1、实现视频录像的几种方式
- UIImagePickerController
- AVCaptureSession + AVCaptureMovieFileOutput
- AVCaptureSession + AVAssetWriter
UIImagePickerController系统封装好的UI，直接输出视频文件
AVCaptureSession + AVCaptureMovieFileOutput 支持自定义UI，直接输出视频文件
AVCaptureSession + AVAssetWriter支持自定义UI，输出的是视频帧和音频帧，需要自己处理，拼接成视频文件
2、系统封装好的 UIImagePickerController
2.1 UIImagePickerController方式
是目前集成相机最简单的方式，但是不知道自定义相机，这是一个封装了完整视频捕获管线和相机 UI 的 view controller。
2.1.1 info.plist 设置
Privacy - Microphone Usage Description 是否允许设备调用您的麦克风？
Privacy - Camera Usage Description 是否允许设备调用您的相机?
2.1.2 是否支持相机录制
在实例化相机之前，首先要检查设备是否支持相机录制：
/// 判断是否支持录像
if UIImagePickerController.isSourceTypeAvailable(UIImagePickerController.SourceType.camera) {
if let availableMediaTypes = UIImagePickerController.availableMediaTypes(for: UIImagePickerController.SourceType.camera) {
if !availableMediaTypes.contains("public.movie") {
print("不支持录像")
return
}
}
}
2.1.3 权限确认
视频权限和音频权限确认
/// 视频权限
AVCaptureDevice.requestAccess(for: AVMediaType.video) {[weak self] (granted) in
guard let weakSelf = self else {
return
}
if !granted {
print("无权限访问相机")
return
}
// 录音权限
AVCaptureDevice.requestAccess(for: AVMediaType.audio) {[weak self] (granted) in
guard let weakSelf = self else {
return
}
if !granted {
print("无权限访问麦克风")
return
}
// 进入录像页面
weakSelf.present(weakSelf.pickerController, animated: true, completion: nil)
}
}
2.1.4 创建UIImagePickerController 对象
然后创建一个 UIImagePickerController 对象，设置好代理便于进一步处理录制好的视频 (比如存到相册) 以及对于用户关闭相机作出响应：
lazy var pickerController: UIImagePickerController = {
let pickerController = UIImagePickerController()
// 设置图像选取控制器的来源模式为相机模式 相机、相册
pickerController.sourceType = UIImagePickerController.SourceType.camera
// 设置相机的类型 public.image public.movie
pickerController.mediaTypes = ["public.movie",]
// 设置摄像头 前、后
pickerController.cameraDevice = UIImagePickerController.CameraDevice.rear;
// 设置摄像头闪光灯模式
// pickerController.cameraFlashMode = UIImagePickerController.CameraFlashMode.auto
// 设置摄像图像品质
pickerController.videoQuality = UIImagePickerController.QualityType.typeHigh
// 设置最长摄像时间
pickerController.videoMaximumDuration = 30
// 允许用户进行编辑
pickerController.allowsEditing = false
// 设置委托对象
pickerController.delegate = self
return pickerController
}()
2.1.5 UIImagePickerControllerDelegate代理的实现
extension RecordVideoViewController: UIImagePickerControllerDelegate, UINavigationControllerDelegate
{
func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [UIImagePickerController.InfoKey : Any]) {
let mediaType = info[UIImagePickerController.InfoKey.mediaType] as! String
if mediaType == "public.movie" {
// 获取视频文件的url
let mediaURL = info[UIImagePickerController.InfoKey.mediaURL] as! NSURL
// 视频文件的地址
let pathString = mediaURL.relativePath
print("视频地址：" + pathString!)
DispatchQueue.global().async {
//判断能不能保存到相簿
if (UIVideoAtPathIsCompatibleWithSavedPhotosAlbum(pathString!)) {
//保存视频到相簿
UISaveVideoAtPathToSavedPhotosAlbum(pathString!, self, #selector(self.saveVideo(videoPath:didFinishSavingWithError:contextInfo:)), nil)
}
DispatchQueue.main.async {
picker.dismiss(animated: true, completion: nil)
}
}
}
}
@objc private func saveVideo(videoPath:String, didFinishSavingWithError error: NSError?, contextInfo: AnyObject) {
if error != nil{
print("保存视频 失败")
}else{
print("保存视频 成功")
}
}
}
3、自定义相机 AVFoundation
AVFoundation 中关于视频捕获的主要的类是 AVCaptureSession。它负责调配影音输入与输出之间的数据流
3.1 AVCaptureSession + AVCaptureMovieFileOutput方式
3.1.1 info.plist 设置
Privacy - Microphone Usage Description 是否允许设备调用您的麦克风？
Privacy - Camera Usage Description 是否允许设备调用您的相机?
