add DiscMountPolicy to control discrepancies in generation of subQ between different disc interfaces.

BizHawk.Client.DiscoHawk/DiscoHawk.cs

@@ -215,17 +215,29 @@ namespace BizHawk.Client.DiscoHawk
 			if (infile == null)
 				return;
 
+
+			if (hawk)
+			{
+				//TODO - write it out
 				var dmj = new DiscMountJob { IN_DiscInterface = loadDiscInterface, IN_FromPath = infile };
 				dmj.Run();
-			var disc = dmj.OUT_Disc;
+				//var disc = dmj.OUT_Disc;
-			
+			}
-			if(hawk) {} //todo - write it out
 
 			StringWriter sw = new StringWriter();
 			foreach (var cmpif in compareDiscInterfaces)
 			{
 				sw.WriteLine("BEGIN COMPARE: SRC {0} vs DST {1}", loadDiscInterface, cmpif);
 
+				//reload the original disc, with new policies as needed
+				var dmj = new DiscMountJob { IN_DiscInterface = loadDiscInterface, IN_FromPath = infile };
+				if (cmpif == DiscInterface.MednaDisc)
+				{
+					dmj.IN_DiscMountPolicy.CUE_PauseContradictionModeA = false;
+				}
+				dmj.Run();
+				var disc = dmj.OUT_Disc;
+
 				var src_disc = disc;
 
 				var dst_dmj = new DiscMountJob { IN_DiscInterface = cmpif, IN_FromPath = infile };

BizHawk.Emulation.DiscSystem/CUE/CUE_Compile.cs

@@ -123,6 +123,7 @@ namespace BizHawk.Emulation.DiscSystem
 
 			/// <summary>
 			/// The context used for this compiling job
+			/// TODO - rename something like context
 			/// </summary>
 			public CUE_Format2 IN_CueFormat;
 

BizHawk.Emulation.DiscSystem/CUE/CUE_Format.cs

@@ -14,5 +14,10 @@ namespace BizHawk.Emulation.DiscSystem
 		/// The CueFileResolver to be used by this instance
 		/// </summary>
 		public CueFileResolver Resolver;
+
+		/// <summary>
+		/// The DiscMountPolicy to be applied to this context
+		/// </summary>
+		public DiscMountPolicy DiscMountPolicy;
 	}
 }

BizHawk.Emulation.DiscSystem/CUE/CUE_Load.cs

@@ -70,7 +70,6 @@ namespace BizHawk.Emulation.DiscSystem
 			void MountBlobs()
 			{
 				IBlob file_blob = null;
-				long file_len = 0;
 
 				BlobInfos = new List<BlobInfo>();
 				foreach (var ccf in IN_CompileJob.OUT_CompiledCueFiles)
@@ -173,6 +172,7 @@ namespace BizHawk.Emulation.DiscSystem
 			{
 				//params
 				var compiled = IN_CompileJob;
+				var context = compiled.IN_CueFormat;
 				OUT_Disc = new Disc();
 
 				//generation state
@@ -282,14 +282,17 @@ namespace BizHawk.Emulation.DiscSystem
 						sq.ap_frame = BCD2.FromDecimal(new Timestamp(LBA).FRAC);
 						int track_relative_msf = curr_blobMSF - cct.Indexes[1].FileMSF.Sector;
 
-						//for index 0, negative MSF required and encoded oppositely.
+						//for index 0, negative MSF required and encoded oppositely. Read more at Policies declaration
 						if (curr_index == 0)
 						{
-							if (track_relative_msf >= 0) throw new InvalidOperationException("Severe error generating cue subQ (positive MSF for pregap)");
+							if (!context.DiscMountPolicy.CUE_PauseContradictionModeA)
+								track_relative_msf += 1;
+
+							if (track_relative_msf > 0) throw new InvalidOperationException("Severe error generating cue subQ (positive relMSF for pregap)");
 							track_relative_msf = -track_relative_msf;
 						}
 						else
-							if (track_relative_msf < 0) throw new InvalidOperationException("Severe error generating cue subQ (negative MSF for non-pregap)");
+							if (track_relative_msf < 0) throw new InvalidOperationException("Severe error generating cue subQ (negative relMSF for non-pregap)");
 
 						sq.min = BCD2.FromDecimal(new Timestamp(track_relative_msf).MIN);
 						sq.sec = BCD2.FromDecimal(new Timestamp(track_relative_msf).SEC);

