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使用c++/winrt API获取RGB相机视频流

网友: 文章列表 2024-03-21 18:08:33

使用c++/winrt API获取RGB相机视频流

使用c++/winrt API获取RGB相机视频流

1、前提条件

该示例使用c++/winrt进行开发，需要编译器支持c++17，本人使用Visual Studio2017，系统版本为Windows10 21H2，由于UWP API是从Windows10系统进行支持的，故而Windows7及Windows8等系统可能不能正常使用。

注：遇到未定义行为请先检查该API是从哪个Windows版本支持的，可能你当前的系统版本还不支持该API。

2、使用MediaCapture获取RGB相机视频的流程

  • 使用FindAllAsync接口获取所有的VideoCapture设备，选择你想要的设备；
  • 根据选好的设备ID及自定义配置初始化MediaCapture对象；
  • 使用刚刚初始化的MediaCapture获取所有的帧源，我们这里选择RGB视频流这个帧源；
  • 为选择好的MeidaFrameSource设置指定的format（width,height）；
  • 获取读取视频流帧对象MediaFrameReader;
  • 使用MediaFrameReader读取相机的视频帧；

3、代码演示

注：演示代码中还需要依赖opencv进行nv12->bgr的转换工作，以及使用opencv进行实时显示取到的视频帧工作。

头文件

//MediaFrameCapture.h#pragma once
#ifdef _WIN32
// winrt
#include <mfapi.h>
#include <mfidl.h>
#include <winrt/base.h>
#include <winrt/Windows.Media.Core.h>
#include <winrt/Windows.Media.Devices.h>
#include <winrt/Windows.Media.Capture.h>
#include <winrt/Windows.Media.Capture.Frames.h>
#include <winrt/Windows.Media.Mediaproperties.h>
#include <winrt/Windows.Foundation.h>
#include <winrt/Windows.Foundation.Collections.h>
#include <winrt/Windows.Storage.Streams.h>
#include <winrt/Windows.Devices.Enumeration.h>
#include <winrt/Windows.Graphics.h>
#include <winrt/Windows.Graphics.Imaging.h>
using namespace winrt;
#include "opencv2/opencv.hpp"
// std
#include <vector>class MediaFrameCapture
{
public:MediaFrameCapture();~MediaFrameCapture();/* @brief 获取已连接的设备数* * @return 返回已连接的mipi RGB的设备数量* @note*/int listDevices();/* @brief 更新已连接mipi RGB相机列表 @return void* @note */void updateListDevices();/* @brief 连接指定deviceId的设备 通过deviceId获取指定设备并初始MediaCapture对象 @param[in] deviceId RGB设备的PID，通过该deviceId查询设备是否存在* @return 返回设置是否被正确的打开和初始化* @note */bool setupDevice(const std::string& deviceId);/* @brief 连接指定deviceId的设备并指定帧的分辨率 通过deviceId获取指定设备并初始MediaCapture对象；指定帧的分辨率，若指定的大小格式不支持则失败 @param[in] deviceId RGB设备的PID，通过该deviceId查询设备是否存在* @param[in] width 分辨率宽* @param[in] height 分辨率高* @return 返回设置是否被正确的打开和初始化* @note*/bool setupDevice(const std::string& deviceId, int width, int height);bool startCapture();bool stopCapture();/* @brief 提供给外部调用返回读取到的新帧* @param[out] oneFrame 返回读取到的新帧* @return false没有获取到新帧，true获取到新帧* @note*/bool read(cv::Mat&);/* @brief 用于通过设备PID号选择指定的设备，初始化m_selectedDevice字段* @param[in] deviceId 设备的PID号* @return false指定的设备不存在，获取失败；true指定的设备存在* @note*/bool selectDeviceByDeviceId(const std::string& deviceId);/* @brief 判断已选设备是否被占用 @param[in] selectedDevice 传入选中的设备信息* @return false设备未被占用，可以使用；true设备已被占用或互斥打开* @note*/bool isDeviceInUse(Windows::Devices::Enumeration::DeviceInformation selectedDevice);/* @brief 获取设备列表 @return 返回设备列表结果集* @note*/Windows::Devices::Enumeration::DeviceInformationCollection getDeviceList();
private:/* @brief 通过选好的设备初始化MediaCapture对象，该对象用于媒体设备流采集* @param[in] selectedDevice 选择的设备信息* @return false初始化失败，true初始化成功* @note*/bool initMediaCapture(const Windows::Devices::Enumeration::DeviceInformation& selectedDevice);/* @brief 选择Color帧源，由于一个设备中可能有color、depth、ir等源，选择color帧 @return false不存在color源，true存在并初始化成功* @note*/bool chooseMediaFrameSource();/* @brief 获取最合适的分辨率 若width和height为0时，选择最高分辨率，不为0时，选择与width、height对应的分辨率 @param[in] width 需要适配的分辨率宽* @param[in] height 需要适配的分辨率高* @return 为nullptr表示没有找到适配的format* @note*/Windows::Media::Capture::Frames::MediaFrameFormat getSupportFormat(int width = 0, int height = 0);private:int m_width;			// 分辨率-宽int m_height;			// 分辨率-高int m_deviceNums;		// 设备数std::string m_deviceId; // 设备的PIDparam::hstring m_subType;std::map<uint32_t, std::pair<int, int>> m_supportFormatMap;// 支持的NV12格式static std::map <std::string, bool> m_deviceOpenedMap;Windows::Devices::Enumeration::DeviceInformation m_selectedDevice;		 // 被选择的设备Windows::Devices::Enumeration::DeviceInformationCollection m_deviceList; // 设备列表Windows::Media::Capture::MediaCapture m_mediaCapture;	 // 媒体流采集Windows::Media::Capture::Frames::MediaFrameSource m_mediaFrameSource;		 // 媒体流源，从mediacapture获取Windows::Media::Capture::Frames::MediaFrameFormat m_defaultFormat;			 // 媒体格式，用于自定义视频流的分辨率Windows::Media::Capture::Frames::MediaFrameReader m_mediaFrameReader;		 // 读取视频流};#endif

