第41月第27天 iOS摄像头分辨率枚举

1.

-(AVCaptureDevice *)getCameraDeviceWithPosition:(AVCaptureDevicePosition )position{

NSArray *cameras= [AVCaptureDevice devicesWithMediaType:AVMediaTypeVideo];

for (AVCaptureDevice *camera in cameras) {

     if ([camera position]==position) {

             [[camera formats] enumerateObjectsUsingBlock:^(AVCaptureDeviceFormat* obj,    NSUInteger idx, BOOL * _Nonnull stop) {

        }];

             return camera;

     }

}

return nil;

}

+ (AVCaptureDevice *)getCaptureDevicePosition:(AVCaptureDevicePosition)position {
    NSArray *devices = nil;
    if ([UIDevice currentDevice].systemVersion.floatValue >= 10.0) {
        AVCaptureDeviceDiscoverySession *deviceDiscoverySession = [AVCaptureDeviceDiscoverySession discoverySessionWithDeviceTypes:@[AVCaptureDeviceTypeBuiltInWideAngleCamera]
                                                                                                                         mediaType:AVMediaTypeVideo
                                                                                                                          position:position];
        devices = deviceDiscoverySession.devices;
    } else {
#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Wdeprecated-declarations"
        devices = [AVCaptureDevice devicesWithMediaType:AVMediaTypeVideo];
#pragma clang diagnostic pop
    }
    
    for (AVCaptureDevice *device in devices) {
        if (device.position == position) {
            return device;
        }
    }
    return NULL;
}


    NSMutableDictionary *formatsDic = [NSMutableDictionary dictionary];
    
    AVCaptureDevicePosition position = AVCaptureDevicePositionFront;
    AVCaptureDevice *captureDevice = [[self class] getCaptureDevicePosition:position];
    
    NSArray<AVCaptureDeviceFormat *> *formats = [captureDevice formats];
    
    for (AVCaptureDeviceFormat *vFormat in formats) {
        CMFormatDescriptionRef formatDescription = vFormat.formatDescription;
        NSLog(@"vFormat formatDescription:%@",formatDescription);
        
        CMFormatDescriptionRef description = vFormat.formatDescription;
        CMVideoDimensions dims = CMVideoFormatDescriptionGetDimensions(description);
        NSLog(@"dims %d height:%d",dims.width, dims.height);
        
        NSString *key = [NSString stringWithFormat:@"%dx%d",dims.width,dims.height];
        if (![formatsDic objectForKey:key]) {
            [formatsDic setObject:key forKey:key];
        }
    }

https://www.jianshu.com/p/1e1dbfb746a9