From 89c6483e10f4c42635d999dec50009825c6c2934 Mon Sep 17 00:00:00 2001
From: brandman211 <brandman211@gmail.com>
Date: Mon, 5 Mar 2012 17:20:30 +0000
Subject: [PATCH] Worked on ImportFCM a little bit. I think I understand the
 delta bytes now and are handling them correctly. However, although this might
 press the right buttons, it does it at the wrong time and with the wrong
 duration. I'll need to investigate this further.

---
 BizHawk.MultiClient/movie/MovieImport.cs | 49 +++++++++++++++++++-----
 1 file changed, 39 insertions(+), 10 deletions(-)

diff --git a/BizHawk.MultiClient/movie/MovieImport.cs b/BizHawk.MultiClient/movie/MovieImport.cs
index ab9a74f1cb..d371558fe6 100644
--- a/BizHawk.MultiClient/movie/MovieImport.cs
+++ b/BizHawk.MultiClient/movie/MovieImport.cs
@@ -333,6 +333,11 @@ namespace BizHawk.MultiClient
 			bool pal = false;
 			if ((int)(flags & 4) != 0)
 				pal = true;
+			/*
+			Starting with version 0.98.12 released on September 19, 2004, a PAL flag was added to the header but
+			unfortunately it is not reliable - the emulator does not take the PAL setting from the ROM, but from a user
+			preference. This means that this site cannot calculate movie lengths reliably.
+			*/
 			m.Header.SetHeaderLine("PAL", pal.ToString());
 			bool movieSyncHackOn = true;
 			if ((int)(flags & 16) != 0)
@@ -391,12 +396,12 @@ namespace BizHawk.MultiClient
 			string[] buttons = new string[8] { "A", "B", "Select", "Start", "Up", "Down", "Left", "Right" };
 			bool fourscore = false;
 			int frame = 1;
+			SimpleController controllers = new SimpleController();
+			controllers.Type = new ControllerDefinition();
+			controllers.Type.Name = "NES Controller";
 			while (frame <= frameCount)
 			{
 				byte update = r.ReadByte();
-				SimpleController controllers = new SimpleController();
-				controllers.Type = new ControllerDefinition();
-				controllers.Type.Name = "NES Controller";
 				if ((int)(update & 0x80) != 0)
 				{
 					// Control update: 1aabbbbb
@@ -418,8 +423,8 @@ namespace BizHawk.MultiClient
 						case 0:
 							break;
 						case 1:
-							reset = true;
-							controllers["Reset"] = true;
+							reset = !controllers["Reset"];
+							controllers["Reset"] = reset;
 							break;
 						case 2:
 							reset = true;
@@ -482,16 +487,40 @@ namespace BizHawk.MultiClient
 					 * 7      Right
 					*/
 					int button = update & 7;
+					/*
+					The controller update toggles the affected input. Controller update data is emitted to the movie file
+					only when the state of the controller changes.
+					*/
 					controllers["P" + player + " " + buttons[button]] = !controllers["P" + player + " " + buttons[button]];
 				}
-				// aa: Number of delta bytes to follow
-				int delta = (update >> 5) & 3;
-				r.ReadBytes(delta);
 				MnemonicsGenerator mg = new MnemonicsGenerator();
 				mg.SetSource(controllers);
 				string mnemonic = mg.GetControllersAsMnemonic();
-				m.AppendFrame(mnemonic);
-				frame++;
+				// aa: Number of delta bytes to follow
+				int delta = (update >> 5) & 3;
+				int frames = 0;
+				/*
+				The delta byte(s) indicate the number of emulator frames between this update and the next update. It is
+				encoded in little-endian format and its size depends on the magnitude of the delta:
+				Delta of:      Number of bytes:
+				0              0
+				1-255          1
+				256-65535      2
+				65536-(2^24-1) 3
+				*/
+				for (int b = 0; b < delta; b++)
+					frames += r.ReadByte() * (int)Math.Pow(2, b * 8);
+				while (frames > 0)
+				{
+					m.AppendFrame(mnemonic);
+					if (controllers["Reset"])
+					{
+						controllers["Reset"] = false;
+						mnemonic = mg.GetControllersAsMnemonic();
+					}
+					frame++;
+					frames--;
+				}
 			}
 			m.Header.SetHeaderLine(MovieHeader.FOURSCORE, fourscore.ToString());
 			r.Close();