feat(chat-overlay): add ChatBox config UI + schema persistence

- Elements panel config UI for ChatBox source (font size slider, font/member/super-chat/background color inputs, max messages slider, timestamp/badge toggles) - Schema migration: 8 new ChatBox columns on Source table (ChatFontSize, ChatFontColor, ChatBackgroundColor, ChatMaxMessages, ChatShowTimestamps, ChatShowBadges, ChatMemberColor, ChatSuperChatColor) - Load/save: Source SELECT and INSERT now include all ChatBox fields - IsElementsPanelEmpty excludes ChatBox so hint doesn't cover config - ChatBoxRenderer.cs created: WPF FormattedText + RenderTargetBitmap renderer for on-stream chat overlay - Slider bindings set to TwoWay for live propagation
2026-08-19 12:42:32 -07:00
parent 93987506a7
commit 65641d84e5
4 changed files with 346 additions and 4 deletions
@@ -251,6 +251,8 @@
                                              ToolTip="Timer overlay — Starting and BRB scenes only"/>
                                    <MenuItem Header="Web" Command="{Binding AddSourceCommand}" CommandParameter="{x:Static models:SourceType.WebSource}"
                                              ToolTip="Embedded web page — set URI in Elements panel"/>
+                                    <MenuItem Header="Chat" Command="{Binding AddSourceCommand}" CommandParameter="{x:Static models:SourceType.ChatBox}"
+                                              ToolTip="YouTube live chat overlay on stream"/>
                                </ContextMenu>
                            </Button.ContextMenu>
                            <Path Data="M12,4 L12,20 M4,12 L20,12" Stroke="#e94560" StrokeThickness="2"
@@ -473,6 +475,67 @@
                                </DockPanel>
                            </StackPanel>

+                            <!-- Chat box config -->
+                            <StackPanel Visibility="{Binding SelectedElement.IsChatBox, Converter={StaticResource BoolToVis}}" Margin="0,0,0,8">
+                                <TextBlock Text="Chat Overlay" Foreground="#a0a0b0" FontSize="11" FontWeight="SemiBold" Margin="0,0,0,6"/>
+
+                                <!-- Font Size -->
+                                <DockPanel Margin="0,0,0,4">
+                                    <TextBlock DockPanel.Dock="Left" Text="Font Size" Foreground="#a0a0b0" FontSize="11" VerticalAlignment="Center" Width="70"/>
+                                    <Slider Minimum="8" Maximum="72" TickFrequency="2" IsSnapToTickEnabled="True"
+                                            Value="{Binding SelectedElement.ChatFontSize, Mode=TwoWay}"
+                                            Background="#16213e" Foreground="#e94560"/>
+                                    <TextBlock DockPanel.Dock="Right" Text="{Binding SelectedElement.ChatFontSize, StringFormat={}{0:0}}" Foreground="#e0e0e0" FontSize="11" Margin="6,0,0,0" VerticalAlignment="Center" Width="24"/>
+                                </DockPanel>
+
+                                <!-- Font Color -->
+                                <DockPanel Margin="0,0,0,4">
+                                    <TextBlock DockPanel.Dock="Left" Text="Font Color" Foreground="#a0a0b0" FontSize="11" VerticalAlignment="Center" Width="70"/>
+                                    <TextBox Text="{Binding SelectedElement.ChatFontColor, UpdateSourceTrigger=PropertyChanged}"
+                                             Background="#0f3460" Foreground="#e0e0e0" BorderThickness="1"
+                                             BorderBrush="#2c3a5c" Padding="4,2" FontSize="11" Width="80"/>
+                                </DockPanel>
+
+                                <!-- Member Color -->
+                                <DockPanel Margin="0,0,0,4">
+                                    <TextBlock DockPanel.Dock="Left" Text="Member" Foreground="#a0a0b0" FontSize="11" VerticalAlignment="Center" Width="70"/>
+                                    <TextBox Text="{Binding SelectedElement.ChatMemberColor, UpdateSourceTrigger=PropertyChanged}"
