一、前言
本章主要讲述，如何获取设备名称以及guid，采集设备的采集格式识别，设备的插拔
设备列表以及属性的获取使用的directshow(后续的MediaFoundation无法获取OBS摄像头)
设备的插拔使用的是QT 捕获系统消息，捕获到设备插拔后，重新获取下设备列表(这里并没有动态的添加或者删除，考虑的主要是维护UI显示时 设备顺序的一致性)
二、设备列表的获取
ICreateDevEnum 接口，创建特定的类（如视频捕获设备，音频捕获设备，视频压缩等）的一个枚举器 ，可以使用CLSID_SystemDeviceEnum来得到该指针。
CreateDevEnum::CreateClassEnumerator(
REFCLSID clsidDeviceClass, //设备类别
IEnumMoniker **ppEnumMoniker, //输出参数，IEnumMoniker ××
DWORD dwFlags
);IEnumMoniker 接口, 表示特定的设备枚举类
IMoniker::Enum 方法获取指向 IEnumMoniker 实现的指针，该实现可以通过名字对象的组件向前或向后枚举。
IRunningObjectTable::EnumRunning 方法返回一个指向 IEnumMoniker 实现的指针，该实现可以枚举在运行对象表中注册的名字对象。
IEnumMoniker::Next 此方法检索枚举序列中下一个设备是否存在
struct CameraDevice
{
int nIndex; // index
std::string uid; // 硬件层uniqueId mac中为BuiltInMicrophoneDevice
std::string name; // 设备名称
};
std::map<std::string, CameraDevice> VideoCoreDevice::getVideoDeviceList()
{
if(!m_pDevEnum)
{
::CoCreateInstance(CLSID_SystemDeviceEnum, NULL, CLSCTX_INPROC, IID_ICreateDevEnum, (void**)&m_pDevEnum);
}
std::map<std::string, CameraDevice> devices;
if (!m_bCoUninitializeIsRequired)
{
goto END;
}
HRESULT hr = m_pDevEnum->CreateClassEnumerator(CLSID_VideoInputDeviceCategory, &m_pMonikerDevEnum, 0);
if (hr != NOERROR)
{
std::cout << "CreateClassEnumerator failed" << std::endl;
goto END;
}
m_pMonikerDevEnum->Reset();
ULONG cFetched;
IMoniker* pM;
int index = 0;
while (S_OK == m_pMonikerDevEnum->Next(1, &pM, &cFetched))
{
IPropertyBag* pBag;
hr = pM->BindToStorage(0, 0, IID_IPropertyBag, (void**)&pBag);
if (S_OK == hr)
{
// Find the description or friendly name.
VARIANT varName;
VariantInit(&varName);
hr = pBag->Read(L"Description", &varName, 0);
if (FAILED(hr))
{
hr = pBag->Read(L"FriendlyName", &varName, 0);
}
if (SUCCEEDED(hr))
{
// ignore all VFW drivers
if ((wcsstr(varName.bstrVal, (L"(VFW)")) == NULL) &&
(_wcsnicmp(varName.bstrVal, (L"Google Camera Adapter"), 21) != 0))
{
// Found a valid device.
