v5 pre-release: multi-track drift fix, more self-tests, logging, CLI, version bump

Multi-track recording drift fix (Ed's question — can the separate tracks drift over an hour?):
 * Root: FlushPeerTracks skipped a peer that produced no samples in a render block, so a peer that
   went quiet long enough for its session to be pruned (>4 s idle) would have its track fall behind
   and desync. Now every peer track is padded to a full render block each cycle (silence when the
   peer produced nothing), so all peer tracks stay sample-locked to the single render clock — they
   can't drift apart however long the recording runs, and all end the same length. Same padding for
   the single-file bypass path. OnRecordBlockComplete now carries the block's float count.
   (The peer tracks are already resampled to the render clock per peer, so this makes peer-to-peer
   sync exact; your own "me" track is capture-clocked — same soundcard for capture+playback = same
   clock = no drift, different interfaces can drift slightly.)

 * Self-test: two new steps — "Per-peer shaping DSP" (PeerDspChain unity/master-off/volume/parametric
   + ParametricToPeaking) and "v5 settings and shaping round-trip" (AppConfig defaults, NamedPeers,
   MainTabOrder, parametric PeerShaping, recording default = Both).
 * Logging (gated by the logging checkbox): master shaping switch, EQ-mode change, parametric band
   add/delete, peer rename/clear/delete, and the applied Appearance settings after Preferences close.
 * CLI: --list-profiles and --list-named-peers (read-only), in --help.
 * Version bumped to 5.0; About-box changelog, RELEASE_NOTES.md and README updated for v5.

Build clean; --selftest passes.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/RemSound.App/AboutDialog.cs

@@ -20,6 +20,18 @@ internal sealed class AboutDialog : Form
     /// updates" path.</summary>
     private const string ReleaseNotes =
         """
+        RemSound v5.0
+
+        A big one. Shape each person, record everyone separately, name your peers, and make the window your own.
+
+        Shape each peer. A new "Volume, pan and EQ for peers" tab lets you set how loud each connected person is, lean them left or right, and change their tone with an equaliser — a simple 3-band, a 12-band graphic, or a full 16-band parametric where you place each band yourself. It's all live, adds no delay, and what you dial in is captured in your recordings too.
+
+        Record everyone on their own track. Recording can now save each connected peer to its own separate file, so you can take a jam or a chat away and mix the parts afterwards.
+
+        Name your peers. Give the people you connect to friendly names that stick to their machine for good, and a new details view shows who's connected, for how long, and what they're sending. Manage them all under Options, Manage named peers.
+
+        Make it yours. RemSound now follows your Windows light or dark theme, has a fresh look and its own icon, and a new Appearance tab in Preferences lets you reorder or hide the window's tabs. Jump straight to any tab with Ctrl and its number.
+
         RemSound v4.9
 
         Lock a profile to fixed addresses.

src/RemSound.App/CommandLine.cs

@@ -80,6 +80,10 @@ internal static class CommandLine
                     return WithConsole(PrintVersion);
                 case "--devices": case "--list-devices":
                     return WithConsole(() => { WriteDevices(Console.Out); return 0; });
+                case "--profiles": case "--list-profiles":
+                    return WithConsole(ListProfiles);
+                case "--named-peers": case "--list-named-peers":
+                    return WithConsole(ListNamedPeers);
                 case "--selftest": case "--self-test": case "--smoke-test": case "--smoketest":
                     return WithConsole(() => SelfTest.Run(args));
                 case "--perftest": case "--perf-test":
@@ -139,6 +143,37 @@ internal static class CommandLine
         return 0;
     }
 
