Adds FileContainer parameter

And use mp4 as default container (this fixes wrong duration on files from crunchyroll)

Wasari.App/GenericDownloadService.cs

@@ -128,7 +128,8 @@ private StringBuilder BuildEpisodeName(IWasariEpisode episode)
         if (episode.Number.HasValue || episode.SeasonNumber.HasValue)
             episodeNameBuilder.Append(" - ");
         episodeNameBuilder.Append(episode.Title);
-        episodeNameBuilder.Append(FFmpegOptions.Value.UseHevc ? ".mkv" : ".mp4");
+        episodeNameBuilder.Append('.');
+        episodeNameBuilder.Append(FFmpegOptions.Value.FileContainer);
         return episodeNameBuilder;
     }
 }

Wasari.Cli/Commands/DownloadCommand.cs

@@ -105,6 +105,9 @@ public DownloadCommand(EnvironmentService environmentService, ILogger<DownloadCo
 
     [CommandOption("webhook-url", Description = "Webhook URL to send notifications to", EnvironmentVariable = "WASARI_WEBHOOK_URL")]
     public Uri? WebhookUrl { get; init; }
+
+    [CommandOption("file-container", Description = "File container to use for final video file")]
+    public string FileContainer { get; set; } = "mp4";
 
     private EnvironmentService EnvironmentService { get; }
 
@@ -158,6 +161,7 @@ public async ValueTask ExecuteAsync(IConsole console)
             o.Shaders = Shaders;
             o.Resolution = Resolution;
             o.Threads = FfmpegThreads;
+            o.FileContainer = FileContainer;
         });
         serviceCollection.Configure<AuthenticationOptions>(o =>
         {

Wasari.FFmpeg/FFmpegOptions.cs

@@ -3,6 +3,8 @@ namespace Wasari.FFmpeg;
 public record FFmpegOptions
 {
     public bool UseHevc { get; set; }
+
+    public string FileContainer { get; set; } = "mp4";
 
     public IFFmpegShader[]? Shaders { get; set; }