Merge pull request #13847 from Shadowghost/rework-chapter-management

Rework chapter management

1 files changed, 313 insertions, 0 deletions

diff --git a/Emby.Server.Implementations/Chapters/ChapterManager.cs b/Emby.Server.Implementations/Chapters/ChapterManager.cs
new file mode 100644
index 000000000..b4daa2a14
--- /dev/null
+++ b/Emby.Server.Implementations/Chapters/ChapterManager.cs
@@ -0,0 +1,313 @@
+using System;
+using System.Collections.Generic;
+using System.Globalization;
+using System.IO;
+using System.Linq;
+using System.Threading;
+using System.Threading.Tasks;
+using Jellyfin.Extensions;
+using MediaBrowser.Controller.Chapters;
+using MediaBrowser.Controller.Entities;
+using MediaBrowser.Controller.IO;
+using MediaBrowser.Controller.Library;
+using MediaBrowser.Controller.MediaEncoding;
+using MediaBrowser.Controller.Persistence;
+using MediaBrowser.Controller.Providers;
+using MediaBrowser.Model.Configuration;
+using MediaBrowser.Model.Dto;
+using MediaBrowser.Model.Entities;
+using MediaBrowser.Model.IO;
+using MediaBrowser.Model.MediaInfo;
+using Microsoft.Extensions.Logging;
+
+namespace Emby.Server.Implementations.Chapters;
+
+/// <summary>
+/// The chapter manager.
+/// </summary>
+public class ChapterManager : IChapterManager
+{
+    private readonly IFileSystem _fileSystem;
+    private readonly ILogger<ChapterManager> _logger;
+    private readonly IMediaEncoder _encoder;
+    private readonly IChapterRepository _chapterRepository;
+    private readonly ILibraryManager _libraryManager;
+    private readonly IPathManager _pathManager;
+
+    /// <summary>
+    /// The first chapter ticks.
+    /// </summary>
+    private static readonly long _firstChapterTicks = TimeSpan.FromSeconds(15).Ticks;
+
+    /// <summary>
+    /// Initializes a new instance of the <see cref="ChapterManager"/> class.
+    /// </summary>
+    /// <param name="logger">The <see cref="ILogger{ChapterManager}"/>.</param>
+    /// <param name="fileSystem">The <see cref="IFileSystem"/>.</param>
+    /// <param name="encoder">The <see cref="IMediaEncoder"/>.</param>
+    /// <param name="chapterRepository">The <see cref="IChapterRepository"/>.</param>
+    /// <param name="libraryManager">The <see cref="ILibraryManager"/>.</param>
+    /// <param name="pathManager">The <see cref="IPathManager"/>.</param>
+    public ChapterManager(
+        ILogger<ChapterManager> logger,
+        IFileSystem fileSystem,
+        IMediaEncoder encoder,
+        IChapterRepository chapterRepository,
+        ILibraryManager libraryManager,
+        IPathManager pathManager)
+    {
+        _logger = logger;
+        _fileSystem = fileSystem;
+        _encoder = encoder;
+        _chapterRepository = chapterRepository;
+        _libraryManager = libraryManager;
+        _pathManager = pathManager;
+    }
+
+    /// <summary>
+    /// Determines whether [is eligible for chapter image extraction] [the specified video].
