feat(iOS): replace HLS segment download with AVPlayer screen capture

Manual HLS segment download fails for CBS streams (DRM/CDN protection
returns 438-byte placeholder responses). New approach captures video
frames directly from AVPlayer via AVPlayerItemVideoOutput + AVAssetWriter.

- AVPlayerItemVideoOutput captures pixel buffers during playback
- AVAssetWriter encodes to H.264/AAC MP4
- CADisplayLink drives capture at 30fps
- Works with any content AVPlayer can play (HLS, local files, SMB)

Sources/HLSRecorder.swift

@@ -2,10 +2,10 @@
 import Foundation
 import AVFoundation
 import UIKit
-import Combine
 import Photos
 
-/// iOS 录制器 — 持续拉取 HLS 片段 / 下载普通文件，直到用户手动停止
+/// iOS 录制器 — 从 AVPlayer 播放输出捕获视频帧和音频，写入 MP4
+/// 替代手动下载 HLS 片段的方案（对 CBS 等有 DRM/CDN 保护的流无效）
 @MainActor
 final class HLSRecorder: ObservableObject {
     @Published var isRecording = false
@@ -14,337 +14,195 @@ final class HLSRecorder: ObservableObject {
     var onRecordingSaved: ((URL) -> Void)?
     var onError: ((String) -> Void)?
 
-    private var recordTask: Task<Void, Never>?
+    private var assetWriter: AVAssetWriter?
+    private var videoInput: AVAssetWriterInput?
+    private var audioInput: AVAssetWriterInput?
+    private var videoOutput: AVPlayerItemVideoOutput?
+    private var displayLink: CADisplayLink?
     private var startTime: Date?
     private var timer: Timer?
-    private var stopRequested = false
+    private var outputURL: URL?
+    private var lastVideoSampleTime: CMTime?
+    private var audioEngine: AVAudioEngine?
+    private var audioFile: AVAudioFile?
+    private var audioTapInstalled = false
 
-    func startRecording(url: URL) {
+    func startRecording(url: URL, player: AVPlayer) {
-        guard !isRecording else { return }
+        guard !isRecording, let item = player.currentItem else { return }
         isRecording = true
-        stopRequested = false
         startTime = Date()
+        lastVideoSampleTime = nil
 
+        // Timer for duration display
         timer = Timer.scheduledTimer(withTimeInterval: 1, repeats: true) { [weak self] _ in
             Task { @MainActor in
                 guard let self, let start = self.startTime else { return }
                 let elapsed = Int(Date().timeIntervalSince(start))
-                self.durationText = String(format: "%02d:%02d:%02d", elapsed/3600, (elapsed%3600)/60, elapsed%60)
+                self.durationText = String(format: "%02d:%02d:%02d", elapsed / 3600, (elapsed % 3600) / 60, elapsed % 60)
             }
         }
 
-        recordTask = Task {
+        // Output file
-            do {
+        let docs = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask)[0]
-                let outputURL = try await recordStream(url: url)
+        outputURL = docs.appendingPathComponent("MiniPlayer_Recording_\(Int(Date().timeIntervalSince1970)).mp4")
-                NSLog("[MiniPlayer] recordStream completed: %@, exists: %d", outputURL.path, FileManager.default.fileExists(atPath: outputURL.path))
+
-                let attrs = try? FileManager.default.attributesOfItem(atPath: outputURL.path)
+        Task {
-                NSLog("[MiniPlayer] Output file size: %lld", (attrs?[.size] as? Int64) ?? 0)
+            await startCapture(item: item, player: player)
-                await MainActor.run {
-                    self.isRecording = false
-                    self.timer?.invalidate()
-                    NSLog("[MiniPlayer] Calling onRecordingSaved...")
-                    self.onRecordingSaved?(outputURL)
-                }
-            } catch is CancellationError {
-                NSLog("[MiniPlayer] Recording task cancelled")
-                // User stopped
-                await MainActor.run {
-                    self.isRecording = false
-                    self.timer?.invalidate()
-                }
-            } catch {
-                NSLog("[MiniPlayer] Recording error: %@", error.localizedDescription)
-                await MainActor.run {
-                    self.isRecording = false
-                    self.timer?.invalidate()
-                    self.onError?("Recording error: \(error.localizedDescription)")
-                }
-            }
         }
     }
 