实现

#ifdef _WIN32
#include "MediaFrameCapture.h"
#include <iostream> // 后期使用log代替
#include "opencv2/core/core.hpp"
#include "opencv2/imgproc.hpp"
std::map<std::string,bool> MediaFrameCapture::m_deviceOpenedMap;MediaFrameCapture::MediaFrameCapture():m_selectedDevice(nullptr),m_mediaFrameSource(nullptr), m_defaultFormat(nullptr), m_deviceList(nullptr),m_mediaFrameReader(nullptr),//m_mediaCapture(nullptr),m_subType(L"NV12")
{init_apartment();updateListDevices();
}MediaFrameCapture::~MediaFrameCapture()
{if (m_mediaFrameReader){stopCapture();m_mediaFrameReader.Close();m_mediaFrameReader = nullptr;}if (m_mediaCapture){m_mediaCapture.Close();}m_deviceOpenedMap[m_deviceId] = false;
}void MediaFrameCapture::updateListDevices()
{// 选择设备类型为视频auto selector = Windows::Devices::Enumeration::DeviceClass::VideoCapture;m_deviceList = Windows::Devices::Enumeration::DeviceInformation::FindAllAsync(selector).get();
}int MediaFrameCapture::listDevices()
{updateListDevices();return m_deviceList.Size();
}bool MediaFrameCapture::selectDeviceByDeviceId(const std::string& deviceId)
{bool haveFound = false;for (const Windows::Devices::Enumeration::DeviceInformation& device : m_deviceList){std::wstring wDeviceId(device.Id().c_str());std::string devId(wDeviceId.begin(), wDeviceId.end());if (m_deviceOpenedMap.find(devId) != m_deviceOpenedMap.end()){if (m_deviceOpenedMap.at(devId)) continue;}if (devId.find("PID_" + deviceId) != std::string::npos){haveFound = true;m_selectedDevice = device;m_deviceId = devId;}}return haveFound;
}bool MediaFrameCapture::initMediaCapture(const Windows::Devices::Enumeration::DeviceInformation& selectedDevice)
{Windows::Media::Capture::MediaCaptureInitializationSettings settings;settings.VideoDeviceId(selectedDevice.Id());settings.SharingMode(winrt::Windows::Media::Capture::MediaCaptureSharingMode::ExclusiveControl);settings.MemoryPreference(winrt::Windows::Media::Capture::MediaCaptureMemoryPreference::Cpu);settings.StreamingCaptureMode(winrt::Windows::Media::Capture::StreamingCaptureMode::Video);try {m_mediaCapture.InitializeAsync(settings).get();}catch (...){std::cout << "MediaCapture初始化失败" << std::endl;return false;}m_deviceOpenedMap[m_deviceId] = true;return true;
}bool MediaFrameCapture::isDeviceInUse(Windows::Devices::Enumeration::DeviceInformation selectedDevice)
{std::wstring wDeviceId(selectedDevice.Id().c_str());std::string devId(wDeviceId.begin(), wDeviceId.end());if (m_deviceOpenedMap.find(devId) != m_deviceOpenedMap.end() && m_deviceOpenedMap.at(devId))return true;return false;
}Windows::Devices::Enumeration::DeviceInformationCollection MediaFrameCapture::getDeviceList()
{updateListDevices();return m_deviceList;
}bool MediaFrameCapture::chooseMediaFrameSource()
{if (m_mediaCapture == nullptr){return false;}auto frameSources = m_mediaCapture.FrameSources();Windows::Media::Capture::Frames::MediaFrameSource mediaFrameSource = nullptr;for (auto frameSource : frameSources){mediaFrameSource = frameSource.Value();if (mediaFrameSource.Info().MediaStreamType() == Windows::Media::Capture::MediaStreamType::VideoRecord&& mediaFrameSource.Info().SourceKind() == Windows::Media::Capture::Frames::MediaFrameSourceKind::Color){m_mediaFrameSource = mediaFrameSource;return true;}}return false;
}Windows::Media::Capture::Frames::MediaFrameFormat MediaFrameCapture::getSupportFormat(int t_width, int t_height)
