一、大致流程：
1、创建AVCaptureSession对象。
2、使用AVCaptureDevice的静态方法获得需要使用的设备，例如拍照和录像就需要获得摄像头设备，录音就要获得麦克风设备。
3、利用输入设备AVCaptureDevice初始化AVCaptureDeviceInput对象。
4、添加一个音频输入到会话（使用[[AVCaptureDevice devicesWithMediaType:AVMediaTypeAudio] firstObject]获得输入设备，然后根据此输入设备创建一个设备输入对象），在拍照程序中已经添加了视频输入所以此时不需要添加视频输入。
5、将数据输入对象AVCaptureDeviceInput、数据输出对象AVCaptureOutput添加到媒体会话管理对象AVCaptureSession中。
6、创建视频预览图层AVCaptureVideoPreviewLayer并指定媒体会话，添加图层到显示容器中，调用AVCaptureSession的startRuning方法开始捕获。
7、创建一个音乐播放文件输出对象AVCaptureMovieFileOutput取代原来的照片输出对象
8、将捕获到的视频数据写入到临时文件并在停止录制之后保存到相簿（通过AVCaptureMovieFileOutput的代理方法）。
二、代码：
1、 //初始化子�视图
func initSubViews(){
movieView = UIView(frame: CGRectMake(0, (view.bounds.height-300)/2, view.bounds.width, 300))
movieView.backgroundColor = UIColor.whiteColor()
view.addSubview(movieView)
print("\(view.bounds.height)")
movieView.addGestureRecognizer(UITapGestureRecognizer(target: self, action: "settingFocusCorsor:"))
focusCursor = UIImageView(frame: CGRectMake(movieView.bounds.width/2-movieView.bounds.height/4, movieView.bounds.height/4, movieView.bounds.height/2, movieView.bounds.height/2))
focusCursor.image = UIImage(named: "camera_focus_red.png")
movieView.addSubview(focusCursor)
focusCursor.alpha = 0
takeButton = UIButton()
takeButton.backgroundColor = UIColor.orangeColor()
takeButton.setTitle("录制", forState: UIControlState.Normal)
takeButton.addTarget(self, action: "beginRecorderMovie:", forControlEvents: UIControlEvents.TouchUpInside)
view.addSubview(takeButton)
takeButton.snp_makeConstraints { (make) -> Void in
make.top.equalTo(150)
make.left.equalTo(50)
make.width.equalTo(60)
make.height.equalTo(30)
}
let button = UIButton()
button.backgroundColor = UIColor.orangeColor()
button.setTitle("切换摄像头", forState: UIControlState.Normal)
button.addTarget(self, action: "changeCamrel", forControlEvents: UIControlEvents.TouchUpInside)
view.addSubview(button)
button.snp_makeConstraints { (make) -> Void in
make.top.equalTo(movieView.snp_bottom).offset(20)
make.left.equalTo(50)
make.width.equalTo(100)
make.height.equalTo(30)
}
}
2、3、4、5、6步骤的代码：
func initCapture(){
//创建AVCaptureSession对象
captureSession = AVCaptureSession()
if captureSession.canSetSessionPreset(AVCaptureSessionPreset1280x720){
captureSession.sessionPreset = AVCaptureSessionPreset1280x720
}
let captureDeive = getCameraDeviceWithPosition(.Back)
if captureDeive.position != .Back {
print("获取后置摄像头失败")
return
}
//添加一个音频设备
let audioCaptureDevice = AVCaptureDevice.devicesWithMediaType(AVMediaTypeAudio).first as!