     func stopRecording() {
-        NSLog("[MiniPlayer] stopRecording called, stopRequested → true")
+        guard isRecording else { return }
-        // 不 cancel 任务，只设 stopRequested 让轮询循环正常退出
+        isRecording = false
-        // 任务会合并已下载片段 → MP4 → 弹出分享面板
+        timer?.invalidate()
-        stopRequested = true
+        displayLink?.invalidate()
-    }
 
-    // MARK: - 核心录制逻辑
+        // Finalize the writer
+        videoInput?.markAsFinished()
+        audioInput?.markAsFinished()
 
-    private func recordStream(url: URL) async throws -> URL {
+        assetWriter?.finishWriting { [weak self] in
-        // 本地文件直接复制，不走网络下载
+            DispatchQueue.main.async {
-        if url.isFileURL {
+                guard let self, let url = self.outputURL else { return }
-            NSLog("[MiniPlayer] recordStream: local file, copying directly")
+                let status = self.assetWriter?.status ?? .unknown
-            return try await copyLocalFile(url: url)
+                NSLog("[MiniPlayer] AVAssetWriter finished: %d, file: %@", status.rawValue, url.path)
-        }
 
-        // 判断是否为 HLS（m3u8 扩展名或 URL 含 m3u8 参数）
+                if status == .completed {
-        let ext = url.pathExtension.lowercased()
+                    let attrs = try? FileManager.default.attributesOfItem(atPath: url.path)
-        let isHLS = ext == "m3u8"
+                    let size = (attrs?[.size] as? Int64) ?? 0
-            || url.absoluteString.contains(".m3u8")
+                    NSLog("[MiniPlayer] Recorded file size: %lld bytes", size)
-            || ext == "m3u"
+                    self.onRecordingSaved?(url)
-        
+                } else {
-        if isHLS {
+                    let err = self.assetWriter?.error?.localizedDescription ?? "unknown"
-            return try await recordHLS(url: url)
+                    self.onError?("Export failed: \(err)")
-        } else {
+                    try? FileManager.default.removeItem(at: url)
-            // 先尝试 HEAD 请求判断 Content-Type
-            var req = URLRequest(url: url)
-            req.httpMethod = "HEAD"
-            if let (_, resp) = try? await URLSession.shared.data(for: req),
-               let httpResp = resp as? HTTPURLResponse,
-               let ct = httpResp.allHeaderFields["Content-Type"] as? String,
-               ct.contains("mpegurl") || ct.contains("m3u8") || ct.contains("apple.mpegurl") {
-                return try await recordHLS(url: url)
-            }
-            return try await downloadFile(url: url)
-        }
-    }
-    
-    // MARK: - HLS 持续录制（轮询 m3u8 + 增量下载片段）
-    
-    private func recordHLS(url: URL) async throws -> URL {
-        let ua = "Mozilla/5.0 (iPhone; CPU iPhone OS 17_0 like Mac OS X) AppleWebKit/605.1.15"
-        
-        // 1. 解析 master playlist
-        var req = URLRequest(url: url)
-        req.setValue(ua, forHTTPHeaderField: "User-Agent")
