yumoqing
42f3cf2b84
之前音频用 player.currentTime() 作为起始时间，视频用 AVPlayerItemVideoOutput 的 firstFrameTime，两者可能不一致 导致音视频不同步。 改为: - prepareAudioCapture: 只预加载音频轨道，不立即开始读取 - captureVideoFrame: 第一帧时设置 firstFrameTime 后调用 beginAudioReading(startTime: firstFrameTime) - 音频和视频共用同一个时间基准，确保精确同步 - 移除 startRecording 的 startTime 参数
364 lines
14 KiB
Swift
364 lines
14 KiB
Swift
import AVFoundation
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#if os(macOS)
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import AppKit
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/// 视频源录制器：从 AVPlayerItemVideoOutput 抓帧 + 源 URL 音频轨道，写入 mp4
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@MainActor
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final class PlayerRecorder: NSObject {
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private var writer: AVAssetWriter?
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private var videoInput: AVAssetWriterInput?
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private var audioInput: AVAssetWriterInput?
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private var timer: Timer?
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private var startDate: Date?
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private var weakOutput: AVPlayerItemVideoOutput?
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private var firstFrameTime: CMTime?
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private var audioReader: AVAssetReader?
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private var audioReaderOutput: AVAssetReaderTrackOutput?
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private var audioCaptureQueue: DispatchQueue?
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private var isRunning = false
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/// 线程安全的音频停止标志，后台队列直接读取
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nonisolated(unsafe) private var audioStopped: Bool = false
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/// 音频线程读取 firstFrameTime 的镜像
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nonisolated(unsafe) private var audioFirstFrameTime: CMTime?
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// 音频预加载状态
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private var pendingAudioAsset: AVURLAsset?
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private var pendingAudioTrack: AVAssetTrack?
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@Published var isRecording = false
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@Published var durationText = "00:00"
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var onRecordingSaved: ((URL) -> Void)?
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var onError: ((String) -> Void)?
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private var tempURL: URL?
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private var saveDirectory: URL {
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let movies = FileManager.default.urls(for: .moviesDirectory, in: .userDomainMask).first!
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let dir = movies.appendingPathComponent("MiniPlayer", isDirectory: true)
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try? FileManager.default.createDirectory(at: dir, withIntermediateDirectories: true)
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return dir
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}
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/// 开始录制
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func startRecording(from output: AVPlayerItemVideoOutput, sourceURL: URL) {
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guard !isRecording else { return }
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weakOutput = output
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firstFrameTime = nil
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isRunning = false
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audioStopped = false
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// 临时文件
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let formatter = DateFormatter()
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formatter.dateFormat = "yyyy-MM-dd_HH-mm-ss"
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let filename = "Recording_\(formatter.string(from: Date())).mp4"
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let url = saveDirectory.appendingPathComponent(filename)
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tempURL = url
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do {
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writer = try AVAssetWriter(outputURL: url, fileType: .mp4)
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} catch {
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onError?("Cannot create writer: \(error.localizedDescription)")
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return
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}
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guard let writer = writer else { return }
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// 视频输入
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let videoSettings: [String: Any] = [
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AVVideoCodecKey: AVVideoCodecType.h264,
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AVVideoWidthKey: 1920,
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AVVideoHeightKey: 1080
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]
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let vInput = AVAssetWriterInput(mediaType: .video, outputSettings: videoSettings)
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vInput.expectsMediaDataInRealTime = true
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if writer.canAdd(vInput) {
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writer.add(vInput)
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videoInput = vInput
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}
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// 音频输入
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let audioSettings: [String: Any] = [
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AVFormatIDKey: kAudioFormatMPEG4AAC,
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AVSampleRateKey: 44100,
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AVNumberOfChannelsKey: 2,
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AVEncoderBitRateKey: 128000
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]
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let aInput = AVAssetWriterInput(mediaType: .audio, outputSettings: audioSettings)
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aInput.expectsMediaDataInRealTime = true
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if writer.canAdd(aInput) {
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writer.add(aInput)
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audioInput = aInput
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}
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writer.startWriting()
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// 启动视频抓帧
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isRecording = true
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isRunning = true // 必须在 startCaptureLoop 之前设置
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startTimer()
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startCaptureLoop()
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// 准备音频读取（等待 firstFrameTime 后才真正开始）
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prepareAudioCapture(sourceURL: sourceURL)
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}
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/// 停止录制
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func stopRecording() {
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guard isRecording else { return }
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isRecording = false
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isRunning = false
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captureTimer?.invalidate()
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captureTimer = nil
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stopTimer()
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stopAudioCapture()
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videoInput?.markAsFinished()
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audioInput?.markAsFinished()
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writer?.finishWriting { [weak self] in
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Task { @MainActor in
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guard let self = self else { return }
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if let url = self.tempURL {
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self.showSaveDialog(tempURL: url)
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}
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}
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}
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}
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// MARK: - 视频抓帧
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private var captureTimer: Timer?
