Improve VLC webm stability

swiftchan/Services/CacheService.swift

@@ -109,4 +109,14 @@ final class CacheManager {
         }
     }
 
+    /// Basic validation to ensure cached WebM files are not corrupted.
+    func isValidWebm(file: URL) -> Bool {
+        guard let handle = try? FileHandle(forReadingFrom: file) else { return false }
+        let header = handle.readData(ofLength: 4)
+        handle.closeFile()
+        let bytes = [UInt8](header)
+        // EBML header 0x1A45DFA3
+        return bytes.count == 4 && bytes[0] == 0x1A && bytes[1] == 0x45 && bytes[2] == 0xDF && bytes[3] == 0xA3
+    }
+
 }

swiftchan/ViewModels/VLCVideoViewModel.swift

@@ -18,16 +18,22 @@ class VLCVideoViewModel {
 
     func download() async throws {
         let cacheURL = CacheManager.shared.cacheURL(video.url)
-        guard !CacheManager.shared.cacheHit(file: cacheURL) else {
-            markDownloadFinished()
-            return
+        if CacheManager.shared.cacheHit(file: cacheURL) {
+            if CacheManager.shared.isValidWebm(file: cacheURL) {
+                video = video.with(url: cacheURL)
+                markDownloadFinished()
+                return
+            } else {
+                try? FileManager.default.removeItem(at: cacheURL)
+            }
         }
 
         debugPrint("Downloading webm: \(cacheURL)")
         let (tempURL, _) = try await URLSession.shared.download(from: video.url, progress: video.downloadProgress)
         debugPrint("Completed Downloading webm: \(cacheURL)")
 
-        guard let cached = CacheManager.shared.cache(tempURL, cacheURL) else { return }
+        guard let cached = CacheManager.shared.cache(tempURL, cacheURL),
+              CacheManager.shared.isValidWebm(file: cached) else { return }
 
         // Update URL and mark download complete
         video = video.with(url: cached)

swiftchan/Views/Media/VLC/VLCContainerView.swift

@@ -58,33 +58,25 @@ struct VLCContainerView: View {
                 }
             }
         }
-        .onChange(of: vlcVideoViewModel.video.downloadProgress.isFinished) {
-            if vlcVideoViewModel.video.downloadProgress.isFinished && isSelected {
-                print("PLaying video 1: \(vlcVideoViewModel.video.url)")
-                vlcVideoViewModel.play()
-            }
-        }
         .onChange(of: isSelected) {
             if isSelected && vlcVideoViewModel.video.downloadProgress.isFinished {
-                print("PLaying video 2: \(vlcVideoViewModel.video.url)")
                 vlcVideoViewModel.play()
-            } else {
+            } else if !isSelected {
                 vlcVideoViewModel.pause()
             }
         }
         .onAppear {
             UIApplication.shared.isIdleTimerDisabled = true
-            if isSelected {
-                print("PLaying video 3: \(vlcVideoViewModel.video.url)")
-                vlcVideoViewModel.play()
-            }
         }
         .onDisappear {
             vlcVideoViewModel.pause()
             appState.vlcPlayerControlModifier = nil
         }
         .task {
             try? await vlcVideoViewModel.download()
+            if isSelected {
+                vlcVideoViewModel.play()
+            }
         }
     }
 }

swiftchan/Views/Media/VLC/VLCMediaListPlayerUIView.swift

@@ -19,6 +19,7 @@ class VLCMediaListPlayerUIView: UIView, VLCMediaPlayerDelegate {
     private weak var delegate: VLCMediaPlayerDelegate?
     let mediaListPlayer = VLCMediaListPlayer()
     var media: VLCMedia?
+    private var currentMediaURL: URL?
 
     init(url: URL, frame: CGRect = .zero) {
         self.url = url
@@ -27,18 +28,40 @@ class VLCMediaListPlayerUIView: UIView, VLCMediaPlayerDelegate {
 
