Add complete stream saving and durable Continue playback

.github/workflows/windows.yml

@@ -0,0 +1,71 @@
+name: Windows portable build
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+    branches: [main]
+  workflow_dispatch:
+
+permissions:
+  contents: read
+
+jobs:
+  windows:
+    runs-on: windows-latest
+    timeout-minutes: 25
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-dotnet@v4
+        with:
+          dotnet-version: '10.0.x'
+      - name: Build self-contained Windows x64 package
+        shell: pwsh
+        run: ./src/Tools/build-portable.ps1
+      - uses: msys2/setup-msys2@v2
+        with:
+          install: gettext
+      - name: Compile translations
+        shell: msys2 {0}
+        run: |
+          set -euo pipefail
+          for po in lang/po/*.po; do
+            language="$(basename "$po" .po)"
+            destination="artifacts/mpv.net-win-x64/Locale/$language/LC_MESSAGES"
+            mkdir -p "$destination"
+            msgfmt "$po" -o "$destination/mpvnet.mo"
+          done
+      - name: Check packaged player and FFmpeg on Windows
+        shell: pwsh
+        run: |
+          $ErrorActionPreference = 'Stop'
+          $package = Join-Path $PWD 'artifacts/mpv.net-win-x64'
+          & "$package/ffmpeg.exe" -version
+          if ($LASTEXITCODE) { throw 'Packaged FFmpeg failed to start.' }
+          $config = Join-Path $env:RUNNER_TEMP 'mpvnet-smoke-config'
+          New-Item $config -ItemType Directory -Force | Out-Null
+          $stdout = Join-Path $env:RUNNER_TEMP 'mpvnet-version.txt'
+          $stderr = Join-Path $env:RUNNER_TEMP 'mpvnet-errors.txt'
+          $process = Start-Process "$package/mpvnet.com" -ArgumentList @(
+            '--version', '--process-instance=multi', "--config-dir=$config"
+          ) -WorkingDirectory $package -RedirectStandardOutput $stdout -RedirectStandardError $stderr -PassThru
+          if (-not $process.WaitForExit(60000)) {
+            $process.Kill($true)
+            throw 'Packaged player startup timed out.'
+          }
+          $output = Get-Content $stdout -Raw
+          Get-Content $stderr
+          Write-Output $output
+          if ($process.ExitCode -ne 0 -or $output -notmatch 'mpv.net v' -or $output -notmatch 'mpv v') {
+            throw 'Packaged player did not initialize libmpv and report its version.'
+          }
+          if (-not (Get-ChildItem "$package/Locale" -Recurse -Filter '*.mo')) {
+            throw 'Compiled translations are missing.'
+          }
+      - name: Upload ready-to-run portable package
+        uses: actions/upload-artifact@v4
+        with:
+          name: mpv.net-win-x64
+          path: artifacts/mpv.net-win-x64/
+          if-no-files-found: error
+          retention-days: 30

docs/manual.md

@@ -13,6 +13,8 @@ Table of contents
 * [Support](#support)
 * [Config Folder](#config-folder)
 * [Input and context menu](#input-and-context-menu)
+* [Continuing interrupted playback](#continuing-interrupted-playback)
+* [Saving a buffered video](#saving-a-buffered-video)
 * [Command Line Interface](#command-line-interface)
 * [Terminal](#terminal)
 * [mpv.net specific commands](#mpvnet-specific-commands)
@@ -132,6 +134,93 @@ The most important files and folders in the config folder are:
 - `script-opts` folder containing user scripts configuration files.
 