+    /// <summary>--list-profiles: print the saved profile titles (read-only).</summary>
+    private static int ListProfiles()
+    {
+        var cfg = AppConfig.Load();
+        var store = new ProfileStore(cfg.ProfilesDirectory ?? AppConfig.ProfilesBaseDirectory);
+        var titles = store.ListProfileTitles();
+        if (titles.Count == 0) { Console.WriteLine("No saved profiles."); return 0; }
+        Console.WriteLine($"Saved profiles ({titles.Count}):");
+        foreach (var t in titles) Console.WriteLine($"  {t}");
+        return 0;
+    }
+
+    /// <summary>--list-named-peers: print the machine-wide named-peers book (read-only) — the friendly
+    /// names you've given peers, with where and when each was last seen.</summary>
+    private static int ListNamedPeers()
+    {
+        var named = AppConfig.Load().NamedPeers;
+        if (named.Count == 0) { Console.WriteLine("No named peers."); return 0; }
+        Console.WriteLine($"Named peers ({named.Count}):");
+        foreach (var kv in named.OrderBy(k => k.Value.FriendlyName, StringComparer.CurrentCultureIgnoreCase))
+        {
+            var np = kv.Value;
+            var seen = np.LastSeenUtc == default
+                ? "not seen yet"
+                : $"last seen {np.LastSeenUtc.ToLocalTime():d MMM yyyy}"
+                  + (string.IsNullOrWhiteSpace(np.LastAddress) ? "" : $", {np.LastAddress}");
+            Console.WriteLine($"  {np.FriendlyName}  ({np.MachineName})  - {seen}");
+        }
+        return 0;
+    }
+
     private static int PrintHelp()
     {
         Console.WriteLine($"RemSound {AppVersion} - command-line options");
@@ -150,6 +185,9 @@ internal static class CommandLine
         Console.WriteLine("  --version             Show the installed version.");
         Console.WriteLine("  --devices             List all microphones, outputs and ASIO drivers,");
         Console.WriteLine("                        with their formats and device ids.");
+        Console.WriteLine("  --list-profiles       List your saved profile names.");
+        Console.WriteLine("  --list-named-peers    List the friendly names you've given peers, with");
+        Console.WriteLine("                        where and when each was last seen.");
         Console.WriteLine("  --selftest [--seconds N]  Run the built-in self-test - a localhost audio");
         Console.WriteLine("  (or --smoke-test)     round-trip plus checks of encryption, the wire format,");
         Console.WriteLine("                        settings, profiles, dialog accessibility and bundled files.");

src/RemSound.App/MainForm.cs

@@ -2599,6 +2599,8 @@ public sealed class MainForm : Form
         // Appearance-tab changes (tab order, show pan/EQ tab, show discovered/remembered lists) apply now.
         ApplyMainTabLayout();
         RefreshConnectivityListVisibility();
+        var appearanceCfg = AppConfig.Load();
+        logFile.Event($"appearance applied: theme={appearanceCfg.ThemeMode}, tabs=[{string.Join(", ", mainTabControl.TabPages.Cast<TabPage>().Select(t => t.Text))}], discovered-list={appearanceCfg.ShowDiscoveredPeers}, remembered-list={appearanceCfg.ShowRememberedPeers}");
         // The Preferences dialog includes per-cue Browse buttons that can change custom
         // WAV paths in AppConfig.CustomCuePaths. Reload the cached SoundPlayer instances
         // here unconditionally — cheap, only six small files, and guarantees the next
@@ -3260,7 +3262,7 @@ public sealed class MainForm : Form
         var panel = new TableLayoutPanel { Dock = DockStyle.Fill, Padding = new Padding(12), ColumnCount = 1, RowCount = 9, AutoScroll = true };
         panel.ColumnStyles.Add(new ColumnStyle(SizeType.Percent, 100));
 
