diff --git a/Sources/PlayerRecorder.swift b/Sources/PlayerRecorder.swift
index 33e90b9..8608bd3 100644
--- a/Sources/PlayerRecorder.swift
+++ b/Sources/PlayerRecorder.swift
@@ -318,101 +318,95 @@ final class PlayerRecorder: NSObject {
     
     // MARK: - Audio Tap Setup
     
-    /// 异步安装音频 Tap（HLS 流需要异步加载 tracks）
+    /// 安装音频 Tap（使用 playerItem.tracks 获取轨道，支持 HLS 虚拟 asset）
     private func installAudioTap(on playerItem: AVPlayerItem) {
         // 确保全局上下文存在
         if gTapContext == nil {
             gTapContext = AudioTapContext()
         }
+        guard let ctx = gTapContext else { return }
         
-        Task { @MainActor in
-            guard let ctx = gTapContext else { return }
-            
-            print("[Recorder:DIAG] === installAudioTap START (async) ===")
-            print("[Recorder:DIAG] asset class: \(type(of: playerItem.asset))")
-            
-            // HLS 流的 tracks 是异步加载的，必须用 loadTracks
-            let audioTracks: [AVAssetTrack]
-            do {
-                audioTracks = try await playerItem.asset.loadTracks(withMediaType: .audio)
-            } catch {
-                print("[Recorder:DIAG] ⚠️ loadTracks failed: \(error)")
-                // 写诊断日志
-                writeDiagLog("loadTracks error: \(error)")
-                return
+        print("[Recorder:DIAG] === installAudioTap START ===")
+        
+        // HLS 虚拟 asset 的 asset.tracks 为空，必须用 playerItem.tracks
+        let itemTracks = playerItem.tracks
+        print("[Recorder:DIAG] playerItem.tracks count: \(itemTracks.count)")
+        
+        // 找到音频轨道
+        var audioTrackID: CMPersistentTrackID = kCMPersistentTrackID_Invalid
+        for (i, t) in itemTracks.enumerated() {
+            let tid = t.assetTrack?.trackID ?? -1
+            let mediaType = t.assetTrack?.mediaType.rawValue ?? "?"
+            let enabled = t.isEnabled
+            print("[Recorder:DIAG]   itemTrack[\(i)]: trackID=\(tid) mediaType=\(mediaType) enabled=\(enabled)")
+            if t.assetTrack?.mediaType == .audio && t.isEnabled {
+                audioTrackID = tid
             }
-            
-            guard let audioTrack = audioTracks.first else {
-                print("[Recorder:DIAG] ⚠️ No audio track found after async load!")
-                writeDiagLog("No audio tracks found")
-                return
-            }
-            
-            print("[Recorder:DIAG] Using audio trackID=\(audioTrack.trackID)")
-            
-            // 列出所有 tracks 用于诊断
-            let allTracks = try? await playerItem.asset.load(.tracks)
-            if let tracks = allTracks {
-                for (i, t) in tracks.enumerated() {
-                    print("[Recorder:DIAG]   track[\(i)]: ID=\(t.trackID) mediaType=\(t.mediaType.rawValue)")
-                }
-            }
-            
-            // 创建 MTAudioProcessingTap
-            var callbacks = MTAudioProcessingTapCallbacks(
-                version: kMTAudioProcessingTapCallbacksVersion_0,
-                clientInfo: Unmanaged.passUnretained(ctx).toOpaque(),
-                init: tapInit,
-                finalize: tapFinalize,
-                prepare: tapPrepare,
-                unprepare: tapUnprepare,
-                process: tapProcess
-            )
-            
-            var tap: MTAudioProcessingTap?
-            let tapStatus = MTAudioProcessingTapCreate(
-                kCFAllocatorDefault, &callbacks,
-                kMTAudioProcessingTapCreationFlag_PreEffects,
-                &tap
-            )
-            print("[Recorder:DIAG] MTAudioProcessingTapCreate status=\(tapStatus) (noErr=\(noErr))")
-            guard tapStatus == noErr, let tapRef = tap else {
-                print("[Recorder:DIAG] ⚠️ Tap creation failed!")
-                return
-            }
-            
-            // 创建 AudioMix
-            let inputParams = AVMutableAudioMixInputParameters()
-            inputParams.trackID = audioTrack.trackID
-            inputParams.audioTapProcessor = tapRef