 
+Continuing interrupted playback
+-------------------------------
+
+**Continue** is the first item in the right-click context menu, including legacy
+custom menus. It resumes healthy paused playback without discarding its buffer.
+After an interruption, or when playback is stalled, it reopens the last successfully
+checkpointed file/URL at its saved fractional position. After restarting mpv.net,
+click Continue to recover the last playback session. It is also available as
+`script-message-to mpvnet continue` for custom key bindings.
+
+Recovery checkpoints are written once per second while playback advances, and
+immediately after seeking, pausing or changing key playback settings. They include
+the original source, mpv's `watch-later-options` (independent of whether watch-later
+resume is enabled), volume/mute, speed, selected tracks, subtitle/audio delays,
+video adjustments, external tracks, and connection settings such as HTTP headers,
+referrer and yt-dlp format. Continue starts playing even if the checkpoint was
+paused. A failed connection keeps the checkpoint so Continue can be tried again
+after the network returns.
+
+The checkpoint is stored as `continue.json` in the config directory, including
+source URLs and any saved HTTP headers. Writes use a flushed temporary file and
+atomic replacement; `continue.json.bak` retains the previous complete checkpoint
+and is used if the primary file is unreadable. Recovery does not depend on a normal
+exit or shutdown handler. Delete both files to forget the saved session.
+
+An abrupt power loss can lose progress since the last completed checkpoint
+(normally up to one second, plus any storage/system delay). Exact seeking requires
+a seekable source and a reachable server; deleted files, expired direct URLs,
+missing external tracks, and live streams without DVR cannot be restored under
+every condition. A failed or imprecise restore reports an error and preserves the
+checkpoint. This restores playback state, not the previous session's temporary
+downloaded cache; reconnecting may need to buffer again.
+
+
+Saving a buffered video
+-----------------------
+
+Use `File > Save Buffered Video...` in the right-click context menu to save a
+network video as a Matroska (`.mkv`) file with the audio track selected when the
+Save dialog opens. Later track switches do not change that export. Separate audio
+and video sources are combined without re-encoding; the selected audio delay is
+preserved. The menu command is also available as
+`script-message-to mpvnet save-buffered-video` for custom bindings and menus.
+
+You can save before the entire movie is buffered. Complete, verified cached streams
+are reused. Missing beginnings, endings, seek gaps, and audio that was not buffered
+before a track switch are completed automatically in a background player. When
+mpv cannot prove that the selected stream is complete, that stream's source is read
+again from the beginning, rather than splicing potentially mismatched cache
+fragments. This can download more than the missing intervals, especially when
+audio and video share a container. Streams sharing a source are fetched together.
+The foreground playback position, pause state and selected tracks remain unchanged.
+The original connection headers, cookies, proxy and TLS settings are used.
+
+The export checks cached packet continuity, reads missing sources through EOF,
+and verifies that every selected stream keeps its packet count and duration after
+muxing. Original source gaps and legitimately shorter audio tracks are preserved.
+The resulting file is decoded before reporting success, including checking decoder
+error messages even when FFmpeg exits successfully. Bad cached data is fetched
+again automatically. Transient download failures
+are retried up to three times. Choose a destination in the Save dialog; an existing
+destination is replaced only after the complete export is verified. A canceled,
+failed or truncated download leaves the destination intact. Closing mpv.net cancels
+an active export. Temporary export files are removed after completion or failure.
+FFmpeg is included in release packages for validation and lossless muxing. For a
+source build, run `src/Tools/update-mpv.ps1` to obtain FFmpeg alongside libmpv, or
+provide `ffmpeg` on PATH. No FFprobe executable is required by the application.
+
+Network videos keep their last frame open at the end, including in playlists,
+so the buffer can still be saved. Use Next to continue to the next playlist entry.
+Stopping, opening another file, or exiting releases the playback buffer; it does
+not survive restarting the player. An export already started retains its chosen
+source and tracks independently of later foreground playback changes.
+
+Disk caching is enabled by default and the back buffer allows 512 MiB of packet
+metadata (typically sufficient for several hours). Video packets occupy disk space
+in mpv's cache directory, potentially as much as the entire video, while metadata
+still uses RAM. The disk cache is temporary and is removed when the video closes.
+These defaults can be overridden in `mpv.conf` with `cache-on-disk` and
+`demuxer-max-back-bytes`. Reduced or disabled caching makes saving read more from
+the source. mpv's experimental `dump-cache` can temporarily stall playback for a
+large cache export. Verification can also take time on long or high-resolution
+videos, and saving requires disk space for intermediate files as well as the final
+output. A source that stays unavailable must become accessible before saving can
+finish successfully.
+
+
 Input and context menu
 ----------------------
 