-        enableAllPeerShapingBox.CheckedChanged += (_, _) => { if (!loadingPanEqControls) { MarkProfileDirty(); ApplyAllPeerShaping(); } };
+        enableAllPeerShapingBox.CheckedChanged += (_, _) => { if (!loadingPanEqControls) { logFile.Event($"shaping: master switch {(enableAllPeerShapingBox.Checked ? "on" : "off")} ({peerShaping.Count} peer(s) with saved shaping)"); MarkProfileDirty(); ApplyAllPeerShaping(); } };
         panEqPeerList.SelectedIndexChanged += (_, _) => OnPanEqPeerSelected();
         panEqPeerList.ItemCheck += OnPeerShapeToggled;
         // First-letter navigation on some Windows configs can accidentally toggle the checkbox; do the
@@ -3520,7 +3522,9 @@ public sealed class MainForm : Form
     private void OnEqModeChanged()
     {
         if (loadingPanEqControls || selectedShapingKey is null) return;
-        GetOrCreateShaping(selectedShapingKey).EqMode = ModeForIndex(eqModeList.SelectedIndex);
+        var mode = ModeForIndex(eqModeList.SelectedIndex);
+        GetOrCreateShaping(selectedShapingKey).EqMode = mode;
+        logFile.Event($"shaping: EQ mode → {mode} for {selectedShapingKey}");
         RebuildEqBandSliders();
         ApplyPeerShaping(selectedShapingKey);
         UpdateEqCurve();
@@ -3744,6 +3748,7 @@ public sealed class MainForm : Form
         if (dlg.ShowDialog(this) == DialogResult.OK)
         {
             s.ParametricBands.Add(dlg.Result);
+            logFile.Event($"shaping: added parametric band {dlg.Result.StartHz:0}-{dlg.Result.EndHz:0} Hz {dlg.Result.GainDb:0.#} dB for {selectedShapingKey} ({s.ParametricBands.Count} band(s))");
             RefreshParametricBandList();
             MarkProfileDirty();
         }
@@ -3759,6 +3764,7 @@ public sealed class MainForm : Form
         int firstIdx = parametricBandList.SelectedIndex;
         var toRemove = parametricBandList.SelectedItems.Cast<ParametricBandItem>().Select(x => x.Band).ToList();
         foreach (var band in toRemove) s.ParametricBands.Remove(band);
+        logFile.Event($"shaping: deleted {toRemove.Count} parametric band(s) for {selectedShapingKey} ({s.ParametricBands.Count} left)");
         RefreshParametricBandList();
         // Put focus on whatever now occupies the first removed slot so NVDA announces it.
         if (parametricBandList.Items.Count > 0)
@@ -4482,6 +4488,9 @@ public sealed class MainForm : Form
     /// refresh every place a peer name shows. A blank/cleared name removes the entry entirely.</summary>
     private void ApplyFriendlyName(string identityKey, string machineName, string? address, string? name)
     {
+        logFile.Event(string.IsNullOrWhiteSpace(name)
+            ? $"named peer: cleared name for {identityKey}"
+            : $"named peer: {identityKey} → \"{name.Trim()}\"");
         if (string.IsNullOrWhiteSpace(name))
         {
             namedPeers.Remove(identityKey);
@@ -4597,6 +4606,7 @@ public sealed class MainForm : Form
         void DeleteSelected()
         {
             if (list.SelectedItem is not NamedPeerItem it) return;
+            logFile.Event($"named peer: deleted \"{it.Peer.FriendlyName}\" ({it.Key})");
             namedPeers.Remove(it.Key);
             SaveNamedPeers();
             lastPanEqPeerSignature = "";

src/RemSound.App/RecordingController.cs

@@ -204,16 +204,21 @@ internal sealed class RecordingController
         t.Len = span.Length;
     }
 
-    // Audio thread. Once per render, flush each peer's summed block to their file and reset.
-    private void FlushPeerTracks()
+    // Audio thread. Once per render, flush each peer's summed block to their file. Every peer track gets
+    // EXACTLY one render block per callback: a peer that produced nothing this block — because it went
+    // quiet and its session was dropped, or it disconnected — is padded with silence to the same length.
+    // That keeps every track sample-locked to the single render clock, so the tracks can never drift
+    // apart from each other however long the recording runs, and they all end up the same length.
+    private void FlushPeerTracks(int floats)
     {
         var tracks = peerTracks;
-        if (tracks is null) return;
+        if (tracks is null || floats <= 0) return;
         foreach (var t in tracks.Values)
         {
-            if (t.Len <= 0) continue;
-            t.Recorder.WriteReceived(t.Accum.AsMemory(0, t.Len), RenderRoute.Mixed);
-            Array.Clear(t.Accum, 0, t.Len);
+            if (t.Accum.Length < floats) { var a = t.Accum; Array.Resize(ref a, floats); t.Accum = a; }
+            for (int i = t.Len; i < floats; i++) t.Accum[i] = 0f;   // pad an empty/short block with silence
+            t.Recorder.WriteReceived(t.Accum.AsMemory(0, floats), RenderRoute.Mixed);
+            Array.Clear(t.Accum, 0, floats);
             t.Len = 0;
         }
     }
@@ -227,13 +232,17 @@ internal sealed class RecordingController
         rawMixLen = span.Length;
     }
 