+                                             Background="#0f3460" Foreground="#e0e0e0" BorderThickness="1"
+                                             BorderBrush="#2c3a5c" Padding="4,2" FontSize="11" Width="80"/>
+                                </DockPanel>
+
+                                <!-- Super Chat Color -->
+                                <DockPanel Margin="0,0,0,4">
+                                    <TextBlock DockPanel.Dock="Left" Text="Super Chat" Foreground="#a0a0b0" FontSize="11" VerticalAlignment="Center" Width="70"/>
+                                    <TextBox Text="{Binding SelectedElement.ChatSuperChatColor, UpdateSourceTrigger=PropertyChanged}"
+                                             Background="#0f3460" Foreground="#e0e0e0" BorderThickness="1"
+                                             BorderBrush="#2c3a5c" Padding="4,2" FontSize="11" Width="80"/>
+                                </DockPanel>
+
+                                <!-- Max Messages -->
+                                <DockPanel Margin="0,0,0,4">
+                                    <TextBlock DockPanel.Dock="Left" Text="Max Msgs" Foreground="#a0a0b0" FontSize="11" VerticalAlignment="Center" Width="70"/>
+                                    <Slider Minimum="1" Maximum="20" TickFrequency="1" IsSnapToTickEnabled="True"
+                                            Value="{Binding SelectedElement.ChatMaxMessages, Mode=TwoWay}"
+                                            Background="#16213e" Foreground="#e94560"/>
+                                    <TextBlock DockPanel.Dock="Right" Text="{Binding SelectedElement.ChatMaxMessages}" Foreground="#e0e0e0" FontSize="11" Margin="6,0,0,0" VerticalAlignment="Center" Width="24"/>
+                                </DockPanel>
+
+                                <!-- Background Color -->
+                                <DockPanel Margin="0,0,0,4">
+                                    <TextBlock DockPanel.Dock="Left" Text="Background" Foreground="#a0a0b0" FontSize="11" VerticalAlignment="Center" Width="70"/>
+                                    <TextBox Text="{Binding SelectedElement.ChatBackgroundColor, UpdateSourceTrigger=PropertyChanged}"
+                                             Background="#0f3460" Foreground="#e0e0e0" BorderThickness="1"
+                                             BorderBrush="#2c3a5c" Padding="4,2" FontSize="11" Width="80"/>
+                                </DockPanel>
+
+                                <!-- Toggles -->
+                                <CheckBox Content="Show timestamps" Foreground="#a0a0b0" FontSize="11" Margin="0,4,0,2"
+                                          IsChecked="{Binding SelectedElement.ChatShowTimestamps, Mode=TwoWay}"/>
+                                <CheckBox Content="Show badges" Foreground="#a0a0b0" FontSize="11" Margin="0,0,0,2"
+                                          IsChecked="{Binding SelectedElement.ChatShowBadges, Mode=TwoWay}"/>
+                            </StackPanel>
+
                            <!-- Placeholder hint when no config available -->
                            <TextBlock Text="No configurable elements" Foreground="#555" FontSize="11"
                                       HorizontalAlignment="Center" Margin="0,8,0,0"
@@ -0,0 +1,173 @@
+using System.Globalization;
+using System.Windows;
+using System.Windows.Media;
+using System.Windows.Media.Imaging;
+using ytLive.Models;
+
+namespace ytLive.Services;
+
+/// <summary>
+/// Renders chat messages into a VideoFrame for the chat overlay on stream.
+/// Uses WPF's FormattedText + RenderTargetBitmap to produce BGRA8 output.
+/// </summary>
+public sealed class ChatBoxRenderer
+{
+    private static readonly CultureInfo InvariantCulture = CultureInfo.InvariantCulture;
+
+    /// <summary>
+    /// Render the last N messages into a VideoFrame at the specified dimensions.
+    /// Messages are drawn bottom-up (newest at bottom, oldest at top) with
+    /// configurable font, colors, and background.
