一、UIImagePickerController
UIImagePickerController是UIKit框架里面的一个class，通过这个系统提供的class我们可以简单的是实现拍照、录制视频和音频。
三个步骤：
- 当前控制器
present一个UIImagePickerController类- 在当前界面就可以拍照、录制视频和音频
- 实现
UIImagePickerController的delegate，在delegate可以获取录制的视频和音频，来进行相应的操作.
定制化UIImagePickerController
// 查看摄像头是否可用
if ([UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypeCamera] == NO) {
return;
}
UIImagePickerController *imagePick = [[UIImagePickerController alloc]init];
imagePick.sourceType = UIImagePickerControllerSourceTypeCamera;
// 我们还可以设置照片和视频拍摄的质量、是否可以开启闪光灯、是否开启手电筒
// 还可以单独设置只支持视频模式
// imagePick.mediaTypes = [[NSArray alloc] initWithObjects: (NSString *) kUTTypeMovie, nil];
imagePick.mediaTypes = [UIImagePickerController availableMediaTypesForSourceType:UIImagePickerControllerSourceTypeCamera];
// UINavigationControllerDelegate,UIImagePickerControllerDelegate;
imagePick.delegate = self;
//拍照或者录制结束后是否可以编辑
imagePick.allowsEditing = NO;
[self presentViewController:imagePick animated:YES completion:nil];
界面的自定义
cameraOverlayView属性可以自定义UIImagePickerController界面顶部的控件，但是只在UIImagePickerController的mediaTypes为UIImagePickerControllerSourceTypeCamera时可用。
实现UIImagePickerController的delegate
- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary<NSString *,id> *)info{
NSString *mediaType = [info objectForKey:UIImagePickerControllerMediaType];
UIImage *originalImage, *editedImage, *imageToSave;
// 处理图片
if ([mediaType isEqualToString:(NSString *)kUTTypeImage]) {
editedImage = info[UIImagePickerControllerOriginalImage];
originalImage = info[UIImagePickerControllerEditedImage];
if (editedImage) {
imageToSave = editedImage;
}else{
imageToSave = originalImage;
}
UIImageWriteToSavedPhotosAlbum(imageToSave, nil, nil, nil);
}
//处理视频
if ([mediaType isEqualToString:(NSString *)kUTTypeMovie]) {
NSString *url = [info[UIImagePickerControllerMediaURL] path];
if (UIVideoAtPathIsCompatibleWithSavedPhotosAlbum(url)) {
UISaveVideoAtPathToSavedPhotosAlbum(url, nil, nil, nil);
}
}
[picker dismissViewControllerAnimated:YES completion:nil];
}
二、AVCaptureSession & AVCaptureMovieFileOutput
要获取摄像机捕捉到的视频或者麦克风捕捉到的音频，我们需要对象表示inputs和outputs，并使用AVCaptureSession的实例来协调它们之间的数据流。
- AVCaptureDevice 对象，表示声音或者视频采集设备，对应摄像头和麦克风。
- AVCaptureInput的子类，配置输入端口。
- AVCaptureOutput的子类， 输出采集到的视频或者图像。
- AVCaptureSession来协调从输入到输出的数据流。
步骤一： 创建AVCaptureDevice 对象
因为我们需要录制视频和音频所以我们需要视频的AVCaptureDevice和音频的AVCaptureDevice。
//我们同时获取了前摄像头和后摄像头因为等会我们要手动切换
//获取音频device
-(AVCaptureDevice *)audioDevice{
if (!_audioDevice) {
_audioDevice = [AVCaptureDevice devicesWithMediaType:AVMediaTypeAudio].firstObject;
}
return _audioDevice;
}
//后置摄像头
-(AVCaptureDevice *)backVideoDevice{
if (!_backVideoDevice) {
_backVideoDevice = [self getDeviceBy:AVCaptureDevicePositionBack];
if ([self.currentVideoDevice isTorchAvailable] && [_backVideoDevice isTorchModeSupported:AVCaptureTorchModeOn]) {
//可以设置是否开启闪光灯，是否开始HDR、视频防抖、白平衡什么的
//设置device之前需要先 lockForConfiguration
if ([_backVideoDevice lockForConfiguration:NULL]==YES) {
self.currentVideoDevice.torchMode = AVCaptureTorchModeOn;
[self.currentVideoDevice unlockForConfiguration];
}
}
}
}
return _backVideoDevice;
}
//前置摄像头
-(AVCaptureDevice *)frontVideoDevice{
if (!_frontVideoDevice) {
_frontVideoDevice = [self getDeviceBy:AVCaptureDevicePositionFront];
}
return _frontVideoDevice;
}
步骤二、配置inputs
每个AVCaptureDevice对应一个input。
//audio input
- (AVCaptureDeviceInput *)audioInput{
if (!_audioInput) {
NSError *error = nil;
_audioInput = [AVCaptureDeviceInput deviceInputWithDevice:self.audioDevice error:&error];
}
return _audioInput;
}
- (AVCaptureDeviceInput *)videoInput{
if (!_videoInput) {
NSError *error = nil;
_videoInput = [AVCaptureDeviceInput deviceInputWithDevice:self.currentVideoDevice error:&error];
