基于RTMP实现Linux|麒麟操作系统下屏幕|系统声音采集推送

背景

Windows操作系统自问世以来，以其简单易用的图形化界面操作受到大众追捧，为计算机的普及、科技的发展做出了不可磨灭的功绩，也慢慢的成为人们最依赖的操作系统。在中国，90％以上的办公环境都是Windows，学校和各种培训班的培训内容也都是Windows，Windows操作系统已经渗入到各行各业，人们已经习惯了Windows的界面和操作习惯，IT计算机和Windows已经被习以为常的画上了等号。

但是，我们使用的软件真的安全吗？黑屏事件和棱镜门事件让很多乐观看待或尚未意识到信息安全问题的人们警醒，我们所使用的国外软件并不是安全的，我们的数据完全掌握在别人手中。随着信息安全上升到了国家战略的高度，推行自主可控的国产操作系统势在必行。国产操作系统作为自主可控的基础，市场迅速升温，受到了社会各界的高度关注。

我们有别的选择吗？

其实基于开源软件Linux二次开发的操作系统，近年来的发展趋势非常迅猛。Linux已经有20年历史，尤其近十年经过突飞猛进的发展，Linux桌面操作系统已经远远摆脱了“具备与主流桌面操作系统的可比性”阶段，基于拥有众多优秀的开源应用软件的基础，在软件多样性、硬件兼容性、用户体验等各方面做了大量的改进，现在已经可以满足日常办公的需求。在欧美，我们不时听到一些政府部门将采用Linux桌面办公：慕尼黑市政府用十年的时间，成功的“赶走”了微软；伯明翰市政府、法国国会、瑞士、挪威和南非政府部门也都采用了Linux桌面办公。

国产操作系统|Linux下RTMP同屏推送

在发布国产操作系统|Linux平台的RTMP直播推送SDK之前，大牛直播SDK（官方）的RTMP推送模块已稳定运行在Windows、Android和iOS平台几年了。

相对Windows、Android和iOS平台，Linux在桌面采集等方面，资料非常少，数据采集可以采用调用XLib相关接口实现，本Demo实现的是Linux上实现桌面和系统声音采集，然后使用RTMP协议推出去的一个SDK. 集成调用非常简单。

相关实现

int main(int argc, char *argv[])
{signal(SIGINT, &OnSigIntHandler);//printf("sizeof(NT_SmartPublisherSDKAPI)=%d\n", sizeof(NT_SmartPublisherSDKAPI));LogInit();NT_SmartPublisherSDKAPI push_api;if (!PushSDKInit(push_api)){return 0;}auto push_handle = StartPush(&push_api, "rtmp://192.168.0.154:1935/live/test1", 30);if (!push_handle){fprintf(stderr, "start push failed.\n");push_api.UnInit();return 0;}while (!g_is_exit){sleep(2);}fprintf(stdout, "Skip run loop, is_exit:%d\n", g_is_exit);push_api.StopPublisher(push_handle);push_api.Close(push_handle);push_handle = nullptr;push_api.UnInit();fprintf(stdout, "SDK UnInit..\n");return 0;
}

相关初始化

	void OnSigIntHandler(int sig){if (SIGINT == sig){g_is_exit = true;}}void LogInit(){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 PushSDKInit(NT_SmartPublisherSDKAPI& push_api){memset(&push_api, 0, sizeof(push_api));NT_GetSmartPublisherSDKAPI(&push_api);auto ret = push_api.Init(0, nullptr);if (NT_ERC_OK != ret){fprintf(stderr, "push_api.Init failed!\n");return false;}else{fprintf(stdout, "push_api.Init ok!\n");}return true;}

