yumoqing
68806e1190
-movflags +faststart requires ffmpeg to write moov atom at the end, which fails when SIGINT interrupts a live HLS recording — the mp4 file has no moov atom and is unplayable (0 bytes effective). Switch to -movflags +frag_keyframe+empty_moov+default_base_moof (fragmented MP4): moov atom written immediately at file start, each segment is self-contained. Even if ffmpeg is killed mid-recording, the file remains fully playable with both video and audio intact. Verified: HLS live stream (CBS News) → 45s 1280x720 h264 + AAC 48kHz, 13MB, SIGINT-safe. Local files unaffected.
310 lines
10 KiB
Swift
310 lines
10 KiB
Swift
import Foundation
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#if os(macOS)
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/// Thread-safe progress state
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final class ProgressState: @unchecked Sendable {
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private var lastTime: String = ""
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private let lock = NSLock()
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func update(_ timeStr: String) -> Bool {
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lock.lock()
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defer { lock.unlock() }
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guard timeStr != lastTime else { return false }
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lastTime = timeStr
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return true
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}
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}
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public final class FFmpegRecorder: StreamRecorderEngine {
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public weak var delegate: StreamRecorderDelegate?
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public private(set) var isRecording = false
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private var process: Process?
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private var duration: Double = 0
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private var stopRequested = false
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public init() {}
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public func start(url: URL, outputPath: String, duration: Double) async throws {
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guard !isRecording else { return }
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self.duration = duration
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// 查找 ffmpeg
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let ffmpegPath = findFFmpeg()
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guard FileManager.default.fileExists(atPath: ffmpegPath) else {
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throw RecordingError.noFFmpeg
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}
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// 解析 HLS 变体
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let resolvedURL = HLSVariantResolver.resolve(url: url, maxWidth: 1280) ?? url
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// 删除已存在的输出文件
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if FileManager.default.fileExists(atPath: outputPath) {
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try? FileManager.default.removeItem(atPath: outputPath)
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}
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// 启动 ffmpeg 进程
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let proc = Process()
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proc.executableURL = URL(fileURLWithPath: ffmpegPath)
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var args = [
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"-y",
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"-i", resolvedURL.absoluteString,
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]
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// duration=0 表示无限录制，不传 -t 参数
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if duration > 0 {
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args += ["-t", String(duration)]
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}
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args += [
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"-c:v", "copy",
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"-c:a", "aac",
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"-b:a", "192k",
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"-movflags", "+frag_keyframe+empty_moov+default_base_moof",
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outputPath
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]
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proc.arguments = args
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let stderrPipe = Pipe()
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proc.standardError = stderrPipe
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proc.standardOutput = FileHandle.nullDevice
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// 解析进度
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let progressState = ProgressState()
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stderrPipe.fileHandleForReading.readabilityHandler = { [weak self] handle in
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guard let self = self else { return }
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let data = handle.availableData
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guard !data.isEmpty else { return }
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let str = String(data: data, encoding: .utf8) ?? ""
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if let timeRange = str.range(of: "time=") {
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let sub = String(str[timeRange.upperBound...])
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if let endRange = sub.range(of: " ") ?? sub.range(of: "\n") ?? sub.range(of: "\r") {
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let timeStr = String(sub[..<endRange.lowerBound])
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if progressState.update(timeStr) {
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if let secs = self.parseTime(timeStr) {
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let progress = RecordingProgress(
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currentTime: secs,
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totalDuration: self.duration,
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bytesWritten: 0,
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bitrate: 1500.0
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)
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self.delegate?.recorder(self, didUpdateProgress: progress)
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}
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}
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}
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}
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}
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isRecording = true
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delegate?.recorderDidStart(self)
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do {
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try proc.run()
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self.process = proc
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} catch {
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isRecording = false
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throw RecordingError.unknown("无法启动 ffmpeg: \(error.localizedDescription)")
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}
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// 等待完成
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proc.waitUntilExit()
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stderrPipe.fileHandleForReading.readabilityHandler = nil
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isRecording = false
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guard proc.terminationStatus == 0 || stopRequested else {
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throw RecordingError.processFailed(Int(proc.terminationStatus))
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}
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guard FileManager.default.fileExists(atPath: outputPath) else {
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throw RecordingError.outputNotFound
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}
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// 分析输出文件
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let ffprobePath = ffmpegPath.replacingOccurrences(of: "ffmpeg", with: "ffprobe")
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let result = try await analyzeOutput(path: outputPath, ffprobePath: ffprobePath)
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delegate?.recorder(self, didFinishWithResult: result)
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}
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public func stop() {
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stopRequested = true
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// 发送 SIGINT (Ctrl+C) 让 ffmpeg 优雅关闭并写出文件头
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if let pid = process?.processIdentifier {
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kill(pid, SIGINT)
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}
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isRecording = false
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}
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// MARK: - Private
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private func findFFmpeg() -> String {
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let paths = [
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"/opt/homebrew/bin/ffmpeg",
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"/usr/local/bin/ffmpeg",
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"/usr/bin/ffmpeg"
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]
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return paths.first { FileManager.default.fileExists(atPath: $0) } ?? "ffmpeg"
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}
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private func parseTime(_ str: String) -> Double? {
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let parts = str.split(separator: ":")
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guard parts.count == 3,
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let h = Double(parts[0]),
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let m = Double(parts[1]),
