Implement IBasicMovieInfo interface for IMovie (#3634)

* Implement IBasicMovieInfo interface for IMovie

this allows parsing basic movie fields into an own class that is independent from Bk2Movie/TasMovie

This is mainly useful for the PlayMovie dialog which can now load movie information from files on disk without having to go through the entire Bk2Movie/TasMovie loading process

* don't potentially iterate input log twice

* Optimize LoadFramecount

src/BizHawk.Client.Common/movie/BasicMovieInfo.cs

@@ -0,0 +1,260 @@
+using System;
+using System.Collections.Generic;
+using System.Globalization;
+using System.IO;
+using BizHawk.Emulation.Common;
+
+namespace BizHawk.Client.Common
+{
+	public class BasicMovieInfo : IBasicMovieInfo
+	{
+		private string _filename;
+		private bool IsPal => Header[HeaderKeys.Pal] == "1";
+
+		protected readonly Bk2Header Header = new();
+
+		public BasicMovieInfo(string filename)
+		{
+			if (string.IsNullOrWhiteSpace(filename))
+			{
+				throw filename is null
+					? new ArgumentNullException(paramName: nameof(filename))
+					: new ArgumentException(message: "path cannot be blank", paramName: nameof(filename));
+			}
+
+			Filename = filename;
+		}
+
+		public string Name { get; private set; }
+
+		public string Filename
+		{
+			get => _filename;
+			set
+			{
+				_filename = value;
+				Name = Path.GetFileName(Filename);
+			}
+		}
+
+		public virtual int FrameCount { get; private set; }
+
+		public TimeSpan TimeLength
+		{
+			get
+			{
+				double dblSeconds;
+
+				if (Header.TryGetValue(HeaderKeys.CycleCount, out var numCyclesStr) && Header.TryGetValue(HeaderKeys.ClockRate, out var clockRateStr))
+				{
+					var numCycles = Convert.ToUInt64(numCyclesStr);
+					var clockRate = Convert.ToDouble(clockRateStr, CultureInfo.InvariantCulture);
+					dblSeconds = numCycles / clockRate;
+				}
+				else
+				{
+					var numFrames = (ulong)FrameCount;
+					dblSeconds = numFrames / FrameRate;
+				}
+
+				var seconds = (int)(dblSeconds % 60);
+				var days = seconds / 86400;
+				var hours = seconds / 3600;
+				var minutes = (seconds / 60) % 60;
+				var milliseconds = (int)((dblSeconds - seconds) * 1000);
+				return new TimeSpan(days, hours, minutes, seconds, milliseconds);
+			}
+		}
+
+		public double FrameRate
+		{
+			get
+			{
+				if (SystemID == VSystemID.Raw.Arcade && Header.TryGetValue(HeaderKeys.VsyncAttoseconds, out var vsyncAttoStr))
+				{
+					const decimal attosInSec = 1000000000000000000;
+					return (double)(attosInSec / Convert.ToUInt64(vsyncAttoStr));
+				}
+				else
+				{
+					return PlatformFrameRates.GetFrameRate(SystemID, IsPal);
+				}
+			}
+		}
+
+		public SubtitleList Subtitles { get; } = new();
+		public IList<string> Comments { get; } = new List<string>();
+
+		public virtual string GameName
+		{
+			get => Header[HeaderKeys.GameName];
+			set => Header[HeaderKeys.GameName] = value;
+		}
+
+		public virtual string SystemID
+		{
+			get => Header[HeaderKeys.Platform];
+			set => Header[HeaderKeys.Platform] = value;
+		}
+
+		public virtual ulong Rerecords
+		{
+			get => ulong.Parse(Header[HeaderKeys.Rerecords]);
+			set => Header[HeaderKeys.Rerecords] = value.ToString();
+		}
+
+		public virtual string Hash
+		{
+			get => Header[HeaderKeys.Sha1];
+			set => Header[HeaderKeys.Sha1] = value;
+		}
+
+		public virtual string Author
+		{
