我有一个非常奇怪的情况，如果我使用13个不同的滤镜链，AVCaptureVideoDataOutputSampleBufferDelegate会丢帧。让我解释一下：
我有CameraController设置，没什么特别的，这是我的委托方法：
func captureOutput(_ output: AVCaptureOutput, didOutput sampleBuffer: CMSampleBuffer, from connection: AVCaptureConnection) {
if !paused {
if connection.output?.connection(with: .audio) == nil {
//capture video
// my try to avoid "Out of buffers error", no luck ;(
lastCapturedBuffer = nil
let err = CMSampleBufferCreateCopy(allocator: kCFAllocatorDefault, sampleBuffer: sampleBuffer, sampleBufferOut: &lastCapturedBuffer)
if err == noErr {
}
connection.videoOrientation = .portrait
// getting image
let pixelBuffer = CMSampleBufferGetImageBuffer(lastCapturedBuffer!)
// remove if any
CVPixelBufferLockBaseAddress(pixelBuffer!, CVPixelBufferLockFlags(rawValue: 0))
// captured - is just ciimage property
captured = CIImage(cvPixelBuffer: pixelBuffer!)
//remove if any
CVPixelBufferUnlockBaseAddress(pixelBuffer!,CVPixelBufferLockFlags(rawValue: 0))
//CVPixelBufferUnlockBaseAddress(pixelBuffer!, .readOnly)
// transform image to targer resolution
let srcWidth = CGFloat(captured.extent.width)
let srcHeight = CGFloat(captured.extent.height)
let dstWidth: CGFloat = ConstantsManager.shared.k_video_width
let dstHeight: CGFloat = ConstantsManager.shared.k_video_height
let scaleX = dstWidth / srcWidth
let scaleY = dstHeight / srcHeight
var transform = CGAffineTransform.init(scaleX: scaleX, y: scaleY)
captured = captured.transformed(by: transform).cropped(to: CGRect(x: 0, y: 0, width: dstWidth, height: dstHeight))
// mirror for front camera
if front {
var t = CGAffineTransform.init(scaleX: -1, y: 1)
t = t.translatedBy(x: -ConstantsManager.shared.k_video_width, y: 0)
captured = captured.transformed(by: t)
}
// video capture logic
let writable = canWrite()
if writable,
sessionAtSourceTime == nil {
sessionAtSourceTime = CMSampleBufferGetPresentationTimeStamp(lastCapturedBuffer!)
videoWriter.startSession(atSourceTime: sessionAtSourceTime!)
}
if writable, (videoWriterInput.isReadyForMoreMediaData) {
videoWriterInput.append(lastCapturedBuffer!)
}
// apply effect in realtime <- here is problem. If I comment next line, it will be fixed but effect will n't be applied
captured = FilterManager.shared.applyFilterForCamera(inputImage: captured)
// current frame in case user wants to save image as photo
self.capturedPhoto = captured
// sent frame to Camcoder view controller
self.delegate?.didCapturedFrame(frame: captured)
} else {
// capture sound
let writable = canWrite()
if writable, (audioWriterInput.isReadyForMoreMediaData) {
//print("write audio buffer")
audioWriterInput?.append(lastCapturedBuffer!)
}
}
} else {
// paused
}
}
我还实现了didDrop委托方法，这是我弄清楚为什么会掉帧的原因：
func captureOutput(_ output: AVCaptureOutput, didDrop sampleBuffer: CMSampleBuffer, from connection: AVCaptureConnection) {
print("did drop")
var mode: CMAttachmentMode = 0
let reason = CMGetAttachment(sampleBuffer, key: kCMSampleBufferAttachmentKey_DroppedFrameReason, attachmentModeOut: &mode)
print("reason \(String(describing: reason))") // Optional(OutOfBuffers)
}
所以我像专家一样做到了，只是注释了部分代码以查找问题所在。因此，它在这里：
captured = FilterManager.shared.applyFilterForCamera(inputImage: captured)
FilterManager-是单例，在这里称为func：
func applyFilterForCamera(inputImage: CIImage) -> CIImage {
return currentVsFilter!.apply(sourceImage: inputImage)
}
currentVsFilter是VSFilter类型的对象-这是一个示例：
import Foundation
import AVKit
class TestFilter: CustomFilter {
let _name = "Тестовый Фильтр"
let _displayName = "Test Filter"
var tempImage: CIImage?
var final: CGImage?
override func name() -> String {
return _name
}
override func displayName() -> String {
return _displayName
}
override init() {
super.init()
print("Test Filter init")
// setup my custom kernel filter
self.noise.type = GlitchFilter.GlitchType.allCases[2]
}
// this returns composition for playback using AVPlayer
override func composition(asset: AVAsset) -> AVMutableVideoComposition {
let composition = AVMutableVideoComposition(asset: asset, applyingCIFiltersWithHandler: { request in
let inputImage = request.sourceImage.cropped(to: request.sourceImage.extent)
DispatchQueue.global(qos: .userInitiated).async {
let output = self.apply(sourceImage: inputImage, forComposition: true)
request.finish(with: output, context: nil)
}
})
let size = FilterManager.shared.cropRectForOrientation().size
composition.renderSize = size
return composition
}
// this returns actual filtered CIImage, used for both AVPlayer composition and realtime camera
override func apply(sourceImage: CIImage, forComposition: Bool = false) -> CIImage {
// rendered text
tempImage = FilterManager.shared.textRenderedImage()
// some filters chained one by one
self.screenBlend?.setValue(tempImage, forKey: kCIInputImageKey)
self.screenBlend?.setValue(sourceImage, forKey: kCIInputBackgroundImageKey)
self.noise.inputImage = self.screenBlend?.outputImage
self.noise.inputAmount = CGFloat.random(in: 1.0...3.0)
// result
tempImage = self.noise.outputImage
// correct crop
let rect = forComposition ? FilterManager.shared.cropRectForOrientation() : FilterManager.shared.cropRect
final = self.context.createCGImage(tempImage!, from: rect!)
return CIImage(cgImage: final!)
}
}
现在，最奇怪的是，我有30个VSFilter，当我达到13个（通过UIButton逐个切换）时，出现错误“缓冲区不足”，这是一个错误：
kCMSampleBufferDroppedFrameReason_OutOfBuffers
我测试过的内容：
看起来它只能处理12个VSFIlter对象，例如它是否以某种方式保留了它们，或者可能与线程有关，我不知道。
此应用程序是为iOs设备制作的，已在iPhone X iOs 13.3.1上进行了测试这是一款视频编辑器应用，可将不同的效果应用于相机的实时流和相机胶卷中的视频文件
也许有人对此有经验？
祝你有美好的一天
Best，Victor
编辑1.如果我重新初始化cameraController（AVCaptureSession。输入/输出设备），它可以工作，但这是难看的选择，并且在切换滤镜时会增加延迟]
我有一个非常奇怪的情况，如果我使用13个不同的滤镜链，AVCaptureVideoDataOutputSampleBufferDelegate会丢帧。让我解释一下：我有CameraController设置，没什么特别的，这里是...
好，所以我最终赢得了这场战斗。如果有人遇到这个“ OutOfBuffer”问题，这是我的解决方法