     /// Initialize the media with options and setup the media player.
     func initialize(url: URL) {
+        guard currentMediaURL != url || mediaListPlayer.mediaPlayer.media == nil else { return }
+        resetPlayer()
         media = VLCMedia(url: url)
         if let media = media {
             media.addOption("-vv")
             mediaListPlayer.rootMedia = media
             mediaListPlayer.mediaPlayer.media = media
             mediaListPlayer.mediaPlayer.drawable = self
+            mediaListPlayer.mediaPlayer.delegate = delegate
             mediaListPlayer.repeatMode = .repeatCurrentItem
-            //mediaListPlayer.mediaPlayer.delegate = self.delegate
 
             #if DEBUG
             mediaListPlayer.mediaPlayer.audio?.isMuted = true
             #endif
+            currentMediaURL = url
+        }
+    }
+
+    /// Safely stop playback and release current media.
+    private func resetPlayer() {
+        let cleanup = {
+            self.mediaListPlayer.stop()
+            self.mediaListPlayer.mediaPlayer.stop()
+            self.mediaListPlayer.mediaPlayer.delegate = nil
+            self.mediaListPlayer.mediaPlayer.drawable = nil
+            self.mediaListPlayer.mediaPlayer.media = nil
+            self.mediaListPlayer.rootMedia = nil
+            self.currentMediaURL = nil
+        }
+
+        if Thread.isMainThread {
+            cleanup()
+        } else {
+            DispatchQueue.main.async(execute: cleanup)
         }
     }
 
@@ -113,10 +136,7 @@ class VLCMediaListPlayerUIView: UIView, VLCMediaPlayerDelegate {
     /// Clean up the media player to prevent callbacks on deallocated objects.
     public static func dismantleUIView(_ uiView: VLCMediaListPlayerUIView, coordinator: VLCVideoView.Coordinator) {
         DispatchQueue.main.async {
-            uiView.mediaListPlayer.mediaPlayer.delegate = nil
-            uiView.mediaListPlayer.mediaPlayer.drawable = nil
-            uiView.mediaListPlayer.stop()
-            uiView.mediaListPlayer.rootMedia = nil
+            uiView.resetPlayer()
         }
     }
 
@@ -126,11 +146,7 @@ class VLCMediaListPlayerUIView: UIView, VLCMediaPlayerDelegate {
 
     deinit {
         debugPrint("🧹 VLCMediaListPlayerUIView deinit")
-        mediaListPlayer.stop()
-        mediaListPlayer.mediaPlayer.delegate = nil
-        mediaListPlayer.mediaPlayer.drawable = nil
-        mediaListPlayer.rootMedia = nil
-        mediaListPlayer.mediaPlayer.media = nil
+        resetPlayer()
     }
 
     func setDelegate(_ delegate: VLCMediaPlayerDelegate) {

swiftchan/Views/Media/VLC/VLCVideoView.swift

@@ -43,15 +43,7 @@ struct VLCVideoView: UIViewRepresentable {
     }
 
     public static func dismantleUIView(_ uiView: VLCMediaListPlayerUIView, coordinator: VLCVideoView.Coordinator) {
-        DispatchQueue.main.async {
-            // Detach delegate and clear drawable to avoid callbacks on deallocated objects
-            uiView.mediaListPlayer.mediaPlayer.delegate = nil
-            uiView.mediaListPlayer.mediaPlayer.drawable = nil
-            // Stop and clear the media to ensure proper cleanup
-            uiView.mediaListPlayer.stop()
-            uiView.mediaListPlayer.mediaPlayer.media = nil
-            uiView.mediaListPlayer.rootMedia = nil
-        }
+        VLCMediaListPlayerUIView.dismantleUIView(uiView, coordinator: coordinator)
     }
 
     // MARK: Coordinator

swiftchanTests/WebmValidationTests.swift

@@ -0,0 +1,11 @@
+import XCTest
+@testable import swiftchan
+
+final class WebmValidationTests: XCTestCase {
+    func testValidWebmHeader() throws {
+        let url = FileManager.default.temporaryDirectory.appendingPathComponent("sample.webm")
+        let bytes: [UInt8] = [0x1A, 0x45, 0xDF, 0xA3]
+        try Data(bytes).write(to: url)
+        XCTAssertTrue(CacheManager.shared.isValidWebm(file: url))
+    }
+}