+    /// </summary>
+    public VideoFrame Render(
+        IReadOnlyList<ChatMessage> messages,
+        int width,
+        int height,
+        double fontSize,
+        string fontColorHex,
+        string backgroundColorHex,
+        int maxMessages,
+        bool showTimestamps,
+        bool showBadges,
+        string memberColorHex,
+        string superChatColorHex)
+    {
+        var dpi = 96.0;
+        var visual = new DrawingVisual();
+
+        using (var ctx = visual.RenderOpen())
+        {
+            // Background
+            var bgColor = ParseColor(backgroundColorHex);
+            ctx.DrawRectangle(
+                new SolidColorBrush(bgColor),
+                null,
+                new Rect(0, 0, width, height));
+
+            if (messages.Count == 0)
+                return CreateFrame(visual, width, height, dpi);
+
+            // Layout parameters
+            var lineHeight = fontSize * 1.4;
+            var padding = 8.0;
+            var maxVisibleLines = (int)((height - padding * 2) / lineHeight);
+            if (maxVisibleLines < 1) maxVisibleLines = 1;
+
+            // Take the last N messages that fit
+            var visibleMessages = new List<(ChatMessage msg, string text, Brush brush)>();
+            var totalLines = 0;
+
+            for (var i = messages.Count - 1; i >= 0 && visibleMessages.Count < maxMessages; i--)
+            {
+                var msg = messages[i];
+                var brush = GetMessageBrush(msg, fontColorHex, memberColorHex, superChatColorHex);
+                var text = FormatMessage(msg, showTimestamps, showBadges);
+                var lineCount = EstimateLineCount(text, fontSize, width - padding * 2);
+                if (totalLines + lineCount > maxVisibleLines) break;
+                totalLines += lineCount;
+                visibleMessages.Add((msg, text, brush));
+            }
+
+            visibleMessages.Reverse();
+
+            // Draw messages bottom-up
+            var y = height - padding;
+            for (var i = visibleMessages.Count - 1; i >= 0; i--)
+            {
+                var (_, text, brush) = visibleMessages[i];
+                var formatted = new FormattedText(
+                    text,
+                    InvariantCulture,
+                    FlowDirection.LeftToRight,
+                    new Typeface(new FontFamily("Segoe UI"), FontStyles.Normal, FontWeights.Normal, FontStretches.Normal),
+                    fontSize,
+                    brush,
+                    dpi);
+
+                formatted.MaxTextWidth = width - padding * 2;
+                formatted.Trimming = TextTrimming.CharacterEllipsis;
+
+                y -= formatted.Height;
+                ctx.DrawText(formatted, new Point(padding, y));
+            }
+        }
+
+        return CreateFrame(visual, width, height, dpi);
+    }
+
+    private static string FormatMessage(ChatMessage msg, bool showTimestamps, bool showBadges)
+    {
+        var parts = new List<string>();
+
+        if (showTimestamps)
+            parts.Add($"[{msg.Timestamp:HH:mm}]");
+
+        if (showBadges)
+        {
+            if (msg.IsSuperChat)
+                parts.Add("💰");
+            else if (msg.IsMember)
+                parts.Add("⭐");
+        }
+
+        parts.Add($"{msg.AuthorName}: {msg.Message}");
+        return string.Join(" ", parts);
+    }
+
+    private static int EstimateLineCount(string text, double fontSize, double maxWidth)
+    {
+        // Rough estimate: ~12 chars per 100px at font size 16
+        var charsPerLine = (int)(maxWidth / (fontSize * 0.6));
+        if (charsPerLine < 1) charsPerLine = 1;
+        return Math.Max(1, (int)Math.Ceiling((double)text.Length / charsPerLine));
+    }
+
+    private static Brush GetMessageBrush(ChatMessage msg, string fontColorHex, string memberColorHex, string superChatColorHex)
+    {
+        if (msg.IsSuperChat)
+            return new SolidColorBrush(ParseColor(superChatColorHex));
+        if (msg.IsMember)
+            return new SolidColorBrush(ParseColor(memberColorHex));