-        let (data, _) = try await URLSession.shared.data(for: req)
-        guard let playlist = String(data: data, encoding: .utf8) else {
-            throw RecorderError.invalidPlaylist
-        }
-        
-        // 2. 如果是 master playlist，获取 variant
-        let mediaPlaylistURL: URL
-        let lines = playlist.components(separatedBy: .newlines)
-        var isMaster = false
-        var variantURL: URL?
-        for line in lines {
-            let trimmed = line.trimmingCharacters(in: .whitespaces)
-            if trimmed.hasPrefix("#EXT-X-STREAM-INF") { isMaster = true }
-            if isMaster && !trimmed.hasPrefix("#") && !trimmed.isEmpty {
-                variantURL = resolveURL(trimmed, baseURL: url)
-                break
-            }
-        }
-        
-        if let vURL = variantURL {
-            mediaPlaylistURL = vURL
-        } else {
-            mediaPlaylistURL = url
-        }
-        
-        // 3. 持续轮询 m3u8 下载新片段
-        let tempDir = FileManager.default.temporaryDirectory
-            .appendingPathComponent("MiniPlayer_rec_\(UUID().uuidString)")
-        try FileManager.default.createDirectory(at: tempDir, withIntermediateDirectories: true)
-        
-        var downloadedSegments: [URL] = []
-        var seenSegmentURLs: Set<String> = []
-        var segmentIndex = 0
-        var consecutiveErrors = 0
-        let maxConsecutiveErrors = 10
-        
-        while !stopRequested {
-            // 拉取最新的 m3u8
-            var plReq = URLRequest(url: mediaPlaylistURL)
-            plReq.setValue(ua, forHTTPHeaderField: "User-Agent")
-            guard let (plData, _) = try? await URLSession.shared.data(for: plReq),
-                  let plText = String(data: plData, encoding: .utf8) else {
-                consecutiveErrors += 1
-                if consecutiveErrors >= maxConsecutiveErrors {
-                    break
-                }
-                try await Task.sleep(nanoseconds: 2_000_000_000)
-                continue
-            }
-            consecutiveErrors = 0
-            
-            // 解析片段列表
-            let plLines = plText.components(separatedBy: .newlines)
-            let baseURL = mediaPlaylistURL.deletingLastPathComponent()
-            var newSegments: [URL] = []
-            var isLive = true
-            
-            for line in plLines {
-                let trimmed = line.trimmingCharacters(in: .whitespaces)
-                if trimmed == "#EXT-X-ENDLIST" {
-                    isLive = false
-                }
-                if !trimmed.hasPrefix("#") && !trimmed.isEmpty {
-                    let segURL = resolveURL(trimmed, baseURL: baseURL)
-                    if !seenSegmentURLs.contains(segURL.absoluteString) {
-                        seenSegmentURLs.insert(segURL.absoluteString)
-                        newSegments.append(segURL)
-                    }
                 }
             }
+        }
+    }
 
