使用 AVFoundation Swift 保存视频
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【中文标题】使用 AVFoundation Swift 保存视频【英文标题】：Save Video Using AVFoundation Swift 【发布时间】：2016-09-10 23:10:18 【问题描述】：您好，我学习了 Jared Davidson 的课程，使用 AVFoundation 创建自定义相机视图并保存图片。 https://www.youtube.com/watch?v=w0O3ZGUS3pk
但是，我想录制和保存视频而不是图像。有人可以在这里帮助我吗？我确信它很简单，但苹果的文档是用 Objective-C 编写的，我无法破译它。
这是我的代码。谢谢。
import UIKit
import AVFoundation
class ViewController: UIViewController
var captureSession = AVCaptureSession()
var sessionOutput = AVCaptureStillImageOutput()
var previewLayer = AVCaptureVideoPreviewLayer()
@IBOutlet var cameraView: UIView!
override func viewWillAppear(animated: Bool)
let devices = AVCaptureDevice.devicesWithMediaType(AVMediaTypeVideo)
for device in devices
if device.position == AVCaptureDevicePosition.Front
do
let input = try AVCaptureDeviceInput(device: device as! AVCaptureDevice)
if captureSession.canAddInput(input)
captureSession.addInput(input)
sessionOutput.outputSettings = [AVVideoCodecKey : AVVideoCodecJPEG]
if captureSession.canAddOutput(sessionOutput)
captureSession.addOutput(sessionOutput)
captureSession.startRunning()
previewLayer = AVCaptureVideoPreviewLayer(session: captureSession)
previewLayer.videoGravity = AVLayerVideoGravityResizeAspectFill
previewLayer.connection.videoOrientation = AVCaptureVideoOrientation.Portrait
cameraView.layer.addSublayer(previewLayer)
previewLayer.position = CGPoint(x: self.cameraView.frame.width / 2, y: self.cameraView.frame.height / 2)
previewLayer.bounds = cameraView.frame
catch
print("Error")
@IBAction func TakePhoto(sender: AnyObject)
if let videoConnection = sessionOutput.connectionWithMediaType(AVMediaTypeVideo)
sessionOutput.captureStillImageAsynchronouslyFromConnection(videoConnection, completionHandler:
buffer, error in
let imageData = AVCaptureStillImageOutput.jpegStillImageNSDataRepresentation(buffer)
UIImageWriteToSavedPhotosAlbum(UIImage(data: imageData)!, nil, nil, nil)
)
【问题讨论】：
【参考方案1】：您可以通过创建AVCaptureMovieFileOutput 并将其添加到您的捕获会话，并使您的ViewController 符合AVCaptureFileOutputRecordingDelegate 来将录制的视频保存到文件中。
此示例将 5 秒的视频录制到应用程序的 Documents 目录中名为“output.mov”的文件中。
class ViewController: UIViewController, AVCaptureFileOutputRecordingDelegate
var captureSession = AVCaptureSession()
var sessionOutput = AVCaptureStillImageOutput()
var movieOutput = AVCaptureMovieFileOutput()
var previewLayer = AVCaptureVideoPreviewLayer()
@IBOutlet var cameraView: UIView!
override func viewWillAppear(animated: Bool)
self.cameraView = self.view
let devices = AVCaptureDevice.devicesWithMediaType(AVMediaTypeVideo)
for device in devices
if device.position == AVCaptureDevicePosition.Front
do
let input = try AVCaptureDeviceInput(device: device as! AVCaptureDevice)
if captureSession.canAddInput(input)
captureSession.addInput(input)
sessionOutput.outputSettings = [AVVideoCodecKey : AVVideoCodecJPEG]
if captureSession.canAddOutput(sessionOutput)
captureSession.addOutput(sessionOutput)
previewLayer = AVCaptureVideoPreviewLayer(session: captureSession)
previewLayer.videoGravity = AVLayerVideoGravityResizeAspectFill
previewLayer.connection.videoOrientation = AVCaptureVideoOrientation.Portrait
cameraView.layer.addSublayer(previewLayer)
previewLayer.position = CGPoint(x: self.cameraView.frame.width / 2, y: self.cameraView.frame.height / 2)
previewLayer.bounds = cameraView.frame
captureSession.addOutput(movieOutput)
captureSession.startRunning()
let paths = NSFileManager.defaultManager().URLsForDirectory(.DocumentDirectory, inDomains: .UserDomainMask)
let fileUrl = paths[0].URLByAppendingPathComponent("output.mov")
try? NSFileManager.defaultManager().removeItemAtURL(fileUrl)
movieOutput.startRecordingToOutputFileURL(fileUrl, recordingDelegate: self)
let delayTime = dispatch_time(DISPATCH_TIME_NOW, Int64(5 * Double(NSEC_PER_SEC)))
dispatch_after(delayTime, dispatch_get_main_queue())
print("stopping")
self.movieOutput.stopRecording()
catch
print("Error")
func captureOutput(captureOutput: AVCaptureFileOutput!, didFinishRecordingToOutputFileAtURL outputFileURL: NSURL!, fromConnections connections: [AnyObject]!, error: NSError!)
