fix: download trailers as separate video+audio and merge with ffmpeg (v1.0.0.10)

YouTube stopped serving muxed streams and YoutubeExplode 6.6.0 failed on
every video ("Video is not available"), so no trailer downloaded. Bump
YoutubeExplode to 6.6.2, download the best video-only + audio-only streams
and stream-copy them into one MP4 with ffmpeg. The separate files are
always deleted afterwards, merge or not.

Also delete the trailer folder when a download fails. Empty folders were
treated as "already downloaded" (never retried) and counted toward
MaxTotalTrailers, so over time they pushed out every real trailer. The
skip check now requires the trailer file itself.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

Jellyfin.Plugin.CinemaTrailers4Jellyfins/Jellyfin.Plugin.CinemaTrailers4Jellyfins.csproj

@@ -3,8 +3,8 @@
   <PropertyGroup>
     <TargetFramework>net9.0</TargetFramework>
     <RootNamespace>Jellyfin.Plugin.CinemaTrailers4Jellyfins</RootNamespace>
-    <AssemblyVersion>1.0.0.9</AssemblyVersion>
+    <AssemblyVersion>1.0.0.10</AssemblyVersion>
-    <FileVersion>1.0.0.9</FileVersion>
+    <FileVersion>1.0.0.10</FileVersion>
     <Nullable>enable</Nullable>
     <GenerateDocumentationFile>false</GenerateDocumentationFile>
     <TreatWarningsAsErrors>false</TreatWarningsAsErrors>
@@ -13,7 +13,7 @@
   <ItemGroup>
     <PackageReference Include="Jellyfin.Controller" Version="10.11.0" />
     <PackageReference Include="Jellyfin.Model" Version="10.11.0" />
-    <PackageReference Include="YoutubeExplode" Version="6.*" />
+    <PackageReference Include="YoutubeExplode" Version="6.6.2" />
   </ItemGroup>
 
   <ItemGroup>

Jellyfin.Plugin.CinemaTrailers4Jellyfins/ScheduledTasks/DownloadTrailersTask.cs

@@ -171,7 +171,7 @@ namespace Jellyfin.Plugin.CinemaTrailers4Jellyfins.ScheduledTasks
 
                 var paths = BuildMediaPaths(movie.Title, movie.Year, config);
 
-                if (config.SkipAlreadyDownloaded && Directory.Exists(paths.MediaFolder))
+                if (config.SkipAlreadyDownloaded && File.Exists(paths.TrailerPath))
                 {
                     _logger.LogDebug("|CinemaTrailers4Jellyfins| Already downloaded: {Path}", paths.MediaFolder);
                     continue;
@@ -197,7 +197,12 @@ namespace Jellyfin.Plugin.CinemaTrailers4Jellyfins.ScheduledTasks
                     cancellationToken).ConfigureAwait(false);
 
                 if (!success)
+                {
+                    // Don't leave an empty folder behind: it would count toward MaxTotalTrailers
+                    // (pushing out real trailers) and would never be retried.
+                    TryDeleteFolder(paths.MediaFolder);
                     continue;
+                }
 
                 var fakeMovieReady = await _fakeMovieService.CopyFakeMovieAsync(paths.FakeMoviePath, cancellationToken).ConfigureAwait(false);
                 if (!fakeMovieReady)
@@ -272,7 +277,7 @@ namespace Jellyfin.Plugin.CinemaTrailers4Jellyfins.ScheduledTasks
 
                 var paths = BuildMediaPaths(show.Title, show.Year, config);
 
-                if (config.SkipAlreadyDownloaded && Directory.Exists(paths.MediaFolder))
+                if (config.SkipAlreadyDownloaded && File.Exists(paths.TrailerPath))
                 {
                     _logger.LogDebug("|CinemaTrailers4Jellyfins| Already downloaded: {Path}", paths.MediaFolder);
                     continue;
@@ -298,7 +303,12 @@ namespace Jellyfin.Plugin.CinemaTrailers4Jellyfins.ScheduledTasks
                     cancellationToken).ConfigureAwait(false);
 
                 if (!success)
+                {
+                    // Don't leave an empty folder behind: it would count toward MaxTotalTrailers
+                    // (pushing out real trailers) and would never be retried.
+                    TryDeleteFolder(paths.MediaFolder);
                     continue;
+                }
 
                 var fakeMovieReady = await _fakeMovieService.CopyFakeMovieAsync(paths.FakeMoviePath, cancellationToken).ConfigureAwait(false);
                 if (!fakeMovieReady)

Jellyfin.Plugin.CinemaTrailers4Jellyfins/Services/FakeMovieService.cs

@@ -109,16 +109,11 @@ namespace Jellyfin.Plugin.CinemaTrailers4Jellyfins.Services
                     "-f mp4",
                     $"\"{tempPath}\"");
 