+			get => Header[HeaderKeys.Author];
+			set => Header[HeaderKeys.Author] = value;
+		}
+
+		public virtual string Core
+		{
+			get => Header[HeaderKeys.Core];
+			set => Header[HeaderKeys.Core] = value;
+		}
+
+		public virtual string BoardName
+		{
+			get => Header[HeaderKeys.BoardName];
+			set => Header[HeaderKeys.BoardName] = value;
+		}
+
+		public virtual string EmulatorVersion
+		{
+			get => Header[HeaderKeys.EmulatorVersion];
+			set => Header[HeaderKeys.EmulatorVersion] = value;
+		}
+
+		public virtual string OriginalEmulatorVersion
+		{
+			get => Header[HeaderKeys.OriginalEmulatorVersion];
+			set => Header[HeaderKeys.OriginalEmulatorVersion] = value;
+		}
+
+		public virtual string FirmwareHash
+		{
+			get => Header[HeaderKeys.FirmwareSha1];
+			set => Header[HeaderKeys.FirmwareSha1] = value;
+		}
+
+		public IDictionary<string, string> HeaderEntries => Header;
+
+		public bool Load()
+		{
+			var file = new FileInfo(Filename);
+			if (!file.Exists)
+			{
+				return false;
+			}
+
+			try
+			{
+				using var bl = ZipStateLoader.LoadAndDetect(Filename, true);
+				if (bl is null) return false;
+				ClearBeforeLoad();
+				LoadFields(bl);
+				if (FrameCount == 0)
+				{
+					// only iterate the input log if it hasn't been loaded already
+					LoadFramecount(bl);
+				}
+
+				return true;
+			}
+			catch (InvalidDataException e) when (e.StackTrace.Contains("ZipArchive.ReadEndOfCentralDirectory"))
+			{
+				throw new Exception("Archive appears to be corrupt. Make a backup, then try to repair it with e.g. 7-Zip.", e);
+			}
+		}
+
+		protected virtual void ClearBeforeLoad()
+		{
+			Header.Clear();
+			Subtitles.Clear();
+			Comments.Clear();
+		}
+
+		protected virtual void LoadFields(ZipStateLoader bl)
+		{
+			bl.GetLump(BinaryStateLump.Movieheader, abort: true, tr =>
+			{
+				while (tr.ReadLine() is string line)
+				{
+					if (!string.IsNullOrWhiteSpace(line))
+					{
+						var pair = line.Split(new[] { ' ' }, 2, StringSplitOptions.RemoveEmptyEntries);
+
+						if (pair.Length > 1)
+						{
+							if (!Header.ContainsKey(pair[0]))
+							{
+								Header.Add(pair[0], pair[1]);
+							}
+						}
+					}
+				}
+			});
+
+			bl.GetLump(BinaryStateLump.Comments, abort: false, tr =>
+			{
+				while (tr.ReadLine() is string line)
+				{
+					if (!string.IsNullOrWhiteSpace(line))
+					{
+						Comments.Add(line);
+					}
+				}
+			});
+
+			bl.GetLump(BinaryStateLump.Subtitles, abort: false, tr =>
+			{
+				while (tr.ReadLine() is string line)
+				{
+					if (!string.IsNullOrWhiteSpace(line))
+					{
+						Subtitles.AddFromString(line);
+					}
+				}
+
+				Subtitles.Sort();
+			});
+
+			bl.GetLump(BinaryStateLump.Subtitles, abort: false, tr =>
+			{
+				while (tr.ReadLine() is string line)
+				{
+					if (!string.IsNullOrWhiteSpace(line))
+					{
+						Subtitles.AddFromString(line);
+					}
+				}
+
+				Subtitles.Sort();
+			});
+		}
+
+		private void LoadFramecount(ZipStateLoader bl)
+		{
+			bl.GetLump(BinaryStateLump.Input, abort: true, tr =>
+			{
+				// just skim through the input log and count input lines
+				// FIXME: this is potentially expensive and shouldn't be necessary for something as simple as frame count
+				while (tr.ReadLine() is string line)
+				{
+					if (line.Length > 0 && line[0] == '|')
+					{
+						FrameCount++;
+					}
+				}
+			});
+		}
+	}
+}