{
char device_name[256] = { 0 };
char unique_name[256] = { 0 };
char product_name[256] = { 0 };
int convResult = WideCharToMultiByte(CP_UTF8, 0, varName.bstrVal, -1, (char*)device_name, sizeof(device_name), NULL, NULL);
if (convResult == 0)
{
std::cout << "WideCharToMultiByte failed" << std::endl;
goto END;
}
hr = pBag->Read(L"DevicePath", &varName, 0);
if (FAILED(hr))
{
strncpy_s((char*)unique_name, sizeof(unique_name),
(char*)device_name, convResult);
}
else
{
convResult = WideCharToMultiByte(CP_UTF8, 0, varName.bstrVal, -1, (char*)unique_name, sizeof(unique_name), NULL, NULL);
if (convResult == 0)
{
std::cout << "WideCharToMultiByte failed" << std::endl;
goto END;
}
}
GetProductId(unique_name, product_name, sizeof(product_name));
CameraDevice camera;
camera.nIndex = index;
camera.name = device_name;
camera.uid = unique_name;
devices.insert(std::make_pair(camera.uid, camera));
}
++index; // increase the number of valid devices
}
}
VariantClear(&varName);
pBag->Release();
pM->Release();
}
}
END:
return devices;
}
// 不同获取方式得到的ID不一致，通过处理得到相同的ID
void GetProductId(const char* devicePath, char* productUniqueIdUTF8, uint32_t productUniqueIdUTF8Length)
{
*productUniqueIdUTF8 = '\0';
char* startPos = strstr((char*)devicePath, "\\\\?\\");
if (!startPos)
{
strncpy_s((char*)productUniqueIdUTF8, productUniqueIdUTF8Length, "", 1);
std::cout << "Failed to get the product Id" << std::endl;
return;
}
startPos += 4;
char* pos = strchr(startPos, '&');
if (!pos || pos >= (char*)devicePath + strlen((char*)devicePath))
{
strncpy_s((char*)productUniqueIdUTF8, productUniqueIdUTF8Length, "", 1);
std::cout << "Failed to get the product Id" << std::endl;
return;
}
// Find the second occurrence.
pos = strchr(pos + 1, '&');
uint32_t bytesToCopy = (uint32_t)(pos - startPos);
if (pos && (bytesToCopy < productUniqueIdUTF8Length) &&
bytesToCopy <= kVideoCaptureProductIdLength)
{
strncpy_s((char*)productUniqueIdUTF8, productUniqueIdUTF8Length,
(char*)startPos, bytesToCopy);
}
else
{
strncpy_s((char*)productUniqueIdUTF8, productUniqueIdUTF8Length, "", 1);
std::cout << "Failed to get the product Id" << std::endl;
}
}
三、设备的插拔检测
目前使用的是Qt::nativeEventFilter 过滤设备插拔信息,然后去响应设备列表
// 头文件
#pragma once
#include <QWidget>
#include <QUuid>
#include <QAbstractNativeEventFilter>
#include <Windows.h>
#include <QHash>
class VideoNotificationClient : public QAbstractNativeEventFilter, public QWidget
{
public:
class Listener
{
public:
virtual void onDeviceAdded(const std::string& uid) = 0;
virtual void onDeviceRemoved(const std::string& uid) = 0;
};
public:
void initialized();
void uninstallFilter();
bool nativeEventFilter(const QByteArray& eventType, void* message, long* result) override;
public:
VideoNotificationClient(VideoNotificationClient::Listener* listener);
~VideoNotificationClient();
private:
bool m_bInitialized;
QHash<QUuid, HDEVNOTIFY> m_hSevNotifys;
VideoNotificationClient::Listener* m_pListener;
};//源文件
#include "VideoNotificationClient.h"
#include <QDebug>
#include <iostream>
#include <Windows.h>
#include <Dbt.h>
#include <devguid.h>
//具体的设备guid如usbiodef需要initguid