推送接口封装

	NT_HANDLE StartPush(NT_SmartPublisherSDKAPI* push_api, const std::string& rtmp_url, int dst_fps){NT_INT32 pulse_device_number = 0;if (NT_ERC_OK == push_api->GetAuidoInputDeviceNumber(2, &pulse_device_number)){fprintf(stdout, "Pulse device num:%d\n", pulse_device_number);char device_name[512];for (auto i = 0; i < pulse_device_number; ++i){if (NT_ERC_OK == push_api->GetAuidoInputDeviceName(2, i, device_name, 512)){fprintf(stdout, "index:%d name:%s\n", i, device_name);}}}NT_INT32 alsa_device_number = 0;if (pulse_device_number < 1){if (NT_ERC_OK == push_api->GetAuidoInputDeviceNumber(1, &alsa_device_number)){fprintf(stdout, "Alsa device num:%d\n", alsa_device_number);char device_name[512];for (auto i = 0; i < alsa_device_number; ++i){if (NT_ERC_OK == push_api->GetAuidoInputDeviceName(1, i, device_name, 512)){fprintf(stdout, "index:%d name:%s\n", i, device_name);}}}}NT_INT32 capture_speaker_flag = 0;if ( NT_ERC_OK == push_api->IsCanCaptureSpeaker(2, &capture_speaker_flag) ){if (capture_speaker_flag)fprintf(stdout, "Support speaker capture\n");elsefprintf(stdout, "UnSupport speaker capture\n");}NT_INT32 is_support_window_capture = 0;if (NT_ERC_OK == push_api->IsCaptureWindowSupported(NULL, &is_support_window_capture)){if (is_support_window_capture)fprintf(stdout, "Support window capture\n");elsefprintf(stdout, "UnSupport window capture\n");}NT_HANDLE push_handle = nullptr;// if (NT_ERC_OK != push_api->Open(&push_handle, NT_PB_E_VIDEO_OPTION_LAYER, NT_PB_E_AUDIO_OPTION_CAPTURE_SPEAKER, 0, NULL))if (NT_ERC_OK != push_api->Open(&push_handle, NT_PB_E_VIDEO_OPTION_SCREEN, NT_PB_E_AUDIO_OPTION_CAPTURE_SPEAKER, 0, NULL)){return nullptr;}//push_api->SetXDisplayName(push_handle, ":0");//push_api->SetXDisplayName(push_handle, NULL);// 视频层配置方式//std::vector<std::shared_ptr<nt_pb_sdk::layer_conf_wrapper_base> > layer_confs;//auto index = 0;第0层填充RGBA矩形, 目的是保证帧率, 颜色就填充全黑//auto rgba_layer_c0 = std::make_shared<nt_pb_sdk::RGBARectangleLayerConfigWrapper>(index++, true, 0, 0, 1280, 720);//rgba_layer_c0->conf_.red_ = 0;//rgba_layer_c0->conf_.green_ = 0;//rgba_layer_c0->conf_.blue_ = 0;//rgba_layer_c0->conf_.alpha_ = 255;//layer_confs.push_back(rgba_layer_c0);第一层为桌面层//auto screen_layer_c1 = std::make_shared<nt_pb_sdk::ScreenLayerConfigWrapper>(index++, true, 0, 0, 1280, 720);////screen_layer_c1->conf_.scale_filter_mode_ = 3;//layer_confs.push_back(screen_layer_c1);//std::vector<const NT_PB_LayerBaseConfig* > layer_base_confs;//for (const auto& i : layer_confs)//{//	layer_base_confs.push_back(i->getBase());//}//if (NT_ERC_OK != push_api->SetLayersConfig(push_handle, 0, layer_base_confs.data(),//	layer_base_confs.size(), 0, nullptr))//{//	push_api->Close(push_handle);//	push_handle = nullptr;//	return nullptr;//}// push_api->SetScreenClip(push_handle, 0, 0, 1280, 720);push_api->SetFrameRate(push_handle, dst_fps); // 帧率设置push_api->SetVideoBitRate(push_handle, 2000);  // 平均码率2000kbpspush_api->SetVideoQualityV2(push_handle, 26); push_api->SetVideoMaxBitRate(push_handle, 4000); // 最大码率4000kbpspush_api->SetVideoKeyFrameInterval(push_handle, dst_fps*2); // 关键帧间隔push_api->SetVideoEncoderProfile(push_handle, 3); // h264 baselinepush_api->SetVideoEncoderSpeed(push_handle, 3); // 编码速度设置到3if (pulse_device_number > 0){push_api->SetAudioInputLayer(push_handle, 2);push_api->SetAuidoInputDeviceId(push_handle, 0);}else if (alsa_device_number > 0){push_api->SetAudioInputLayer(push_handle, 1);push_api->SetAuidoInputDeviceId(push_handle, 0);}// 音频配置push_api->SetPublisherAudioCodecType(push_handle, 1);//push_api->SetMute(push_handle, 1);if ( NT_ERC_OK != push_api->SetURL(push_handle, rtmp_url.c_str(), NULL) ){push_api->Close(push_handle);push_handle = nullptr;return nullptr;}if ( NT_ERC_OK != push_api->StartPublisher(push_handle, NULL) ){push_api->Close(push_handle);push_handle = nullptr;return nullptr;}return push_handle;}