src/BizHawk.Client.Common/movie/MovieSession.cs

@@ -188,7 +188,7 @@ namespace BizHawk.Client.Common
 			return true;
 		}
 
-		/// <exception cref="MoviePlatformMismatchException"><paramref name="record"/> is <see langword="false"/> and <paramref name="movie"/>.<see cref="IMovie.SystemID"/> does not match <paramref name="systemId"/>.<see cref="IEmulator.SystemId"/></exception>
+		/// <exception cref="MoviePlatformMismatchException"><paramref name="record"/> is <see langword="false"/> and <paramref name="movie"/>.<see cref="IBasicMovieInfo.SystemID"/> does not match <paramref name="systemId"/>.<see cref="IEmulator.SystemId"/></exception>
 		public void QueueNewMovie(IMovie movie, bool record, string systemId, IDictionary<string, string> preferredCores)
 		{
 			if (movie.IsActive() && movie.Changes)
@@ -198,7 +198,7 @@ namespace BizHawk.Client.Common
 
 			if (!record) // The semantics of record is that we are starting a new movie, and even wiping a pre-existing movie with the same path, but non-record means we are loading an existing movie into playback mode
 			{
-				movie.Load(false);
+				movie.Load();
 				
 				if (movie.SystemID != systemId)
 				{
@@ -400,4 +400,4 @@ namespace BizHawk.Client.Common
 			Movie.RecordFrame(Movie.Emulator.Frame, MovieController);
 		}
 	}
-}
+}

src/BizHawk.Client.Common/movie/bk2/Bk2Movie.HeaderApi.cs

@@ -1,18 +1,11 @@
-using System.Collections.Generic;
+using System.Text;
-using System.Text;
 
 namespace BizHawk.Client.Common
 {
 	public partial class Bk2Movie
 	{
-		protected readonly Bk2Header Header = new Bk2Header();
 		private string _syncSettingsJson = "";
 
-		public IDictionary<string, string> HeaderEntries => Header;
-
-		public SubtitleList Subtitles { get; } = new SubtitleList();
-		public IList<string> Comments { get; } = new List<string>();
-
 		public string SyncSettingsJson
 		{
 			get => _syncSettingsJson;
@@ -26,11 +19,8 @@ namespace BizHawk.Client.Common
 			}
 		}
 
-		public ulong Rerecords
+		public override ulong Rerecords
 		{
-			get => Header.TryGetValue(HeaderKeys.Rerecords, out var s)
-				? ulong.Parse(s)
-				: 0UL; // Modifying the header itself can cause a race condition between loading a movie and rendering the rerecord count, causing a movie's rerecord count to be overwritten with 0 during loading.
 			set
 			{
 				if (Header[HeaderKeys.Rerecords] != value.ToString())
@@ -80,9 +70,8 @@ namespace BizHawk.Client.Common
 			}
 		}
 
-		public string GameName
+		public override string GameName
 		{
-			get => Header.TryGetValue(HeaderKeys.GameName, out var s) ? s : string.Empty;
 			set
 			{
 				if (Header[HeaderKeys.GameName] != value)
@@ -93,9 +82,8 @@ namespace BizHawk.Client.Common
 			}
 		}
 
-		public string SystemID
+		public override string SystemID
 		{
-			get => Header.TryGetValue(HeaderKeys.Platform, out var s) ? s : string.Empty;
 			set
 			{
 				if (Header[HeaderKeys.Platform] != value)
@@ -106,9 +94,8 @@ namespace BizHawk.Client.Common
 			}
 		}
 
-		public string Hash
+		public override string Hash
 		{
-			get => Header[HeaderKeys.Sha1];
 			set
 			{
 				if (Header[HeaderKeys.Sha1] != value)
@@ -119,9 +106,8 @@ namespace BizHawk.Client.Common
 			}
 		}
 
-		public string Author
+		public override string Author
 		{
-			get => Header[HeaderKeys.Author];
 			set
 			{
 				if (Header[HeaderKeys.Author] != value)
@@ -132,9 +118,8 @@ namespace BizHawk.Client.Common
 			}
 		}
 
-		public string Core
+		public override string Core
 		{
-			get => Header[HeaderKeys.Core];
 			set
 			{
 				if (Header[HeaderKeys.Core] != value)
@@ -145,9 +130,8 @@ namespace BizHawk.Client.Common
 			}
 		}
 
-		public string BoardName
+		public override string BoardName
 		{
-			get => Header[HeaderKeys.BoardName];
 			set
 			{
 				if (Header[HeaderKeys.BoardName] != value)
@@ -158,9 +142,8 @@ namespace BizHawk.Client.Common
 			}
 		}
 
-		public string EmulatorVersion
+		public override string EmulatorVersion
 		{
-			get => Header[HeaderKeys.EmulatorVersion];
 			set
 			{
 				if (Header[HeaderKeys.EmulatorVersion] != value)
@@ -171,9 +154,8 @@ namespace BizHawk.Client.Common
 			}
 		}
 