}
return _videoInput;
}
步骤三: 写入文件
Output有四种：
AVCaptureMovieFileOutput写入文件
AVCaptureVideoDataOutput加工视频输出
AVCaptureAudioDataOutput加工音频输出
AVCaptureStillImageOutput捕捉输出的图像
写入文件只需要AVCaptureMovieFileOutput就可以了。
// output
- (AVCaptureMovieFileOutput *)movieFileOutput{
if (!_movieFileOutput) {
_movieFileOutput = [[AVCaptureMovieFileOutput alloc]init];
//CMTime drution = CMTimeMake(1, 60);
//设置视频录制时间限制 kCMTimeInvalid(无限制)
_movieFileOutput.maxRecordedDuration = kCMTimeInvalid;
// 文件大小限制
//_movieFileOutput.maxRecordedFileSize = 1024 * 1024;
AVCaptureConnection *videoConnection = [_movieFileOutput connectionWithMediaType:AVMediaTypeVideo];
// 是否支持科学防抖
if ([videoConnection isVideoStabilizationSupported]) {
videoConnection.preferredVideoStabilizationMode = AVCaptureVideoStabilizationModeAuto;
}
videoConnection.videoOrientation = self.previewLayer.connection.videoOrientation;
}
return _movieFileOutput;
}
步骤四： 获取AVCaptureSession
- (AVCaptureSession *)session{
if (!_session) {
_session = [[AVCaptureSession alloc]init];
// 设置视频质量
if ([_session canSetSessionPreset:AVCaptureSessionPresetLow]) {
[_session setSessionPreset:AVCaptureSessionPresetLow];
}
//增加videoinput
if ([_session canAddInput:self.videoInput]) {
[_session addInput:self.videoInput];
}
//增加videoinput
if ([_session canAddInput:self.audioInput]) {
[_session addInput:self.audioInput];
}
//增加fileOutput
if ([_session canAddOutput:self.movieFileOutput]) {
[_session addOutput:self.movieFileOutput];
}
}
return _session;
}
这个地方需要注意下，每次我们更改AVCaptureSession的属性的时候我们都需要：
[session beginConfiguration];
// Remove an existing capture device.
// Add a new capture device.
// Reset the preset.
[session commitConfiguration];
现在就可以录制视频并写入文件了
为了实时查看我们录制的内容，我们加一个预览层。
-(AVCaptureVideoPreviewLayer *)previewLayer{
if (!_previewLayer) {
_previewLayer = [[AVCaptureVideoPreviewLayer alloc] initWithSession:self.session];
_previewLayer.frame = [UIScreen mainScreen].bounds;
_previewLayer.videoGravity = AVLayerVideoGravityResizeAspectFill;
_previewLayer.connection.videoOrientation = AVCaptureVideoOrientationPortrait;
}
return _previewLayer;
}
在控制器里面调用session的startRuning方法，这个时候只是采集到了视频显示在了预览层上面，并未开始录制。
- (void)viewDidLoad {
[super viewDidLoad];
self.recodingView.delegate = self;
[self.view.layer insertSublayer:self.previewLayer atIndex:0];
[self.session startRunning];
}
点击录制视频,recodingView是我自定义的控件。
-(void)writePath{
if ([self.movieFileOutput isRecording] ) {
[self.movieFileOutput stopRecording];
return;
}
NSDateFormatter * dateFormatter = [[NSDateFormatter alloc] init ];
[dateFormatter setDateFormat:@"yyyyMMddHHmmss"];
NSString * fileName = [[dateFormatter stringFromDate:[NSDate date]] stringByAppendingString:@".mov"];
NSString * filePath = [[NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) lastObject] stringByAppendingPathComponent:fileName];
NSURL *filePathUrl = [NSURL fileURLWithPath:filePath];
//写文件到指定的路径，并设置代理
[self.movieFileOutput startRecordingToOutputFileURL:filePathUrl recordingDelegate:self];
}
设置代理,在视频录制的过程中会发生许多情况，比如说突然来电话，摄像头被其他程序占用，系统会发送相应的通知给我们。
- (void)captureOutput:(AVCaptureFileOutput *)captureOutput
didFinishRecordingToOutputFileAtURL:(NSURL *)outputFileURL
fromConnections:(NSArray *)connections
error:(NSError *)error{
BOOL recordSuccessfully = YES;
if ([error code] != noErr) {
id value = [[error userInfo] objectForKey:AVErrorRecordingSuccessfullyFinishedKey];
if (value) {
recordSuccessfully = [value boolValue];
}
}
// 有error的话 有可能也是录制成功了
/*
AVErrorMaximumDurationReached 时间限制
AVErrorMaximumFileSizeReached 文件大小限制
AVErrorDiskFull 磁盘已满
AVErrorDeviceWasDisconnected device连接失败
AVErrorSessionWasInterrupted 被切断（比如说来电话了）
*/
}
