_w, main_h, 0, white_pixel, black_pixel);if (!main_wid_){fprintf(stderr, "Cannot Create Main Window\n");player_api.UnInit();XCloseDisplay(display);return 0;}XSelectInput(display, main_wid_, StructureNotifyMask | KeyPressMask);auto sub_wid = CreateSubWindow(display, screen, main_wid_);if (!sub_wid){fprintf(stderr, "Cannot Create Render Window\n");player_api.UnInit();XDestroyWindow(display, main_wid_);XCloseDisplay(display);return 0;}XMapWindow(display, main_wid_);XStoreName(display, main_wid_, win_base_title);XMapWindow(display, sub_wid);NT_HANDLE handle = nullptr;// 打开一个播放实例，可以Open多个播放实例, 然后播放多路if (NT_ERC_OK != player_api.Open(&handle, 0, nullptr)){player_api.UnInit();fprintf(stderr, "player_api.Open failed!\n");XDestroyWindow(display, sub_wid);XDestroyWindow(display, main_wid_);XCloseDisplay(display);return 0;}player_api.SetEventCallBack(handle, nullptr, &NT_OnSDKEventHandle);player_api.SetVideoSizeCallBack(handle, nullptr, &NT_SDKVideoSizeHandle);player_api.SetReportDownloadSpeed(handle, 1, 5); // 5秒上报一次下载速度player_api.SetRtspTimeout(handle, 15);player_api.SetRtspAutoSwitchTcpUdp(handle, 1);player_api.SetBuffer(handle, 0); // 设置缓存player_api.SetIsOutputAudioDevice(handle, 1);player_api.SetAudioOutputLayer(handle, 0); // 使用pluse 或者 alsa播放, 两个可以选择一个//player_api.SetAudioVolume(handle, 100);player_api.SetURL(handle, player_url_); // 设置播放地址, rtsp或者rtmp地址player_api.SetXDisplay(handle, display);player_api.SetXScreenNumber(handle, screen);player_api.SetRenderXWindow(handle, sub_wid); // 设置绘制的X窗口player_api.SetRenderScaleMode(handle, 1); // 按比例绘制或者全填充player_api.SetRenderTextureScaleFilterMode(handle, 3); player_api.SetFastStartup(handle, 1);player_api.SetLowLatencyMode(handle, 0);if (NT_ERC_OK != player_api.StartPlay(handle)){player_api.Close(handle);handle = nullptr;player_api.UnInit();fprintf(stderr, "player_api.StartPlay failed!\n");XDestroyWindow(display, sub_wid);XDestroyWindow(display, main_wid_);XCloseDisplay(display);return 0;}while (true){while (MY_X11_Pending(display, 10)){XEvent xev;memset(&xev, 0, sizeof(xev));XNextEvent(display, &xev);if (xev.type == ConfigureNotify){if (xev.xconfigure.window == main_wid_){if (xev.xconfigure.width != main_w || xev.xconfigure.height != main_h){main_w = xev.xconfigure.width;main_h = xev.xconfigure.height;XMoveResizeWindow(display, sub_wid, 0, 0, main_w-4, main_h-4);}}else{if (sub_wid == xev.xconfigure.window){player_api.OnWindowSize(handle, xev.xconfigure.width, xev.xconfigure.height);}}}else if (xev.type == KeyPress){if (xev.xkey.keycode == XKeysymToKeycode(display, XK_Escape)){fprintf(stdout, "ESC Key Press\n");if (handle != nullptr){player_api.StopPlay(handle); // 停止播放player_api.Close(handle);handle = nullptr;}XDestroyWindow(display, sub_wid);XDestroyWindow(display, main_wid_);XCloseDisplay(display);player_api.UnInit();fprintf(stdout, "Close Player....\n");return 0;}}}}
}

日志设置和SDK Init相关

void NT_SDKLogInit()
{SmartLogAPI log_api;memset(&log_api, 0, sizeof(log_api));GetSmartLogAPI(&log_api);log_api.SetLevel(SL_INFO_LEVEL);log_api.SetPath((NT_PVOID)"./");
}bool NT_PlayerSDKInit(SmartPlayerSDKAPI& player_api)
{memset(&player_api, 0, sizeof(player_api));GetSmartPlayerSDKAPI(&player_api);auto ret = player_api.Init(0, nullptr);if (NT_ERC_OK != ret){fprintf(stderr, "player_api.Init failed!\n");return false;}else{fprintf(stdout, "player_api.Init ok!\n");}return true;
}

窗体相关

Display* display_ = nullptr;
Window   main_wid_ = None;const char* win_base_title = "Rtmp/Rtsp Live Player Demo";int EventPoll(int fd, bool is_write, int timeout_ms)
{int result;do{struct pollfd info;info.fd = fd;if (is_write){info.events = POLLOUT;}else{info.events = POLLIN | POLLPRI;}result = poll(&info, 1, timeout_ms);} while (result < 0 && errno == EINTR);return result;
}bool MY_X11_Pending(Display* display, int timeout_ms)
{XFlush(display);if (XEventsQueued(display, QueuedAlready) > 0){return true;}if (EventPoll(ConnectionNumber(display), false, timeout_ms)){if (XPending(display) > 0){return true;}}return false;
}Window CreateSubWindow(Display* display, int screen, Window parent)
{XWindowAttributes  parent_win_att;XGetWindowAttributes(display, parent, &parent_win_att);fprintf(stdout, "parent w:%d, h:%d\n", parent_win_att.width, parent_win_att.height);XSetWindowAttributes swa;swa.border_pixel = WhitePixel(display, screen);swa.event_mask = KeyPressMask | StructureNotifyMask;return XCreateWindow(display, parent, 0, 0, parent_win_att.width-4, parent_win_att.height-4,2, parent_win_att.depth, InputOutput, parent_win_att.visual, CWEventMask | CWBorderPixel, &swa);
}

Event回调

void NT_OnSDKEventHandle(NT_HANDLE handle, NT_PVOID user_data,NT_UINT32 event_id,NT_INT64  param1,NT_INT64  param2,NT_UINT64 param3,NT_PCSTR  param4,NT_PCSTR  param5,NT_PVOID  param6)
{if (NT_SP_E_EVENT_ID_DOWNLOAD_SPEED == event_id){fprintf(stdout, "OnSDKEventHandle handle:%p speed:%lldkbps, %lldKB/s. \r", handle, (param1 * 8) / 1000, param1 / 1024);fflush(stdout);}
}

视频分辨率回调

void NT_SDKVideoSizeHandle(NT_HANDLE handle, NT_PVOID userData,NT_INT32 width, NT_INT32 height)
{if (display_ && main_wid_){std::ostringstream ss;ss << win_base_title << "  [Video Size: " << width << "*" << height << " ]";XStoreName(display_, main_wid_, ss.str().c_str());}
}