-		public string OriginalEmulatorVersion
+		public override string OriginalEmulatorVersion
 		{
-			get => Header[HeaderKeys.OriginalEmulatorVersion];
 			set
 			{
 				if (Header[HeaderKeys.OriginalEmulatorVersion] != value)
@@ -184,9 +166,8 @@ namespace BizHawk.Client.Common
 			}
 		}
 
-		public string FirmwareHash
+		public override string FirmwareHash
 		{
-			get => Header[HeaderKeys.FirmwareSha1];
 			set
 			{
 				if (Header[HeaderKeys.FirmwareSha1] != value)
@@ -209,10 +190,6 @@ namespace BizHawk.Client.Common
 			return sb.ToString();
 		}
 
-		// ReSharper disable SimplifyConditionalTernaryExpression
-		public bool IsPal => Header.TryGetValue(HeaderKeys.Pal, out var s) ? s == "1" : false;
-		// ReSharper restore SimplifyConditionalTernaryExpression
-
 		public string TextSavestate { get; set; }
 		public byte[] BinarySavestate { get; set; }
 		public int[] SavestateFramebuffer { get; set; }

src/BizHawk.Client.Common/movie/bk2/Bk2Movie.IO.cs

@@ -29,31 +29,6 @@ namespace BizHawk.Client.Common
 			Write(backupName, isBackup: true);
 		}
 
-		public virtual bool Load(bool preload)
-		{
-			var file = new FileInfo(Filename);
-			if (!file.Exists)
-			{
-				return false;
-			}
-
-			try
-			{
-				using var bl = ZipStateLoader.LoadAndDetect(Filename, true);
-				if (bl is null) return false;
-				ClearBeforeLoad();
-				LoadFields(bl, preload);
-				Changes = false;
-				return true;
-			}
-			catch (InvalidDataException e) when (e.StackTrace.Contains("ZipArchive.ReadEndOfCentralDirectory"))
-			{
-				throw new Exception("Archive appears to be corrupt. Make a backup, then try to repair it with e.g. 7-Zip.", e);
-			}
-		}
-
-		public bool PreLoadHeaderAndLength() => Load(true);
-
 		protected virtual void Write(string fn, bool isBackup = false)
 		{
 			SetCycleValues();
@@ -136,49 +111,28 @@ namespace BizHawk.Client.Common
 			}
 		}
 
-		protected virtual void ClearBeforeLoad()
+		protected override void ClearBeforeLoad()
 		{
+			base.ClearBeforeLoad();
 			ClearBk2Fields();
 		}
 
-		protected void ClearBk2Fields()
+		private void ClearBk2Fields()
 		{
-			Header.Clear();
 			Log.Clear();
-			Subtitles.Clear();
-			Comments.Clear();
 			_syncSettingsJson = "";
 			TextSavestate = null;
 			BinarySavestate = null;
 		}
 
-		protected virtual void LoadFields(ZipStateLoader bl, bool preload)
+		protected override void LoadFields(ZipStateLoader bl)
 		{
-			LoadBk2Fields(bl, preload);
+			base.LoadFields(bl);
+			LoadBk2Fields(bl);
 		}
 
-		protected void LoadBk2Fields(ZipStateLoader bl, bool preload)
+		private void LoadBk2Fields(ZipStateLoader bl)
 		{
-			bl.GetLump(BinaryStateLump.Movieheader, abort: true, tr =>
-			{
-				string line;
-				while ((line = tr.ReadLine()) != null)
-				{
-					if (!string.IsNullOrWhiteSpace(line))
-					{
-						var pair = line.Split(new[] { ' ' }, 2, StringSplitOptions.RemoveEmptyEntries);
-
-						if (pair.Length > 1)
-						{
-							if (!Header.ContainsKey(pair[0]))
-							{
-								Header.Add(pair[0], pair[1]);
-							}
-						}
-					}
-				}
-			});
-
 			bl.GetLump(BinaryStateLump.Input, abort: true, tr =>
 			{
 				IsCountingRerecords = false;
@@ -186,37 +140,6 @@ namespace BizHawk.Client.Common
 				IsCountingRerecords = true;
 			});
 