src/MpvNet.Windows/GuiCommand.cs

@@ -3,6 +3,8 @@
 using System.Text.Json;
 using System.Text.RegularExpressions;
 using System.Globalization;
+using System.Threading;
+using System.Threading.Tasks;
 using System.Windows.Forms;
 using System.Windows.Interop;
 using System.Windows;
@@ -20,6 +22,9 @@ namespace MpvNet;
 public class GuiCommand
 {
     Dictionary<string, Action<IList<string>>>? _commands;
+    bool _savingBufferedVideo;
+    CancellationTokenSource? _saveCancellation;
+    Task? _saveTask;
 
     public event Action<float>? ScaleWindow;
     public event Action<string>? MoveWindow;
@@ -31,6 +36,7 @@ public class GuiCommand
     public Dictionary<string, Action<IList<string>>> Commands => _commands ??= new()
     {
         ["add-to-path"] = args => AddToPath(),
+        ["continue"] = args => ContinuePlayback(),
         ["edit-conf-file"] = EditCongFile,
         ["load-audio"] = LoadAudio,
         ["load-sub"] = LoadSubtitle,
@@ -40,6 +46,7 @@ public class GuiCommand
         ["open-optical-media"] = Open_DVD_Or_BD_Folder,
         ["reg-file-assoc"] = RegisterFileAssociations,
         ["remove-from-path"] = args => RemoveFromPath(),
+        ["save-buffered-video"] = args => SaveBufferedVideo(),
         ["scale-window"] = args => ScaleWindow?.Invoke(float.Parse(args[0], CultureInfo.InvariantCulture)),
         ["show-about"] = args => ShowDialog(typeof(AboutWindow)),
         ["show-bindings"] = args => ShowBindings(),
@@ -76,6 +83,94 @@ void ShowDialog(Type winType)
         win?.ShowDialog();
     }
 
+    async void ContinuePlayback()
+    {
+        try
+        {
+            await Player.Recovery.ContinueAsync();
+        }
+        catch (OperationCanceledException)
+        {
+            // libmpv cancels pending commands during shutdown.
+        }
+        catch (Exception ex)
+        {
+            Msg.ShowError(ex.Message);
+        }
+    }
+
+    public Task CancelVideoSaveAsync()
+    {
+        _saveCancellation?.Cancel();
+        return _saveTask ?? Task.CompletedTask;
+    }
+
+    async void SaveBufferedVideo()
+    {
+        if (_savingBufferedVideo)
+        {
+            Msg.ShowInfo(_("A buffered video is already being saved."));
+            return;
+        }
+
+        _savingBufferedVideo = true;
+
+        try
+        {
+            long generation = Player.PlaybackGeneration;
+
+            if (!Player.GetPropertyBool("demuxer-via-network"))
+            {
+                Msg.ShowInfo(_("Open a network video before saving its buffer."));
+                return;
+            }
+
+            var selection = BufferedVideo.Capture(Player, generation);
+
+            string title = Player.GetPropertyString("media-title");
+            title = string.Concat(title.Select(c => Path.GetInvalidFileNameChars().Contains(c) ? '_' : c));
+            title = title[..Math.Min(title.Length, 120)].TrimEnd(' ', '.');
+
+            using var dialog = new SaveFileDialog {
+                Title = _("Save Buffered Video"),
+                Filter = _("Matroska video (*.mkv)|*.mkv"),
+                DefaultExt = "mkv",
+                FileName = "video - " + title + ".mkv",
+                OverwritePrompt = true
+            };
+
+            if (dialog.ShowDialog() != DialogResult.OK)
+                return;
+
+            Player.CommandV("show-text", _("Saving buffered video..."), "5000");
+            _saveCancellation = new();
+            _saveTask = BufferedVideo.SaveAsync(Player, dialog.FileName, selection, _saveCancellation.Token,
+                new Progress<string>(message => {
+                    if (_saveCancellation is { IsCancellationRequested: false })
+                        Player.CommandV("show-text", message, int.MaxValue.ToString(CultureInfo.InvariantCulture));
+                }));
+            await _saveTask;
+            if (!_saveCancellation.IsCancellationRequested)
+                Msg.ShowInfo(_("Buffered video saved.") + BR2 + dialog.FileName);
+        }
+        catch (OperationCanceledException)
+        {
+            // libmpv cancels pending commands during shutdown.
+        }
+        catch (Exception ex)
+        {
+            if (_saveCancellation?.IsCancellationRequested != true) Msg.ShowError(ex.Message);
+        }
+        finally
+        {
+            if (_saveTask != null && Player.IsQuitNeeded) Player.CommandV("show-text", "");
+            _saveTask = null;
+            _saveCancellation?.Dispose();
+            _saveCancellation = null;
+            _savingBufferedVideo = false;
+        }
+    }
+
     void LoadSubtitle(IList<string> args)
     {
         using var dialog = new OpenFileDialog();