#include <initguid.h>
//USB设备
//GUID_DEVINTERFACE_USB_DEVICE
#include <usbiodef.h>
//HID人机交互设备-鼠标键盘等
#include <hidclass.h>
//GUID_DEVINTERFACE_KEYBOARD
#include <ntddkbd.h>
//GUID_DEVINTERFACE_MOUSE
#include <ntddmou.h>
#include <QCoreApplication>
#pragma comment(lib, "user32.lib")
#pragma comment(lib, "setupapi.lib")
static const GUID GUID_DEVINTERFACE_LIST[] =
{
// GUID_DEVINTERFACE_CAMERA_DEVICE
{ 0x65E8773D, 0x8F56, 0x11D0, { 0xA3, 0xB9, 0x00, 0xA0, 0xC9, 0x22, 0x31, 0x96 } },
// GUID_DEVINTERFACE_USB_DEVICE
{ 0xA5DCBF10, 0x6530, 0x11D2, { 0x90, 0x1F, 0x00, 0xC0, 0x4F, 0xB9, 0x51, 0xED } },
// GUID_DEVINTERFACE_DISK
{ 0x53f56307, 0xb6bf, 0x11d0, { 0x94, 0xf2, 0x00, 0xa0, 0xc9, 0x1e, 0xfb, 0x8b } },
// GUID_DEVINTERFACE_HID,
{ 0x4D1E55B2, 0xF16F, 0x11CF, { 0x88, 0xCB, 0x00, 0x11, 0x11, 0x00, 0x00, 0x30 } },
// GUID_NDIS_LAN_CLASS
{ 0xad498944, 0x762f, 0x11d0, { 0x8d, 0xcb, 0x00, 0xc0, 0x4f, 0xc3, 0x35, 0x8c } },
// GUID_DEVINTERFACE_COMPORT
{ 0x86e0d1e0, 0x8089, 0x11d0, { 0x9c, 0xe4, 0x08, 0x00, 0x3e, 0x30, 0x1f, 0x73 } },
// GUID_DEVINTERFACE_SERENUM_BUS_ENUMERATOR
{ 0x4D36E978, 0xE325, 0x11CE, { 0xBF, 0xC1, 0x08, 0x00, 0x2B, 0xE1, 0x03, 0x18 } },
// GUID_DEVINTERFACE_PARALLEL
{ 0x97F76EF0, 0xF883, 0x11D0, { 0xAF, 0x1F, 0x00, 0x00, 0xF8, 0x00, 0x84, 0x5C } },
// GUID_DEVINTERFACE_PARCLASS
{ 0x811FC6A5, 0xF728, 0x11D0, { 0xA5, 0x37, 0x00, 0x00, 0xF8, 0x75, 0x3E, 0xD1 } }
};
VideoNotificationClient::VideoNotificationClient(VideoNotificationClient::Listener *listener)
: QWidget(nullptr)
, m_bInitialized(false)
, m_pListener(listener)
{
this->hide();
qApp->installNativeEventFilter(this);
}
VideoNotificationClient::~VideoNotificationClient()
{
uninstallFilter();
qApp->removeNativeEventFilter(this);
}
void VideoNotificationClient::initialized()
{
HANDLE winid = (HANDLE)this->winId();
if (!winid)
{
return;
}
//注册插拔事件
HDEVNOTIFY hDevNotify;
DEV_BROADCAST_DEVICEINTERFACE NotifacationFiler;
ZeroMemory(&NotifacationFiler, sizeof(DEV_BROADCAST_DEVICEINTERFACE));
NotifacationFiler.dbcc_size = sizeof(DEV_BROADCAST_DEVICEINTERFACE);
NotifacationFiler.dbcc_devicetype = DBT_DEVTYP_DEVICEINTERFACE;
for (int i = 0; i < sizeof(GUID_DEVINTERFACE_LIST) / sizeof(GUID); i++)
{
NotifacationFiler.dbcc_classguid = GUID_DEVINTERFACE_LIST[i];
hDevNotify = RegisterDeviceNotification(winid, &NotifacationFiler, DEVICE_NOTIFY_WINDOW_HANDLE);
if (!hDevNotify)
{
qDebug() << "注册失败" << endl;
m_bInitialized = false;
return;
}
m_hSevNotifys.insert(QUuid(NotifacationFiler.dbcc_classguid), hDevNotify);
}
m_bInitialized = true;
}
void VideoNotificationClient::uninstallFilter()
{
for (HDEVNOTIFY handle : qAsConst(m_hSevNotifys))
{
::UnregisterDeviceNotification(handle);
}
m_hSevNotifys.clear();
}
bool VideoNotificationClient::nativeEventFilter(const QByteArray& eventType, void* message, long* result)
{
Q_UNUSED(result);
MSG* msg = reinterpret_cast<MSG*>(message);
int msgType = msg->message;
if (msgType == WM_DEVICECHANGE)
{
PDEV_BROADCAST_HDR lpdb = (PDEV_BROADCAST_HDR)msg->lParam;
switch (msg->wParam) {
case DBT_DEVICEARRIVAL:
if (lpdb->dbch_devicetype = DBT_DEVTYP_DEVICEINTERFACE)