3.1.2 权限确认
视频权限和音频权限确认
/// 视频权限
AVCaptureDevice.requestAccess(for: AVMediaType.video) {[weak self] (granted) in
guard let weakSelf = self else {
return
}
if !granted {
print("无权限访问相机")
return
}
// 录音权限
AVCaptureDevice.requestAccess(for: AVMediaType.audio) {[weak self] (granted) in
guard let weakSelf = self else {
return
}
if !granted {
print("无权限访问麦克风")
return
}
}
}
3.1.3 创建AVCaptureSession
使用一个 capture session，你需要先实例化，添加输入与输出，设置分辨率，接着启动从输入到输出之间的数据流：
/// 视频捕获会话
let captureSession = AVCaptureSession()
3.1.4 添加视频输入设备
//MARK: 添加视频输入设备
func addInputVideo() {
self.captureSession.beginConfiguration()
let videoDevice = AVCaptureDevice.default(for: AVMediaType.video)!
let videoInput = try? AVCaptureDeviceInput(device: videoDevice)
if self.captureSession.canAddInput(videoInput!) {
self.captureSession.addInput(videoInput!)
}
self.captureSession.commitConfiguration()
}
3.1.5 添加音频输入设备
//MARK: 添加音频输入设备
func addInputAudio() {
self.captureSession.beginConfiguration()
let audioDevice = AVCaptureDevice.default(for: AVMediaType.audio)
let audioInput = try? AVCaptureDeviceInput(device: audioDevice!)
if self.captureSession.canAddInput(audioInput!) {
self.captureSession.addInput(audioInput!);
}
self.captureSession.commitConfiguration()
}
3.1.6 设置分辨率
//MARK: 设置分辨率
func setPreset() {
self.captureSession.beginConfiguration()
if self.captureSession.canSetSessionPreset(AVCaptureSession.Preset.hd1280x720) {
self.captureSession.sessionPreset = AVCaptureSession.Preset.hd1280x720
}
self.captureSession.commitConfiguration()
}
3.1.7 设置输出
//MARK: 设置输出
func setOutput() {
self.captureSession.beginConfiguration()
if let captureConnection = self.fileOutput.connection(with: AVMediaType.video) {
// 防止抖动
if captureConnection.isVideoStabilizationSupported {
captureConnection.preferredVideoStabilizationMode = .auto
}
// 预览图层和视频方向保存一直
captureConnection.videoOrientation = (self.videoLayer.connection?.videoOrientation)!
}
// 视频时长默认10秒，此设置不受限制
self.fileOutput.movieFragmentInterval = CMTime.invalid
if self.captureSession.canAddOutput(self.fileOutput) {
self.captureSession.addOutput(self.fileOutput)
}
self.captureSession.commitConfiguration()
}
3.1.8 设置显示采集画面，并开始采集
/// 摄像头采集画面
lazy var videoLayer: AVCaptureVideoPreviewLayer = {
let videoLayer = AVCaptureVideoPreviewLayer(session: self.captureSession)
videoLayer.videoGravity = AVLayerVideoGravity.resizeAspectFill
videoLayer.masksToBounds = true
return videoLayer
}()
//使用AVCaptureVideoPreviewLayer可以将摄像头的拍摄的实时画面显示在ViewController上
DispatchQueue.main.async {
weakSelf.videoLayer.frame = weakSelf.view.bounds
weakSelf.view.layer.addSublayer(weakSelf.videoLayer)
weakSelf.captureSession.startRunning()
//创建按钮
weakSelf.setUI()
}
3.1.9 开始录制
//MARK: 开始录制
@objc func starRecordVideo() {
if !self.isRecording {
//设置录像的保存地址
let filePath = self.getNewPath(videoTyle: AVFileType.mp4)
let fileURL = URL(fileURLWithPath: filePath)
//启动视频编码输出
fileOutput.startRecording(to:fileURL, recordingDelegate: self )
//记录状态：录像中...