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private func startCaptureLoop() {
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// 用 Timer 每 1/30 秒抓一帧
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captureTimer = Timer.scheduledTimer(withTimeInterval: 1.0 / 30.0, repeats: true) { [weak self] _ in
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Task { @MainActor in
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self?.captureVideoFrame()
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}
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}
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}
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private func captureVideoFrame() {
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guard let output = weakOutput, let input = videoInput, input.isReadyForMoreMediaData else { return }
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let hostTime = CACurrentMediaTime()
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let itemTime = output.itemTime(forHostTime: hostTime)
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guard output.hasNewPixelBuffer(forItemTime: itemTime),
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let pb = output.copyPixelBuffer(forItemTime: itemTime, itemTimeForDisplay: nil) else { return }
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// 第一帧：用它的时间作为 session 起点
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if firstFrameTime == nil {
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firstFrameTime = itemTime
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audioFirstFrameTime = itemTime // 同步给音频线程
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writer?.startSession(atSourceTime: itemTime)
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isRunning = true
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// 音频预加载完成后，用 firstFrameTime 作为起始时间开始读取
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beginAudioReading(startTime: itemTime)
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}
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// 相对时间戳
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guard let firstTime = firstFrameTime else { return }
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let relativeTime = CMTimeSubtract(itemTime, firstTime)
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guard relativeTime.seconds >= 0 else { return }
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let sampleBuffer = Self.createSampleBuffer(from: pb, time: relativeTime)
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if let sb = sampleBuffer {
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_ = input.append(sb)
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}
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}
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private static func createSampleBuffer(from pixelBuffer: CVPixelBuffer, time: CMTime) -> CMSampleBuffer? {
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var info = CMSampleTimingInfo()
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info.presentationTimeStamp = time
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info.duration = CMTime(value: 1, timescale: 30)
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info.decodeTimeStamp = .invalid
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var formatDescription: CMFormatDescription?
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CMVideoFormatDescriptionCreateForImageBuffer(allocator: kCFAllocatorDefault, imageBuffer: pixelBuffer, formatDescriptionOut: &formatDescription)
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guard let fd = formatDescription else { return nil }
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var sampleBuffer: CMSampleBuffer?
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CMSampleBufferCreateReadyWithImageBuffer(allocator: kCFAllocatorDefault, imageBuffer: pixelBuffer, formatDescription: fd, sampleTiming: &info, sampleBufferOut: &sampleBuffer)
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return sampleBuffer
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}
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// MARK: - 音频读取（从源 URL）
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/// 预加载音频轨道（异步），不立即开始读取
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private func prepareAudioCapture(sourceURL: URL) {
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let asset = AVURLAsset(url: sourceURL)
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pendingAudioAsset = asset
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pendingAudioTrack = nil
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Task {
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do {
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let audioTracks = try await asset.loadTracks(withMediaType: .audio)
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guard let audioTrack = audioTracks.first else {
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print("[Recorder] No audio track in source")
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return
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}
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self.pendingAudioTrack = audioTrack
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// 如果 firstFrameTime 已经设置好了，立即开始读取
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if let fft = self.firstFrameTime {
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self.beginAudioReading(startTime: fft)
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}
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} catch {
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print("[Recorder] Audio track load failed: \(error)")
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}
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}
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}
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/// 用 firstFrameTime 作为起始时间，创建 reader 并开始后台读取
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private func beginAudioReading(startTime: CMTime) {
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guard let asset = pendingAudioAsset, let audioTrack = pendingAudioTrack else {
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return // 轨道还没加载好，prepareAudioCapture 的回调会再次调用
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}
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guard let aInput = audioInput else { return }
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// 防止重复启动
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guard audioReader == nil else { return }
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do {
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let reader = try AVAssetReader(asset: asset)
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let output = AVAssetReaderTrackOutput(track: audioTrack, outputSettings: [
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AVFormatIDKey: kAudioFormatLinearPCM,
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AVSampleRateKey: 44100,
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AVNumberOfChannelsKey: 2,
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AVLinearPCMBitDepthKey: 16,
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AVLinearPCMIsFloatKey: false,
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AVLinearPCMIsBigEndianKey: false,
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AVLinearPCMIsNonInterleaved: false
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])
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output.alwaysCopiesSampleData = false
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// 从视频第一帧时间开始读取，确保音视频同步
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reader.timeRange = CMTimeRange(start: startTime, duration: .positiveInfinity)
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if reader.canAdd(output) {
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reader.add(output)
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reader.startReading()
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self.audioReader = reader
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self.audioReaderOutput = output
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// 后台线程读取音频
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let queue = DispatchQueue(label: "recorder.audio.capture")
