add FFmpegWriter, pipes data to ffmpeg for encoding. Only handles video directly; audio is saved as .wav file separately (via WaveWriterV).

ffmpeg parameters cannot be set at the moment,  defaults to x264 rgb lossless in mkv

BizHawk.MultiClient/BizHawk.MultiClient.csproj

@@ -164,6 +164,7 @@
     </Compile>
     <Compile Include="DisplayManager\DisplayManager.cs" />
     <Compile Include="DisplayManager\Filters\Hq2x.cs" />
+    <Compile Include="FFmpegWriter.cs" />
     <Compile Include="Gameboy\Debugger.cs">
       <SubType>Form</SubType>
     </Compile>

BizHawk.MultiClient/FFmpegWriter.cs

@@ -0,0 +1,229 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Net.Sockets;
+using System.Net;
+using System.Diagnostics;
+
+namespace BizHawk.MultiClient
+{
+	/// <summary>
+	/// uses tcp sockets to launch an external ffmpeg process and encode
+	/// </summary>
+	class FFmpegWriter : WavWriterV, IVideoWriter
+	{
+		/// <summary>
+		/// handle to external ffmpeg process
+		/// </summary>
+		Process ffmpeg;
+
+		/// <summary>
+		/// the commandline actually sent to ffmpeg; for informative purposes
+		/// </summary>
+		string commandline;
+
+		/// <summary>
+		/// current file segment (for multires)
+		/// </summary>
+		int segment;
+
+		/// <summary>
+		/// base filename before segment number is attached
+		/// </summary>
+		string baseName;
+
+		/// <summary>
+		/// recent lines in ffmpeg's stderr, for informative purposes
+		/// </summary>
+		Queue<string> stderr;
+
+		/// <summary>
+		/// number of lines of stderr to buffer
+		/// </summary>
+		const int consolebuffer = 5;
+
+		public new void OpenFile(string baseName)
+		{
+			string s = System.IO.Path.GetFileNameWithoutExtension(baseName);
+
+			base.OpenFile(s + ".wav");
+
+			this.baseName = s;
+
+			segment = 0;
+			OpenFileSegment();
+		}
+		
+		/// <summary>
+		/// starts an ffmpeg process and sets up associated sockets
+		/// </summary>
+		void OpenFileSegment()
+		{
+			ffmpeg = new Process();
+			ffmpeg.StartInfo.FileName = "ffmpeg";
+
+			string filename = String.Format("{0}_{1,4:D4}", baseName, segment);
+
+			ffmpeg.StartInfo.Arguments = String.Format
+			(
+				"-y -f rawvideo -pix_fmt bgra -s {0}x{1} -r {2}/{3} -i - -vcodec libx264rgb -crf 0 \"{4}.mkv\"",
+				width,
+				height,
+				fpsnum,
+				fpsden,
+				filename
+			);
+
+			ffmpeg.StartInfo.CreateNoWindow = true;
+
+			// ffmpeg sends informative display to stderr, and nothing to stdout
+			ffmpeg.StartInfo.RedirectStandardError = true;
+			ffmpeg.StartInfo.RedirectStandardInput = true;
+			ffmpeg.StartInfo.UseShellExecute = false;
+
+			commandline = "ffmpeg " + ffmpeg.StartInfo.Arguments;
+
+			ffmpeg.ErrorDataReceived += new DataReceivedEventHandler(StderrHandler);
+
+			stderr = new Queue<string>(consolebuffer);
+
+			ffmpeg.Start();
+			ffmpeg.BeginErrorReadLine();
+		}
+
+		/// <summary>
+		/// saves stderr lines from ffmpeg in a short queue
+		/// </summary>
+		/// <param name="p"></param>
+		/// <param name="line"></param>
+		void StderrHandler(object p, DataReceivedEventArgs line)
+		{
+			if (!String.IsNullOrEmpty(line.Data))
+			{
+				if (stderr.Count == consolebuffer)
+					stderr.Dequeue();
+				stderr.Enqueue(line.Data + "\n");
+			}
+		}
+
+		/// <summary>
+		/// finishes an ffmpeg process
+		/// </summary>
+		void CloseFileSegment()
+		{
+			ffmpeg.StandardInput.Close();
+
+			// how long should we wait here?
+			ffmpeg.WaitForExit(20000);
+			ffmpeg = null;
+			stderr = null;
+			commandline = null;
+		}
+
+
+		public new void CloseFile()
+		{
+			CloseFileSegment();
+			baseName = null;
+			base.CloseFile();
+		}
+
+		/// <summary>
+		/// returns a string containing the commandline sent to ffmpeg and recent console (stderr) output
+		/// </summary>
+		/// <returns></returns>
+		string ffmpeg_geterror()
+		{
+			if (ffmpeg.StartInfo.RedirectStandardError)
+			{
+				ffmpeg.CancelErrorRead();
+			}
+			StringBuilder s = new StringBuilder();
+			s.Append(commandline);
+			s.Append('\n');
+			while (stderr.Count > 0)
+			{
+				var foo = stderr.Dequeue();
+				System.Windows.Forms.MessageBox.Show(foo);
+				s.Append(foo);
+			}
+			return s.ToString();
+		}
+
+
+		public new void AddFrame(IVideoProvider source)
+		{
+			if (source.BufferWidth != width || source.BufferHeight != height)
+				SetVideoParameters(source.BufferWidth, source.BufferHeight);
+
+			if (ffmpeg.HasExited)
+				throw new Exception("unexpected ffmpeg death:\n" + ffmpeg_geterror());
+			var a = source.GetVideoBuffer();
+			var b = new byte[a.Length * sizeof (int)];
+			Buffer.BlockCopy(a, 0, b, 0, b.Length);
+			// have to do binary write!
+			ffmpeg.StandardInput.BaseStream.Write(b, 0, b.Length);
+		}
+
+
+		/// <summary>
+		/// codec token for FFmpegWriter
+		/// </summary>
+		class FFmpegWriterToken : IDisposable
+		{
+			public void Dispose()
+			{
+			}
+		}
+
+		public new IDisposable AcquireVideoCodecToken(IntPtr hwnd)
+		{
+			return new FFmpegWriterToken();
+		}
+	
+		public new void SetVideoCodecToken(IDisposable token)
+		{
+			// nyi
+		}
+
+		/// <summary>
+		/// video params
+		/// </summary>
+		int fpsnum, fpsden, width, height;
+
+		public new void SetMovieParameters(int fpsnum, int fpsden)
+		{
+			this.fpsnum = fpsnum;
+			this.fpsden = fpsden;
+		}
+
+		public new void SetVideoParameters(int width, int height)
+		{
+			this.width = width;
+			this.height = height;
+
+			/* ffmpeg theoretically supports variable resolution videos, but there's no way to
+			 * signal that metadata in a raw pipe.  so if we're currently in a segment,
+			 * start a new one */
+			if (ffmpeg != null)
+			{
+				CloseFileSegment();
+				segment++;
+				OpenFileSegment();
+			}
+		}
+
+
+		public new void SetMetaData(string gameName, string authors, ulong lengthMS, ulong rerecords)
+		{
+			// can be implemented with ffmpeg "-metadata" parameter???
+			// nyi
+		}
+
+		public new void Dispose()
+		{
+			base.Dispose();
+		}
+	}
+}