-                // Prefer Jellyfin's bundled ffmpeg; fall back to whatever is on PATH.
-                var ffmpegPath = File.Exists("/usr/lib/jellyfin-ffmpeg/ffmpeg")
-                    ? "/usr/lib/jellyfin-ffmpeg/ffmpeg"
-                    : "ffmpeg";
-
                 using var process = new Process
                 {
                     StartInfo = new ProcessStartInfo
                     {
-                        FileName = ffmpegPath,
+                        FileName = FfmpegLocator.Path,
                         Arguments = args,
                         RedirectStandardOutput = true,
                         RedirectStandardError = true,

Jellyfin.Plugin.CinemaTrailers4Jellyfins/Services/FfmpegLocator.cs

@@ -0,0 +1,12 @@
+using System.IO;
+
+namespace Jellyfin.Plugin.CinemaTrailers4Jellyfins.Services
+{
+    internal static class FfmpegLocator
+    {
+        private const string JellyfinFfmpeg = "/usr/lib/jellyfin-ffmpeg/ffmpeg";
+
+        // Prefer Jellyfin's bundled ffmpeg; fall back to whatever is on PATH.
+        public static string Path => File.Exists(JellyfinFfmpeg) ? JellyfinFfmpeg : "ffmpeg";
+    }
+}

Jellyfin.Plugin.CinemaTrailers4Jellyfins/Services/TrailerDownloadService.cs

@@ -77,6 +77,10 @@ namespace Jellyfin.Plugin.CinemaTrailers4Jellyfins.Services
             int preferredHeight,
             CancellationToken ct)
         {
+            // Separate video/audio downloads land next to the output and are always removed,
+            // whether the merge succeeds or not.
+            var videoTemp = outputPath + ".video.tmp";
+            var audioTemp = outputPath + ".audio.tmp";
             try
             {
                 var youtube = new YoutubeClient(_httpClient);
@@ -84,30 +88,42 @@ namespace Jellyfin.Plugin.CinemaTrailers4Jellyfins.Services
                     .GetManifestAsync($"https://www.youtube.com/watch?v={key}", ct)
                     .ConfigureAwait(false);
 
-                // Muxed streams include audio+video in one file. Quality is capped at 720p by YouTube.
+                // Muxed streams include audio+video in one file. YouTube rarely serves them
+                // anymore, but use one when it exists since it needs no merge.
                 var muxedStreams = manifest.GetMuxedStreams().ToList();
-                if (muxedStreams.Count == 0)
+                if (muxedStreams.Count > 0)
                 {
-                    _logger.LogWarning("|CinemaTrailers4Jellyfins| No muxed streams available for {Key}. Consider configuring yt-dlp for 1080p support.", key);
+                    var muxed = PickByHeight(muxedStreams, preferredHeight);
+                    _logger.LogInformation(
+                        "|CinemaTrailers4Jellyfins| Downloading {Key} at {Quality} (muxed) to {Path}",
+                        key, muxed.VideoQuality.Label, outputPath);
+                    await youtube.Videos.Streams.DownloadAsync(muxed, outputPath, cancellationToken: ct).ConfigureAwait(false);
+                    return true;
+                }
+
+                // Otherwise download the best video-only and audio-only streams and merge them.
+                // MP4 (H.264/AAC) is preferred for client compatibility; any container is the fallback.
+                var videoStreams = manifest.GetVideoOnlyStreams().ToList();
+                var audioStreams = manifest.GetAudioOnlyStreams().ToList();
+                if (videoStreams.Count == 0 || audioStreams.Count == 0)
+                {
+                    _logger.LogWarning("|CinemaTrailers4Jellyfins| No usable video/audio streams for {Key}.", key);
                     return false;
                 }
 
-                // Prefer the highest quality at or below the configured height limit.
+                var mp4Video = videoStreams.Where(s => s.Container == Container.Mp4).ToList();
-                var stream = muxedStreams
+                var video = PickByHeight(mp4Video.Count > 0 ? mp4Video : videoStreams, preferredHeight);
-                    .Where(s => s.VideoQuality.MaxHeight <= preferredHeight)
+                var mp4Audio = audioStreams.Where(s => s.Container == Container.Mp4).ToList();
-                    .OrderByDescending(s => s.VideoQuality.MaxHeight)
+                var audio = (mp4Audio.Count > 0 ? mp4Audio : audioStreams).GetWithHighestBitrate();
-                    .FirstOrDefault()
-                    ?? muxedStreams.OrderByDescending(s => s.VideoQuality.MaxHeight).First();
 
                 _logger.LogInformation(
-                    "|CinemaTrailers4Jellyfins| Downloading {Key} at {Quality} to {Path}",
+                    "|CinemaTrailers4Jellyfins| Downloading {Key} at {Quality} (video + audio, merged with ffmpeg) to {Path}",
-                    key, stream.VideoQuality.Label, outputPath);
+                    key, video.VideoQuality.Label, outputPath);
 
