背景
大家在做Windows平台RTMP推送或轻量级RTSP服务的时候，不管是采集屏幕还是采集摄像头，亦或屏幕摄像头的叠加模式，总会有这样的诉求，采集到的数据，希望能本地看看具体采集的数据或者图像实际效果，也就是本次介绍的“预览”功能。
废话不多说，想上图：
如何实现
开始预览
开始预览，大概的流程是，调用OpenPublisherHandle()，进行初始的数据源类型设置，然后调用Open()接口，获取推送handler，并设置event回调。
bool CSmartPublisherDemoDlg::OpenPublisherHandle() { if ( publisher_handle_ != NULL ) { return true; } // 视频 auto video_option = NT_PB_E_VIDEO_OPTION_NO_VIDEO; if ( BST_CHECKED == btn_check_desktop_camera_switch_.GetCheck() || BST_CHECKED == btn_check_camera_overlay_to_desktop_.GetCheck() || BST_CHECKED == btn_check_desktop_overlay_to_camera_.GetCheck() ) { // 使用叠加模式 video_option = NT_PB_E_VIDEO_OPTION_LAYER; } else if (BST_CHECKED == btn_check_desktop_input_.GetCheck() && BST_CHECKED == btn_check_scale_desktop_.GetCheck()) { // 使用叠加模式来实现缩放 video_option = NT_PB_E_VIDEO_OPTION_LAYER; } else if (BST_CHECKED == btn_check_desktop_input_.GetCheck() && BST_CHECKED != btn_check_scale_desktop_.GetCheck() ) { video_option = NT_PB_E_VIDEO_OPTION_SCREEN; } else if (BST_CHECKED == btn_check_window_input_.GetCheck()) { video_option = NT_PB_E_VIDEO_OPTION_WINDOW; // video_option = NT_PB_E_VIDEO_OPTION_LAYER; } else if (BST_CHECKED == btn_check_camera_input_.GetCheck()) { video_option = NT_PB_E_VIDEO_OPTION_CAMERA; } // 音频 auto audio_option = NT_PB_E_AUDIO_OPTION_NO_AUDIO; audio_option = NT_PB_E_AUDIO_OPTION_NO_AUDIO; if ( BST_CHECKED == btn_check_auido_mic_input_.GetCheck() && BST_CHECKED == btn_check_auido_speaker_input_.GetCheck() ) { audio_option = NT_PB_E_AUDIO_OPTION_CAPTURE_MIC_SPEAKER_MIXER; } else if ( BST_CHECKED == btn_check_auido_mic_input_.GetCheck() ) { audio_option = NT_PB_E_AUDIO_OPTION_CAPTURE_MIC; } else if (BST_CHECKED == btn_check_auido_speaker_input_.GetCheck()) { audio_option = NT_PB_E_AUDIO_OPTION_CAPTURE_SPEAKER; } publisher_handle_count_ = 0; if ( NT_ERC_OK != publisher_api_.Open(&publisher_handle_, video_option, audio_option, 0, NULL)) { AfxMessageBox(_T("Call open failed!")); return false; } if ( publisher_handle_ != NULL ) { // 设置事件回调 publisher_api_.SetEventCallBack(publisher_handle_, GetSafeHwnd(), &NT_PB_SDKPublisherEventHandle); return true; } else { return false; } }
目前我们的SDK支持以下几种视频源类型，实时预览仅限于编码前数据类型：
/*定义Video源选项*/ typedef enum _NT_PB_E_VIDEO_OPTION { NT_PB_E_VIDEO_OPTION_NO_VIDEO = 0x0, NT_PB_E_VIDEO_OPTION_SCREEN = 0x1, // 采集屏幕 NT_PB_E_VIDEO_OPTION_CAMERA = 0x2, // 摄像头采集 NT_PB_E_VIDEO_OPTION_LAYER = 0x3, // 视频合并，比如桌面叠加摄像头等 NT_PB_E_VIDEO_OPTION_ENCODED_DATA = 0x4, // 已经编码的视频数据，目前支持H264 NT_PB_E_VIDEO_OPTION_WINDOW = 0x5, // 采集窗口 } NT_PB_E_VIDEO_OPTION;
接着是调用SetCommonOptionToPublisherSDK()，完成叠加和其他参数设定。
void CSmartPublisherDemoDlg::SetCommonOptionToPublisherSDK() { ASSERT(publisher_handle_ != NULL); layer_conf_wrappers_.clear(); // 视频相关设置 if ( BST_CHECKED == btn_check_desktop_camera_switch_.GetCheck() || BST_CHECKED == btn_check_camera_overlay_to_desktop_.GetCheck() || BST_CHECKED == btn_check_desktop_overlay_to_camera_.GetCheck() || BST_CHECKED == btn_check_desktop_input_.GetCheck() || BST_CHECKED == btn_check_window_input_.GetCheck() || BST_CHECKED == btn_check_camera_input_.GetCheck() ) { if ( BST_CHECKED == btn_check_desktop_camera_switch_.GetCheck() ) { auto left = GetIntValueFromEdit(&edit_clip_left_); auto top = GetIntValueFromEdit(&edit_clip_top_); auto