一、引入AVFoundation框架
添加頭文件
#import <AVFoundation/AVFoundation.h>
二、定義以下對象：
AVCaptureDevice * device;? // 圖像捕捉設(shè)備
AVCaptureDeviceInput * input; // 輸入流
AVCaptureStillImageOutput * output; //輸出流
?AVCaptureSession * session; // 輸入設(shè)備和輸出設(shè)備之間的數(shù)據(jù)傳遞
AVCaptureVideoPreviewLayer * preview; // 預(yù)覽圖層，顯示攝像頭捕捉到的畫面
?UIButton * cameraButton;? // 拍照按鈕
三、初始化對象
//1.實例化捕捉會話
self.session = [[AVCaptureSession alloc]init];
// 將捕捉會話的預(yù)設(shè)設(shè)置為圖像
self.session.sessionPreset = AVCaptureSessionPresetPhoto;
//2.初始化捕捉設(shè)備
//self.device = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
self.device = [self backCamera]; ?// 這里使用后置攝像頭
//3.用captureDevice創(chuàng)建輸入流
self.input = [[AVCaptureDeviceInput alloc]initWithDevice:self.device error:nil];
// 將輸入流添加到會話中
if ([self.session canAddInput:self.input]) {
[self.session addInput:self.input];
}
//4.創(chuàng)建媒體數(shù)據(jù)輸出流為靜態(tài)圖像
self.output = [[AVCaptureStillImageOutput alloc]init];
// 將輸出流設(shè)置成JPEG的圖片格式輸出，這里輸出流的設(shè)置參數(shù)AVVideoCodecJPEG參數(shù)表示以JPEG的圖片格式輸出圖片
NSDictionary * outputSettings = [[NSDictionary alloc] initWithObjectsAndKeys:AVVideoCodecJPEG,AVVideoCodecKey, nil];
[self.output setOutputSettings:outputSettings];
// 5.將輸出流添加到會話中
if ([self.session canAddOutput:self.output]) {
[self.session addOutput:self.output];
}
// 6. 通過會話創(chuàng)建預(yù)覽圖層
self.preview = [AVCaptureVideoPreviewLayer layerWithSession:self.session];
// 設(shè)置預(yù)覽圖層填充方式
self.preview.videoGravity = AVLayerVideoGravityResizeAspectFill;
CGFloat max = MAX([UIScreen mainScreen].bounds.size.width, [UIScreen mainScreen].bounds.size.height);
CGFloat min = MIN([UIScreen mainScreen].bounds.size.width, [UIScreen mainScreen].bounds.size.height);
// 設(shè)置預(yù)覽圖層的大小
self.preview.frame = CGRectMake(0, 0, min, max);
// 將預(yù)覽圖層放置在最上面
[self.view.layer insertSublayer:self.preview atIndex:0];
- (void)viewDidAppear:(BOOL)animated{
if (self.session) {
[self.session startRunning];
}
}
- (void)viewDidDisappear:(BOOL)animated{
if (self.session) {
[self.session stopRunning];
}
}
四、初始化設(shè)備時，可選擇前置或后置攝影頭；
// 根據(jù)位置獲取前后攝像頭設(shè)備
- (AVCaptureDevice *)cameraWithPosition:(AVCaptureDevicePosition) position {
? ? AVCaptureDeviceDiscoverySession * deviceDiscoverSession = [AVCaptureDeviceDiscoverySession discoverySessionWithDeviceTypes:@[AVCaptureDeviceTypeBuiltInWideAngleCamera] mediaType:AVMediaTypeVideo position:position];
? ? NSArray * devices = deviceDiscoverSession.devices;
? ? for (AVCaptureDevice *device in devices) {
? ? ? ? if ([device position] == position) {
? ? ? ? return device;
? ? ? ? }
? ? }
return nil;
}
// 獲取前置攝像頭
- (AVCaptureDevice *)frontCamera {
return [self cameraWithPosition:AVCaptureDevicePositionFront];
}
// 獲取后置攝像頭
- (AVCaptureDevice *)backCamera {
return [self cameraWithPosition:AVCaptureDevicePositionBack];
}
// 切換攝像頭
- (void)switchDevice{
NSArray *inputs = self.session.inputs;
for ( AVCaptureDeviceInput *input in inputs ) {
AVCaptureDevice *device = input.device;
if ( [device hasMediaType:AVMediaTypeVideo] ) {
AVCaptureDevicePosition position = device.position;
AVCaptureDevice *newCamera = nil;
AVCaptureDeviceInput *newInput = nil;
if (position == AVCaptureDevicePositionFront)
newCamera = [self cameraWithPosition:AVCaptureDevicePositionBack];
else
newCamera = [self cameraWithPosition:AVCaptureDevicePositionFront];
newInput = [AVCaptureDeviceInput deviceInputWithDevice:newCamera error:nil];
[self.session beginConfiguration];
[self.session removeInput:input];
[self.session addInput:newInput];
[self.session commitConfiguration];
break;
}
}
}
五、在拍照按鈕的點(diǎn)擊事件中獲取捕捉到的圖像，并可將其轉(zhuǎn)成base64字符串
- (void)captureStillImage{
AVCaptureConnection * videoConnection = [self.output connectionWithMediaType:AVMediaTypeVideo];
if (!videoConnection) {
NSLog(@"take photo failed!");
return;
}
[self.output captureStillImageAsynchronouslyFromConnection:videoConnection
completionHandler:^(CMSampleBufferRef imageDataSampleBuffer, NSError *error) {
if (imageDataSampleBuffer == NULL) {
return;
}
NSData * imageData = [AVCaptureStillImageOutput jpegStillImageNSDataRepresentation:imageDataSampleBuffer];
UIImage * image = [UIImage imageWithData:imageData];
UIImage * smallImage = [self scaleImage:image toScale:0.5];
NSData * resultImageData = UIImageJPEGRepresentation(smallImage, 1.0);
NSString * imageBase64String = [resultImageData base64EncodedStringWithOptions:NSDataBase64Encoding64CharacterLineLength];
}];
}
P.S. 這里可以將獲取到的圖片進(jìn)行縮??；
// 等比率縮放圖片
- (UIImage *)scaleImage:(UIImage *)image toScale:(float)scaleSize{
UIGraphicsBeginImageContext(CGSizeMake(image.size.width * scaleSize, image.size.height * scaleSize));
[image drawInRect:CGRectMake(0, 0, image.size.width * scaleSize, image.size.height * scaleSize)];
UIImage * scaledImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return scaledImage;
}
六、橫屏?xí)r，調(diào)整預(yù)覽圖層frame
- (void)willRotateToInterfaceOrientation:(UIInterfaceOrientation)toInterfaceOrientation duration:(NSTimeInterval)duration {
[super willRotateToInterfaceOrientation:toInterfaceOrientation duration:duration];
CGFloat max = MAX([UIScreen mainScreen].bounds.size.width, [UIScreen mainScreen].bounds.size.height);
CGFloat min = MIN([UIScreen mainScreen].bounds.size.width, [UIScreen mainScreen].bounds.size.height);
if (toInterfaceOrientation == UIInterfaceOrientationLandscapeLeft) {
self.preview.frame = CGRectMake(0, 0, max, min);
}
if (toInterfaceOrientation == UIInterfaceOrientationLandscapeRight) {
self.preview.frame = CGRectMake(0, 0, max, min);
}
if (toInterfaceOrientation == UIInterfaceOrientationPortrait) {
self.preview.frame = CGRectMake(0, 0, min, max);
}
}