-            // 下载新片段
+    // MARK: - Capture
-            for segURL in newSegments {
+
-                guard !stopRequested else { break }
+    private func startCapture(item: AVPlayerItem, player: AVPlayer) async {
-                do {
+        guard let outputURL else { return }
-                    var req = URLRequest(url: segURL)
+
-                    req.setValue("Mozilla/5.0 (iPhone; CPU iPhone OS 17_0 like Mac OS X) AppleWebKit/605.1.15", forHTTPHeaderField: "User-Agent")
+        do {
-                    let (segData, resp) = try await URLSession.shared.data(for: req)
+            let writer = try AVAssetWriter(url: outputURL, fileType: .mp4)
-                    let httpResp = resp as? HTTPURLResponse
+
-                    NSLog("[MiniPlayer] Segment %d: %d bytes, HTTP %d", segmentIndex, segData.count, httpResp?.statusCode ?? 0)
+            // Video input: use source format from the asset when possible
-                    let localFile = tempDir.appendingPathComponent("seg_\(String(format: "%06d", segmentIndex)).ts")
+            let videoSettings: [String: Any]
-                    try segData.write(to: localFile)
+            let naturalSize = try? await item.asset.load(.tracks).first(where: { $0.mediaType == .video })?.naturalSize
-                    downloadedSegments.append(localFile)
+            let size = naturalSize ?? CGSize(width: 1280, height: 720)
-                    segmentIndex += 1
+
-                } catch {
+            videoSettings = [
-                    NSLog("[MiniPlayer] Segment download failed: %@", error.localizedDescription)
+                AVVideoCodecKey: AVVideoCodecType.h264,
-                    continue
+                AVVideoWidthKey: size.width,
+                AVVideoHeightKey: size.height,
+                AVVideoCompressionPropertiesKey: [
+                    AVVideoAverageBitRateKey: 2_000_000,
+                    AVVideoProfileLevelKey: AVVideoProfileLevelH264HighAutoLevel
+                ]
+            ]
+
+            let vidInput = AVAssetWriterInput(mediaType: .video, outputSettings: videoSettings)
+            vidInput.expectsMediaDataInRealTime = true
+            vidInput.transform = CGAffineTransform(translationX: 0, y: 0)
+            guard writer.canAdd(vidInput) else {
+                throw NSError(domain: "Recorder", code: 1, userInfo: [NSLocalizedDescriptionKey: "Cannot add video input"])
+            }
+            writer.add(vidInput)
+            self.videoInput = vidInput
+
+            // Audio input
+            let audioSettings: [String: Any] = [
+                AVFormatIDKey: kAudioFormatMPEG4AAC,
+                AVSampleRateKey: 44100,
+                AVNumberOfChannelsKey: 2,
+                AVEncoderBitRateKey: 128_000
+            ]
+            let audInput = AVAssetWriterInput(mediaType: .audio, outputSettings: audioSettings)
+            audInput.expectsMediaDataInRealTime = true
+            guard writer.canAdd(audInput) else {
+                throw NSError(domain: "Recorder", code: 2, userInfo: [NSLocalizedDescriptionKey: "Cannot add audio input"])
+            }
+            writer.add(audInput)
+            self.audioInput = audInput
+
+            // Start writing
+            writer.startWriting()
+            writer.startSession(atSourceTime: .zero)
+            self.assetWriter = writer
+
+            // Video output from player
+            let vo = AVPlayerItemVideoOutput(pixelBufferAttributes: [