{if (!m_mediaFrameSource) return nullptr;int max_width = 0;int max_height = 0;Windows::Media::Capture::Frames::MediaFrameFormat preffered_format = nullptr;for (Windows::Media::Capture::Frames::MediaFrameFormat format : m_mediaFrameSource.SupportedFormats()){std::wcout << format.Subtype().data() << " "<< format.VideoFormat().Width() << " "<< format.VideoFormat().Height() << std::endl;std::wstring subType = format.Subtype().data();auto width = format.VideoFormat().Width();auto height = format.VideoFormat().Height();if (L"NV12" == subType){if (t_width == 0 && t_height == 0){if (max_width < width && max_height < height){max_width = width;max_height = height;preffered_format = format;}}else if (t_width == width && t_height == height){preffered_format = format;break;}}}if (preffered_format){if (t_width == 0 && t_height == 0){m_width = max_width;m_height = max_height;}else{m_width = t_width;m_height = t_height;}}return preffered_format;
}bool MediaFrameCapture::setupDevice(const std::string& deviceId)
{if (!initMediaCapture(m_selectedDevice)){return false;}if (!chooseMediaFrameSource()){return false;}m_defaultFormat = getSupportFormat();if (!m_defaultFormat){return false;}try{m_mediaFrameSource.SetFormatAsync(m_defaultFormat).get();m_mediaFrameReader = m_mediaCapture.CreateFrameReaderAsync(m_mediaFrameSource, m_subType).get();}catch (...){return false;}return startCapture();
}bool MediaFrameCapture::setupDevice(const std::string& deviceId, int t_width, int t_height)
{if (!initMediaCapture(m_selectedDevice)){return false;}if (!chooseMediaFrameSource()){return false;}m_defaultFormat = getSupportFormat(t_width, t_height);if (!m_defaultFormat){return false;}try{m_mediaFrameSource.SetFormatAsync(m_defaultFormat).get();m_mediaFrameReader = m_mediaCapture.CreateFrameReaderAsync(m_mediaFrameSource, m_subType).get();}catch (...){return false;}return startCapture();
}bool MediaFrameCapture::startCapture()
{if (!m_mediaFrameReader) return false;try {m_mediaFrameReader.StartAsync().get();}catch (...){return false;}return true;
}bool MediaFrameCapture::stopCapture()
{if (!m_mediaFrameReader) return false;try {m_mediaFrameReader.StopAsync().get();}catch (...){return false;}return true;
}bool MediaFrameCapture::read(cv::Mat& oneFrame)
{Windows::Media::Capture::Frames::MediaFrameReference videoMediaFrame = m_mediaFrameReader.TryAcquireLatestFrame();if (videoMediaFrame){auto videoFrame = videoMediaFrame.VideoMediaFrame().GetVideoFrame();cv::Mat bgrMat;if (videoFrame != nullptr){auto ff = videoMediaFrame.Format();std::wcout << ff.Subtype().data()<< " " << ff.VideoFormat().Width()<< " " << ff.VideoFormat().Height() << std::endl;uint32_t cap = m_width * m_height * 1.5;Windows::Storage::Streams::Buffer buffer(cap);videoFrame.SoftwareBitmap().CopyToBuffer(buffer);uint8_t *data = buffer.data();cv::Mat yuvMat(m_height * 3 / 2, m_width, CV_8UC1, data);cv::cvtColor(yuvMat, bgrMat, cv::COLOR_YUV2BGR_NV12);oneFrame = bgrMat.clone();return true;}}return false;
}#endif

测试代码

#include "MediaFrameCapture.h"
#include <opencv2/opencv.hpp>int main(int argc, char*argv[])
{std::string PID = "";if (argc > 1){PID = argv[1];}MediaFrameCapture frameCapture;if (!frameCapture.selectDeviceByDeviceId(PID)){std::cout << "没有找到对应PID为<" << PID << ">的相机" << std::endl;return false;}bool ret = frameCapture.setupDevice(PID, 1280, 720);if (!ret){std::cout << "open PID : " << PID << " failed" << std::endl;return 0;}while (1){cv::Mat readFrame;ret = frameCapture.read(readFrame);if (ret){cv::imshow("NV12 Image", readFrame);cv::waitKey(50);}}return 0;
}
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