30分鐘搞定iOS自定義相機
最近公司的項目中用到了相機,由于不用系統(tǒng)的相機,UI給的相機切圖,必須自定義才可以。就花時間簡單研究了一下相機的自定義。
相機屬于系統(tǒng)硬件,這就需要我們來手動調用iPhone的相機硬件,分為以下步驟:
1、首先聲明以下對象
- #import <AVFoundation/AVFoundation.h>
- //捕獲設備,通常是前置攝像頭,后置攝像頭,麥克風(音頻輸入)
- @property (nonatomic, strong) AVCaptureDevice *device;
- //AVCaptureDeviceInput 代表輸入設備,他使用AVCaptureDevice 來初始化
- @property (nonatomic, strong) AVCaptureDeviceInput *input;
- //輸出圖片
- @property (nonatomic ,strong) AVCaptureStillImageOutput *imageOutput;
- //session:由他把輸入輸出結合在一起,并開始啟動捕獲設備(攝像頭)
- @property (nonatomic, strong) AVCaptureSession *session;
- //圖像預覽層,實時顯示捕獲的圖像
- @property (nonatomic ,strong) AVCaptureVideoPreviewLayer *previewLayer;
2、初始化各個對象
- - (void)cameraDistrict
- {
- // AVCaptureDevicePositionBack 后置攝像頭
- // AVCaptureDevicePositionFront 前置攝像頭
- self.device = [self cameraWithPosition:AVCaptureDevicePositionFront];
- self.input = [[AVCaptureDeviceInput alloc] initWithDevice:self.device error:nil];
- self.imageOutput = [[AVCaptureStillImageOutput alloc] init];
- self.session = [[AVCaptureSession alloc] init];
- // 拿到的圖像的大小可以自行設定
- // AVCaptureSessionPreset320x240
- // AVCaptureSessionPreset352x288
- // AVCaptureSessionPreset640x480
- // AVCaptureSessionPreset960x540
- // AVCaptureSessionPreset1280x720
- // AVCaptureSessionPreset1920x1080
- // AVCaptureSessionPreset3840x2160
- self.session.sessionPreset = AVCaptureSessionPreset640x480;
- //輸入輸出設備結合
- if ([self.session canAddInput:self.input]) {
- [self.session addInput:self.input];
- }
- if ([self.session canAddOutput:self.imageOutput]) {
- [self.session addOutput:self.imageOutput];
- }
- //預覽層的生成
- self.previewLayer = [[AVCaptureVideoPreviewLayer alloc] initWithSession:self.session];
- self.previewLayer.frame = CGRectMake(0, 64, SCREEN_WIDTH, SCREEN_HEIGHT-64);
- self.previewLayer.videoGravity = AVLayerVideoGravityResizeAspectFill;
- [self.view.layer addSublayer:self.previewLayer];
- //設備取景開始
- [self.session startRunning];
- if ([_device lockForConfiguration:nil]) {
- //自動閃光燈,
- if ([_device isFlashModeSupported:AVCaptureFlashModeAuto]) {
- [_device setFlashMode:AVCaptureFlashModeAuto];
- }
- //自動白平衡,但是好像一直都進不去
- if ([_device isWhiteBalanceModeSupported:AVCaptureWhiteBalanceModeAutoWhiteBalance]) {
- [_device setWhiteBalanceMode:AVCaptureWhiteBalanceModeAutoWhiteBalance];
- }
- [_device unlockForConfiguration];
- }
- }
根據(jù)前后置位置拿到相應的攝像頭:
- - (AVCaptureDevice *)cameraWithPosition:(AVCaptureDevicePosition)position{
- NSArray *devices = [AVCaptureDevice devicesWithMediaType:AVMediaTypeVideo];
- for ( AVCaptureDevice *device in devices )
- if ( device.position == position ){
- return device;
- }
- return nil;
- }
3、拍照拿到相應圖片:
- - (void)photoBtnDidClick
- {
- AVCaptureConnection *conntion = [self.imageOutput connectionWithMediaType:AVMediaTypeVideo];
- if (!conntion) {
- NSLog(@"拍照失敗!");
- return;
- }
- [self.imageOutput captureStillImageAsynchronouslyFromConnection:conntion completionHandler:^(CMSampleBufferRef imageDataSampleBuffer, NSError *error) {
- if (imageDataSampleBuffer == nil) {
- return ;
- }
- NSData *imageData = [AVCaptureStillImageOutput jpegStillImageNSDataRepresentation:imageDataSampleBuffer];
- self.image = [UIImage imageWithData:imageData];
- [self.session stopRunning];
- [self.view addSubview:self.cameraImageView];
- }
4、前后置攝像頭的切換
- - (void)changeCamera{
- NSUInteger cameraCount = [[AVCaptureDevice devicesWithMediaType:AVMediaTypeVideo] count];
- if (cameraCount > 1) {
- NSError *error;
- //給攝像頭的切換添加翻轉動畫