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self.audioCaptureQueue = queue
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queue.async { [weak self] in
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guard let self = self else { return }
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self.readAudioLoop(reader: reader, output: output, audioInput: aInput)
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}
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}
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} catch {
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print("[Recorder] Audio capture setup failed: \(error)")
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}
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// 清理预加载状态
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pendingAudioAsset = nil
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pendingAudioTrack = nil
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}
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private nonisolated func readAudioLoop(reader: AVAssetReader, output: AVAssetReaderTrackOutput, audioInput: AVAssetWriterInput) {
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while !audioStopped && reader.status == .reading {
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guard let sampleBuffer = output.copyNextSampleBuffer() else {
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break
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}
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// 直接在后台队列处理，不走 MainActor（避免队列积压）
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guard let firstTime = audioFirstFrameTime else {
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// 视频第一帧还没到，跳过这个音频 buffer
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continue
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}
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guard audioInput.isReadyForMoreMediaData else { continue }
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let pts = CMSampleBufferGetPresentationTimeStamp(sampleBuffer)
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let relativeTime = CMTimeSubtract(pts, firstTime)
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guard relativeTime.seconds >= 0 else { continue }
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// 重建 sample buffer with new time
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var count: CMItemCount = 0
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CMSampleBufferGetSampleTimingInfoArray(sampleBuffer, entryCount: 0, arrayToFill: nil, entriesNeededOut: &count)
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var timingInfo = [CMSampleTimingInfo](repeating: CMSampleTimingInfo(), count: count)
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CMSampleBufferGetSampleTimingInfoArray(sampleBuffer, entryCount: count, arrayToFill: &timingInfo, entriesNeededOut: nil)
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for i in 0..<count {
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timingInfo[i].decodeTimeStamp = .invalid
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timingInfo[i].presentationTimeStamp = CMTimeSubtract(timingInfo[i].presentationTimeStamp, firstTime)
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}
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var newBuffer: CMSampleBuffer?
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CMSampleBufferCreateCopyWithNewTiming(allocator: kCFAllocatorDefault, sampleBuffer: sampleBuffer, sampleTimingEntryCount: count, sampleTimingArray: &timingInfo, sampleBufferOut: &newBuffer)
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if let nb = newBuffer {
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_ = audioInput.append(nb)
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}
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}
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}
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private func stopAudioCapture() {
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audioStopped = true // 先设标志，loop 立即退出
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audioReader?.cancelReading()
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audioReader = nil
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audioReaderOutput = nil
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}
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// MARK: - Timer
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private func startTimer() {
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startDate = Date()
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durationText = "00:00"
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timer = Timer.scheduledTimer(withTimeInterval: 1.0, repeats: true) { [weak self] _ in
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Task { @MainActor in
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guard let self = self, let start = self.startDate else { return }
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let elapsed = Int(Date().timeIntervalSince(start))
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let m = elapsed / 60
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let s = elapsed % 60
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let h = m / 60
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if h > 0 {
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self.durationText = String(format: "%d:%02d:%02d", h, m % 60, s)
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} else {
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self.durationText = String(format: "%02d:%02d", m, s)
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}
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}
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}
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}
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private func stopTimer() {
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timer?.invalidate()
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timer = nil
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startDate = nil
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durationText = "00:00"
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}
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// MARK: - 保存对话框
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private func showSaveDialog(tempURL: URL) {
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let panel = NSSavePanel()
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panel.nameFieldStringValue = tempURL.lastPathComponent
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panel.allowedContentTypes = [.mpeg4Movie]
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panel.directoryURL = saveDirectory
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panel.title = "Save Recording"
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panel.begin { [weak self] response in
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guard let self = self else { return }
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if response == .OK, let destURL = panel.url {
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do {
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if FileManager.default.fileExists(atPath: destURL.path) {
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try FileManager.default.removeItem(at: destURL)
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}
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try FileManager.default.moveItem(at: tempURL, to: destURL)
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self.onRecordingSaved?(destURL)
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} catch {
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self.onError?("Save failed: \(error.localizedDescription)")
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}
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} else {
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try? FileManager.default.removeItem(at: tempURL)
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}
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}
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}
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}
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#endif
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