swift - 如何从 Swift 中的本地视频文件中获取帧？

Question

我需要从本地视频文件中获取帧，以便在播放视频之前处理它们。我已经尝试过使用 AVAssetReader 和 VideoOutput。

[编辑] 这是我在 Accesing Individual Frames using AV Player 中使用的代码

let asset = AVAsset(URL: inputUrl)
let reader = try! AVAssetReader(asset: asset)

let videoTrack = asset.tracksWithMediaType(AVMediaTypeVideo)[0]

// read video frames as BGRA
let trackReaderOutput = AVAssetReaderTrackOutput(track: videoTrack, outputSettings:[String(kCVPixelBufferPixelFormatTypeKey): NSNumber(unsignedInt: kCVPixelFormatType_32BGRA)])

reader.addOutput(trackReaderOutput)
reader.startReading()

while let sampleBuffer = trackReaderOutput.copyNextSampleBuffer() {
    print("sample at time \(CMSampleBufferGetPresentationTimeStamp(sampleBuffer))")
    if let imageBuffer = CMSampleBufferGetImageBuffer(sampleBuffer) {
        // process each CVPixelBufferRef here
        // see CVPixelBufferGetWidth, CVPixelBufferLockBaseAddress, CVPixelBufferGetBaseAddress, etc
    }
}

Answer 1

我相信 AVAssetReader 应该可以工作。你尝试了什么？您看过 Apple 的示例代码吗？ https://developer.apple.com/library/content/samplecode/ReaderWriter/Introduction/Intro.html