如何使用增强现实录制视频？（从iPhone/iPad相机中的帧添加文本、图像和标志）
之前我正在尝试如何在CIImage中绘制文本（如何在CIImage中绘制文本？），并将CIImage转换回CMSampleBuffer（将CIImage转换回CMSampleBuffer）
我几乎做到了一切，只有一个问题，就是使用新的CMSampleBuffer在AVAssetWriterInput中录制视频
但这种解决方案根本不好，它会消耗大量的CPU资源，同时将CIImage转换为CVPixelBuffer（ciContext.render(ciImage!, to: aBuffer)）
所以我想到此为止，并寻找其他方法来记录具有增强现实的视频（例如在将视频编码为mp4文件时动态添加（绘制）文本）
这里是我尝试过的，不想再使用的方法...
// convert original CMSampleBuffer to CIImage,
// combine multiple `CIImage`s into one (adding augmented reality -
// text or some additional images)
let pixelBuffer: CVPixelBuffer = CMSampleBufferGetImageBuffer(sampleBuffer)!
let ciimage : CIImage = CIImage(cvPixelBuffer: pixelBuffer)
var outputImage: CIImage?
let images : Array<CIImage> = [ciimage, ciimageSec!] // add all your CIImages that you'd like to combine
for image in images {
outputImage = outputImage == nil ? image : image.composited(over: outputImage!)
}
// allocate this class variable once
if pixelBufferNew == nil {
CVPixelBufferCreate(kCFAllocatorSystemDefault, CVPixelBufferGetWidth(pixelBuffer), CVPixelBufferGetHeight(pixelBuffer), kCVPixelFormatType_32BGRA, nil, &pixelBufferNew)
}
// convert CIImage to CVPixelBuffer
let ciContext = CIContext(options: nil)
if let aBuffer = pixelBufferNew {
ciContext.render(outputImage!, to: aBuffer) // >>> IT EATS A LOT OF <<< CPU
}
// convert new CVPixelBuffer to new CMSampleBuffer
var sampleTime = CMSampleTimingInfo()
sampleTime.duration = CMSampleBufferGetDuration(sampleBuffer)
sampleTime.presentationTimeStamp = CMSampleBufferGetPresentationTimeStamp(sampleBuffer)
sampleTime.decodeTimeStamp = CMSampleBufferGetDecodeTimeStamp(sampleBuffer)
var videoInfo: CMVideoFormatDescription? = nil
CMVideoFormatDescriptionCreateForImageBuffer(kCFAllocatorDefault, pixelBufferNew!, &videoInfo)
var oBuf: CMSampleBuffer?
CMSampleBufferCreateForImageBuffer(kCFAllocatorDefault, pixelBufferNew!, true, nil, nil, videoInfo!, &sampleTime, &oBuf)
/*
try to append new CMSampleBuffer into a file (.mp4) using
AVAssetWriter & AVAssetWriterInput... (I met errors with it, original buffer works ok
- "from func captureOutput(_ output: AVCaptureOutput, didOutput sampleBuffer: CMSampleBuffer, from connection: AVCaptureConnection)")
*/*
有更好的解决方案吗？