self.isRecording = true
//开始、结束按钮颜色改变
self.starButton.backgroundColor = UIColor.lightGray
self.starButton.isEnabled = false
self.stopButton.backgroundColor = UIColor.blue
self.stopButton.isEnabled = true
}
}
3.1.10 结束录制
//MARK: 结束录制
@objc func stopRecordVideo() {
if self.isRecording {
//停止视频编码输出
fileOutput.stopRecording()
//记录状态：录像结束
self .isRecording = false
//开始、结束按钮颜色改变
self.starButton.backgroundColor = UIColor.red
self.starButton.isEnabled = true
self.stopButton.backgroundColor = UIColor.lightGray
self.stopButton.isEnabled = false
}
}
3.1.11 AVCaptureFileOutputRecordingDelegate
//MARK: AVCaptureFileOutputRecordingDelegate
extension RecordVideo2ViewController:AVCaptureFileOutputRecordingDelegate
{
// 开始录制
func fileOutput(_ output: AVCaptureFileOutput, didStartRecordingTo fileURL: URL, from connections: [AVCaptureConnection]) {
}
// 结束录制
func fileOutput(_ output: AVCaptureFileOutput, didFinishRecordingTo outputFileURL: URL, from connections: [AVCaptureConnection], error: Error?) {
// 获取视频文件大小
self.getVideoSize(videoUrl: outputFileURL)
// 获取视频文件时长
self.getVideoLength(videoUrl: outputFileURL)
// 保存相册一份，便于测试
self.saveVideoToAlbum(videoUrl: outputFileURL)
// 获取指定时间的帧
self.getImage(videoUrl: outputFileURL, cmtime: CMTimeMake(value: 1, timescale: 1), width: 300)
// 压缩视频
let newPath = self.getNewPath(videoTyle: AVFileType.mov)
print(newPath)
self.convertVideo(inputURL: outputFileURL, outputURL: URL(fileURLWithPath: newPath), presetName: AVAssetExportPresetMediumQuality) { (success) in
if success {
print("压缩成功")
}else{
print("压缩失败")
}
}
}
}
3.2 AVCaptureSession + AVAssetWriter方式
对视频进一步了解，可以使用AVCaptureVideoDataOutput 和 AVCaptureAudioDataOutput来会各自捕获视频和音频的样本缓存，而不是AVCaptureMovieFileOutpu。
接着我们可以使用他们的代理AVCaptureVideoDataOutputSampleBufferDelegate和AVCaptureAudioDataOutputSampleBufferDelegate，可以对采样缓冲进行处理 (比如给视频加滤镜)，或者保持原样传送。
然后使用 AVAssetWriter 对象可以将样本缓存写入文件
3.2.1 info.plist 设置
Privacy - Microphone Usage Description 是否允许设备调用您的麦克风？
Privacy - Camera Usage Description 是否允许设备调用您的相机?
3.2.2 权限确认
视频权限和音频权限确认
/// 视频权限
AVCaptureDevice.requestAccess(for: AVMediaType.video) {[weak self] (granted) in
guard let weakSelf = self else {
return
}
if !granted {
print("无权限访问相机")
return
}
// 录音权限
AVCaptureDevice.requestAccess(for: AVMediaType.audio) {[weak self] (granted) in
guard let weakSelf = self else {
return
}
if !granted {
print("无权限访问麦克风")
return
}
}
}
3.2.3 创建AVCaptureSession
使用一个 capture session，你需要先实例化，添加输入与输出，设置分辨率，接着启动从输入到输出之间的数据流：
/// 视频捕获会话
let captureSession = AVCaptureSession()
3.2.4 添加视频输入设备
//MARK: 添加视频输入设备
func addInputVideo() {
self.captureSession.beginConfiguration()
let videoDevice = AVCaptureDevice.default(for: AVMediaType.video)!
let videoInput = try? AVCaptureDeviceInput(device: videoDevice)
if self.captureSession.canAddInput(videoInput!) {
self.captureSession.addInput(videoInput!)