-    // Audio thread. Flush the summed raw mix for this render to the single recorder, then reset.
-    private void FlushRawMix()
+    // Audio thread. Flush the summed raw mix for this render to the single recorder, padding a silent
+    // block so the file stays aligned to real time even through total silence, then reset.
+    private void FlushRawMix(int floats)
     {
         var rec = active;
-        int n = rawMixLen;
-        if (rec is not null && n > 0) rec.WriteReceived(rawMixAccum.AsMemory(0, n), RenderRoute.Mixed);
-        if (n > 0) { Array.Clear(rawMixAccum, 0, n); rawMixLen = 0; }
+        if (rec is null || floats <= 0) return;
+        if (rawMixAccum.Length < floats) { var a = rawMixAccum; Array.Resize(ref a, floats); rawMixAccum = a; }
+        for (int i = rawMixLen; i < floats; i++) rawMixAccum[i] = 0f;
+        rec.WriteReceived(rawMixAccum.AsMemory(0, floats), RenderRoute.Mixed);
+        Array.Clear(rawMixAccum, 0, floats);
+        rawMixLen = 0;
     }
 
     private void StopRecorder(AudioRecorder? r)

src/RemSound.App/RemSound.App.csproj

@@ -18,7 +18,7 @@
          tag_name on the latest GitHub release; bump it on every public release. The
          AssemblyVersion / FileVersion default to this value, and Assembly.GetName().Version
          is what the About dialog and the updater both read. -->
-    <Version>4.9</Version>
+    <Version>5.0</Version>
   </PropertyGroup>
 
   <ItemGroup>

src/RemSound.App/SelfTest.cs

@@ -5,6 +5,7 @@ using System.Text;
 using System.Text.Json;
 using System.Windows.Forms;
 using RemSound.Core;
+using RemSound.Receiver;
 
 namespace RemSound.App;
 
@@ -56,6 +57,8 @@ internal static class SelfTest
         RunStep(results, "Packet framing and rejection", PacketFraming);
         RunStep(results, "Server wire-format compatibility", ServerWireCompat);
         RunStep(results, "App settings save and reload", SettingsRoundTrip);
+        RunStep(results, "Per-peer shaping DSP", PeerShapingDsp);
+        RunStep(results, "v5 settings and shaping round-trip", V5ConfigRoundTrip);
         RunStep(results, "Profile save and reload", ProfileRoundTrip);
         RunStep(results, "What's-new update marker", WhatsNewMarkerRoundTrip);
         RunStep(results, "Diagnostics report privacy", DiagnosticsPrivacy);
@@ -218,6 +221,76 @@ internal static class SelfTest
         return "12-byte 'RMND' header; relay-visible fields unchanged";
     }
 