+    /// </summary>
+    /// <param name="video">The video.</param>
+    /// <param name="libraryOptions">The library options for the video.</param>
+    /// <returns><c>true</c> if [is eligible for chapter image extraction] [the specified video]; otherwise, <c>false</c>.</returns>
+    private bool IsEligibleForChapterImageExtraction(Video video, LibraryOptions libraryOptions)
+    {
+        if (video.IsPlaceHolder)
+        {
+            return false;
+        }
+
+        if (libraryOptions is null || !libraryOptions.EnableChapterImageExtraction)
+        {
+            return false;
+        }
+
+        if (video.IsShortcut)
+        {
+            return false;
+        }
+
+        if (!video.IsCompleteMedia)
+        {
+            return false;
+        }
+
+        // Can't extract images if there are no video streams
+        return video.DefaultVideoStreamIndex.HasValue;
+    }
+
+    private long GetAverageDurationBetweenChapters(IReadOnlyList<ChapterInfo> chapters)
+    {
+        if (chapters.Count < 2)
+        {
+            return 0;
+        }
+
+        long sum = 0;
+        for (int i = 1; i < chapters.Count; i++)
+        {
+            sum += chapters[i].StartPositionTicks - chapters[i - 1].StartPositionTicks;
+        }
+
+        return sum / chapters.Count;
+    }
+
+    /// <inheritdoc />
+    public async Task<bool> RefreshChapterImages(Video video, IDirectoryService directoryService, IReadOnlyList<ChapterInfo> chapters, bool extractImages, bool saveChapters, CancellationToken cancellationToken)
+    {
+        if (chapters.Count == 0)
+        {
+            return true;
+        }
+
+        var libraryOptions = _libraryManager.GetLibraryOptions(video);
+
+        if (!IsEligibleForChapterImageExtraction(video, libraryOptions))
+        {
+            extractImages = false;
+        }
+
+        var averageChapterDuration = GetAverageDurationBetweenChapters(chapters);
+        var threshold = TimeSpan.FromSeconds(1).Ticks;
+        if (averageChapterDuration < threshold)
+        {
+            _logger.LogInformation("Skipping chapter image extraction for {Video} as the average chapter duration {AverageDuration} was lower than the minimum threshold {Threshold}", video.Name, averageChapterDuration, threshold);
+            extractImages = false;
+        }
+
+        var success = true;
+        var changesMade = false;
+
+        var runtimeTicks = video.RunTimeTicks ?? 0;
+
+        var currentImages = GetSavedChapterImages(video, directoryService);
+
+        foreach (var chapter in chapters)
+        {
+            if (chapter.StartPositionTicks >= runtimeTicks)
+            {
+                _logger.LogInformation("Stopping chapter extraction for {0} because a chapter was found with a position greater than the runtime.", video.Name);
+                break;
+            }
+
+            var path = _pathManager.GetChapterImagePath(video, chapter.StartPositionTicks);
+
+            if (!currentImages.Contains(path, StringComparison.OrdinalIgnoreCase))
+            {
+                if (extractImages)
+                {
+                    cancellationToken.ThrowIfCancellationRequested();
+
+                    try
+                    {
+                        // Add some time for the first chapter to make sure we don't end up with a black image
+                        var time = chapter.StartPositionTicks == 0 ? TimeSpan.FromTicks(Math.Min(_firstChapterTicks, video.RunTimeTicks ?? 0)) : TimeSpan.FromTicks(chapter.StartPositionTicks);
+
+                        var inputPath = video.Path;
+                        var directoryPath = Path.GetDirectoryName(path);
+                        if (!string.IsNullOrEmpty(directoryPath))
+                        {
+                            Directory.CreateDirectory(directoryPath);
+                        }
+
+                        var container = video.Container;
+                        var mediaSource = new MediaSourceInfo
+                        {
+                            VideoType = video.VideoType,
+                            IsoType = video.IsoType,
+                            Protocol = video.PathProtocol ?? MediaProtocol.File,
+                        };
+
+                        _logger.LogInformation("Extracting chapter image for {Name} at {Path}", video.Name, inputPath);
+                        var tempFile = await _encoder.ExtractVideoImage(inputPath, container, mediaSource, video.GetDefaultVideoStream(), video.Video3DFormat, time, cancellationToken).ConfigureAwait(false);