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let s = Double(parts[2]) else { return nil }
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return h * 3600 + m * 60 + s
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}
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private func analyzeOutput(path: String, ffprobePath: String) async throws -> RecordingResult {
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guard FileManager.default.fileExists(atPath: ffprobePath) else {
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let attrs = try? FileManager.default.attributesOfItem(atPath: path)
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let fileSize = attrs?[.size] as? Int64 ?? 0
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return RecordingResult(
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outputPath: path,
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duration: duration,
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fileSize: fileSize,
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hasVideo: true,
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hasAudio: true,
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videoInfo: nil,
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audioInfo: nil,
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audioLevel: nil
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)
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}
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let proc = Process()
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proc.executableURL = URL(fileURLWithPath: ffprobePath)
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proc.arguments = [
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"-v", "quiet",
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"-print_format", "json",
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"-show_format",
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"-show_streams",
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path
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]
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let pipe = Pipe()
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proc.standardOutput = pipe
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proc.standardError = FileHandle.nullDevice
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do {
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try proc.run()
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proc.waitUntilExit()
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} catch {
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throw RecordingError.unknown("无法分析输出文件")
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}
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let data = pipe.fileHandleForReading.readDataToEndOfFile()
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guard let json = try? JSONSerialization.jsonObject(with: data) as? [String: Any] else {
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throw RecordingError.unknown("无法解析文件信息")
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}
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let format = json["format"] as? [String: Any]
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let fileDuration = Double(format?["duration"] as? String ?? "0") ?? duration
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let fileSize = Int64(format?["size"] as? String ?? "0") ?? 0
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let streams = json["streams"] as? [[String: Any]] ?? []
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var hasVideo = false
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var hasAudio = false
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var videoInfo: VideoInfo?
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var audioInfo: AudioInfo?
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for stream in streams {
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let codecType = stream["codec_type"] as? String ?? ""
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if codecType == "video" {
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hasVideo = true
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videoInfo = VideoInfo(
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codec: stream["codec_name"] as? String ?? "unknown",
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width: stream["width"] as? Int ?? 0,
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height: stream["height"] as? Int ?? 0,
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fps: parseFPS(stream["r_frame_rate"] as? String),
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pixelFormat: stream["pix_fmt"] as? String ?? "unknown"
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)
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} else if codecType == "audio" {
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hasAudio = true
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audioInfo = AudioInfo(
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codec: stream["codec_name"] as? String ?? "unknown",
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sampleRate: Int(stream["sample_rate"] as? String ?? "0") ?? 0,
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channels: stream["channels"] as? Int ?? 0
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)
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}
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}
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let audioLevel = await checkAudioLevel(path: path)
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return RecordingResult(
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outputPath: path,
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duration: fileDuration,
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fileSize: fileSize,
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hasVideo: hasVideo,
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hasAudio: hasAudio,
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videoInfo: videoInfo,
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audioInfo: audioInfo,
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audioLevel: audioLevel
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)
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}
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private func parseFPS(_ str: String?) -> Double {
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guard let str = str else { return 30.0 }
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let parts = str.split(separator: "/")
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guard parts.count == 2,
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let num = Double(parts[0]),
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let den = Double(parts[1]),
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den > 0 else { return 30.0 }
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return num / den
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}
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private func checkAudioLevel(path: String) async -> AudioLevel? {
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let ffmpegPath = findFFmpeg()
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guard FileManager.default.fileExists(atPath: ffmpegPath) else { return nil }
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let proc = Process()
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proc.executableURL = URL(fileURLWithPath: ffmpegPath)
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proc.arguments = [
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"-i", path,
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"-af", "volumedetect",
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"-f", "null",
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"-"
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]
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proc.standardOutput = FileHandle.nullDevice
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let pipe = Pipe()
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proc.standardError = pipe
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do {
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try proc.run()
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proc.waitUntilExit()
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} catch {
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return nil
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}
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let data = pipe.fileHandleForReading.readDataToEndOfFile()
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let str = String(data: data, encoding: .utf8) ?? ""
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var meanVolume: Double?
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var maxVolume: Double?
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if let meanRange = str.range(of: "mean_volume:") {
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let sub = String(str[meanRange.upperBound...])
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if let dbRange = sub.range(of: " dB") {
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let volStr = String(sub[..<dbRange.lowerBound]).trimmingCharacters(in: .whitespaces)
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meanVolume = Double(volStr)
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}
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}
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if let maxRange = str.range(of: "max_volume:") {
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let sub = String(str[maxRange.upperBound...])
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if let dbRange = sub.range(of: " dB") {
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let volStr = String(sub[..<dbRange.lowerBound]).trimmingCharacters(in: .whitespaces)
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maxVolume = Double(volStr)
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}
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}
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guard let mean = meanVolume, let max = maxVolume else { return nil }
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return AudioLevel(
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meanVolume: mean,
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maxVolume: max,
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isSilent: mean < -60
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)
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}
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}
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#endif
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