AVCaptureDevice
//根据使用设备初始化输出设备对象audioCaptureDevice
do {
captureDeviceInput = try AVCaptureDeviceInput(device: captureDeive)
} catch {
print("获取输出设备失败")
return
}
do {
audioCaptureDeviceInput = try AVCaptureDeviceInput(device: audioCaptureDevice )
} catch {
print("获取输出对象失败")
return
}
//初始化输出对象，用于获得输出数据
captureMovieFileOutPut = AVCaptureMovieFileOutput()
//将设备添加到会话层
if captureSession.canAddInput(captureDeviceInput) {
captureSession.addInput(captureDeviceInput)
captureSession.addInput(audioCaptureDeviceInput)
if let captureConnection = captureMovieFileOutPut.connectionWithMediaType(AVMediaTypeAudio){
if captureConnection.supportsVideoStabilization{
captureConnection.preferredVideoStabilizationMode = .Auto
}
}
}
//将设备添加到会话中
if captureSession.canAddOutput(captureMovieFileOutPut){
captureSession.addOutput(captureMovieFileOutPut)
}
//创建视频浏览层，用于实时展示摄像头状态
captureVideoPreviewLayer = AVCaptureVideoPreviewLayer(session: captureSession )
let layer = movieView.layer
layer.masksToBounds = true
captureVideoPreviewLayer.frame = layer.bounds
captureVideoPreviewLayer.videoGravity = AVLayerVideoGravityResizeAspectFill
//将视频预览层添加到界面中
layer.insertSublayer(captureVideoPreviewLayer, above: focusCursor.layer)
//添加设备区域改变通知
//注意添加区域改变捕获通知必须首先设置设备允许捕获
addNotificationToCaptureDevice(captureDeive)
}
7、8的步骤代码:
//录制按钮
func beginRecorderMovie(button:UIButton){
//根据设备输出链接
let captureConnection = captureMovieFileOutPut.connectionWithMediaType(AVMediaTypeAudio)
//根据连接获得设备输出的数据
if !captureMovieFileOutPut.recording {
button.setTitle("录制中", forState: UIControlState.Normal)
//enableRotation = false //声明的时候默认为false
//如果有多任务就开启多任务
if UIDevice.currentDevice().multitaskingSupported {
backgroundTaskIdentifier = UIApplication.sharedApplication().beginBackgroundTaskWithExpirationHandler(nil)
}
//预览图层与视频方向保持一致
captureConnection.videoOrientation = captureVideoPreviewLayer.connection.videoOrientation
let outputFielPath = NSTemporaryDirectory() + "myMovie.mov"
let url = NSURL(fileURLWithPath:outputFielPath)
captureMovieFileOutPut.startRecordingToOutputFileURL(url, recordingDelegate: self)
} else {
button.setTitle("录制", forState: UIControlState.Normal)
captureMovieFileOutPut.stopRecording()
}
}
//切换摄像头
func changeCamrel(){
//获得设备
let currentDevice = captureDeviceInput.device
//获得设备位置
let currentPosition = currentDevice.position
//改变设备发出通知
NSNotificationCenter.defaultCenter().removeObserver(self, name: AVCaptureDeviceSubjectAreaDidChangeNotification, object: currentDevice)
var toChangePosition = AVCaptureDevicePosition.Front
if currentPosition == AVCaptureDevicePosition.Unspecified || currentPosition == AVCaptureDevicePosition.Front {
toChangePosition = AVCaptureDevicePosition.Back
}
let toChangeDevice = getCameraDeviceWithPosition(toChangePosition)
addNotificationToCaptureDevice(toChangeDevice)
//获得要调整的输入对象
var toChangeDeviceInput :AVCaptureDeviceInput!