-            
-            let audioMix = AVMutableAudioMix()
-            audioMix.inputParameters = [inputParams]
-            
-            playerItem.audioMix = audioMix
-            
-            // 验证
-            let verifyMix = playerItem.audioMix
-            print("[Recorder:DIAG] playerItem.audioMix set=\(verifyMix != nil)")
-            if let vMix = verifyMix, let params = vMix.inputParameters.first {
-                print("[Recorder:DIAG] verified trackID=\(params.trackID)")
-            }
-            print("[Recorder:DIAG] === installAudioTap DONE ===")
-            
-            ctx.mixTrackID = audioTrack.trackID
-            
-            // 写诊断日志
-            var diagLog = "=== installAudioTap Log ===\n"
-            diagLog += "Time: \(Date())\n"
-            diagLog += "Asset class: \(type(of: playerItem.asset))\n"
-            diagLog += "Audio trackID used: \(audioTrack.trackID)\n"
-            diagLog += "TapCreate status: \(tapStatus)\n"
-            diagLog += "audioMix set: \(verifyMix != nil)\n"
-            if let vMix = verifyMix, let params = vMix.inputParameters.first {
-                diagLog += "Verified trackID: \(params.trackID)\n"
-            }
-            writeDiagLog(diagLog)
         }
+        
+        guard audioTrackID != kCMPersistentTrackID_Invalid else {
+            print("[Recorder:DIAG] ⚠️ No enabled audio track in playerItem.tracks!")
+            writeDiagLog("No audio track in playerItem.tracks (count=\(itemTracks.count))")
+            return
+        }
+        
+        print("[Recorder:DIAG] Using audio trackID=\(audioTrackID)")
+        
+        // 创建 MTAudioProcessingTap
+        var callbacks = MTAudioProcessingTapCallbacks(
+            version: kMTAudioProcessingTapCallbacksVersion_0,
+            clientInfo: Unmanaged.passUnretained(ctx).toOpaque(),
+            init: tapInit,
+            finalize: tapFinalize,
+            prepare: tapPrepare,
+            unprepare: tapUnprepare,
+            process: tapProcess
+        )
+        
+        var tap: MTAudioProcessingTap?
+        let tapStatus = MTAudioProcessingTapCreate(
+            kCFAllocatorDefault, &callbacks,
+            kMTAudioProcessingTapCreationFlag_PreEffects,
+            &tap
+        )
+        print("[Recorder:DIAG] MTAudioProcessingTapCreate status=\(tapStatus) (noErr=\(noErr))")
+        guard tapStatus == noErr, let tapRef = tap else {
+            print("[Recorder:DIAG] ⚠️ Tap creation failed!")
+            return
+        }
+        
+        // 创建 AudioMix
+        let inputParams = AVMutableAudioMixInputParameters()
+        inputParams.trackID = audioTrackID
+        inputParams.audioTapProcessor = tapRef
+        
+        let audioMix = AVMutableAudioMix()
+        audioMix.inputParameters = [inputParams]
+        
+        playerItem.audioMix = audioMix
+        
+        // 验证
+        let verifyMix = playerItem.audioMix
+        print("[Recorder:DIAG] playerItem.audioMix set=\(verifyMix != nil)")
+        if let vMix = verifyMix, let params = vMix.inputParameters.first {
+            print("[Recorder:DIAG] verified trackID=\(params.trackID)")
+        }
+        print("[Recorder:DIAG] === installAudioTap DONE ===")
+        
+        ctx.mixTrackID = audioTrackID
+        
+        // 写诊断日志
+        var diagLog = "=== installAudioTap Log ===\n"
+        diagLog += "Time: \(Date())\n"
+        diagLog += "Source: playerItem.tracks\n"
+        diagLog += "playerItem.tracks count: \(itemTracks.count)\n"
+        for (i, t) in itemTracks.enumerated() {
+            diagLog += "  itemTrack[\(i)]: trackID=\(t.assetTrack?.trackID ?? -1) mediaType=\(t.assetTrack?.mediaType.rawValue ?? "?") enabled=\(t.isEnabled)\n"
+        }
+        diagLog += "Audio trackID used: \(audioTrackID)\n"
+        diagLog += "TapCreate status: \(tapStatus)\n"
+        diagLog += "audioMix set: \(verifyMix != nil)\n"
+        writeDiagLog(diagLog)
     }
     
     private func writeDiagLog(_ content: String) {