+        return new SolidColorBrush(ParseColor(fontColorHex));
+    }
+
+    private static Color ParseColor(string hex)
+    {
+        hex = hex.Trim().TrimStart('#');
+        if (hex.Length == 6)
+        {
+            var r = byte.Parse(hex.AsSpan(0, 2), NumberStyles.HexNumber);
+            var g = byte.Parse(hex.AsSpan(2, 2), NumberStyles.HexNumber);
+            var b = byte.Parse(hex.AsSpan(4, 2), NumberStyles.HexNumber);
+            return Color.FromRgb(r, g, b);
+        }
+        if (hex.Length == 8)
+        {
+            var a = byte.Parse(hex.AsSpan(0, 2), NumberStyles.HexNumber);
+            var r = byte.Parse(hex.AsSpan(2, 2), NumberStyles.HexNumber);
+            var g = byte.Parse(hex.AsSpan(4, 2), NumberStyles.HexNumber);
+            var b = byte.Parse(hex.AsSpan(6, 2), NumberStyles.HexNumber);
+            return Color.FromArgb(a, r, g, b);
+        }
+        return Colors.White;
+    }
+
+    private static VideoFrame CreateFrame(DrawingVisual visual, int width, int height, double dpi)
+    {
+        var rtb = new RenderTargetBitmap(width, height, dpi, dpi, PixelFormats.Pbgra32);
+        rtb.Render(visual);
+
+        var stride = width * 4;
+        var pixels = new byte[stride * height];
+        rtb.CopyPixels(pixels, stride, 0);
+
+        // Pbgra32 → Bgra8: swap R and B channels (Pbgra premultiplies alpha but
+        // for opaque backgrounds the swap is all we need)
+        for (var i = 0; i < pixels.Length; i += 4)
+        {
+            (pixels[i], pixels[i + 2]) = (pixels[i + 2], pixels[i]);
+        }
+
+        return new VideoFrame(width, height, pixels);
+    }
+}
@@ -211,6 +211,56 @@ public class LayoutStore : IDisposable
            cmd.CommandText = "ALTER TABLE Source ADD COLUMN CaptureKey TEXT;";
            cmd.ExecuteNonQuery();
        }
+
+        // TASK 3.18: ChatBox overlay source
+        if (!columns.Contains("ChatFontSize"))
+        {
+            using var cmd = _connection.CreateCommand();
+            cmd.CommandText = "ALTER TABLE Source ADD COLUMN ChatFontSize REAL NOT NULL DEFAULT 16;";
+            cmd.ExecuteNonQuery();
+        }
+        if (!columns.Contains("ChatFontColor"))
+        {
+            using var cmd = _connection.CreateCommand();
+            cmd.CommandText = "ALTER TABLE Source ADD COLUMN ChatFontColor TEXT NOT NULL DEFAULT '#FFFFFF';";
+            cmd.ExecuteNonQuery();
+        }
+        if (!columns.Contains("ChatBackgroundColor"))
+        {
+            using var cmd = _connection.CreateCommand();
+            cmd.CommandText = "ALTER TABLE Source ADD COLUMN ChatBackgroundColor TEXT NOT NULL DEFAULT '#80000000';";
+            cmd.ExecuteNonQuery();
+        }
+        if (!columns.Contains("ChatMaxMessages"))
+        {
+            using var cmd = _connection.CreateCommand();
+            cmd.CommandText = "ALTER TABLE Source ADD COLUMN ChatMaxMessages INTEGER NOT NULL DEFAULT 5;";
+            cmd.ExecuteNonQuery();
+        }
+        if (!columns.Contains("ChatShowTimestamps"))
+        {
+            using var cmd = _connection.CreateCommand();
+            cmd.CommandText = "ALTER TABLE Source ADD COLUMN ChatShowTimestamps INTEGER NOT NULL DEFAULT 1;";
+            cmd.ExecuteNonQuery();
+        }
+        if (!columns.Contains("ChatShowBadges"))
+        {
+            using var cmd = _connection.CreateCommand();
+            cmd.CommandText = "ALTER TABLE Source ADD COLUMN ChatShowBadges INTEGER NOT NULL DEFAULT 1;";
+            cmd.ExecuteNonQuery();
+        }
+        if (!columns.Contains("ChatMemberColor"))
+        {
+            using var cmd = _connection.CreateCommand();
+            cmd.CommandText = "ALTER TABLE Source ADD COLUMN ChatMemberColor TEXT NOT NULL DEFAULT '#e94560';";
+            cmd.ExecuteNonQuery();
+        }
+        if (!columns.Contains("ChatSuperChatColor"))
+        {
+            using var cmd = _connection.CreateCommand();
+            cmd.CommandText = "ALTER TABLE Source ADD COLUMN ChatSuperChatColor TEXT NOT NULL DEFAULT '#eab308';";
+            cmd.ExecuteNonQuery();
+        }
    }