{
PDEV_BROADCAST_DEVICEINTERFACE pDevInf = (PDEV_BROADCAST_DEVICEINTERFACE)lpdb;
GUID cameraGuid = { 0x65E8773D, 0x8F56, 0x11D0, { 0xA3, 0xB9, 0x00, 0xA0, 0xC9, 0x22, 0x31, 0x96 } };
if (cameraGuid == pDevInf->dbcc_classguid)
{
QString devicePath = QString::fromWCharArray(pDevInf->dbcc_name);
QStringList parts = devicePath.split('#');
if (parts.length() != 4)
{
qDebug() << "camera logic error";
return false;
}
QString usbPortStr = parts[2];
QStringList usbPortParts = usbPortStr.split('&');
if (usbPortParts.length() != 4)
{
qDebug() << "camera logic error";
return false;
}
if ("0000" != usbPortParts[3])
{
return false;
}
devicePath = devicePath.toLower();
m_pListener->onDeviceAdded(devicePath.toStdString());
//emit cameraPlugged(true, devicePath);
}
}
break;
case DBT_DEVICEREMOVECOMPLETE:
if (lpdb->dbch_devicetype = DBT_DEVTYP_DEVICEINTERFACE)
{
PDEV_BROADCAST_DEVICEINTERFACE pDevInf = (PDEV_BROADCAST_DEVICEINTERFACE)lpdb;
GUID cameraGuid = { 0x65E8773D, 0x8F56, 0x11D0, { 0xA3, 0xB9, 0x00, 0xA0, 0xC9, 0x22, 0x31, 0x96 } };
if (cameraGuid == pDevInf->dbcc_classguid)
{
// USB拔出马上触发
QString devicePath = QString::fromWCharArray(pDevInf->dbcc_name);
QStringList parts = devicePath.split('#');
if (parts.length() != 4)
{
qDebug() << "camera logic error";
return false;
}
QString usbPortStr = parts[2];
QStringList usbPortParts = usbPortStr.split('&');
if (usbPortParts.length() != 4)
{
qDebug() << "camera logic error";
return false;
}
if ("0000" != usbPortParts[3])
{
return false;
}
devicePath = devicePath.toLower();
m_pListener->onDeviceRemoved(devicePath.toStdString());
}
}
break;
}
}
return false;
}
四、设备插拔库设计
项目完整代码，在后续的文章中给出文章来源：https://www.toymoban.com/news/detail-725902.html
文章来源地址https://www.toymoban.com/news/detail-725902.html
// camra
struct CameraDevice
{
int nIndex = 0; // index
std::string uid = ""; // 硬件层uniqueId mac中为BuiltInMicrophoneDevice
std::string name = ""; // 设备名称
};
// IVideoCore
class VIDEODEVICE_SHARED_EXPORT IVideoCore
{
public:
static IVideoCore* getInstance();
virtual void addListener(IVideoDeviceListner* listner) = 0;
virtual void removeListener(IVideoDeviceListner* listner) = 0;
virtual std::map<std::string, CameraDevice> getVideoDevicesList() = 0;
};
// IVideoDevice
class VIDEODEVICE_SHARED_EXPORT IVideoDevice
{
public:
virtual bool initlized() = 0;
virtual std::map<std::string, CameraDevice> getVideoDevicesList() = 0;
virtual void addListener(IVideoDeviceListner* listener) = 0;
virtual void removeListener(IVideoDeviceListner* listener) = 0;
};
// IVideoDeviceListner
class VIDEODEVICE_SHARED_EXPORT IVideoDeviceListner
{
public:
virtual void onDeviceAdded(CameraDevice device) = 0;
virtual void onDeviceRemoved(CameraDevice device) = 0;
virtual void onDeviceListUpdate(std::map<std::string, CameraDevice> cameraList) = 0;
};
class VideoNotificationClient
{
public:
class Listener
{
public:
virtual void onDeviceAdded(const std::string& uid) = 0;
virtual void onDeviceRemoved(const std::string& uid) = 0;
};
}到了这里，关于三、视频设备的枚举以及插拔检测的文章就介绍完了。如果您还想了解更多内容，请在右上角搜索TOY模板网以前的文章或继续浏览下面的相关文章，希望大家以后多多支持TOY模板网！
