proxy external subtitle files (#1203)

CHANGELOG.md

@@ -10,6 +10,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
   - Note that these subtitles are not currently supported in ETV, but they did cause a playback issue
 - Fix Jellyfin, Emby and Plex library scans that wouldn't work in certain timezones
 - Fix song normalization to match FFmpeg Profile bit depth
+- Fix bug playing some external subtitle files (e.g. with an apostrophe in the file name)
 
 ### Changed
 - Ignore case of video and audio file extensions in local folder scanner

ErsatzTV.Application/Subtitles/Queries/GetSubtitlePathById.cs

@@ -0,0 +1,5 @@
+using ErsatzTV.Core;
+
+namespace ErsatzTV.Application.Subtitles.Queries;
+
+public record GetSubtitlePathById(int Id) : IRequest<Either<BaseError, string>>;

ErsatzTV.Application/Subtitles/Queries/GetSubtitlePathByIdHandler.cs

@@ -0,0 +1,27 @@
+using ErsatzTV.Core;
+using ErsatzTV.Infrastructure.Data;
+using ErsatzTV.Infrastructure.Extensions;
+using Microsoft.EntityFrameworkCore;
+
+namespace ErsatzTV.Application.Subtitles.Queries;
+
+public class GetSubtitlePathByIdHandler : IRequestHandler<GetSubtitlePathById, Either<BaseError, string>>
+{
+    private readonly IDbContextFactory<TvContext> _dbContextFactory;
+
+    public GetSubtitlePathByIdHandler(IDbContextFactory<TvContext> dbContextFactory)
+    {
+        _dbContextFactory = dbContextFactory;
+    }
+
+    public async Task<Either<BaseError, string>> Handle(
+        GetSubtitlePathById request,
+        CancellationToken cancellationToken)
+    {
+        await using TvContext dbContext = await _dbContextFactory.CreateDbContextAsync(cancellationToken);
+        Option<string> maybeSubtitlePath = await dbContext.Subtitles
+            .SelectOneAsync(s => s.Id, s => s.Id == request.Id)
+            .MapT(s => s.Path);
+        return maybeSubtitlePath.ToEither(BaseError.New($"Unable to locate subtitle with id {request.Id}"));
+    }
+}

ErsatzTV.Core/FFmpeg/FFmpegLibraryProcessService.cs

@@ -98,6 +98,15 @@ public class FFmpegLibraryProcessService : IFFmpegProcessService
                 preferredSubtitleLanguage,
                 subtitleMode);
 
+        foreach (Subtitle subtitle in maybeSubtitle)
+        {
+            if (subtitle.SubtitleKind == SubtitleKind.Sidecar)
+            {
+                // proxy to avoid dealing with escaping
+                subtitle.Path = $"http://localhost:{Settings.ListenPort}/media/subtitle/{subtitle.Id}";
+            }
+        }
+
         Option<WatermarkOptions> watermarkOptions = disableWatermarks
             ? None
             : await _ffmpegProcessService.GetWatermarkOptions(
@@ -194,9 +203,12 @@ public class FFmpegLibraryProcessService : IFFmpegProcessService
                     subtitle.Codec,
                     StreamKind.Video);
 
-                string path = subtitle.IsImage
-                    ? videoPath
-                    : Path.Combine(FileSystemLayout.SubtitleCacheFolder, subtitle.Path);
+                string path = subtitle.IsImage switch
+                {
+                    true => videoPath,
+                    false when subtitle.SubtitleKind == SubtitleKind.Sidecar => subtitle.Path,
+                    _ => Path.Combine(FileSystemLayout.SubtitleCacheFolder, subtitle.Path)
+                };
 
                 return new SubtitleInputFile(
                     path,

ErsatzTV.FFmpeg/Filter/SubtitlesFilter.cs

@@ -34,7 +34,8 @@ public class SubtitlesFilter : BaseFilter
             // escape brackets after escaping for windows
             effectiveFile = effectiveFile
                 .Replace(@"[", @"\[")
-                .Replace(@"]", @"\]");
+                .Replace(@"]", @"\]")
+                .Replace(@"http://localhost:", @"http\\://localhost\\:");
 
             return $"subtitles={effectiveFile}:fontsdir={fontsDir}";
         }

ErsatzTV.Infrastructure/Data/TvContext.cs

@@ -84,6 +84,7 @@ public class TvContext : DbContext
     public DbSet<LanguageCode> LanguageCodes { get; set; }
     public DbSet<TraktList> TraktLists { get; set; }
     public DbSet<FillerPreset> FillerPresets { get; set; }
+    public DbSet<Subtitle> Subtitles { get; set; }
 
     protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder) =>
         optionsBuilder.UseLoggerFactory(_loggerFactory);

ErsatzTV/Controllers/InternalController.cs

@@ -4,6 +4,7 @@ using ErsatzTV.Application.Emby;
 using ErsatzTV.Application.Jellyfin;
 using ErsatzTV.Application.Plex;
 using ErsatzTV.Application.Streaming;
+using ErsatzTV.Application.Subtitles.Queries;
 using ErsatzTV.Core;
 using ErsatzTV.Core.FFmpeg;
 using ErsatzTV.Extensions;
@@ -143,4 +144,23 @@ public class InternalController : ControllerBase
                 return new RedirectResult(fullPath.ToString());
             });
     }
+
+    [HttpGet("/media/subtitle/{id:int}")]
+    public async Task<IActionResult> GetSubtitle(int id)
+    {
+        Either<BaseError, string> path = await _mediator.Send(new GetSubtitlePathById(id));
+        return path.Match<IActionResult>(
+            Left: _ => new NotFoundResult(),
+            Right: r =>
+            {
+                string mimeType = Path.GetExtension(r).ToLowerInvariant() switch
+                {
+                    "ass" or "ssa" => "text/x-ssa",
+                    "vtt" => "text/vtt",
+                    _ => "application/x-subrip",
+                };
+
+                return new PhysicalFileResult(r, mimeType);
+            });
+    }
 }