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Ich versuche, Kamera-Video im Speicher mit AVCaptureSession zu erfassen, damit ich später die Videodaten in eine Filmdatei schreiben kann. Obwohl ich eine Capture-Sitzung erfolgreich starten konnte, kann ich die von mir erfassten CMSampleBuffers nicht erfolgreich mit AVAssetWriter in eine komprimierte Filmdatei schreiben.AVAssetWriterInput Append schlägt mit Fehlercode -11800 fehl AVErrorUnknown -12780
Anfügen Abtastpuffern AVAssetWriterInput der Append-Methode schlägt fehl, und wenn ich die Fehler Unterkunft AVAssetWriter prüfen, erhalte ich die folgende:
Fehler Domain = AVFoundationErrorDomain-Code = -11.800 „Der Vorgang konnte nicht abgeschlossen werden“ Userinfo = {NSUnderlyingError = 0x17005d070 {Fehler Domain = NSOSStatusErrorDomain-Code = -12.780 "(null)"}, = NSLocalizedFailureReason Ein unbekannter Fehler ist aufgetreten (-12.780), NSLocalizedDescription = Der Vorgang konnte nicht abgeschlossen werden}
Soweit ich sagen kann, -11800 zeigt einen AVErrorUnknown an, jedoch konnte ich keine Informationen über den Fehlercode -12780 finden, der, soweit ich feststellen kann, nicht dokumentiert ist . Im Folgenden habe ich die Hauptdateien in das Beispielprojekt eingefügt, das ich eingerichtet habe, um das Problem zu demonstrieren.
Jede Anleitung würde sehr geschätzt werden. Vielen Dank!
ViewController.swift
import UIKit
import AVFoundation
class ViewController: UIViewController, AVCaptureVideoDataOutputSampleBufferDelegate {
private let recordingClipQueue = DispatchQueue(label: "com.example.recordingClipQueue")
private let videoDataOutputQueue = DispatchQueue(label: "com.example.videoDataOutputQueue")
private let session = AVCaptureSession()
private var backfillSampleBufferList = [CMSampleBuffer]()
override func viewDidLoad() {
super.viewDidLoad()
session.sessionPreset = AVCaptureSessionPreset640x480
let videoDevice = AVCaptureDevice.defaultDevice(withMediaType: AVMediaTypeVideo);
let videoDeviceInput: AVCaptureDeviceInput;
do {
videoDeviceInput = try AVCaptureDeviceInput(device: videoDevice)
} catch {
print("Error creating device input from video device: \(error).")
return
}
guard session.canAddInput(videoDeviceInput) else {
print("Could not add video device input to capture session.")
return
}
session.addInput(videoDeviceInput)
let videoDataOutput = AVCaptureVideoDataOutput()
videoDataOutput.videoSettings = [ kCVPixelBufferPixelFormatTypeKey as NSString : Int(kCMPixelFormat_32BGRA) ]
videoDataOutput.alwaysDiscardsLateVideoFrames = true
videoDataOutput.setSampleBufferDelegate(self, queue: videoDataOutputQueue)
guard session.canAddOutput(videoDataOutput) else {
print("Could not add video data output to capture session.")
return
}
session.addOutput(videoDataOutput)
videoDataOutput.connection(withMediaType: AVMediaTypeVideo).isEnabled = true
session.startRunning()
}
private func backfillSizeInSeconds() -> Double {
if backfillSampleBufferList.count < 1 {
return 0.0
}
let earliestSampleBuffer = backfillSampleBufferList.first!
let latestSampleBuffer = backfillSampleBufferList.last!
let earliestSampleBufferPTS = CMSampleBufferGetOutputPresentationTimeStamp(earliestSampleBuffer).value
let latestSampleBufferPTS = CMSampleBufferGetOutputPresentationTimeStamp(latestSampleBuffer).value
let timescale = CMSampleBufferGetOutputPresentationTimeStamp(latestSampleBuffer).timescale
return Double(latestSampleBufferPTS - earliestSampleBufferPTS)/Double(timescale)
}
private func createClipFromBackfill() {
guard backfillSampleBufferList.count > 0 else {
print("createClipFromBackfill() called before any samples were recorded.")
return
}
let clipURL = URL(fileURLWithPath:
NSSearchPathForDirectoriesInDomains(.documentDirectory, .userDomainMask, true)[0] +
"/recorded_clip.mp4")
if FileManager.default.fileExists(atPath: clipURL.path) {
do {
try FileManager.default.removeItem(atPath: clipURL.path)
} catch {
print("Could not delete existing clip file: \(error).")