}
self.captureSession.commitConfiguration()
}
3.2.5 添加音频输入设备
//MARK: 添加音频输入设备
func addInputAudio() {
self.captureSession.beginConfiguration()
let audioDevice = AVCaptureDevice.default(for: AVMediaType.audio)
let audioInput = try? AVCaptureDeviceInput(device: audioDevice!)
if self.captureSession.canAddInput(audioInput!) {
self.captureSession.addInput(audioInput!);
}
self.captureSession.commitConfiguration()
}
3.2.6 设置分辨率
//MARK: 设置分辨率
func setPreset() {
self.captureSession.beginConfiguration()
if self.captureSession.canSetSessionPreset(AVCaptureSession.Preset.hd1280x720) {
self.captureSession.sessionPreset = AVCaptureSession.Preset.hd1280x720
}
self.captureSession.commitConfiguration()
}
3.2.7 添加视频输出、音频输出
//MARK: 添加视频输出、音频输出
func addOutputVideoAndAudio() {
self.captureSession.beginConfiguration()
self.videoDataOutput.setSampleBufferDelegate(self, queue: self.sessionQueue!)
if self.captureSession.canAddOutput(self.videoDataOutput) {
self.captureSession.addOutput(self.videoDataOutput)
}
self.audioDataOutput.setSampleBufferDelegate(self, queue: self.sessionQueue)
if self.captureSession.canAddOutput(self.audioDataOutput) {
self.captureSession.addOutput(self.audioDataOutput)
}
self.captureSession.commitConfiguration()
}
3.2.8 设置显示采集画面，并开始采集
/// 摄像头采集画面
lazy var videoLayer: AVCaptureVideoPreviewLayer = {
let videoLayer = AVCaptureVideoPreviewLayer(session: self.captureSession)
videoLayer.videoGravity = AVLayerVideoGravity.resizeAspectFill
videoLayer.masksToBounds = true
return videoLayer
}()
//使用AVCaptureVideoPreviewLayer可以将摄像头的拍摄的实时画面显示在ViewController上
DispatchQueue.main.async {
weakSelf.videoLayer.frame = weakSelf.view.bounds
weakSelf.view.layer.addSublayer(weakSelf.videoLayer)
weakSelf.captureSession.startRunning()
//创建按钮
weakSelf.setUI()
}
3.2.9 开始录制
//MARK: 开始录制
@objc func starRecordVideo() {
if !self.isRecording {
print("开始录制")
//设置录像的保存地址
self.videoPath = self.getNewPath(videoTyle: AVFileType.mp4)
print(self.videoPath)
setAssetWriter(videoPath: self.videoPath)
//记录状态：录像中...
self.isRecording = true
//开始、结束按钮颜色改变
self.starButton.backgroundColor = UIColor.lightGray
self.starButton.isEnabled = false
self.stopButton.backgroundColor = UIColor.blue
self.stopButton.isEnabled = true
}
}
3.2.10 设置AVAssetWrite
//MARK: 设置AssetWrite
func setAssetWriter(videoPath: String) {
//设置录像的保存地址
let fileURL = URL(fileURLWithPath: videoPath)
if let assetWriter = try? AVAssetWriter.init(url: fileURL, fileType: AVFileType.mp4) {
self.assetWriter = assetWriter
var width = UIScreen.main.bounds.size.height
var height = UIScreen.main.bounds.size.width
//写入视频大小
let numPixels = width*height
//每像素比特
let bitsPerPixel:CGFloat = 12.0;
let bitsPerSecond = numPixels * bitsPerPixel;
if (false) // 是否是刘海屏
{
width = UIScreen.main.bounds.size.height - 146;
height = UIScreen.main.bounds.size.width;
}
let compressionProperties = [
// 视频尺寸*比率，10.1相当于AVCaptureSessionPresetHigh，数值越大，显示越精细
AVVideoAverageBitRateKey : bitsPerSecond,
// 设置输出帧率
AVVideoExpectedSourceFrameRateKey : 15,
// 关键帧最大间隔，1为每个都是关键帧，数值越大压缩率越高
AVVideoMaxKeyFrameIntervalKey : 15,
// 画面质量
AVVideoProfileLevelKey : AVVideoProfileLevelH264BaselineAutoLevel
] as [String : Any]
let videoCompressionSettings = [
AVVideoCodecKey : AVVideoCodecH264,
AVVideoWidthKey : width * 2,
AVVideoHeightKey : height * 2,
// AVVideoScalingModeKey : AVVideoScalingModeResizeAspectFill,
AVVideoCompressionPropertiesKey : compressionProperties
] as [String : Any]
self.assetWriterVideoInput = AVAssetWriterInput.init(mediaType: AVMediaType.video, outputSettings: videoCompressionSettings)
//expectsMediaDataInRealTime 必须设为yes，需要从capture session 实时获取数据
self.assetWriterVideoInput?.expectsMediaDataInRealTime = true
// 音频设置
let audioCompressionSettings = [
// 每个声道的比特率
AVEncoderBitRatePerChannelKey : 28000,
// 设置录音格式
AVFormatIDKey : kAudioFormatMPEG4AAC,
// 设置通道,单声道，双声道 mp3 必须双声道
AVNumberOfChannelsKey : 1,
// 设置录音采样率，8000是电话采样率，对于一般录音已经够了
AVSampleRateKey : 22050,
// 每个采样点位数,分为8、16、24、32
AVLinearPCMBitDepthKey: 16,
// 质量
AVEncoderAudioQualityKey: AVAudioQuality.medium
] as [String : Any]
self.assetWriterAudioInput = AVAssetWriterInput.init(mediaType: AVMediaType.audio, outputSettings: audioCompressionSettings)
self.assetWriterAudioInput?.expectsMediaDataInRealTime = true
if self.assetWriter!.canAdd(self.assetWriterVideoInput!) {
self.assetWriter?.add(self.assetWriterVideoInput!)
