add an option to capture the Lua without capturing the full OSD, when recording an AVI

src/BizHawk.Client.Common/config/Config.cs

@@ -92,6 +92,7 @@ namespace BizHawk.Client.Common
 		public bool SkipLagFrame { get; set; }
 		public bool SuppressAskSave { get; set; }
 		public bool AviCaptureOsd { get; set; }
+		public bool AviCaptureLua { get; set; }
 		public bool ScreenshotCaptureOsd { get; set; }
 		public bool FirstBoot { get; set; } = true;
 		public bool UpdateAutoCheckEnabled { get; set; }

src/BizHawk.Client.EmuHawk/DisplayManager/DisplayManager.cs

@@ -546,6 +546,23 @@ namespace BizHawk.Client.EmuHawk
 			UpdateSourceInternal(job);
 			return job.OffscreenBb;
 		}
+		/// <summary>
+		/// Does the display process to an offscreen buffer, suitable for a Lua-inclusive movie.
+		/// </summary>
+		public BitmapBuffer RenderOffscreenLua(IVideoProvider videoProvider)
+		{
+			var job = new JobInfo
+			{
+				VideoProvider = videoProvider,
+				Simulate = false,
+				ChainOutsize = new Size(videoProvider.BufferWidth, videoProvider.BufferHeight),
+				Offscreen = true,
+				IncludeOSD = false,
+				IncludeUserFilters = false,
+			};
+			UpdateSourceInternal(job);
+			return job.OffscreenBb;
+		}
 
 		private class FakeVideoProvider : IVideoProvider
 		{

src/BizHawk.Client.EmuHawk/MainForm.Events.cs

@@ -215,6 +215,7 @@ namespace BizHawk.Client.EmuHawk
 			ConfigAndRecordAVMenuItem.ShortcutKeyDisplayString = Config.HotkeyBindings["Record A/V"].Bindings;
 			StopAVIMenuItem.ShortcutKeyDisplayString = Config.HotkeyBindings["Stop A/V"].Bindings;
 			CaptureOSDMenuItem.Checked = Config.AviCaptureOsd;
+			CaptureLuaMenuItem.Checked = Config.AviCaptureOsd || Config.AviCaptureLua;
 
 			RecordAVMenuItem.Enabled = !string.IsNullOrEmpty(Config.VideoWriter) && _currAviWriter == null;
 
@@ -538,6 +539,15 @@ namespace BizHawk.Client.EmuHawk
 		private void CaptureOSDMenuItem_Click(object sender, EventArgs e)
 		{
 			Config.AviCaptureOsd ^= true;
+			if (Config.AviCaptureOsd)
+				Config.AviCaptureLua = true;
+		}
+
+		private void CaptureLuaMenuItem_Click(object sender, EventArgs e)
+		{
+			Config.AviCaptureLua = !CaptureLuaMenuItem.Checked;
+			if (!Config.AviCaptureLua)
+				Config.AviCaptureOsd = false;
 		}
 
 		private void ScreenshotMenuItem_Click(object sender, EventArgs e)

src/BizHawk.Client.EmuHawk/MainForm.cs

@@ -2507,6 +2507,12 @@ namespace BizHawk.Client.EmuHawk
 			bb.DiscardAlpha();
 			return bb;
 		}
+		public BitmapBuffer CaptureLua()
+		{
+			var bb = DisplayManager.RenderOffscreenLua(_currentVideoProvider);
+			bb.DiscardAlpha();
+			return bb;
+		}
 
 		private void IncreaseWindowSize()
 		{
@@ -3418,6 +3424,11 @@ namespace BizHawk.Client.EmuHawk
 							output = new BitmapBufferVideoProvider(CaptureOSD());
 							disposableOutput = (IDisposable) output;
 						}
+						else if (Config.AviCaptureLua)
+						{
+							output = new BitmapBufferVideoProvider(CaptureLua());
+							disposableOutput = (IDisposable) output;
+						}
 						else
 						{
 							output = _currentVideoProvider;