Transitions: fade starts from the outgoing picture (was an instant cut)

The transition started with no from-frame, so BlendFrame returned the new scene at once.
Start now requests a capture and the frame pump supplies its last output on the next tick.
Test: TransitionFadeTests. Docs: ai.md, TASKS.md.

Not pushed.

Services/Encoder/FramePump.cs

@@ -32,6 +32,7 @@ public sealed class FramePump : IDisposable
     private readonly Func<VideoFrame?>? _alertTicker;
     private readonly Func<VideoFrame?>? _brandFlash;
     private readonly TransitionService? _transition;
+    private VideoFrame? _lastOutput;
     private readonly SceneGraph? _sceneGraph;
     private readonly SceneCompositor _compositor = new();
 
@@ -497,6 +498,9 @@ public sealed class FramePump : IDisposable
                     socialBarTicks += sw.ElapsedTicks;
 
                     VideoFrame frame;
+                    if (_transition is { CaptureRequested: true } capture && _lastOutput != null)
+                        capture.SupplyFromFrame(new VideoFrame(_lastOutput.Width, _lastOutput.Height,
+                            (byte[])_lastOutput.BgraPixels.Clone()));
                     var scratchSize = compositorOptions.SourceRectWidth
                         * compositorOptions.SourceRectHeight * 4;
                     renderSw.Restart();
@@ -567,6 +571,7 @@ public sealed class FramePump : IDisposable
                     // tick's buffers are recyclable once the enqueue snapshot them.
                     // The free-list Contains guard keeps the Cut path (BlendFrame
                     // returns toFrame itself, aliasing scratch) safe.
+                    _lastOutput = frame;
                     ReleaseScratch(frame.BgraPixels);
                     ReleaseScratch(scratch);
 

Services/TransitionService.cs

@@ -45,12 +45,23 @@ public sealed class TransitionService
     /// </summary>
     public VideoFrame? FromFrame { get; private set; }
 
+    /// <summary>True when a transition started without its "from" picture; the frame pump
+    /// supplies the outgoing program frame on its next tick via <see cref="SupplyFromFrame"/>.</summary>
+    public bool CaptureRequested { get; private set; }
+
+    public void SupplyFromFrame(VideoFrame frame)
+    {
+        FromFrame = frame;
+        CaptureRequested = false;
+    }
+
     /// <summary>Begin a transition. Caller should capture FromFrame from the current LiveScene render.</summary>
     public void Start(TransitionType type, double durationMs, VideoFrame? fromFrame)
     {
         CurrentType = type;
         DurationMs = durationMs > 0 ? durationMs : DefaultDurationMs;
         FromFrame = fromFrame;
+        CaptureRequested = fromFrame == null && type != TransitionType.Cut;
         ElapsedMs = 0;
         Active = true;
 

TASKS.md

@@ -451,3 +451,14 @@ These were explicitly ruled out:
 - **OBS-style source expansion** (game capture, browser source, media playlist, VLC, color-key, MIDI — the minimal source set is deliberate; creators who need more have graduated to OBS)
 - **Multi-layout** (auto-save, single layout; multi-layout = OBS territory)
 - **Cross-process stream resume** (API makes it impossible; creator ruling 2026-09-01)
+
+## Transitions & brand logo (queued 2026-10-27)
+
+- ✅ **Fade fix** — swaps fade from the outgoing picture (`TransitionFadeTests`). On-screen check pending.
+- ☐ **Transition picker** in App Settings (type + duration).
+- ☐ **Wipe** — CPU blend, direction setting.
+- ☐ **Move** — persistent layers (per-layer "carry across scenes" flag), per-scene placement, fixed z band.
+- ☐ **Brand logo** — permanent "Brand logo" layer above background in every scene; file in App Settings
+  (imported to the asset table); per-scene eye toggle; top-left default.
+- ☐ **Cube** — GPU path gated on capability; CPU path only if it holds 60fps.
+- Gear: right-click opens App Settings (built, on-screen check pending). Left-click menu stays for now.

ai.md

@@ -1287,3 +1287,12 @@ nothing. COPPA is very unlikely to bind (not child-directed), but note the enfor
 (FTC Sept 2025 *Apitor*: operators are responsible for what third-party components collect) —
 so the answer is a documented inquiry, and ours is "no third-party analytics or ad SDKs, no
 persisted chat or reward payloads."
+
+## Transitions (2026-10-27)
+
+- **Fade starts from the outgoing picture.** `TransitionService.Start` with no "from" frame sets
+  `CaptureRequested`; the frame pump copies its last output at the top of its next tick and calls
+  `SupplyFromFrame`. Before that fix the blend had no starting frame and a scene swap was instant.
+  Guard: `ytLive.Tests/TransitionFadeTests.cs`.
+- **Planned next (see TASKS.md):** transition picker in App Settings, Wipe, Move (persistent layers),
+  brand logo layer, GPU cube (capability-gated).

ytLive.Tests/TransitionFadeTests.cs

@@ -0,0 +1,26 @@
+using ytLive.Services;
+using Xunit;
+
+namespace ytLive.Tests;
+
+public class TransitionFadeTests
+{
+    [Fact]
+    public void Fade_Without_A_From_Frame_Requests_Capture_And_Blends_Once_Supplied()
+    {
+        var transition = new TransitionService();
+        var to = new VideoFrame(2, 2, Enumerable.Repeat((byte)255, 16).ToArray());
+        var from = new VideoFrame(2, 2, new byte[16]);
+
+        transition.Start(TransitionType.Fade, 300, null);
+        Assert.True(transition.CaptureRequested);
+
+        transition.SupplyFromFrame(from);
+        Assert.False(transition.CaptureRequested);
+
+        transition.Tick(150);
+        var blended = transition.BlendFrame(to);
+        Assert.NotSame(to, blended);
+        Assert.NotEqual((byte)255, blended.BgraPixels[0]);
+    }
+}