-			if (preload)
-			{
-				return;
-			}
-
-			bl.GetLump(BinaryStateLump.Comments, abort: false, tr =>
-			{
-				string line;
-				while ((line = tr.ReadLine()) != null)
-				{
-					if (!string.IsNullOrWhiteSpace(line))
-					{
-						Comments.Add(line);
-					}
-				}
-			});
-
-			bl.GetLump(BinaryStateLump.Subtitles, abort: false, tr =>
-			{
-				string line;
-				while ((line = tr.ReadLine()) != null)
-				{
-					if (!string.IsNullOrWhiteSpace(line))
-					{
-						Subtitles.AddFromString(line);
-					}
-				}
-
-				Subtitles.Sort();
-			});
-
 			bl.GetLump(BinaryStateLump.SyncSettings, abort: false, tr =>
 			{
 				string line;

src/BizHawk.Client.Common/movie/bk2/Bk2Movie.cs

@@ -1,26 +1,15 @@
-using System;
+using System.Collections.Generic;
-using System.Collections.Generic;
-using System.Globalization;
-using System.IO;
 using BizHawk.Emulation.Common;
 
 namespace BizHawk.Client.Common
 {
-	public partial class Bk2Movie : IMovie
+	public partial class Bk2Movie : BasicMovieInfo, IMovie
 	{
 		private Bk2Controller _adapter;
 
-		public Bk2Movie(IMovieSession session, string filename)
+		public Bk2Movie(IMovieSession session, string filename) : base(filename)
 		{
-			if (string.IsNullOrWhiteSpace(filename))
-			{
-				throw filename is null
-					? new ArgumentNullException(paramName: nameof(filename))
-					: new ArgumentException(message: "path cannot be blank", paramName: nameof(filename));
-			}
-
 			Session = session;
-			Filename = filename;
 			Header[HeaderKeys.MovieVersion] = "BizHawk v2.0.0";
 		}
 
@@ -36,20 +25,6 @@ namespace BizHawk.Client.Common
 
 		protected bool MakeBackup { get; set; } = true;
 
-		private string _filename;
-
-		public string Filename
-		{
-			get => _filename;
-			set
-			{
-				_filename = value;
-				Name = Path.GetFileName(Filename);
-			}
-		}
-
-		public string Name { get; private set; }
-
 		public virtual string PreferredExtension => Extension;
 
 		public const string Extension = "bk2";
@@ -62,52 +37,9 @@ namespace BizHawk.Client.Common
 			return new Bk2LogEntryGenerator(Emulator?.SystemId ?? SystemID, source);
 		}
 
-		public int FrameCount => Log.Count;
+		public override int FrameCount => Log.Count;
 		public int InputLogLength => Log.Count;
 
-		public TimeSpan TimeLength
-		{
-			get
-			{
-				double dblSeconds;
-
-				if (Header.TryGetValue(HeaderKeys.CycleCount, out var numCyclesStr) && Header.TryGetValue(HeaderKeys.ClockRate, out var clockRateStr))
-				{
-					var numCycles = Convert.ToUInt64(numCyclesStr);
-					var clockRate = Convert.ToDouble(clockRateStr, CultureInfo.InvariantCulture);
-					dblSeconds = numCycles / clockRate;
-				}
-				else
-				{
-					var numFrames = (ulong)FrameCount;
-					dblSeconds = numFrames / FrameRate;
-				}
-
-				var seconds = (int)(dblSeconds % 60);
-				var days = seconds / 86400;
-				var hours = seconds / 3600;
-				var minutes = (seconds / 60) % 60;
-				var milliseconds = (int)((dblSeconds - seconds) * 1000);
-				return new TimeSpan(days, hours, minutes, seconds, milliseconds);
-			}
-		}
-
-		public double FrameRate
-		{
-			get
-			{
-				if (SystemID == VSystemID.Raw.Arcade && Header.TryGetValue(HeaderKeys.VsyncAttoseconds, out var vsyncAttoStr))
-				{
-					const decimal attosInSec = 1000000000000000000;
-					return (double)(attosInSec / Convert.ToUInt64(vsyncAttoStr));
-				}
-				else
-				{
-					return PlatformFrameRates.GetFrameRate(SystemID, IsPal);
-				}
-			}
-		}
-
 		public IStringLog GetLogEntries() => Log;
 
 		public void CopyLog(IEnumerable<string> log)