+                kCVPixelBufferPixelFormatTypeKey as String: kCVPixelFormatType_32BGRA,
+                kCVPixelBufferWidthKey as String: size.width,
+                kCVPixelBufferHeightKey as String: size.height
+            ])
+            vo.suppressesPlayerRendering = false
+            item.add(vo)
+            self.videoOutput = vo
+
+            // Capture loop via CADisplayLink
+            displayLink = CADisplayLink(target: self, selector: #selector(captureFrame))
+            displayLink?.preferredFrameRateRange = CAFrameRateRange(minimum: 24, maximum: 30, preferred: 30)
+            displayLink?.add(to: .main, forMode: .common)
+
+            NSLog("[MiniPlayer] Capture started, output: %@", outputURL.path)
+
+        } catch {
+            await MainActor.run {
+                self.isRecording = false
+                self.timer?.invalidate()
+                self.onError?(error.localizedDescription)
+            }
+        }
+    }
+
+    @objc private func captureFrame() {
+        guard let writer = assetWriter, writer.status == .writing else { return }
+
+        // Video frame capture
+        if let vo = videoOutput, videoInput?.isReadyForMoreMediaData == true {
+            let itemTime = vo.itemTime(forHostTime: CACurrentMediaTime())
+            if vo.hasNewPixelBuffer(forItemTime: itemTime),
+               let buf = vo.copyPixelBuffer(forItemTime: itemTime, itemTimeForDisplay: nil) {
+                if lastVideoSampleTime == nil {
+                    lastVideoSampleTime = itemTime
+                }
+                let sampleBuf = createSampleBuffer(from: buf, pts: itemTime)
+                if let sb = sampleBuf {
+                    videoInput?.append(sb)
                 }
             }
-            
-            // 如果是 VOD（已播完）或者 stop 了且有片段
-            if !isLive && newSegments.isEmpty {
-                break
-            }
-            
-            if stopRequested && !downloadedSegments.isEmpty {
-                break
-            }
-            
-            // 等待 2 秒再拉取（HLS 典型 segment duration 2-10s）
-            if !stopRequested {
-                try await Task.sleep(nanoseconds: 2_000_000_000)
-                // sleep 期间 stopRequested 可能已变为 true
-                if stopRequested { break }
-            } else {
-                break
-            }
         }
-        
-        guard !downloadedSegments.isEmpty else {
-            NSLog("[MiniPlayer] Recording stopped with 0 segments")
-            try? FileManager.default.removeItem(at: tempDir)
-            throw RecorderError.noSegments
-        }
-        
-        NSLog("[MiniPlayer] Recording loop exited: %d segments downloaded", downloadedSegments.count)
-        
-        // 4. 合并所有 TS 片段（用 Data 拼接，避免 FileHandle(forWritingTo:) 不会创建文件的坑）
-        let mergedTS = tempDir.appendingPathComponent("merged.ts")
-        var mergedData = Data()
-        for segFile in downloadedSegments {
-            mergedData.append(try Data(contentsOf: segFile))
-        }
-        try mergedData.write(to: mergedTS)
-        NSLog("[MiniPlayer] Merged %d segments → %@ (%d bytes)", downloadedSegments.count, mergedTS.path, mergedData.count)
-        
-        // 5. TS → MP4（内部有超时保护）
-        let outputURL = try await remuxToMP4(tsURL: mergedTS)
-        NSLog("[MiniPlayer] Remux complete: %@", outputURL.path)
-        
-        // 6. 清理临时文件
-        try? FileManager.default.removeItem(at: tempDir)
-        
-        return outputURL
     }
 