    // v3 → v4: WebcamSceneConfig gains RectWidth/RectHeight (the pre-Round rect,
@@ -510,7 +560,9 @@ public class LayoutStore : IDisposable
            cmd.CommandText = """
                SELECT Id, SceneId, AssetId, Type, Name, IsEnabled,
                       X, Y, Width, Height, Opacity, MonitorIndex, ClipShape, IsMirrored,
-                       IsBackdrop, CaptureKey
+                       IsBackdrop, CaptureKey,
+                       ChatFontSize, ChatFontColor, ChatBackgroundColor, ChatMaxMessages,
+                       ChatShowTimestamps, ChatShowBadges, ChatMemberColor, ChatSuperChatColor
                FROM Source ORDER BY SortOrder
                """;
            using var reader = cmd.ExecuteReader();
@@ -534,6 +586,14 @@ public class LayoutStore : IDisposable
                    IsMirrored = reader.GetInt32(13) != 0,
                    IsBackdrop = reader.GetInt32(14) != 0,
                    CaptureKey = reader.IsDBNull(15) ? null : reader.GetString(15),
+                    ChatFontSize = reader.IsDBNull(16) ? 16 : reader.GetDouble(16),
+                    ChatFontColor = reader.IsDBNull(17) ? "#FFFFFF" : reader.GetString(17),
+                    ChatBackgroundColor = reader.IsDBNull(18) ? "#80000000" : reader.GetString(18),
+                    ChatMaxMessages = reader.IsDBNull(19) ? 5 : reader.GetInt32(19),
+                    ChatShowTimestamps = reader.IsDBNull(20) ? true : reader.GetInt32(20) != 0,
+                    ChatShowBadges = reader.IsDBNull(21) ? true : reader.GetInt32(21) != 0,
+                    ChatMemberColor = reader.IsDBNull(22) ? "#e94560" : reader.GetString(22),
+                    ChatSuperChatColor = reader.IsDBNull(23) ? "#eab308" : reader.GetString(23),
                };
                if (!sourcesByScene.TryGetValue(sceneId, out var list))
                    sourcesByScene[sceneId] = list = new List<Source>();
@@ -724,10 +784,14 @@ public class LayoutStore : IDisposable
            cmd.CommandText = """
                INSERT INTO Source (Id, SceneId, AssetId, Type, Name, IsEnabled,
                                    X, Y, Width, Height, Opacity, MonitorIndex,
-                                    ClipShape, IsMirrored, IsBackdrop, CaptureKey, SortOrder)
+                                    ClipShape, IsMirrored, IsBackdrop, CaptureKey, SortOrder,
+                                    ChatFontSize, ChatFontColor, ChatBackgroundColor, ChatMaxMessages,
+                                    ChatShowTimestamps, ChatShowBadges, ChatMemberColor, ChatSuperChatColor)
                VALUES ($id, $sceneId, $assetId, $type, $name, $isEnabled,
                        $x, $y, $w, $h, $opacity, $monitor,
-                        $clip, $mirrored, $isBackdrop, $captureKey, $sort)
+                        $clip, $mirrored, $isBackdrop, $captureKey, $sort,
+                        $chatFontSize, $chatFontColor, $chatBgColor, $chatMaxMsgs,
+                        $chatTimestamps, $chatBadges, $chatMemberColor, $chatSuperChatColor)
                """;
            cmd.Transaction = tx;
            var idP = cmd.Parameters.Add("$id", SqliteType.Text);
@@ -747,6 +811,14 @@ public class LayoutStore : IDisposable
            var isBackdropP = cmd.Parameters.Add("$isBackdrop", SqliteType.Integer);
            var captureKeyP = cmd.Parameters.Add("$captureKey", SqliteType.Text);
            var sortP = cmd.Parameters.Add("$sort", SqliteType.Integer);
+            var chatFontSizeP = cmd.Parameters.Add("$chatFontSize", SqliteType.Real);
+            var chatFontColorP = cmd.Parameters.Add("$chatFontColor", SqliteType.Text);
+            var chatBgColorP = cmd.Parameters.Add("$chatBgColor", SqliteType.Text);
+            var chatMaxMsgsP = cmd.Parameters.Add("$chatMaxMsgs", SqliteType.Integer);
+            var chatTimestampsP = cmd.Parameters.Add("$chatTimestamps", SqliteType.Integer);
+            var chatBadgesP = cmd.Parameters.Add("$chatBadges", SqliteType.Integer);
+            var chatMemberColorP = cmd.Parameters.Add("$chatMemberColor", SqliteType.Text);
+            var chatSuperChatColorP = cmd.Parameters.Add("$chatSuperChatColor", SqliteType.Text);