src/BizHawk.Client.Common/movie/interfaces/IBasicMovieInfo.cs

@@ -0,0 +1,59 @@
+using System;
+using System.Collections.Generic;
+
+namespace BizHawk.Client.Common
+{
+	public interface IBasicMovieInfo
+	{
+		// Filename of the movie, settable by the client
+		string Filename { get; set; }
+
+		string Name { get; }
+
+		string GameName { get; set; }
+
+		/// <summary>
+		/// Gets the total number of frames that count towards the completion time of the movie
+		/// </summary>
+		int FrameCount { get; }
+
+		/// <summary>
+		/// Gets the actual length of time a movie lasts for. For subframe cores, this will be different then the above two options
+		/// </summary>
+		TimeSpan TimeLength { get; }
+
+		/// <summary>
+		/// Gets the frame rate in frames per second for the movie's system.
+		/// </summary>
+		double FrameRate { get; }
+
+		SubtitleList Subtitles { get; }
+
+		IList<string> Comments { get; }
+
+		string SystemID { get; set; }
+
+		ulong Rerecords { get; set; }
+
+		/// <value>either CRC32, MD5, or SHA1, hex-encoded, unprefixed</value>
+		string Hash { get; set; }
+
+		string Author { get; set; }
+		string Core { get; set; }
+		string EmulatorVersion { get; set; }
+		string OriginalEmulatorVersion { get; set; }
+		string FirmwareHash { get; set; }
+		string BoardName { get; set; }
+
+		/// <summary>
+		/// Gets the header key value pairs stored in the movie file
+		/// </summary>
+		IDictionary<string, string> HeaderEntries { get; }
+
+		/// <summary>
+		/// Tells the movie to load the contents of Filename
+		/// </summary>
+		/// <returns>Return whether or not the file was successfully loaded</returns>
+		bool Load();
+	}
+}

src/BizHawk.Client.Common/movie/interfaces/IMovie.cs

@@ -1,5 +1,4 @@
-using System;
+using System.Collections.Generic;
-using System.Collections.Generic;
 using System.IO;
 using BizHawk.Emulation.Common;
 
@@ -30,7 +29,7 @@ namespace BizHawk.Client.Common
 
 	// TODO: message callback / event handler
 	// TODO: consider other event handlers, switching modes?
-	public interface IMovie
+	public interface IMovie : IBasicMovieInfo
 	{
 		/// <summary>
 		/// Gets the current movie mode
@@ -41,29 +40,12 @@ namespace BizHawk.Client.Common
 
 		bool Changes { get; }
 
-		string Name { get; }
-
-		/// <summary>
-		/// Gets the total number of frames that count towards the completion time of the movie
-		/// </summary>
-		int FrameCount { get; }
-
 		/// <summary>
 		/// Gets the actual length of the input log, should only be used by code that needs the input log length
 		/// specifically, not the frame count
 		/// </summary>
 		int InputLogLength { get; }
 
-		/// <summary>
-		/// Gets the actual length of time a movie lasts for. For subframe cores, this will be different then the above two options
-		/// </summary>
-		TimeSpan TimeLength { get; }
-
-		/// <summary>
-		/// Gets the frame rate in frames per second for the movie's system.
-		/// </summary>
-		double FrameRate { get; }
-
 		/// <summary>
 		/// Gets the file extension for the current <see cref="IMovie"/> implementation
 		/// </summary>
@@ -74,9 +56,6 @@ namespace BizHawk.Client.Common
 		/// </summary>
 		string SyncSettingsJson { get; set; }
 
-		SubtitleList Subtitles { get; }
-		IList<string> Comments { get; }
-
 		// savestate anchor.
 		string TextSavestate { get; set; }
 		byte[] BinarySavestate { get; set; }
@@ -85,34 +64,11 @@ namespace BizHawk.Client.Common
 		// saveram anchor
 		byte[] SaveRam { get; set; }
 
-		ulong Rerecords { get; set; }
 		bool StartsFromSavestate { get; set; }
 		bool StartsFromSaveRam { get; set; }
-		string GameName { get; set; }
-		string SystemID { get; set; }
 
-		/// <value>either CRC32, MD5, or SHA1, hex-encoded, unprefixed</value>
-		string Hash { get; set; }
-
-		string Author { get; set; }
-		string Core { get; set; }
-		string EmulatorVersion { get; set; }
-		string OriginalEmulatorVersion { get; set; }
-		string FirmwareHash { get; set; }
-		string BoardName { get; set; }
 		string LogKey { get; set; }
 