do {
toChangeDeviceInput = try AVCaptureDeviceInput(device: toChangeDevice)
} catch {}
//改变配置之前一定要先开启配置，配置完成后提交配置改变
captureSession.beginConfiguration()
//移除原有输入对象
captureSession.removeInput(captureDeviceInput)
//添加新的输入对象
if captureSession.canAddInput(toChangeDeviceInput){
captureSession.addInput(toChangeDeviceInput)
captureDeviceInput = toChangeDeviceInput
}
//提交会话配置
captureSession.commitConfiguration()
}
// 获取指定摄像头
func getCameraDeviceWithPosition(position:AVCaptureDevicePosition) -> AVCaptureDevice{
let cameras = AVCaptureDevice.devicesWithMediaType(AVMediaTypeVideo)
for camera in cameras {
if camera.position == position {
return camera as! AVCaptureDevice
}
}
return cameras.first as! AVCaptureDevice
}
//手势获取焦点
func settingFocusCorsor(tap:UITapGestureRecognizer){
let point = tap.locationInView(tap.view)
//将UI坐标转化为摄像头坐标
let cameraPoint = captureVideoPreviewLayer.captureDevicePointOfInterestForPoint(point)
setFocusCursorWithPoint(point)
focusWithMode(.AutoFocus, exposureMode:.AutoExpose, point: cameraPoint)
}
//设置聚焦光标位置
func setFocusCursorWithPoint(point:CGPoint){
focusCursor.center = point
focusCursor.transform = CGAffineTransformMakeScale(1.2, 1.2)
focusCursor.alpha = 1
UIView.animateWithDuration(1, animations: { () -> Void in
self.focusCursor.transform = CGAffineTransformMakeScale(1, 1)
}) { (finish) -> Void in
self.focusCursor.alpha = 1
}
}
//给设备添加通知
func addNotificationToCaptureDevice(captureDevice:AVCaptureDevice){
changeDeviceProperty { (captureDevice) -> Void in
captureDevice.subjectAreaChangeMonitoringEnabled = true
}
}
//设置焦点
func focusWithMode(focusModel:AVCaptureFocusMode,exposureMode:AVCaptureExposureMode,point:CGPoint){
changeDeviceProperty { (captureDevice) -> Void in
if captureDevice.isFocusModeSupported(focusModel) {
captureDevice.focusMode = focusModel
}
if captureDevice.isExposureModeSupported(exposureMode) {
captureDevice.exposureMode = exposureMode
}
captureDevice.exposurePointOfInterest = point
captureDevice.focusPointOfInterest = point
}
}
//通知
func areaChange(notification:NSNotification){
print("设备区域改变")
}
//改变设备属性的统一操作方法
func changeDeviceProperty(closure :(captureDevice:AVCaptureDevice) -> Void) {
let cDevice = captureDeviceInput.device
do {
try cDevice.lockForConfiguration()
closure(captureDevice: cDevice)
cDevice.unlockForConfiguration()
} catch {
print("设置设备属性的过程中发生错误")
}
}
}
extension ViewController :AVCaptureFileOutputRecordingDelegate{
//视频输出代理
func captureOutput(captureOutput: AVCaptureFileOutput!, didFinishRecordingToOutputFileAtURL outputFileURL: NSURL!, fromConnections connections: [AnyObject]!, error: NSError!) {
print("录制完毕")
// enableRotation = false
let lastBackgroundTaskIdentifier = backgroundTaskIdentifier
backgroundTaskIdentifier = UIBackgroundTaskInvalid
let assetsLibrary = ALAssetsLibrary()
assetsLibrary.writeVideoAtPathToSavedPhotosAlbum(outputFileURL) { (assetUrl, error) -> Void in
if error != nil {
print("保存相册过程中失败")
}
do {
try NSFileManager.defaultManager().removeItemAtURL(outputFileURL)
}catch{}
if lastBackgroundTaskIdentifier != UIBackgroundTaskInvalid {
UIApplication.sharedApplication().endBackgroundTask(lastBackgroundTaskIdentifier)
}
}
}
func captureOutput(captureOutput: AVCaptureFileOutput!, didStartRecordingToOutputFileAtURL fileURL: NSURL!, fromConnections connections: [AnyObject]!) {
print("开始录制")
}
//是否支持旋转
override func shouldAutorotate() -> Bool {
return enableRotation
}
//屏幕旋转时调整视屏预览图层方向
override func willRotateToInterfaceOrientation(toInterfaceOrientation: UIInterfaceOrientation, duration: NSTimeInterval) {
let captureConnection = captureVideoPreviewLayer.connection
switch toInterfaceOrientation {
case .Portrait:
captureConnection.videoOrientation = .Portrait
case .PortraitUpsideDown:
captureConnection.videoOrientation = .PortraitUpsideDown
case .LandscapeLeft:
captureConnection.videoOrientation = .LandscapeRight
case .LandscapeRight:
captureConnection.videoOrientation = .LandscapeLeft
default:
print("")
}
}
//旋转后重新设置大小
override func didRotateFromInterfaceOrientation(fromInterfaceOrientation: UIInterfaceOrientation) {
captureVideoPreviewLayer.frame = movieView.bounds
}
}
效果图：
出来效果图了，大家看一下。（没图纯代码，我怎么知道是否我需要的，嘻嘻）
自学笔记，适当观看切勿入歧途。