+                        File.Copy(tempFile, path, true);
+
+                        try
+                        {
+                            _fileSystem.DeleteFile(tempFile);
+                        }
+                        catch (IOException ex)
+                        {
+                            _logger.LogError(ex, "Error deleting temporary chapter image encoding file {Path}", tempFile);
+                        }
+
+                        chapter.ImagePath = path;
+                        chapter.ImageDateModified = _fileSystem.GetLastWriteTimeUtc(path);
+                        changesMade = true;
+                    }
+                    catch (Exception ex)
+                    {
+                        _logger.LogError(ex, "Error extracting chapter images for {0}", string.Join(',', video.Path));
+                        success = false;
+                        break;
+                    }
+                }
+                else if (!string.IsNullOrEmpty(chapter.ImagePath))
+                {
+                    chapter.ImagePath = null;
+                    changesMade = true;
+                }
+            }
+            else if (!string.Equals(path, chapter.ImagePath, StringComparison.OrdinalIgnoreCase))
+            {
+                chapter.ImagePath = path;
+                chapter.ImageDateModified = _fileSystem.GetLastWriteTimeUtc(path);
+                changesMade = true;
+            }
+            else if (libraryOptions?.EnableChapterImageExtraction != true)
+            {
+                // We have an image for the current chapter but the user has disabled chapter image extraction -> delete this chapter's image
+                chapter.ImagePath = null;
+                changesMade = true;
+            }
+        }
+
+        if (saveChapters && changesMade)
+        {
+            _chapterRepository.SaveChapters(video.Id, chapters);
+        }
+
+        DeleteDeadImages(currentImages, chapters);
+
+        return success;
+    }
+
+    /// <inheritdoc />
+    public void SaveChapters(Video video, IReadOnlyList<ChapterInfo> chapters)
+    {
+        _chapterRepository.SaveChapters(video.Id, chapters);
+    }
+
+    /// <inheritdoc />
+    public ChapterInfo? GetChapter(Guid baseItemId, int index)
+    {
+        return _chapterRepository.GetChapter(baseItemId, index);
+    }
+
+    /// <inheritdoc />
+    public IReadOnlyList<ChapterInfo> GetChapters(Guid baseItemId)
+    {
+        return _chapterRepository.GetChapters(baseItemId);
+    }
+
+    /// <inheritdoc />
+    public void DeleteChapterImages(Video video)
+    {
+        var path = _pathManager.GetChapterImageFolderPath(video);
+        try
+        {
+            if (Directory.Exists(path))
+            {
+                _logger.LogInformation("Removing chapter images for {Name} [{Id}]", video.Name, video.Id);
+                Directory.Delete(path, true);
+            }
+        }
+        catch (Exception ex)
+        {
+            _logger.LogWarning("Failed to remove chapter image folder for {Item}: {Exception}", video.Id, ex);
+        }
+
+        _chapterRepository.DeleteChapters(video.Id);
+    }
+
+    private IReadOnlyList<string> GetSavedChapterImages(Video video, IDirectoryService directoryService)
+    {
+        var path = _pathManager.GetChapterImageFolderPath(video);
+        if (!Directory.Exists(path))
+        {
+            return [];
+        }
+
+        try
+        {
+            return directoryService.GetFilePaths(path);
+        }
+        catch (IOException)
+        {
+            return [];
+        }
+    }
+
+    private void DeleteDeadImages(IEnumerable<string> images, IEnumerable<ChapterInfo> chapters)
+    {
+        var existingImages = chapters.Select(i => i.ImagePath).Where(i => !string.IsNullOrEmpty(i));
+        var deadImages = images
+            .Except(existingImages, StringComparer.OrdinalIgnoreCase)
+            .Where(i => BaseItem.SupportedImageExtensions.Contains(Path.GetExtension(i.AsSpan()), StringComparison.OrdinalIgnoreCase))
+            .ToList();
+
+        foreach (var image in deadImages)
+        {
+            _logger.LogDebug("Deleting dead chapter image {Path}", image);
+
+            try
+            {
+                _fileSystem.DeleteFile(image!);
+            }
+            catch (IOException ex)
+            {
+                _logger.LogError(ex, "Error deleting {Path}.", image);
+            }
+        }
+    }
+}