- CATransition *animation = [CATransition animation];
- animation.duration = .5f;
- animation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut];
- animation.type = @"oglFlip";
- AVCaptureDevice *newCamera = nil;
- AVCaptureDeviceInput *newInput = nil;
- //拿到另外一個攝像頭位置
- AVCaptureDevicePosition position = [[_input device] position];
- if (position == AVCaptureDevicePositionFront){
- newCamera = [self cameraWithPosition:AVCaptureDevicePositionBack];
- animation.subtype = kCATransitionFromLeft;//動畫翻轉方向
- }
- else {
- newCamera = [self cameraWithPosition:AVCaptureDevicePositionFront];
- animation.subtype = kCATransitionFromRight;//動畫翻轉方向
- }
- //生成新的輸入
- newInput = [AVCaptureDeviceInput deviceInputWithDevice:newCamera error:nil];
- [self.previewLayer addAnimation:animation forKey:nil];
- if (newInput != nil) {
- [self.session beginConfiguration];
- [self.session removeInput:self.input];
- if ([self.session canAddInput:newInput]) {
- [self.session addInput:newInput];
- self.input = newInput;
- } else {
- [self.session addInput:self.input];
- }
- [self.session commitConfiguration];
- } else if (error) {
- NSLog(@"toggle carema failed, error = %@", error);
- }
- }
- }
5、相機的其它參數(shù)設置
- //AVCaptureFlashMode 閃光燈
- //AVCaptureFocusMode 對焦
- //AVCaptureExposureMode 曝光
- //AVCaptureWhiteBalanceMode 白平衡
- //閃光燈和白平衡可以在生成相機時候設置
- //曝光要根據(jù)對焦點的光線狀況而決定,所以和對焦一塊寫
- //point為點擊的位置
- - (void)focusAtPoint:(CGPoint)point{
- CGSize size = self.view.bounds.size;
- CGPoint focusPoint = CGPointMake( point.y /size.height ,1-point.x/size.width );
- NSError *error;
- if ([self.device lockForConfiguration:&error]) {
- //對焦模式和對焦點
- if ([self.device isFocusModeSupported:AVCaptureFocusModeAutoFocus]) {
- [self.device setFocusPointOfInterest:focusPoint];
- [self.device setFocusMode:AVCaptureFocusModeAutoFocus];
- }
- //曝光模式和曝光點
- if ([self.device isExposureModeSupported:AVCaptureExposureModeAutoExpose ]) {
- [self.device setExposurePointOfInterest:focusPoint];
- [self.device setExposureMode:AVCaptureExposureModeAutoExpose];
- }
- [self.device unlockForConfiguration];
- //設置對焦動畫
- _focusView.center = point;
- _focusView.hidden = NO;
- [UIView animateWithDuration:0.3 animations:^{
- _focusView.transform = CGAffineTransformMakeScale(1.25, 1.25);
- }completion:^(BOOL finished) {
- [UIView animateWithDuration:0.5 animations:^{
- _focusView.transform = CGAffineTransformIdentity;
- } completion:^(BOOL finished) {
- _focusView.hidden = YES;
- }];
- }];
- }
- }
6、遇到的一些坑和解決辦法
1) 前后置攝像頭的切換
前后值不能切換,各種嘗試找了半天沒找到有原因。后來發(fā)現(xiàn)我在設置圖片尺寸的時候設置為1080P [self.session canSetSessionPreset: AVCaptureSessionPreset1920x1080] ,前置攝像頭并不支持這么大的尺寸,所以就不能切換前置攝像頭。我驗證了下 前置攝像頭最高支持720P,720P以內可自由切換。
當然也可以在前后置攝像頭切換的時候,根據(jù)前后攝像頭來設置不同的尺寸,這里不在贅述。
2)焦點位置
CGPoint focusPoint = CGPointMake( point.y /size.height ,1-point.x/size.width );
setExposurePointOfInterest:focusPoint 函數(shù)后面Point取值范圍是取景框左上角(0,0)到取景框右下角(1,1)之間。官方是這么寫的:
The value of this property is a CGPoint that determines the receiver's focus point of interest, if it has one. A value of (0,0) indicates that the camera should focus on the top left corner of the image, while a value of (1,1) indicates that it should focus on the bottom right. The default value is (0.5,0.5).
我也試了按這個來但位置就是不對,只能按上面的寫法才可以。前面是點擊位置的y/PreviewLayer的高度,后面是1-點擊位置的x/PreviewLayer的寬度
3)對焦和曝光
我在設置對焦是 先設置了模式setFocusMode,后設置對焦位置,就會導致很奇怪的現(xiàn)象,對焦位置是你上次點擊的位置。所以一定要先設置位置,再設置對焦模式。
曝光同上
7、寫在最后
附上demo:https://github.com/nanshanyi/photographDemo
常用到的基本就這么多,寫的并不完善,有什么不對的,歡迎大家批評指正,共同學習。