-		/// <summary>
-		/// Loads from the HawkFile the minimal amount of information needed to determine Header info and Movie length.
-		/// This method is intended to be more performant than a full load
-		/// </summary>
-		bool PreLoadHeaderAndLength();
-		
-		/// <summary>
-		/// Gets the header key value pairs stored in the movie file
-		/// </summary>
-		IDictionary<string, string> HeaderEntries { get; }
-
 		/// <summary>
 		/// Forces the creation of a backup file of the current movie state
 		/// </summary>
@@ -123,15 +79,6 @@ namespace BizHawk.Client.Common
 		/// </summary>
 		ILogEntryGenerator LogGeneratorInstance(IController source);
 
-		// Filename of the movie, settable by the client
-		string Filename { get; set; }
-
-		/// <summary>
-		/// Tells the movie to load the contents of Filename
-		/// </summary>
-		/// <returns>Return whether or not the file was successfully loaded</returns>
-		bool Load(bool preload);
-
 		/// <summary>
 		/// Instructs the movie to save the current contents to Filename
 		/// </summary>

src/BizHawk.Client.Common/movie/tasproj/TasMovie.IO.cs

@@ -49,7 +49,7 @@ namespace BizHawk.Client.Common
 
 		protected override void ClearBeforeLoad()
 		{
-			ClearBk2Fields();
+			base.ClearBeforeLoad();
 			ClearTasprojExtras();
 		}
 
@@ -61,21 +61,18 @@ namespace BizHawk.Client.Common
 			ChangeLog.Clear();
 		}
 		
-		protected override void LoadFields(ZipStateLoader bl, bool preload)
+		protected override void LoadFields(ZipStateLoader bl)
 		{
-			LoadBk2Fields(bl, preload);
+			base.LoadFields(bl);
 
-			if (!preload)
+			if (MovieService.IsCurrentTasVersion(Header[HeaderKeys.MovieVersion]))
 			{
-				if (MovieService.IsCurrentTasVersion(Header[HeaderKeys.MovieVersion]))
+				LoadTasprojExtras(bl);
-				{
+			}
-					LoadTasprojExtras(bl);
+			else
-				}
+			{
-				else
+				Session.PopupMessage("The current .tasproj is not compatible with this version of BizHawk! .tasproj features failed to load.");
-				{
+				Markers.Add(0, StartsFromSavestate ? "Savestate" : "Power on");
-					Session.PopupMessage("The current .tasproj is not compatible with this version of BizHawk! .tasproj features failed to load.");
-					Markers.Add(0, StartsFromSavestate ? "Savestate" : "Power on");
-				}
 			}
 		}
 		

src/BizHawk.Client.EmuHawk/movie/PlayMovie.cs

@@ -27,7 +27,7 @@ namespace BizHawk.Client.EmuHawk
 		private readonly IEmulator _emulator;
 		private readonly IMovieSession _movieSession;
 
-		private List<IMovie> _movieList = new List<IMovie>();
+		private List<IBasicMovieInfo> _movieList = new();
 		private bool _sortReverse;
 		private string _sortedCol;
 
@@ -66,8 +66,10 @@ namespace BizHawk.Client.EmuHawk
 
 		private void PlayMovie_Load(object sender, EventArgs e)
 		{
+			_suppressCheckedChanged = true;
 			IncludeSubDirectories.Checked = _config.PlayMovieIncludeSubDir;
 			MatchHashCheckBox.Checked = _config.PlayMovieMatchHash;
+			_suppressCheckedChanged = false;
 			ScanFiles();
 			PreHighlightMovie();
 			TurboCheckbox.Checked = _config.TurboSeek;
@@ -87,7 +89,9 @@ namespace BizHawk.Client.EmuHawk
 			var indices = MovieView.SelectedIndices;
 			if (indices.Count > 0) // Import file if necessary
 			{
-				_mainForm.StartNewMovie(_movieList[MovieView.SelectedIndices[0]], false);
+				var movie = _movieSession.Get(_movieList[MovieView.SelectedIndices[0]].Filename);
+				movie.Load();
+				_mainForm.StartNewMovie(movie, false);
 			}
 		}
 
@@ -99,7 +103,7 @@ namespace BizHawk.Client.EmuHawk
 				return null;
 			}
 				
-			var movie = PreLoadMovieFile(file, force);
+			var movie = LoadMovieInfo(file, force);
 			if (movie == null)
 			{
 				return null;
@@ -138,13 +142,13 @@ namespace BizHawk.Client.EmuHawk
 			return null;
 		}
 