print("FINISHED \(error)")
// save video to camera roll
if error == nil
UISaveVideoAtPathToSavedPhotosAlbum(outputFileURL.path!, nil, nil, nil)
【讨论】：
您可以在 Xcode > Devices > iPhone > app name > Download Container 中从设备下载 Documents 目录。您可以通过从didFinishRecordingToOutputFileAtURL 委托方法调用UISaveVideoAtPathToSavedPhotosAlbum() 将视频保存到相机胶卷。如果您的问题得到解答，请接受此答案。
哈哈非常感谢！希望这也对其他人有所帮助，因为我看到很多人都在问。【参考方案2】：
谢谢你。这对我很有帮助。这是 Rhythmic Fistman 的答案的一个版本，它使用所需的导入语句和委托方法移植到 Swift 3。
import UIKit
import AVFoundation
class ViewController: UIViewController,
AVCaptureFileOutputRecordingDelegate
var captureSession = AVCaptureSession()
var sessionOutput = AVCaptureStillImageOutput()
var movieOutput = AVCaptureMovieFileOutput()
var previewLayer = AVCaptureVideoPreviewLayer()
@IBOutlet var cameraView: UIView!
override func viewWillAppear(_ animated: Bool)
self.cameraView = self.view
let devices = AVCaptureDevice.devices(withMediaType: AVMediaTypeVideo)
for device in devices!
if (device as AnyObject).position == AVCaptureDevicePosition.front
do
let input = try AVCaptureDeviceInput(device: device as! AVCaptureDevice)
if captureSession.canAddInput(input)
captureSession.addInput(input)
sessionOutput.outputSettings = [AVVideoCodecKey : AVVideoCodecJPEG]
if captureSession.canAddOutput(sessionOutput)
captureSession.addOutput(sessionOutput)
previewLayer = AVCaptureVideoPreviewLayer(session: captureSession)
previewLayer.videoGravity = AVLayerVideoGravityResizeAspectFill
previewLayer.connection.videoOrientation = AVCaptureVideoOrientation.portrait
cameraView.layer.addSublayer(previewLayer)
previewLayer.position = CGPoint(x: self.cameraView.frame.width / 2, y: self.cameraView.frame.height / 2)
previewLayer.bounds = cameraView.frame
captureSession.addOutput(movieOutput)
captureSession.startRunning()
let paths = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask)
let fileUrl = paths[0].appendingPathComponent("output.mov")
try? FileManager.default.removeItem(at: fileUrl)
movieOutput.startRecording(toOutputFileURL: fileUrl, recordingDelegate: self)
let delayTime = DispatchTime.now() + 5
DispatchQueue.main.asyncAfter(deadline: delayTime)
print("stopping")
self.movieOutput.stopRecording()
catch
print("Error")
//MARK: AVCaptureFileOutputRecordingDelegate Methods
func capture(_ captureOutput: AVCaptureFileOutput!, didStartRecordingToOutputFileAt fileURL: URL!, fromConnections connections: [Any]!)
func capture(_ captureOutput: AVCaptureFileOutput!, didFinishRecordingToOutputFileAt outputFileURL: URL!, fromConnections connections: [Any]!, error: Error!)
