Cleanup instantiation of FFmpegDownloaderForm and FFmpegService

src/BizHawk.Client.DiscoHawk/AudioExtractor.cs

@@ -47,8 +47,7 @@ namespace BizHawk.Client.DiscoHawk
 				try
 				{
 					File.WriteAllBytes(tempfile, waveData);
-					var ffmpeg = new FFmpegService();
-					ffmpeg.Run("-f", "s16le", "-ar", "44100", "-ac", "2", "-i", tempfile, "-f", "mp3", "-ab", "192k", mp3Path);
+					FFmpegService.Run("-f", "s16le", "-ar", "44100", "-ac", "2", "-i", tempfile, "-f", "mp3", "-ab", "192k", mp3Path);
 				}
 				finally
 				{

src/BizHawk.Client.EmuHawk/AVOut/FFmpegDownloaderForm.cs

@@ -94,8 +94,7 @@ namespace BizHawk.Client.EmuHawk
 				}
 
 				//make sure it worked
-				if (!new FFmpegService().QueryServiceAvailable())
-					throw new Exception("download failed");
+				if (!FFmpegService.QueryServiceAvailable()) throw new Exception("download failed");
 
 				succeeded = true;
 			}
@@ -110,12 +109,6 @@ namespace BizHawk.Client.EmuHawk
 			}
 		}
 
-		public static void Run(IDialogParent parent)
-		{
-			var form = new FFmpegDownloaderForm();
-			parent.ShowDialogWithTempMute(form);
-		}
-
 		private void btnDownload_Click(object sender, EventArgs e)
 		{
 			btnDownload.Text = "Downloading...";

src/BizHawk.Client.EmuHawk/AVOut/FFmpegWriter.cs

@@ -209,18 +209,13 @@ namespace BizHawk.Client.EmuHawk
 
 		public IDisposable AcquireVideoCodecToken(IDialogParent parent, Config config)
 		{
-			if (new FFmpegService().QueryServiceAvailable())
+			if (!FFmpegService.QueryServiceAvailable())
 			{
-				return FFmpegWriterForm.DoFFmpegWriterDlg(parent.SelfAsHandle, config);
+				using var form = new FFmpegDownloaderForm();
+				parent.ShowDialogWithTempMute(form);
+				if (!FFmpegService.QueryServiceAvailable()) return null;
 			}
-
-			FFmpegDownloaderForm.Run(parent);
-			if (new FFmpegService().QueryServiceAvailable())
-			{
-				return FFmpegWriterForm.DoFFmpegWriterDlg(parent.SelfAsHandle, config);
-			}
-
-			return null;
+			return FFmpegWriterForm.DoFFmpegWriterDlg(parent.SelfAsHandle, config);
 		}
 
 		/// <exception cref="ArgumentException"><paramref name="token"/> does not inherit <see cref="FFmpegWriterForm.FormatPreset"/></exception>

src/BizHawk.Common/FFmpegService.cs

@@ -8,7 +8,7 @@ using System.IO;
 
 namespace BizHawk.Common
 {
-	public class FFmpegService
+	public static class FFmpegService
 	{
 		public static string FFmpegPath = string.Empty; // always updated in DiscoHawk.Program/EmuHawk.Program
 
@@ -31,7 +31,7 @@ namespace BizHawk.Common
 		//note: accepts . or : in the stream stream/substream separator in the stream ID format, since that changed at some point in FFMPEG history
 		//if someone has a better idea how to make the determination of whether an audio stream is available, I'm all ears
 		private static readonly Regex rxHasAudio = new Regex(@"Stream \#(\d*(\.|\:)\d*)\: Audio", RegexOptions.Compiled);
-		public AudioQueryResult QueryAudio(string path)
+		public static AudioQueryResult QueryAudio(string path)
 		{
 			var ret = new AudioQueryResult();
 			string stdout = Run("-i", path).Text;
@@ -42,7 +42,7 @@ namespace BizHawk.Common
 		/// <summary>
 		/// queries whether this service is available. if ffmpeg is broken or missing, then you can handle it gracefully
 		/// </summary>
-		public bool QueryServiceAvailable()
+		public static bool QueryServiceAvailable()
 		{
 			try
 			{
@@ -61,7 +61,7 @@ namespace BizHawk.Common
 			public int ExitCode;
 		}
 
-		public RunResults Run(params string[] args)
+		public static RunResults Run(params string[] args)
 		{
 			args = Escape(args);
 			StringBuilder sbCmdline = new StringBuilder();
@@ -92,7 +92,7 @@ namespace BizHawk.Common
 		}
 
 		/// <exception cref="InvalidOperationException">FFmpeg exited with non-zero exit code or produced no output</exception>
-		public byte[] DecodeAudio(string path)
+		public static byte[] DecodeAudio(string path)
 		{
 			string tempfile = Path.GetTempFileName();
 			try

src/BizHawk.Emulation.DiscSystem/DiscDecoding.cs

@@ -20,12 +20,7 @@ namespace BizHawk.Emulation.DiscSystem
 		{
 		}
 
-		private bool CheckForAudio(string path)
-		{
-			FFmpegService ffmpeg = new FFmpegService();
-			var qa = ffmpeg.QueryAudio(path);
-			return qa.IsAudio;
-		}
+		private bool CheckForAudio(string path) => FFmpegService.QueryAudio(path).IsAudio;
 
 		/// <summary>
 		/// finds audio at a path similar to the provided path (i.e. finds Track01.mp3 for Track01.wav)
@@ -59,7 +54,7 @@ namespace BizHawk.Emulation.DiscSystem
 		}
 
 		/// <exception cref="AudioDecoder_Exception">could not find source audio for <paramref name="audioPath"/></exception>
-		public byte[] AcquireWaveData(string audioPath) => new FFmpegService()
+		public byte[] AcquireWaveData(string audioPath) => FFmpegService
 			.DecodeAudio(FindAudio(audioPath) ?? throw new AudioDecoder_Exception($"Could not find source audio for: {Path.GetFileName(audioPath)}"));
 	}
-}
+}

src/BizHawk.Emulation.DiscSystem/DiscFormats/CUE/CUE_Compile.cs

@@ -327,9 +327,7 @@ namespace BizHawk.Emulation.DiscSystem.CUE
 			//check whether processing was available
 			if (needsCodec)
 			{
-				FFmpegService ffmpeg = new FFmpegService();
-				if (!ffmpeg.QueryServiceAvailable())
-					Warn("Decoding service will be required for further processing, but is not available");
+				if (!FFmpegService.QueryServiceAvailable()) Warn("Decoding service will be required for further processing, but is not available");
 			}
 		}
 

src/BizHawk.Emulation.DiscSystem/DiscFormats/CUE/CUE_Load.cs

@@ -114,8 +114,7 @@ namespace BizHawk.Emulation.DiscSystem.CUE
 						}
 					case CompiledCueFileType.DecodeAudio:
 						{
-							FFmpegService ffmpeg = new FFmpegService();
-							if (!ffmpeg.QueryServiceAvailable())
+							if (!FFmpegService.QueryServiceAvailable())
 							{
 								throw new DiscReferenceException(ccf.FullPath, "No decoding service was available (make sure ffmpeg.exe is available. Even though this may be a wav, ffmpeg is used to load oddly formatted wave files. If you object to this, please send us a note and we'll see what we can do. It shouldn't be too hard.)");
 							}