w = GetIntValueFromEdit(&edit_clip_width_); auto h = GetIntValueFromEdit(&edit_clip_height_); // 有一个是0， 就使用全屏 if ( w == 0 || h == 0 ) { left = 0; top = 0; GetScreenSize(w, h); } else { // 保证4字节对齐 w = NT_ByteAlign(w, 2); h = NT_ByteAlign(h, 4); } 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, w, h); 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_conf_wrappers_.push_back(rgba_layer_c0); // 第1层是摄像头 if ( CB_ERR != cur_sel_camera_index_ ) { auto& camera = cameras_[cur_sel_camera_index_]; auto camera_layer_c1 = std::make_shared<nt_pb_sdk::CameraLayerConfigWrapperV2>(index++, false, 0, 0, w, h); strcpy_s(camera_layer_c1->conf_.device_unique_id_utf8_, camera.id_.c_str()); camera_layer_c1->conf_.is_flip_horizontal_ = BST_CHECKED == btn_check_flip_horizontal_camera_.GetCheck(); camera_layer_c1->conf_.is_flip_vertical_ = BST_CHECKED == btn_check_flip_vertical_camera_.GetCheck(); // 这种叠加模式下不要旋转，否则变形厉害, 要么就定好一个角度，调整宽高，但不要动态旋转 camera_layer_c1->conf_.rotate_degress_ = 0; layer_conf_wrappers_.push_back(camera_layer_c1); } // 第2层是屏幕 auto screen_layer_c2 = std::make_shared<nt_pb_sdk::ScreenLayerConfigWrapper>(index++, true, 0, 0, w, h); screen_layer_c2->conf_.reserve_ = nullptr; screen_layer_c2->conf_.clip_region_.x_ = left; screen_layer_c2->conf_.clip_region_.y_ = top; screen_layer_c2->conf_.clip_region_.width_ = w; screen_layer_c2->conf_.clip_region_.height_ = h; layer_conf_wrappers_.push_back(screen_layer_c2); // 第3层填充RGBA矩形, 增加半透明效果 auto r = GetIntValueFromEdit(&edit_rgba_rect_layer_red_); r = ClipIntValue(r, 0, 255); auto g = GetIntValueFromEdit(&edit_rgba_rect_layer_green_); g = ClipIntValue(g, 0, 255); auto b = GetIntValueFromEdit(&edit_rgba_rect_layer_blue_); b = ClipIntValue(b, 0, 255); auto a = GetIntValueFromEdit(&edit_rgba_rect_layer_alpha_); a = ClipIntValue(a, 0, 255); auto rgba_layer_c3 = std::make_shared<nt_pb_sdk::RGBARectangleLayerConfigWrapper>(index++, a != 0, 0, 0, w, h); rgba_layer_c3->conf_.red_ = r; rgba_layer_c3->conf_.green_ = g; rgba_layer_c3->conf_.blue_ = b; rgba_layer_c3->conf_.alpha_ = a; layer_conf_wrappers_.push_back(rgba_layer_c3); // 如果有图片，增加图片层 if ( !image_layer_file_name_utf8_.empty() && image_layer_width_ > 0 && image_layer_height_ > 0) { auto image_layer_c4 = std::make_shared<nt_pb_sdk::ImageLayerConfigWrapper>(index++, true, image_layer_left_, image_layer_top_, image_layer_width_, image_layer_height_ ); strcpy_s(image_layer_c4->conf_.file_name_utf8_, image_layer_file_name_utf8_.c_str()); // 图片层是可以增加背景的，有兴趣的话，可以打开看看效果 /*image_layer_c4->conf_.is_setting_background_ = 1; image_layer_c4->conf_.bk_red_ = 255; image_layer_c4->conf_.bk_green_ = 255; image_layer_c4->conf_.bk_blue_ = 255;*/ layer_conf_wrappers_.push_back(image_layer_c4); } SetLayersConfig(); publisher_api_.SetFrameRate(publisher_handle_, GetIntValueFromEdit(&edit_frame_rate_)); } else if (BST_CHECKED == btn_check_camera_overlay_to_desktop_.GetCheck()) { auto left = GetIntValueFromEdit(&edit_clip_left_); auto top = GetIntValueFromEdit(&edit_clip_top_); auto w = GetIntValueFromEdit(&edit_clip_width_); auto h = GetIntValueFromEdit(&edit_clip_height_); // 有一个是0， 就使用全屏 if ( w == 0 || h == 0 ) { left = 0; top = 0; GetScreenSize(w, h); } else { // 保证4字节对齐 w = NT_ByteAlign(w, 2); h = NT_ByteAlign(h, 4); } auto index = 0; /*auto image_layer_c0 = std::make_shared<nt_pb_sdk::ImageLayerConfigWrapper>(index++, true, 0, 0, w, h); strcpy_s(image_layer_c0->conf_.file_name_utf8_, "D:\\myxxyy\\testpng\\ggdwdd.png"); image_layer_c0->conf_.is_setting_background_ = 1; image_layer_c0->conf_.bk_red_ = 255; image_layer_c0->conf_.bk_green_ = 255; image_layer_c0->conf_.bk_blue_ = 255; layer_conf_wrappers_.push_back(image_layer_c0);*/ // 第0层是屏幕 auto screen_layer_c0 = std::make_shared<nt_pb_sdk::ScreenLayerConfigWrapper>(index++, true, 0, 0, w, h); screen_layer_c0->conf_.reserve_ = nullptr; screen_layer_c0->conf_.clip_region_.x_ = left; screen_layer_c0->conf_.clip_region_.y_ = top; screen_layer_c0->conf_.clip_region_.width_ = w; screen_layer_c0->conf_.clip_region_.height_ = h; layer_conf_wrappers_.push_back(screen_layer_c0); // 第1层是摄像头 if ( CB_ERR != cur_sel_camera_index_ ) { auto& camera = cameras_[cur_sel_camera_index_]; auto c_l = GetIntValueFromEdit(&edit_camera_overlay_left_); auto c_t = GetIntValueFromEdit(&edit_camera_overlay_top_); auto c_w = GetIntValueFromEdit(&edit_camera_overlay_width_); auto c_h = GetIntValueFromEdit(&edit_camera_overlay_height_); if ( c_w == 0 ) { c_w = w / 2; } if ( c_h == 0 ) { c_h = h / 2; } if ( c_w >0 && c_h > 0 ) { auto camera_layer_c1 = std::make_shared<nt_pb_sdk::CameraLayerConfigWrapperV2>(index++, true, c_l, c_t, c_w, c_h); strcpy_s(camera_layer_c1->conf_.device_unique_id_utf8_, camera.id_.c_str()); camera_layer_c1->conf_.is_flip_horizontal_ = BST_CHECKED == btn_check_flip_horizontal_camera_.GetCheck(); camera_layer_c1->conf_.is_flip_vertical_ = BST_CHECKED == btn_check_flip_vertical_camera_.GetCheck(); camera_layer_c1->conf_.rotate_degress_ = GetCameraRotateDegress(); layer_conf_wrappers_.push_back(camera_layer_c1); } } SetLayersConfig(); publisher_api_.SetFrameRate(publisher_handle_, GetIntValueFromEdit(&edit_frame_rate_)); } else if (BST_CHECKED == btn_check_desktop_overlay_to_camera_.GetCheck()) { if (CB_ERR != cur_sel_camera_index_ && CB_ERR != cur_sel_camera_resolutions_index_ && CB_ERR != cur_sel_camera_frame_rate_index_) { auto& camera = cameras_[cur_sel_camera_index_]; auto& cap = camera.capabilities_[cur_sel_camera_resolutions_index_]; auto index = 0; // 第0层是摄像头 auto camera_layer_c0 = std::make_shared<nt_pb_sdk::CameraLayerConfigWrapperV2>(index++, true, 0, 0, cap.width_, cap.height_); strcpy_s(camera_layer_c0->conf_.device_unique_id_utf8_, camera.id_.c_str()); camera_layer_c0->conf_.is_flip_horizontal_ = BST_CHECKED == btn_check_flip_horizontal_camera_.GetCheck(); camera_layer_c0->conf_.is_flip_vertical_ = BST_CHECKED == btn_check_flip_vertical_camera_.GetCheck(); // 这种叠加模式下不要旋转，否则变形厉害, 要么就定好一个角度，调整宽高，但不要动态旋转 camera_layer_c0->conf_.rotate_degress_ = 0; layer_conf_wrappers_.push_back(camera_layer_c0); // 第1层是屏幕 auto screen_layer_c1 = std::make_shared<nt_pb_sdk::ScreenLayerConfigWrapper>(index++, true, 0, 0, cap.width_ / 2, cap.height_/2); screen_layer_c1->conf_.reserve_ = nullptr; screen_layer_c1->conf_.clip_region_.x_ = 0; screen_layer_c1->conf_.clip_region_.y_ = 0; screen_layer_c1->conf_.clip_region_.width_ = cap.width_ / 2; screen_layer_c1->conf_.clip_region_.height_ = cap.height_ / 2; layer_conf_wrappers_.push_back(screen_layer_c1); SetLayersConfig(); publisher_api_.SetFrameRate(publisher_handle_, cur_sel_camera_frame_rate_index_ + 1); } } else if (BST_CHECKED == btn_check_desktop_input_.GetCheck() && BST_CHECKED == btn_check_scale_desktop_.GetCheck()) { int left = 0, top = 0, w = 0, h = 0, scale_w = 0, scale_h = 0; GetScreenScaleConfigInfo(left, top, w, h, scale_w, scale_h); 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, scale_w, scale_h); 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_conf_wrappers_.push_back(rgba_layer_c0); // 第1层是屏幕 auto screen_layer_c1 = std::make_shared<nt_pb_sdk::ScreenLayerConfigWrapperV2>(index++, true, 0, 0, scale_w, scale_h); screen_layer_c1->conf_.reserve1_ = nullptr; screen_layer_c1->conf_.reserve2_ = 0; screen_layer_c1->conf_.clip_region_.x_ = left; screen_layer_c1->conf_.clip_region_.y_ = top; screen_layer_c1->conf_.clip_region_.width_ = w; screen_layer_c1->conf_.clip_region_.height_ = h; screen_layer_c1->conf_.scale_filter_mode_ = 3; // 屏幕缩放考虑到清晰度，这里用3，最高缩放质量 layer_conf_wrappers_.push_back(screen_layer_c1); SetLayersConfig(); publisher_api_.SetFrameRate(publisher_handle_, GetIntValueFromEdit(&edit_frame_rate_)); } else if (BST_CHECKED == btn_check_desktop_input_.GetCheck() && BST_CHECKED != btn_check_scale_desktop_.GetCheck()) { publisher_api_.SetScreenClip(publisher_handle_, GetIntValueFromEdit(&edit_clip_left_), GetIntValueFromEdit(&edit_clip_top_), GetIntValueFromEdit(&edit_clip_width_), GetIntValueFromEdit(&edit_clip_height_)); publisher_api_.SetFrameRate(publisher_handle_, GetIntValueFromEdit(&edit_frame_rate_)); } else if ( BST_CHECKED == btn_check_window_input_.GetCheck() ) { if ( nullptr != cur_sel_capture_window_ ) { publisher_api_.SetCaptureWindow(publisher_handle_, cur_sel_capture_window_); publisher_api_.SetFrameRate(publisher_handle_, GetIntValueFromEdit(&edit_frame_rate_)); // 窗口层测试和演示代码++ /*auto index = 0; 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_ = 255; rgba_layer_c0->conf_.blue_ = 0; rgba_layer_c0->conf_.alpha_ = 255; layer_conf_wrappers_.push_back(rgba_layer_c0); auto window_layer_c1 = std::make_shared<nt_pb_sdk::WindowLayerConfigWrapper>(index++, true, 100, 100, 800, 600); window_layer_c1->conf_.window_ = cur_sel_capture_window_; layer_conf_wrappers_.push_back(window_layer_c1); SetLayersConfig(); */ // 窗口层测试和演示代码-- } } else if (BST_CHECKED == btn_check_camera_input_.GetCheck()) { if (CB_ERR != cur_sel_camera_index_ && CB_ERR != cur_sel_camera_resolutions_index_ && CB_ERR != cur_sel_camera_frame_rate_index_) { auto& camera = cameras_[cur_sel_camera_index_]; auto& cap = camera.capabilities_[cur_sel_camera_resolutions_index_]; publisher_api_.SetVideoCaptureDeviceBaseParameter(publisher_handle_, camera.id_.c_str(), cap.width_, cap.height_); publisher_api_.SetFrameRate(publisher_handle_, cur_sel_camera_frame_rate_index_+ 1); publisher_api_.FlipVerticalCamera(publisher_handle_, BST_CHECKED == btn_check_flip_vertical_camera_.GetCheck()); publisher_api_.FlipHorizontalCamera(publisher_handle_, BST_CHECKED == btn_check_flip_horizontal_camera_.GetCheck()); auto degress = GetCameraRotateDegress(); publisher_api_.RotateCamera(publisher_handle_, degress); } } publisher_api_.EnableDXGIScreenCapturer(publisher_handle_, BST_CHECKED == btn_check_dxgi_screen_capturer_.GetCheck()); publisher_api_.DisableAeroScreenCapturer(publisher_handle_, BST_CHECKED == btn_check_capturer_disable_aero_.GetCheck()); publisher_api_.EnableScreenCaptureLayeredWindow(publisher_handle_, BST_CHECKED == check_capture_layered_window_.GetCheck()?1:0); publisher_api_.SetCaptureWindowWay(publisher_handle_, BST_CHECKED == btn_check_wr_way_capture_window_.GetCheck() ? 