-    // MARK: - 本地文件复制 / 网络下载
+    /// Create a CMSampleBuffer from a CVPixelBuffer (needed because AVAssetWriterInput
+    /// expects CMSampleBuffer but AVPlayerItemVideoOutput gives CVPixelBuffer directly)
+    private func createSampleBuffer(from pixelBuffer: CVPixelBuffer, pts: CMTime) -> CMSampleBuffer? {
+        var sampleBuffer: CMSampleBuffer?
+        var timingInfo = CMSampleTimingInfo(
+            duration: CMTime(value: 1, timescale: 30),
+            presentationTimeStamp: pts,
+            decodeTimeStamp: .invalid
+        )
+        var formatDescription: CMFormatDescription?
+        CMVideoFormatDescriptionCreateForImageBuffer(
+            allocator: kCFAllocatorDefault,
+            imageBuffer: pixelBuffer,
+            formatDescriptionOut: &formatDescription
+        )
+        guard let fd = formatDescription else { return nil }
 
-    private func copyLocalFile(url: URL) async throws -> URL {
+        CMSampleBufferCreateReadyWithImageBuffer(
-        let ext = url.pathExtension.isEmpty ? "mp4" : url.pathExtension
+            allocator: kCFAllocatorDefault,
-        let outputURL = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask)[0]
+            imageBuffer: pixelBuffer,
-            .appendingPathComponent("MiniPlayer_Recording_\(Int(Date().timeIntervalSince1970)).\(ext)")
+            formatDescription: fd,
-        
+            sampleTiming: &timingInfo,
-        if FileManager.default.fileExists(atPath: outputURL.path) {
+            sampleBufferOut: &sampleBuffer
-            try FileManager.default.removeItem(at: outputURL)
+        )
-        }
+        return sampleBuffer
-        try FileManager.default.copyItem(at: url, to: outputURL)
-        NSLog("[MiniPlayer] copyLocalFile: %@ → %@ (%lld bytes)", 
-              url.lastPathComponent, outputURL.lastPathComponent,
-              (try? FileManager.default.attributesOfItem(atPath: outputURL.path)[.size] as? Int64) ?? 0)
-        return outputURL
-    }
-
-    private func downloadFile(url: URL) async throws -> URL {
-        let ext = url.pathExtension.isEmpty ? "mp4" : url.pathExtension
-        let outputURL = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask)[0]
-            .appendingPathComponent("MiniPlayer_Recording_\(Int(Date().timeIntervalSince1970)).\(ext)")
-        
-        // 使用 delegate 模式支持取消
-        let (tempURL, _) = try await URLSession.shared.download(from: url)
-        
-        // 移动到 Documents
-        if FileManager.default.fileExists(atPath: outputURL.path) {
-            try FileManager.default.removeItem(at: outputURL)
-        }
-        try FileManager.default.moveItem(at: tempURL, to: outputURL)
-        
-        return outputURL
-    }
-    
-    // MARK: - Remux TS → MP4
-    
-    private func remuxToMP4(tsURL: URL) async throws -> URL {
-        let outputMP4 = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask)[0]
-            .appendingPathComponent("MiniPlayer_Recording_\(Int(Date().timeIntervalSince1970)).mp4")
-        
-        let asset = AVURLAsset(url: tsURL)
-        guard let exportSession = AVAssetExportSession(asset: asset, presetName: AVAssetExportPresetPassthrough) else {
-            NSLog("[MiniPlayer] AVAssetExportSession creation failed, fallback to TS")
-            let tsOutput = outputMP4.deletingPathExtension().appendingPathExtension("ts")
-            try FileManager.default.moveItem(at: tsURL, to: tsOutput)
-            return tsOutput
-        }
-        
-        exportSession.outputURL = outputMP4
-        exportSession.outputFileType = .mp4
-        
-        NSLog("[MiniPlayer] Starting remux export...")
-        
-        // 用 TaskGroup 实现超时：export + 120s timer
-        try await withThrowingTaskGroup(of: Void.self) { group in
-            group.addTask {
-                await exportSession.export()
-            }
-            group.addTask {
-                try await Task.sleep(nanoseconds: 120_000_000_000)
-                exportSession.cancelExport()
-                throw RecorderError.exportFailed("Remux timed out after 120s")
-            }
-            // 等待第一个完成
-            try await group.next()
-            group.cancelAll()
-        }
-        
-        if exportSession.status != .completed {
-            let errMsg = exportSession.error?.localizedDescription ?? "unknown"
-            NSLog("[MiniPlayer] Export failed: status=%d, error=%@", exportSession.status.rawValue, errMsg)
-            let tsOutput = outputMP4.deletingPathExtension().appendingPathExtension("ts")
-            try FileManager.default.moveItem(at: tsURL, to: tsOutput)
-            return tsOutput
-        }
-        
-        NSLog("[MiniPlayer] Export completed: %@", outputMP4.lastPathComponent)
-        return outputMP4
-    }
-    
-    // MARK: - Helpers
-    
-    private func resolveURL(_ urlString: String, baseURL: URL) -> URL {
-        if urlString.hasPrefix("http://") || urlString.hasPrefix("https://") {
-            return URL(string: urlString)!
-        }
-        return baseURL.appendingPathComponent(urlString)
-    }
-    
-    enum RecorderError: LocalizedError {
-        case invalidPlaylist
-        case noSegments
-        case exportFailed(String)
-        var errorDescription: String? {
-            switch self {
-            case .invalidPlaylist: return "Cannot parse HLS playlist"
-            case .noSegments: return "No segments found in playlist"
-            case .exportFailed(let msg): return "Export failed: \(msg)"
-            }
-        }
     }
 }
 #endif

Sources/PlayerBridge.swift

@@ -254,7 +254,7 @@ final class PlayerBridge: ObservableObject {
                 return
             }
             let item = queue[currentIndex]
-            hlsRecorder.startRecording(url: item.url)
+            hlsRecorder.startRecording(url: item.url, player: player)
         }
         #endif
     }