}
}
var _videoFileWriter: AVAssetWriter?
do {
_videoFileWriter = try AVAssetWriter(url: clipURL, fileType: AVFileTypeQuickTimeMovie)
} catch {
print("Could not create video file writer: \(error).")
return
}
guard let videoFileWriter = _videoFileWriter else {
print("Video writer was nil.")
return
}
let settingsAssistant = AVOutputSettingsAssistant(preset: AVOutputSettingsPreset640x480)!
guard videoFileWriter.canApply(outputSettings: settingsAssistant.videoSettings, forMediaType: AVMediaTypeVideo) else {
print("Video file writer could not apply video output settings.")
return
}
let earliestRecordedSampleBuffer = backfillSampleBufferList.first!
let _formatDescription = CMSampleBufferGetFormatDescription(earliestRecordedSampleBuffer)
guard let formatDescription = _formatDescription else {
print("Earliest recording pixel buffer format description was nil.")
return
}
let videoWriterInput = AVAssetWriterInput(mediaType: AVMediaTypeVideo,
outputSettings: settingsAssistant.videoSettings,
sourceFormatHint: formatDescription)
guard videoFileWriter.canAdd(videoWriterInput) else {
print("Could not add video writer input to video file writer.")
return
}
videoFileWriter.add(videoWriterInput)
guard videoFileWriter.startWriting() else {
print("Video file writer not ready to write file.")
return
}
videoFileWriter.startSession(atSourceTime: CMSampleBufferGetOutputPresentationTimeStamp(earliestRecordedSampleBuffer))
videoWriterInput.requestMediaDataWhenReady(on: recordingClipQueue) {
while videoWriterInput.isReadyForMoreMediaData {
if self.backfillSampleBufferList.count > 0 {
let sampleBufferToAppend = self.backfillSampleBufferList.first!.deepCopy()
let appendSampleBufferSucceeded = videoWriterInput.append(sampleBufferToAppend)
if !appendSampleBufferSucceeded {
print("Failed to append sample buffer to asset writer input: \(videoFileWriter.error!)")
print("Video file writer status: \(videoFileWriter.status.rawValue)")
}
self.backfillSampleBufferList.remove(at: 0)
} else {
videoWriterInput.markAsFinished()
videoFileWriter.finishWriting {
print("Saved clip to \(clipURL)")
}
break
}
}
}
}
// MARK: AVCaptureVideoDataOutputSampleBufferDelegate
func captureOutput(_ captureOutput: AVCaptureOutput!,
didOutputSampleBuffer sampleBuffer: CMSampleBuffer!,
from connection: AVCaptureConnection!) {
guard let buffer = sampleBuffer else {
print("Captured sample buffer was nil.")
return
}
let sampleBufferCopy = buffer.deepCopy()
backfillSampleBufferList.append(sampleBufferCopy)
if backfillSizeInSeconds() > 3.0 {
session.stopRunning()
createClipFromBackfill()
}
}
func captureOutput(_ captureOutput: AVCaptureOutput!,
didDrop sampleBuffer: CMSampleBuffer!,
from connection: AVCaptureConnection!) {
print("Sample buffer dropped.")
}
}
CVPixelBuffer + Copy.swift:
import CoreVideo
extension CVPixelBuffer {
func deepCopy() -> CVPixelBuffer {
precondition(CFGetTypeID(self) == CVPixelBufferGetTypeID(), "deepCopy() cannot copy a non-CVPixelBuffer")
var _copy : CVPixelBuffer?
CVPixelBufferCreate(
nil,
CVPixelBufferGetWidth(self),
CVPixelBufferGetHeight(self),
CVPixelBufferGetPixelFormatType(self),
CVBufferGetAttachments(self, CVAttachmentMode.shouldPropagate),
&_copy)
guard let copy = _copy else {
print("Pixel buffer copy was nil.")
fatalError()
}
CVBufferPropagateAttachments(self, copy)
CVPixelBufferLockBaseAddress(self, CVPixelBufferLockFlags.readOnly)
CVPixelBufferLockBaseAddress(copy, CVPixelBufferLockFlags(rawValue: 0))
let sourceBaseAddress = CVPixelBufferGetBaseAddress(self)
let copyBaseAddress = CVPixelBufferGetBaseAddress(copy)
memcpy(copyBaseAddress, sourceBaseAddress, CVPixelBufferGetHeight(self) * CVPixelBufferGetBytesPerRow(self))
CVPixelBufferUnlockBaseAddress(copy, CVPixelBufferLockFlags(rawValue: 0))
CVPixelBufferUnlockBaseAddress(self, CVPixelBufferLockFlags.readOnly)
return copy
}
}
CMSampleBuffer + Copy.swift:
import CoreMedia
extension CMSampleBuffer {
func deepCopy() -> CMSampleBuffer {
let _pixelBuffer = CMSampleBufferGetImageBuffer(self)
guard let pixelBuffer = _pixelBuffer else {
print("Pixel buffer to copy was nil.")
fatalError()
}
let pixelBufferCopy = pixelBuffer.deepCopy()
let _formatDescription = CMSampleBufferGetFormatDescription(self)
guard let formatDescription = _formatDescription else {
print("Format description to copy was nil.")
fatalError()
}
var timingInfo = kCMTimingInfoInvalid
let getTimingInfoResult = CMSampleBufferGetSampleTimingInfo(self, 0, &timingInfo)
guard getTimingInfoResult == noErr else {
print("Could not get timing info to copy: \(getTimingInfoResult).")
fatalError()
}
timingInfo.presentationTimeStamp = CMSampleBufferGetOutputPresentationTimeStamp(self)
var _copy : CMSampleBuffer?
let createCopyResult = CMSampleBufferCreateForImageBuffer(kCFAllocatorDefault,
pixelBufferCopy,
true,
nil,
nil,
formatDescription,
&timingInfo,
&_copy);
guard createCopyResult == noErr else {
print("Error creating copy of sample buffer: \(createCopyResult).")
fatalError()
}
guard let copy = _copy else {
print("Copied sample buffer was nil.")
fatalError()
}
return copy
}
}