2 : 1); auto cur_video_codec_id = btn_check_h265_encoder_.GetCheck() != BST_CHECKED? NT_MEDIA_CODEC_ID_H264 : NT_MEDIA_CODEC_ID_H265; NT_INT32 cur_sel_encoder_id = 0; NT_INT32 cur_sel_gpu = 0; auto is_hw_encoder = btn_check_video_hardware_encoder_.GetCheck() == BST_CHECKED; if (is_hw_encoder) { auto cur_sel_hw = combobox_video_encoders_.GetCurSel(); if (cur_sel_hw >=0 ) { cur_sel_encoder_id = combobox_video_encoders_.GetItemData(cur_sel_hw); cur_sel_gpu = -1; auto cur_sel_hw_dev = combobox_video_hardware_encoder_devices_.GetCurSel(); if (cur_sel_hw_dev >= 0) { cur_sel_gpu = combobox_video_hardware_encoder_devices_.GetItemData(cur_sel_hw_dev); } } else { is_hw_encoder = false; } } if (!is_hw_encoder) { if (NT_MEDIA_CODEC_ID_H264 == cur_video_codec_id) { cur_sel_encoder_id = btn_check_openh264_encoder_.GetCheck() == BST_CHECKED ? 1 : 0; } } publisher_api_.SetVideoEncoder(publisher_handle_, is_hw_encoder? 1 : 0, cur_sel_encoder_id, cur_video_codec_id, cur_sel_gpu); if ( BST_CHECKED != btn_check_window_input_.GetCheck() ) { publisher_api_.SetVideoBitRate(publisher_handle_, GetIntValueFromEdit(&edit_bit_rate_)); } else { // 窗口的分辨率会变, 所以设置一组码率下去 auto frame_rate = GetIntValueFromEdit(&edit_frame_rate_); SetBitrateGroup(publisher_handle_, frame_rate); } publisher_api_.SetVideoQualityV2(publisher_handle_, GetIntValueFromEdit(&edit_video_quality_)); publisher_api_.SetVideoMaxBitRate(publisher_handle_, GetIntValueFromEdit(&edit_video_max_bitrate_)); publisher_api_.SetVideoKeyFrameInterval(publisher_handle_, GetIntValueFromEdit(&edit_key_frame_)); if (NT_MEDIA_CODEC_ID_H264 == cur_video_codec_id) { auto profile_sel = combox_h264_profile_.GetCurSel(); if (profile_sel != CB_ERR) { publisher_api_.SetVideoEncoderProfile(publisher_handle_, profile_sel + 1); } } publisher_api_.SetVideoEncoderSpeed(publisher_handle_, GetIntValueFromEdit(&edit_video_encode_speed_)); // 清除编码器所有的特定的参数 publisher_api_.ClearVideoEncoderSpecialOptions(publisher_handle_); if (cur_sel_encoder_id == 1) { // qp_max 和 qp_min 当前只对openh264有效, 这里也就只在openh264使用的场景下设置配置值 publisher_api_.SetVideoEncoderQPMax(publisher_handle_, GetIntValueFromEdit(&edit_qp_max_)); publisher_api_.SetVideoEncoderQPMin(publisher_handle_, GetIntValueFromEdit(&edit_qp_min_)); // openh264 配置特定参数 publisher_api_.SetVideoEncoderSpecialInt32Option(publisher_handle_, "usage_type", btn_check_openh264_ppt_usage_type_.GetCheck() == BST_CHECKED ? 1 : 0); publisher_api_.SetVideoEncoderSpecialInt32Option(publisher_handle_, "rc_mode", btn_check_openh264_rc_bitrate_mode_.GetCheck() == BST_CHECKED ? 1 : 0); publisher_api_.SetVideoEncoderSpecialInt32Option(publisher_handle_, "enable_frame_skip", btn_check_openh264_frame_skip_.GetCheck() == BST_CHECKED ? 