BizHawk.Emulation.DiscSystem/Disc.cs

@@ -82,6 +82,12 @@ namespace BizHawk.Emulation.DiscSystem
 
 	public partial class Disc : IDisposable
 	{
+		/// <summary>
+		/// The DiscMountPolicy used to mount the disc. Consider this read-only.
+		/// NOT SURE WE NEED THIS
+		/// </summary>
+		//public DiscMountPolicy DiscMountPolicy;
+
 		/// <summary>
 		/// Free-form optional memos about the disc
 		/// </summary>

BizHawk.Emulation.DiscSystem/Jobs/DiscMountJob.cs

@@ -6,6 +6,30 @@ using System.Collections.Generic;
 
 namespace BizHawk.Emulation.DiscSystem
 {
+	/// <summary>
+	/// General disc policies to be logically applied at mounting time. The choices are irreversible once a disc is loaded.
+	/// Maybe these are only for CUEs, but maybe not. Not sure yet.
+	/// </summary>
+	public class DiscMountPolicy
+	{
+		/// <summary>
+		/// "At the beginning of a Pause (i.e. Index = 00) the relative time is 
+		/// --A-- set to the duration of the Pause.
+		/// During the Pause this relative time decreases and 
+		/// --B-- equals zero in the last Section"
+		/// This is a contradiction. 
+		/// By choosing true, mode A is selected, and the final sector of the pause is -1. I like this better. Defaulting until proven otherwise (write test case here)
+		/// By choosing false, mode B is selected, and the final sector of the pause is 0. Mednafen does it this way.
+		/// Discs (including PSX) exist using A, or B, or possibly (reference please) neither.
+		/// </summary>
+		public bool CUE_PauseContradictionModeA = true;
+
+		public void SetForPlaystation()
+		{
+			//probably set CUE_PauseContradictionModeA to follow mednafen, but not proven yet
+		}
+	}
+	
 	public partial class DiscMountJob : LoggedJob
 	{
 		/// <summary>
@@ -19,6 +43,11 @@ namespace BizHawk.Emulation.DiscSystem
 		/// </summary>
 		public int IN_SlowLoadAbortThreshold = 10;
 
+		/// <summary>
+		/// Cryptic policies to be used when mounting the disc.
+		/// </summary>
+		public DiscMountPolicy IN_DiscMountPolicy = new DiscMountPolicy();
+
 		/// <summary>
 		/// The interface to be used for loading the disc.
 		/// Usually you'll want DiscInterface.BizHawk, but others can be used for A/B testing
@@ -74,6 +103,7 @@ namespace BizHawk.Emulation.DiscSystem
 				//perhaps the CUE_Format2 (once renamed to something like Context) can handle that
 				var cuePath = IN_FromPath;
 				var cue2 = new CUE_Format2();
+				cue2.DiscMountPolicy = IN_DiscMountPolicy;
 
 				cue2.Resolver = cfr;
 				if (!cfr.IsHardcodedResolve) cfr.SetBaseDirectory(Path.GetDirectoryName(infile));
@@ -90,7 +120,7 @@ namespace BizHawk.Emulation.DiscSystem
 				//compile the cue file:
 				//includes this work: resolve required bin files and find out what it's gonna take to load the cue
 				var compileJob = new CUE_Format2.CompileCueJob();
-				compileJob.IN_CueFormat = new CUE_Format2() { Resolver = cfr };
+				compileJob.IN_CueFormat = cue2;
 				compileJob.IN_CueFile = parseJob.OUT_CueFile;
 				compileJob.Run();
 				if (compileJob.OUT_Log != "") Console.WriteLine(compileJob.OUT_Log);
@@ -111,6 +141,7 @@ namespace BizHawk.Emulation.DiscSystem
 				ConcatenateJobLog(loadJob);
 
 				OUT_Disc = loadJob.OUT_Disc;
+				//OUT_Disc.DiscMountPolicy = IN_DiscMountPolicy; //NOT SURE WE NEED THIS
 
 				//apply SBI if it exists (TODO - for formats other than cue?)
 				var sbiPath = Path.ChangeExtension(IN_FromPath, ".sbi");