}
if self.assetWriter!.canAdd(self.assetWriterAudioInput!) {
self.assetWriter?.add(self.assetWriterAudioInput!)
}
self.canWrite = false
} else {
print("加载AVAssetWriter失败")
}
}
3.2.12 视频和音频每一帧处理
extension RecordVideo3ViewController: AVCaptureVideoDataOutputSampleBufferDelegate,AVCaptureAudioDataOutputSampleBufferDelegate
{
func captureOutput(_ output: AVCaptureOutput, didOutput sampleBuffer: CMSampleBuffer, from connection: AVCaptureConnection) {
autoreleasepool {
if !isRecording {
return
}
if connection == self.videoDataOutput.connection(with: AVMediaType.video) {
objc_sync_enter(self)
self.appendSampleBuffer(sampleBuffer: sampleBuffer, mediaType: AVMediaType.video)
objc_sync_exit(self)
}
if connection == self.audioDataOutput.connection(with: AVMediaType.audio) {
objc_sync_enter(self)
self.appendSampleBuffer(sampleBuffer: sampleBuffer, mediaType: AVMediaType.audio)
objc_sync_exit(self)
}
}
}
func appendSampleBuffer(sampleBuffer:CMSampleBuffer, mediaType:AVMediaType) {
autoreleasepool {
if (!self.canWrite && mediaType == AVMediaType.video) {
print("开始写入AVAssetWriter")
self.assetWriter?.startWriting()
self.assetWriter?.startSession(atSourceTime: CMSampleBufferGetPresentationTimeStamp(sampleBuffer))
self.canWrite = true
}
//写入视频数据
if mediaType == AVMediaType.video {
if self.assetWriterVideoInput!.isReadyForMoreMediaData {
let success = self.assetWriterVideoInput!.append(sampleBuffer)
if !success {
//停止录像
objc_sync_enter(self)
self.stopRecordVideo()
objc_sync_exit(self)
}
}
}
//写入视频数据
if mediaType == AVMediaType.audio {
if self.assetWriterAudioInput!.isReadyForMoreMediaData {
let success = self.assetWriterAudioInput!.append(sampleBuffer)
if !success {
//停止录像
objc_sync_enter(self)
self.stopRecordVideo()
objc_sync_exit(self)
}
}
}
}
}
}
3.2.13 结束录制
//MARK: 结束录制
@objc func stopRecordVideo() {
if self.isRecording {
print("结束录制")
//停止视频编码输出
if self.assetWriter != nil && self.assetWriter?.status == AVAssetWriter.Status.writing {
self.assetWriter?.finishWriting { [weak self] in
guard let weakSelf = self else {
return
}
weakSelf.canWrite = false
weakSelf.assetWriter = nil
weakSelf.assetWriterAudioInput = nil
weakSelf.assetWriterVideoInput = nil
}
}
//记录状态：录像结束
self .isRecording = false
//开始、结束按钮颜色改变
self.starButton.backgroundColor = UIColor.red
self.starButton.isEnabled = true
self.stopButton.backgroundColor = UIColor.lightGray
self.stopButton.isEnabled = false
}
}
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