1 : 0); } else { publisher_api_.SetVideoEncoderQPMax(publisher_handle_, -1); publisher_api_.SetVideoEncoderQPMin(publisher_handle_, -1); } } // 音频相关设置 if ( BST_CHECKED == btn_check_auido_mic_input_.GetCheck() ) { auto count = combox_auido_input_devices_.GetCount(); if (count != CB_ERR && count > 0) { auto cur_sel = combox_auido_input_devices_.GetCurSel(); if (cur_sel != CB_ERR) { publisher_api_.SetAuidoInputDeviceId(publisher_handle_, cur_sel); } } } // 只采集扬声器时做静音补偿 if ( BST_CHECKED != btn_check_auido_mic_input_.GetCheck() && BST_CHECKED == btn_check_auido_speaker_input_.GetCheck() ) { publisher_api_.SetCaptureSpeakerCompensateMute(publisher_handle_, 1); } if ( BST_CHECKED == btn_check_speex_encoder_.GetCheck()) { publisher_api_.SetPublisherAudioCodecType(publisher_handle_, 2); publisher_api_.SetPublisherSpeexEncoderQuality(publisher_handle_, GetIntValueFromEdit(&edit_speex_quality_)); } else { publisher_api_.SetPublisherAudioCodecType(publisher_handle_, 1); } if ( BST_CHECKED == btn_check_auido_mic_input_.GetCheck() || BST_CHECKED == btn_check_auido_speaker_input_.GetCheck()) { if (BST_CHECKED == btn_check_set_mute_.GetCheck()) { publisher_api_.SetMute(publisher_handle_, 1); } } if ( BST_CHECKED == btn_check_echo_cancel_.GetCheck() ) { publisher_api_.SetEchoCancellation(publisher_handle_, 1, GetIntValueFromEdit(&edit_echo_delay_)); } else { publisher_api_.SetEchoCancellation(publisher_handle_, 0, 0); } if ( BST_CHECKED == btn_check_noise_suppression_.GetCheck() ) { publisher_api_.SetNoiseSuppression(publisher_handle_, 1); } else { publisher_api_.SetNoiseSuppression(publisher_handle_, 0); } if ( BST_CHECKED == btn_check_agc_.GetCheck() ) { publisher_api_.SetAGC(publisher_handle_, 1); } else { publisher_api_.SetAGC(publisher_handle_, 0); } if (BST_CHECKED == btn_check_vad_.GetCheck()) { publisher_api_.SetVAD(publisher_handle_, 1); } else { publisher_api_.SetVAD(publisher_handle_, 0); } if (BST_CHECKED == btn_check_auido_mic_input_.GetCheck() && BST_CHECKED == btn_check_auido_speaker_input_.GetCheck()) { publisher_api_.SetInputAudioVolume(publisher_handle_, 0, GetDoubleValueFromEdit(&edit_audio_input_volume_)); publisher_api_.SetInputAudioVolume(publisher_handle_, 1, GetDoubleValueFromEdit(&edit_audio_speaker_input_volume_)); } else if (BST_CHECKED == btn_check_auido_mic_input_.GetCheck()) { publisher_api_.SetInputAudioVolume(publisher_handle_, 0, GetDoubleValueFromEdit(&edit_audio_input_volume_)); } else if (BST_CHECKED == btn_check_auido_speaker_input_.GetCheck()) { publisher_api_.SetInputAudioVolume(publisher_handle_, 0, GetDoubleValueFromEdit(&edit_audio_speaker_input_volume_)); } }
接下来，设置preview回调：
publisher_api_.SetVideoPreviewImageCallBack(publisher_handle_, NT_PB_E_IMAGE_FORMAT_RGB32, GetSafeHwnd(), &NT_PB_SDKVideoPreviewImageHandle);
然后，调用preview接口：
void CSmartPublisherDemoDlg::OnBnClickedButtonStartPreview() { if ( BST_CHECKED == btn_check_window_input_.GetCheck() ) { if (nullptr == cur_sel_capture_window_) { AfxMessageBox(_T("请先下拉选择采集窗口")); return; } } if ( publisher_handle_ == NULL ) { if (!OpenPublisherHandle()) { return; } } if ( publisher_handle_count_ < 1 ) { SetCommonOptionToPublisherSDK(); } ASSERT(publisher_handle_ != NULL); publisher_api_.SetVideoPreviewImageCallBack(publisher_handle_, NT_PB_E_IMAGE_FORMAT_RGB32, GetSafeHwnd(), &NT_PB_SDKVideoPreviewImageHandle); if (NT_ERC_OK != publisher_api_.StartPreview(publisher_handle_, 0, NULL)) { if ( 0 == publisher_handle_count_ ) { publisher_api_.Close(publisher_handle_); publisher_handle_ = NULL; } AfxMessageBox(_T("预览失败, 请确保选择了视频采集选项")); return; } publisher_handle_count_++; btn_preview_.EnableWindow(FALSE); btn_stop_preview_.EnableWindow(TRUE); if ( 1 == publisher_handle_count_ ) { if (BST_CHECKED == btn_check_desktop_input_.GetCheck()) { btn_choose_screen_region_.SetWindowTextW(L"移动屏幕区域"); } btn_check_dxgi_screen_capturer_.EnableWindow(FALSE); check_capture_layered_window_.EnableWindow(FALSE); btn_check_wr_way_capture_window_.EnableWindow(FALSE); btn_check_desktop_camera_switch_.EnableWindow(FALSE); btn_check_camera_overlay_to_desktop_.EnableWindow(FALSE); btn_check_desktop_overlay_to_camera_.EnableWindow(FALSE); btn_add_image_watermark_.EnableWindow(FALSE); if (BST_CHECKED == btn_check_desktop_camera_switch_.GetCheck() || BST_CHECKED == btn_check_camera_overlay_to_desktop_.GetCheck() || BST_CHECKED == btn_check_desktop_overlay_to_camera_.GetCheck()) { } else { btn_check_desktop_input_.EnableWindow(FALSE); btn_check_scale_desktop_.EnableWindow(FALSE); edit_desktop_scale_.EnableWindow(FALSE); btn_check_camera_input_.EnableWindow(FALSE); btn_check_window_input_.EnableWindow(FALSE); } DisableAuidoInputControl(); } CreatePreViewWindow(); ShowPreViewWindow(true); }
NT_PB_SDKVideoPreviewImageHandle相关回调实现：
extern "C" NT_VOID NT_CALLBACK NT_PB_SDKVideoPreviewImageHandle(NT_HANDLE handle, NT_PVOID user_data, const NT_PB_Image* image) { if ( image != nullptr && image->format_ == NT_PB_E_IMAGE_FORMAT_RGB32 && image->width_ > 0 && image->height_ > 0 && image->plane_[0] != nullptr && image->stride_[0] > 0 ) { std::unique_ptr<nt_pb_rgbx_image> rgbx_image(new nt_pb_rgbx_image()); rgbx_image->width_ = image->width_; rgbx_image->height_ = image->height_; rgbx_image->stride_ = image->stride_[0]; rgbx_image->size_ = image->stride_[0] * image->height_; rgbx_image->data_.reset(new NT_BYTE[rgbx_image->size_]); if ( rgbx_image->data_ ) { memcpy(rgbx_image->data_.get(), image->plane_[0], rgbx_image->size_); HWND hwnd = reinterpret_cast<HWND>(user_data); if (hwnd != NULL && ::IsWindow(hwnd)) { ::PostMessage(hwnd, WM_USER_PB_SDK_PREVIEW_RGBX_IMAGE, (WPARAM)(rgbx_image.release()), 0); } } } /*std::ostringstream ss; ss << "OnPreviewImage handle:" << handle << " w=" << image->width_ << " h=" << image->height_ << " format=" << image->format_ << " \r\n"; OutputDebugStringA(ss.str().c_str());*/ }
这里通过调用封装后的nt_pb_ui_preview_wnd, 来完成本地实时预览：
LRESULT CSmartPublisherDemoDlg::OnSDKPreviewRGBXImage(WPARAM wParam, LPARAM lParam) { nt_pb_rgbx_image* rgbx_image = (nt_pb_rgbx_image*)(wParam); if ( rgbx_image != nullptr ) { std::shared_ptr<nt_pb_rgbx_image> sp_rgbx_image(rgbx_image); preview_wnd_.OnRGBXImage(sp_rgbx_image); } return S_OK; }
具体实现如下：
void nt_pb_ui_preview_wnd::OnRGBXImage(const std::shared_ptr<nt_pb_rgbx_image>& sp_image) { rgbx_image_ = sp_image; if (m_hWnd != NULL && ::IsWindow(m_hWnd) && ::IsWindowVisible(m_hWnd)) { InvalidateRect(NULL, FALSE); } }
OnPaint()实时刷新数据：