-		private IMovie PreLoadMovieFile(HawkFile hf, bool force)
+		private IBasicMovieInfo LoadMovieInfo(HawkFile hf, bool force)
 		{
-			var movie = _movieSession.Get(hf.CanonicalFullPath);
+			IBasicMovieInfo movie = new BasicMovieInfo(hf.CanonicalFullPath);
 
 			try
 			{
-				movie.PreLoadHeaderAndLength();
+				movie.Load();
 
 				// Don't do this from browse
 				if (movie.Hash == _game.Hash
@@ -338,8 +342,8 @@ namespace BizHawk.Client.EmuHawk
 			Close();
 		}
 
-		private static readonly RigidMultiPredicateSort<IMovie> ColumnSorts
+		private static readonly RigidMultiPredicateSort<IBasicMovieInfo> ColumnSorts
-			= new RigidMultiPredicateSort<IMovie>(new Dictionary<string, Func<IMovie, IComparable>>
+			= new(new Dictionary<string, Func<IBasicMovieInfo, IComparable>>
 			{
 				["File"] = x => Path.GetFileName(x.Filename),
 				["SysID"] = x => x.SystemID,
@@ -499,7 +503,11 @@ namespace BizHawk.Client.EmuHawk
 			var indices = MovieView.SelectedIndices;
 			if (indices.Count > 0)
 			{
-				var form = new EditCommentsForm(_movieList[MovieView.SelectedIndices[0]], _movieSession.ReadOnly);
+				// TODO this will allocate unnecessary memory when this movie is a TasMovie due to TasStateManager
+				var movie = _movieSession.Get(_movieList[MovieView.SelectedIndices[0]].Filename);
+				movie.Load();
+				// TODO movie should be disposed if movie is ITasMovie
+				var form = new EditCommentsForm(movie, _movieSession.ReadOnly);
 				form.Show();
 			}
 		}
@@ -509,7 +517,11 @@ namespace BizHawk.Client.EmuHawk
 			var indices = MovieView.SelectedIndices;
 			if (indices.Count > 0)
 			{
-				using EditSubtitlesForm s = new(DialogController, _movieList[MovieView.SelectedIndices[0]], _config.PathEntries, readOnly: true);
+				// TODO this will allocate unnecessary memory when this movie is a TasMovie due to TasStateManager
+				var movie = _movieSession.Get(_movieList[MovieView.SelectedIndices[0]].Filename);
+				movie.Load();
+				// TODO movie should be disposed if movie is ITasMovie
+				using EditSubtitlesForm s = new(DialogController, movie, _config.PathEntries, readOnly: true);
 				s.Show();
 			}
 		}
@@ -543,6 +555,8 @@ namespace BizHawk.Client.EmuHawk
 
 		private void IncludeSubDirectories_CheckedChanged(object sender, EventArgs e)
 		{
+			if (_suppressCheckedChanged) return;
+
 			_config.PlayMovieIncludeSubDir = IncludeSubDirectories.Checked;
 			ScanFiles();
 			PreHighlightMovie();
@@ -550,6 +564,8 @@ namespace BizHawk.Client.EmuHawk
 
 		private void MatchHashCheckBox_CheckedChanged(object sender, EventArgs e)
 		{
+			if (_suppressCheckedChanged) return;
+
 			_config.PlayMovieMatchHash = MatchHashCheckBox.Checked;
 			ScanFiles();
 			PreHighlightMovie();
@@ -578,6 +594,8 @@ namespace BizHawk.Client.EmuHawk
 		}
 
 		private bool _programmaticallyChangingStopFrameCheckbox;
+		private bool _suppressCheckedChanged;
+
 		private void StopOnFrameCheckbox_CheckedChanged(object sender, EventArgs e)
 		{
 			if (!_programmaticallyChangingStopFrameCheckbox)

src/BizHawk.Client.EmuHawk/tools/TAStudio/HeaderEditor.cs

@@ -7,10 +7,10 @@ namespace BizHawk.Client.EmuHawk
 {
 	public partial class MovieHeaderEditor : Form
 	{
-		private readonly IMovie _movie;
+		private readonly IBasicMovieInfo _movie;
 		private readonly Config _config;
 
-		public MovieHeaderEditor(IMovie movie, Config config)
+		public MovieHeaderEditor(IBasicMovieInfo movie, Config config)
 		{
 			_movie = movie;
 			_config = config;