-                await youtube.Videos.Streams
+                await youtube.Videos.Streams.DownloadAsync(video, videoTemp, cancellationToken: ct).ConfigureAwait(false);
-                    .DownloadAsync(stream, outputPath, cancellationToken: ct)
+                await youtube.Videos.Streams.DownloadAsync(audio, audioTemp, cancellationToken: ct).ConfigureAwait(false);
-                    .ConfigureAwait(false);
 
-                return true;
+                return await MergeAsync(key, videoTemp, audioTemp, outputPath, ct).ConfigureAwait(false);
             }
             catch (OperationCanceledException)
             {
@@ -118,6 +134,85 @@ namespace Jellyfin.Plugin.CinemaTrailers4Jellyfins.Services
                 _logger.LogError(ex, "|CinemaTrailers4Jellyfins| YoutubeExplode download failed for {Key}", key);
                 return false;
             }
+            finally
+            {
+                TryDeleteFile(videoTemp);
+                TryDeleteFile(audioTemp);
+            }
+        }
+
+        // Highest quality at or below the configured height limit, else the lowest available.
+        private static T PickByHeight<T>(System.Collections.Generic.IReadOnlyList<T> streams, int preferredHeight)
+            where T : IVideoStreamInfo
+            => streams
+                .Where(s => s.VideoQuality.MaxHeight <= preferredHeight)
+                .OrderByDescending(s => s.VideoQuality.MaxHeight)
+                .FirstOrDefault()
+               ?? streams.OrderBy(s => s.VideoQuality.MaxHeight).First();
+
+        // Stream-copies (no re-encode) the video and audio tracks into one MP4.
+        // Writes to a temp file first so a failed merge never leaves a broken trailer.
+        private async Task<bool> MergeAsync(string key, string videoPath, string audioPath, string outputPath, CancellationToken ct)
+        {
+            var mergeTemp = outputPath + ".merge.tmp";
+            try
+            {
+                var args = string.Join(" ",
+                    "-y -loglevel error",
+                    $"-i \"{videoPath}\"",
+                    $"-i \"{audioPath}\"",
+                    "-map 0:v:0 -map 1:a:0 -c copy -movflags +faststart",
+                    "-f mp4",
+                    $"\"{mergeTemp}\"");
+
+                using var process = new Process
+                {
+                    StartInfo = new ProcessStartInfo
+                    {
+                        FileName = FfmpegLocator.Path,
+                        Arguments = args,
+                        RedirectStandardOutput = true,
+                        RedirectStandardError = true,
+                        UseShellExecute = false,
+                        CreateNoWindow = true,
+                    }
+                };
+
+                process.Start();
+                // Drain both pipes while ffmpeg runs so a full buffer can never block it.
+                var stdoutTask = process.StandardOutput.ReadToEndAsync(ct);
+                var stderrTask = process.StandardError.ReadToEndAsync(ct);
+                await process.WaitForExitAsync(ct).ConfigureAwait(false);
+                await stdoutTask.ConfigureAwait(false);
+                var stderr = await stderrTask.ConfigureAwait(false);
+
+                if (process.ExitCode != 0 || !File.Exists(mergeTemp))
+                {
+                    _logger.LogError("|CinemaTrailers4Jellyfins| ffmpeg merge failed for {Key} (exit code {Code}): {Error}",
+                        key, process.ExitCode, stderr);
+                    return false;
+                }
+
+                File.Move(mergeTemp, outputPath, overwrite: true);
+                return true;
+            }
+            finally
+            {
+                TryDeleteFile(mergeTemp);
+            }
+        }
+
+        private void TryDeleteFile(string path)
+        {
+            try
+            {
+                if (File.Exists(path))
+                    File.Delete(path);
+            }
+            catch (Exception ex)
+            {
+                _logger.LogWarning(ex, "|CinemaTrailers4Jellyfins| Could not delete temporary file {Path}", path);
+            }
         }
 
         private async Task<bool> DownloadWithYtDlpAsync(

build.yaml

@@ -1,5 +1,5 @@
 ---
-version: 1.0.0.9
+version: 1.0.0.10
 name: CinemaTrailers4Jellyfins
 guid: b581493e-1046-40ed-b6dc-cb8027624984
 description: >
@@ -12,10 +12,13 @@ category: General
 owner: 514mart
 targetAbi: 10.11.0.0
 changelog:
-  - Skip trailers and pre-roll/feature pre-roll bumpers the current user
+  - Fix trailer downloads, broken by a YouTube change. YouTube no longer
-    can't actually access (e.g. a library not in their library access list)
+    serves combined video+audio files, so the built-in downloader now fetches
-    — some Cinema Mode clients hang indefinitely trying to play an
+    the video and audio separately, merges them with ffmpeg (no re-encode)
-    inaccessible item, so these are now filtered out per-user instead
+    and deletes the separate files afterwards
+  - A failed download no longer leaves an empty trailer folder behind.
+    Empty folders counted toward "Max trailers to keep" (pushing out real
+    trailers) and were never retried
 
 dotnetProjects:
   - name: Jellyfin.Plugin.CinemaTrailers4Jellyfins