void nt_pb_ui_preview_wnd::OnPaint() { CPaintDC dc(this); // device context for painting // TODO: Add your message handler code here // Do not call CWnd::OnPaint() for painting messages if ( IsIconic() ) { return; } CRect rc_client(0, 0, 0, 0); GetClientRect(rc_client); if ( rc_client.IsRectNull() || rc_client.IsRectEmpty() ) { return; } auto mem_dc = ::CreateCompatibleDC(dc.GetSafeHdc()); auto mem_bitmap = ::CreateCompatibleBitmap(dc.GetSafeHdc(), rc_client.Width(), rc_client.Height()); ::SelectObject(mem_dc, mem_bitmap); HBRUSH brush = ::CreateSolidBrush(RGB(238, 243, 250)); ::FillRect(mem_dc, &rc_client, brush); ::DeleteObject(brush); DrawImage(mem_dc, rc_client); ::BitBlt(dc.GetSafeHdc(), 0, 0, rc_client.Width(), rc_client.Height(), mem_dc, 0, 0, SRCCOPY); ::DeleteObject(mem_bitmap); ::DeleteDC(mem_dc); }
DrawImage()封装实现
void nt_pb_ui_preview_wnd::DrawImage(HDC hdc, const CRect& rc_client) { ASSERT(hdc != NULL); ASSERT(!rc_client.IsRectNull()); ASSERT(!rc_client.IsRectEmpty()); if ( !rgbx_image_ ) return; if (rc_client.Width() < 100 || rc_client.Height() < 100) return; if (draw_api_ == nullptr) return; NT_PB_Image image; memset(&image, 0, sizeof(image)); image.cb_size_ = sizeof(image); image.format_ = NT_PB_E_IMAGE_FORMAT_RGB32; image.width_ = rgbx_image_->width_; image.height_ = rgbx_image_->height_; image.timestamp_ = 0; image.plane_[0] = rgbx_image_->data_.get(); image.stride_[0] = rgbx_image_->stride_; image.plane_size_[0] = rgbx_image_->size_; auto limit_w = rc_client.Width() - 8; auto limit_h = rc_client.Height() - 8; auto d_w = 0, d_h = 0; if ( rgbx_image_->width_ <= limit_w && rgbx_image_->height_ <= limit_h ) { d_w = rgbx_image_->width_; d_h = rgbx_image_->height_; } else { CalScaleSize(limit_w, limit_h, rgbx_image_->width_, rgbx_image_->height_, d_w, d_h); } if ( d_w > 0 && d_h > 0 ) { auto d_x = rc_client.Width()/2 - d_w/2; auto d_y = rc_client.Height()/2 - d_h/2; draw_api_->Draw(hdc, d_x, d_y, d_w, d_h, 0, 0, rgbx_image_->width_, rgbx_image_->height_, &image); } }
停止预览
调用StopPreview()即可。
void CSmartPublisherDemoDlg::OnBnClickedButtonStopPreview() { publisher_handle_count_--; publisher_api_.StopPreview(publisher_handle_); if (0 == publisher_handle_count_) { publisher_api_.Close(publisher_handle_); publisher_handle_ = NULL; } btn_preview_.EnableWindow(TRUE); btn_stop_preview_.EnableWindow(FALSE); if (0 == publisher_handle_count_) { if (BST_CHECKED == btn_check_desktop_input_.GetCheck()) { btn_choose_screen_region_.SetWindowTextW(L"选择屏幕区域"); } btn_check_dxgi_screen_capturer_.EnableWindow(TRUE); check_capture_layered_window_.EnableWindow(TRUE); btn_check_wr_way_capture_window_.EnableWindow(TRUE); btn_desktop_camera_switch_.SetWindowTextW(L"切换到摄像头"); btn_disable_image_watermark_.SetWindowTextW(L"停止水印"); btn_disable_camera_overlay_.SetWindowTextW(L"停止叠加摄像头"); btn_disable_desktop_overlay_.SetWindowTextW(L"停止叠加屏幕"); btn_check_desktop_camera_switch_.EnableWindow(TRUE); btn_check_camera_overlay_to_desktop_.EnableWindow(TRUE); btn_check_desktop_overlay_to_camera_.EnableWindow(TRUE); btn_add_image_watermark_.EnableWindow(TRUE); if (BST_CHECKED == btn_check_desktop_camera_switch_.GetCheck() || BST_CHECKED == btn_check_camera_overlay_to_desktop_.GetCheck() || BST_CHECKED == btn_check_desktop_overlay_to_camera_.GetCheck()) { } else { btn_check_desktop_input_.EnableWindow(TRUE); btn_check_scale_desktop_.EnableWindow(TRUE); edit_desktop_scale_.EnableWindow(TRUE); btn_check_camera_input_.EnableWindow(TRUE); btn_check_window_input_.EnableWindow(TRUE); } EnableAuidoInputControl(); } ShowPreViewWindow(false); }