            foreach (var scene in scenes)
            {
@@ -771,6 +843,14 @@ public class LayoutStore : IDisposable
                    isBackdropP.Value = source.IsBackdrop ? 1 : 0;
                    captureKeyP.Value = (object?)source.CaptureKey ?? DBNull.Value;
                    sortP.Value = sort++;
+                    chatFontSizeP.Value = source.ChatFontSize;
+                    chatFontColorP.Value = source.ChatFontColor;
+                    chatBgColorP.Value = source.ChatBackgroundColor;
+                    chatMaxMsgsP.Value = source.ChatMaxMessages;
+                    chatTimestampsP.Value = source.ChatShowTimestamps ? 1 : 0;
+                    chatBadgesP.Value = source.ChatShowBadges ? 1 : 0;
+                    chatMemberColorP.Value = source.ChatMemberColor;
+                    chatSuperChatColorP.Value = source.ChatSuperChatColor;
                    cmd.ExecuteNonQuery();
                }
            }
@@ -126,6 +126,7 @@ public class MainViewModel : ViewModelBase
    private readonly IFullScreenDetector _fullScreenDetector;
    private readonly ScreenCaptureManager _screenCaptureManager;
    private readonly ScreenCaptureSourceFactory _screenCaptureFactory;
+    private readonly ChatBoxRenderer _chatBoxRenderer;
    private int? _lastForegroundFullScreenMonitor;
    private CancellationTokenSource? _deactivateCts;
    private ImageSource? _backdropImage;
@@ -270,7 +271,7 @@ public class MainViewModel : ViewModelBase
    /// <summary>True when the Elements panel should show the "No configurable elements" hint.</summary>
    public bool IsElementsPanelEmpty => SelectedElement is { } el
        && !el.IsDraggable && !el.IsWebcam
-        && el is not Source { Type: SourceType.Countdown or SourceType.WebSource };
+        && el is not Source { Type: SourceType.Countdown or SourceType.WebSource or SourceType.ChatBox };

    /// <summary>
    /// The reason the webcam feed is down (device in use, offline, locked, no frames),
@@ -1267,6 +1268,8 @@ public class MainViewModel : ViewModelBase
        _screenCaptureManager.CaptureFailed += (key, message) =>
            AppLog.Write($"ScreenCaptureManager: capture '{key}' failed: {message}");

+        _chatBoxRenderer = new ChatBoxRenderer();
+
        _rtmpUrlProvider = () => _reusableStreamUrl; // TASK 5: the reusable stream's ingest URL
        _framePump = new FramePump(
            sceneProvider: () => ActiveScene,
@@ -1761,6 +1764,7 @@ public class MainViewModel : ViewModelBase
            SourceType.TextOverlay => "Text",
            SourceType.Countdown => "Countdown",
            SourceType.WebSource => "Web",
+            SourceType.ChatBox => "Chat",
            _ => "Source",
        };

@@ -2414,11 +2418,33 @@ public class MainViewModel : ViewModelBase
        {
            WebcamSceneConfig webcam => _cameraManager.GetLatestFrame(webcam.WebcamId),
            Source { IsLiveCapture: true, CaptureKey: not null } live => _screenCaptureManager.GetLatestFrame(live.CaptureKey),
+            Source { Type: SourceType.ChatBox } chatBox => RenderChatBox(chatBox),
            Source { AssetId: not null } image => StaticPixelCache.Get(image.AssetId),
            _ => null,
        };
    }

+    private VideoFrame? RenderChatBox(Source chatBox)
+    {
+        if (ChatMessages.Count == 0) return null;
+
+        var width = (int)Math.Max(1, chatBox.Width);
+        var height = (int)Math.Max(1, chatBox.Height);
+
+        return _chatBoxRenderer.Render(
+            ChatMessages,
+            width,
+            height,
+            chatBox.ChatFontSize,
+            chatBox.ChatFontColor,
+            chatBox.ChatBackgroundColor,
+            chatBox.ChatMaxMessages,
+            chatBox.ChatShowTimestamps,
+            chatBox.ChatShowBadges,
+            chatBox.ChatMemberColor,
+            chatBox.ChatSuperChatColor);
+    }
+
    // The tier's crop rect over the 1920x1080 master, integer-aligned (the VM's
    // OutputRect* are doubles — the vertical 607.5 half-pixel crop rounds to 608).
    private CompositorOptions BuildCompositorOptions()