src/MpvNet.Windows/Resources/editor_conf.txt

@@ -1190,3 +1190,19 @@ file = mpv
 directory = Demuxer
 help = <bytesize> Controls how much the demuxer is allowed to buffer ahead.\nSuffixes such as KiB and MiB are supported.
 url = https://mpv.io/manual/master/#options-demuxer-max-bytes
+
+name = cache-on-disk
+file = mpv
+directory = Cache
+help = Keep cached packets in a temporary disk file instead of RAM, so buffered network videos can be saved. The file is removed when playback closes.\nmpv.net default: yes
+url = https://mpv.io/manual/master/#options-cache-on-disk
+default = yes
+option = yes
+option = no
+
+name = demuxer-max-back-bytes
+file = mpv
+directory = Cache
+help = Maximum past data retained in the cache. With disk caching this limits packet metadata in RAM, not video bytes on disk. Raising it retains more of a watched video for saving.\nmpv.net default: 512MiB
+url = https://mpv.io/manual/master/#options-demuxer-max-back-bytes
+default = 512MiB

src/MpvNet.Windows/WinForms/MainForm.cs

@@ -40,6 +40,7 @@ public partial class MainForm : Form
     int _taskbarButtonCreatedMessage;
     int _cursorAutohide = 1000;
 
+    bool _waitingForVideoSave;
     bool _contextMenuIsReady;
     bool _wasMaximized;
     bool _maxSizeSet;
@@ -69,6 +70,7 @@ public MainForm()
             GuiCommand.Current.ShowMenu += GuiCommand_ShowMenu;
 
             Player.Init(Handle, true);
+            Player.Recovery.Failed += message => Msg.ShowError(message);
 
             Player.ObserveProperty("window-maximized", PropChangeWindowMaximized); // bool methods not working correctly
             Player.ObserveProperty("window-minimized", PropChangeWindowMinimized); // bool methods not working correctly
@@ -1421,9 +1423,22 @@ protected override void OnResize(EventArgs e)
         }
     }
 
-    protected override void OnFormClosing(FormClosingEventArgs e)
+    protected override async void OnFormClosing(FormClosingEventArgs e)
     {
         base.OnFormClosing(e);
+        if (e.Cancel) return;
+        var save = GuiCommand.Current.CancelVideoSaveAsync();
+        if (!save.IsCompleted)
+        {
+            e.Cancel = true;
+            if (_waitingForVideoSave) return;
+            _waitingForVideoSave = true;
+            try { await save; }
+            catch (OperationCanceledException) { }
+            catch (Exception ex) { Terminal.WriteError(ex); }
+            Close();
+            return;
+        }
 
         if (Player.IsQuitNeeded)
             Player.CommandV("quit");