Objective c AVCaptureDevice的USB接口
如果我有AVCaptureDevice,如何获得相关的USB接口,以便通过IOKit访问底层硬件 我试着通过vid&pid找到它,但是如果我用相同的vid&pid插入两个设备,这将不起作用。下面是我用来从AVCaptureDevice提取vid和pid的代码:Objective c AVCaptureDevice的USB接口,objective-c,c,macos,avfoundation,iokit,Objective C,C,Macos,Avfoundation,Iokit,如果我有AVCaptureDevice,如何获得相关的USB接口,以便通过IOKit访问底层硬件 我试着通过vid&pid找到它,但是如果我用相同的vid&pid插入两个设备,这将不起作用。下面是我用来从AVCaptureDevice提取vid和pid的代码: AVCaptureDevice *device = [AVCaptureDevice defaultDeviceWithDeviceType:AVMediaTypeVideo]; NSString *modelID = [device m
AVCaptureDevice *device = [AVCaptureDevice defaultDeviceWithDeviceType:AVMediaTypeVideo];
NSString *modelID = [device modelID];
NSRange vidRange = [modelID rangeOfString:@"VendorID_"];
int vid = [[modelID substringWithRange:NSMakeRange(vidRange.location + 9, 5)] intValue];
NSRange pidRange = [modelID rangeOfString:@"ProductID_"];
int vid = [[modelID substringWithRange:NSMakeRange(pidRange.location + 10, 5)] intValue];
然后我搜索匹配的IOService:
CFMutableDictionaryRef matchingDict = IOServiceMatching(kIOUSBDeviceClassName);
CFNumberRef numberRef;
numberRef = CFNumberCreate(kCFAllocatorDefault, kCFNumberSInt32Type, &vid);
CFDictionarySetValue(matchingDict, CFSTR(kUSBVendorID), numberRef);
CFRelease(numberRef);
numberRef = CFNumberCreate(kCFAllocatorDefault, kCFNumberSInt32Type, &pid);
CFDictionarySetValue(matchingDict, CFSTR(kUSBProductID), numberRef);
CFRelease(numberRef);
io_service_t camera = IOServiceGetMatchingService(kIOMasterPortDefault, matchingDict);
也许
AVCaptureDevice
modelID
和uniqueID
的组合可以帮助您找到匹配的IOService
。这两个ID的格式看起来都是未记录的,并且依赖于传输和媒体类型,但是您应该能够找到一些解决方法。以下是基于两个设备的USB音频的暂定映射(因为我没有任何USB摄像头):
modelID: USB Headphone Set:0C76:1607
uniqueID: AppleUSBAudioEngine:Unknown Manufacturer:USB Headphone Set:14200000:2,1,
USB Headphone Set:
Product ID: 0x1607
Vendor ID: 0x0c76 (Solid State System Co., Ltd.)
Version: 1.00
Speed: Up to 12 Mb/sec
Location ID: 0x14200000 / 9
Current Available (mA): 1000
Current Required (mA): 100
Extra Operating Current (mA): 0
uniqueID: AppleUSBAudioEngine:Burr-Brown from TI :USB Audio CODEC :14200000:2,
modelID: USB Audio CODEC :08BB:2902
USB Audio CODEC :
Product ID: 0x2902
Vendor ID: 0x08bb (Texas Instruments Japan)
Version: 1.00
Speed: Up to 12 Mb/sec
Manufacturer: Burr-Brown from TI
Location ID: 0x14200000 / 10
Current Available (mA): 1000
Current Required (mA): 100
Extra Operating Current (mA): 0
(usb音频)格式类似于
modelID: name:vendorID:productID
uniqueID: AppleUSBAudioEngine:Manufacturer or Unknown Manufacturer:location ID:???
如果USB视频的uniqueID
类似,那么productID
、vendorID
和locationID
(哪个USB端口)的组合应该足以唯一地识别底层设备的硬件,尽管是以脆弱且未记录的方式