print("FINISHED \(error)")
// save video to camera roll
if error == nil
UISaveVideoAtPathToSavedPhotosAlbum(outputFileURL.path, nil, nil, nil)
【讨论】：
视频正在录制并保存在库中，但没有录制声音。请帮帮我。【参考方案3】：您可以使用此代码将视频保存在照片库中，您必须提供以下参数，其中最重要的是 OutputURL.path，它是要保存到相机胶卷相册的电影文件的文件系统路径, 对于其余参数，您可以传递各自的值，也可以根据需要分配 nil
func fileOutput(_ output: AVCaptureFileOutput, didFinishRecordingTo outputFileURL: URL, from connections: [AVCaptureConnection], error: Error?)
if (error != nil)
print("Error recording movie: \(error!.localizedDescription)")
else
UISaveVideoAtPathToSavedPhotosAlbum(outputFileURL.path, nil, #selector(CameraController.video(_:didFinishSavingWithError:contextInfo:)), nil)
outputURL = nil
【讨论】：
您好，请避免仅使用代码回答。为您的答案添加解释，谢谢【参考方案4】：if (device as AnyObject).position == AVCaptureDevicePosition.front之后
添加
// Audio Input
let audioInputDevice = AVCaptureDevice.defaultDevice(withMediaType: AVMediaTypeAudio)
do
let audioInput = try AVCaptureDeviceInput(device: audioInputDevice)
// Add Audio Input
if captureSession.canAddInput(audioInput)
captureSession.addInput(audioInput)
else
NSLog("Can't Add Audio Input")
catch let error
NSLog("Error Getting Input Device: \(error)")
谢谢
【讨论】：
【参考方案5】：关于录音问题，
在创建 captureSession 时添加此代码
askMicroPhonePermission(completion: (isMicrophonePermissionGiven) in
if isMicrophonePermissionGiven
do
try self.captureSession.addInput(AVCaptureDeviceInput(device: self.captureAudio))
catch
print("Error creating the database")
)
/////////////////////////////////////// ////////////////
askMicroPhonePermission 函数如下
func askMicroPhonePermission(completion: @escaping (_ success: Bool)-> Void)
switch AVAudiosession.sharedInstance().recordPermission()
case AVAudioSessionRecordPermission.granted:
completion(true)
case AVAudioSessionRecordPermission.denied:
completion(false) //show alert if required
case AVAudioSessionRecordPermission.undetermined:
AVAudioSession.sharedInstance().requestRecordPermission( (granted) in
if granted
completion(true)
else
completion(false) // show alert if required
)
default:
completion(false)
你必须在 info.plist 文件中添加 NSMicrophoneUsageDescription 键值。
【讨论】：
【参考方案6】：func getCurrentFrame(url:String) -> UIImage?
let asset = AVAsset(url: URL(string: url)!)
let assetImgGenerate = AVAssetImageGenerator(asset: asset)
assetImgGenerate.appliesPreferredTrackTransform = true
//Can set this to improve performance if target size is known before hand
//assetImgGenerate.maximumSize = CGSize(width,height)
let time = CMTimeMakeWithSeconds(1.0, preferredTimescale: 600)
do
let img = try assetImgGenerate.copyCGImage(at: time, actualTime: nil)
let thumbnail = UIImage(cgImage: img)
return thumbnail
catch
print(error.localizedDescription)
return nil
【讨论】：
【参考方案7】：对于没有调用委托的人来说只有一个小提示：（我在 Xcode 12.x / iOS 14.5 下）
假设你有一个 f。打开本地 dest。 URL（上一个示例中的代码...文档目录..）
如果你这样做：
DispatchQueue.global(qos: .userInitiated).async //[weak self] in
self.captureSession.startRunning()
self.addDest()
有效，
但如果你交换：
DispatchQueue.global(qos: .userInitiated).async //[weak self] in
**self.addDest()**
self.captureSession.startRunning()
委托未被调用。
设置输出后调用“startRunning”：
if captureSession.canAddInput(input!) && captureSession.canAddOutput(stillImageOutput)
captureSession.addInput(input!)
captureSession.addOutput(stillImageOutput)
setupLivePreview()
self.videoPreviewLayer.frame = self.previewView.bounds
if addVideoOutput()
DispatchQueue.global(qos: .userInitiated).async //[weak self] in
self.captureSession.startRunning()
self.addDest()
...
在哪里
func addVideoOutput() -> Bool
movieOutput = AVCaptureMovieFileOutput()
if captureSession.canAddOutput(movieOutput)
captureSession.addOutput(movieOutput)
return true
return false
【讨论】：
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