+    /// <summary>Per-peer volume/pan/EQ DSP: nothing-to-do builds a null chain, the master-off state
+    /// bypasses, a real volume actually attenuates the signal, and the parametric range→peaking maths
+    /// is sane. This is the receive-side shaping that also feeds recordings.</summary>
+    private static string? PeerShapingDsp()
+    {
+        Check(PeerDspChain.Build(null, enabled: true) is null, "no shaping must build a null (do-nothing) chain");
+        Check(PeerDspChain.Build(new PeerShaping(), enabled: true) is null, "default (unity) shaping must build a null chain");
+
+        var half = new PeerShaping { Volume = 0.5f };
+        Check(PeerDspChain.Build(half, enabled: false) is null, "master switch off must bypass shaping (null chain)");
+
+        var chain = PeerDspChain.Build(half, enabled: true);
+        Check(chain is { IsNoOp: false }, "a 50% volume must build a real chain");
+        var buf = new float[8];
+        Array.Fill(buf, 1.0f);
+        chain!.Process(buf, buf.Length / 2);   // 4 stereo frames
+        Check(buf.All(v => Math.Abs(v - 0.5f) < 0.001f), $"volume 50% must halve the signal (got {buf[0]:0.000})");
+
+        var para = new PeerShaping { EqMode = PeerEqMode.Parametric16Band };
+        para.ParametricBands.Add(new ParametricBand { StartHz = 200, EndHz = 800, GainDb = 6 });
+        Check(PeerDspChain.Build(para, enabled: true) is { IsNoOp: false }, "a parametric band must build a real chain");
+        PeerEqBands.ParametricToPeaking(200, 800, out var centre, out var q);
+        Check(centre > 200 && centre < 800 && q is > 0.1f and < 12f,
+            $"parametric range→peaking must give a sane centre ({centre:0} Hz) and Q ({q:0.00})");
+        return "unity→null, master-off→null, volume, parametric";
+    }
+
+    /// <summary>The v5 machine-wide settings and per-peer shaping survive a JSON save/reload: new
+    /// AppConfig defaults, the named-peers book, the main tab order, per-peer shaping with parametric
+    /// bands, and the new recording default. All in-memory — the real config/profiles aren't touched.</summary>
+    private static string? V5ConfigRoundTrip()
+    {
+        var fresh = new AppConfig();
+        Check(fresh.ShowPanEqTab, "ShowPanEqTab must default to true");
+        Check(fresh.ThemeMode == "system", "ThemeMode must default to 'system'");
+        Check(fresh.ShowDiscoveredPeers && fresh.ShowRememberedPeers, "the peer lists must default to shown");
+
+        var cfg = new AppConfig
+        {
+            ThemeMode = "dark",
+            MainTabOrder = ["audioio", "connectivity", "paneq", "audioprofile"],
+            ShowDiscoveredPeers = false,
+        };
+        cfg.NamedPeers["ANDRE-PC"] = new NamedPeer
+        {
+            MachineName = "ANDRE-PC",
+            FriendlyName = "Andre's desktop",
+            LastAddress = "100.72.4.13",
+            LastSeenUtc = new DateTime(2026, 7, 8, 12, 0, 0, DateTimeKind.Utc),
+        };
+        var json = JsonSerializer.Serialize(cfg, new JsonSerializerOptions { WriteIndented = true });
+        var back = JsonSerializer.Deserialize<AppConfig>(json);
+        Check(back is not null, "config must deserialise");
+        Check(back!.ThemeMode == "dark" && !back.ShowDiscoveredPeers, "theme and list toggles must round-trip");
+        Check(back.MainTabOrder is { Count: 4 } && back.MainTabOrder[0] == "audioio", "tab order must round-trip");
+        Check(back.NamedPeers.TryGetValue("ANDRE-PC", out var np)
+              && np.FriendlyName == "Andre's desktop" && np.LastAddress == "100.72.4.13",
+            "named peers must round-trip");
+
+        var shaping = new PeerShaping { Volume = 0.7f, Pan = -0.5f, EqMode = PeerEqMode.Parametric16Band };
+        shaping.ParametricBands.Add(new ParametricBand { StartHz = 100, EndHz = 500, GainDb = 3.5f });
+        var sback = JsonSerializer.Deserialize<PeerShaping>(JsonSerializer.Serialize(shaping));
+        Check(sback is not null && sback.EqMode == PeerEqMode.Parametric16Band
+              && sback.ParametricBands.Count == 1 && Math.Abs(sback.ParametricBands[0].GainDb - 3.5f) < 0.001f,
+            "peer shaping (with parametric bands) must round-trip");
+
+        Check(new RecordingSettings().Source == RecordingSource.Both, "recording source must default to Both");
+        return "config defaults, named peers, tab order, parametric shaping, recording default";
+    }
+
     /// <summary>App settings survive a save-and-reload (the same JSON serialisation
     /// <see cref="AppConfig.Save"/> / <see cref="AppConfig.Load"/> use) without touching the real
     /// config on disk.</summary>