BizHawk.MultiClient/MainForm.cs

@@ -2748,7 +2748,7 @@ namespace BizHawk.MultiClient
 				sfd.FileName = "NULL";
 				sfd.InitialDirectory = PathManager.MakeAbsolutePath(Global.Config.AVIPath, "");
 			}
-			sfd.Filter = "AVI (*.avi)|*.avi|JMD (*.jmd)|*.jmd|WAV (*.wav)|*.wav|All Files|*.*";
+			sfd.Filter = "AVI (*.avi)|*.avi|JMD (*.jmd)|*.jmd|WAV (*.wav)|*.wav|Matroska (*.mkv)|*.mkv|All Files|*.*";
 			Global.Sound.StopSound();
 			var result = sfd.ShowDialog();
 			Global.Sound.StartSound();
@@ -2768,6 +2768,8 @@ namespace BizHawk.MultiClient
 				aw = new AviWriter();
 			else if (ext == ".wav")
 				aw = new WavWriterV();
+			else if (ext == ".mkv")
+				aw = new FFmpegWriter();
 			else // hmm?
 				aw = new AviWriter();
 			try

BizHawk.MultiClient/WavWriter.cs

@@ -254,7 +254,7 @@ namespace BizHawk.MultiClient
 
 		public void OpenFile(string baseName)
 		{
-			wavwriter = new WavWriter(CreateStreamIterator (baseName), sampleRate, channels);
+			wavwriter = new WavWriter(CreateStreamIterator(baseName), sampleRate, channels);
 		}
 
 		public void CloseFile()