AudioBook playback now working as desired.

Emby.Naming/Common/NamingOptions.cs

@@ -729,7 +729,9 @@ namespace Emby.Naming.Common
                 // Sometimes named as 0001_005 (chapter_part)
                 "(?<chapter>[0-9]+)_(?<part>[0-9]+)",
                 // Some audiobooks are ripped from cd's, and will be named by disk number.
-                @"dis(?:c|k)[\s_-]?(?<chapter>[0-9]+)"
+                @"dis(?:c|k)[\s_-]?(?<chapter>[0-9]+)",
+                // Use number at end of file name before extension
+                "[0-9]+$"
             };
 
             AudioBookNamesExpressions = new[]

Emby.Server.Implementations/Dto/DtoService.cs

@@ -407,6 +407,7 @@ namespace Emby.Server.Implementations.Dto
             }
             else
             {
+                // TODO: Why is this here? Seems redundant
                 if (options.EnableUserData)
                 {
                     dto.UserData = _userDataRepository.GetUserDataDto(item, user);

Emby.Server.Implementations/Library/UserDataManager.cs

@@ -289,15 +289,11 @@ namespace Emby.Server.Implementations.Library
             }
             else if (positionTicks > 0 && hasRuntime && item is AudioBookFile)
             {
-                var playbackPositionInMinutes = TimeSpan.FromTicks(positionTicks).TotalMinutes;
                 var remainingTimeInMinutes = TimeSpan.FromTicks(runtimeTicks - positionTicks).TotalMinutes;
+                data.Played = playedToCompletion = false;
 
-                if (playbackPositionInMinutes < _config.Configuration.MinAudiobookResume)
-                {
-                    // ignore progress during the beginning
-                    positionTicks = 0;
-                }
-                else if (remainingTimeInMinutes < _config.Configuration.MaxAudiobookResume || positionTicks >= runtimeTicks)
+                // TODO: Use percentage of total runtime ticks for completion comparison
+                if (remainingTimeInMinutes < _config.Configuration.MaxAudiobookResume || positionTicks >= runtimeTicks)
                 {
                     // mark as completed close to the end
                     positionTicks = 0;

Jellyfin.Api/Controllers/ItemsController.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Collections.Generic;
 using System.ComponentModel.DataAnnotations;
 using System.Linq;
 using Jellyfin.Api.Extensions;
@@ -9,6 +10,7 @@ using Jellyfin.Extensions;
 using MediaBrowser.Common.Extensions;
 using MediaBrowser.Controller.Dto;
 using MediaBrowser.Controller.Entities;
+using MediaBrowser.Controller.Entities.AudioBooks;
 using MediaBrowser.Controller.Library;
 using MediaBrowser.Controller.Session;
 using MediaBrowser.Model.Dto;
@@ -516,10 +518,25 @@ public class ItemsController : BaseJellyfinApiController
             result = new QueryResult<BaseItem>(itemsArray);
         }
 
-        return new QueryResult<BaseItemDto>(
+        var queryResult = new QueryResult<BaseItemDto>(
             startIndex,
             result.TotalRecordCount,
             _dtoService.GetBaseItemDtos(result.Items, dtoOptions, user));
+
+        // TODO: Sort return items by chapter for audio book
+        if (item is AudioBook)
+        {
+            for (int i = 0; i < queryResult.Items.Count; i++)
+            {
+                if (!queryResult.Items[i].UserData.Played)
+                {
+                    queryResult.StartIndex = i;
+                    break;
+                }
+            }
+        }
+
+        return queryResult;
     }
 
     /// <summary>

MediaBrowser.Controller/Entities/AudioBooks/AudioBookFile.cs

@@ -160,17 +160,7 @@ namespace MediaBrowser.Controller.Entities.AudioBooks
 
         protected override IEnumerable<(BaseItem Item, MediaSourceType MediaSourceType)> GetAllItemsForMediaSources()
         {
-            var chapters = AudioBookEntity.Chapters;
-            var nextChapters = new List<(BaseItem Item, MediaSourceType MediaSourceType)>();
-            foreach (var chapter in chapters)
-            {
-                if (chapter.Chapter >= this.Chapter)
-                {
-                    nextChapters.Add((chapter, MediaSourceType.Default));
-                }
-            }
-
-            return nextChapters;
+            return [(this, MediaSourceType.Default)];
         }
     }
 }

MediaBrowser.Model/Configuration/ServerConfiguration.cs

@@ -150,13 +150,13 @@ public class ServerConfiguration : BaseApplicationConfiguration
     /// Gets or sets the minimum minutes of a book that must be played in order for playstate to be updated.
     /// </summary>
     /// <value>The min resume in minutes.</value>
-    public int MinAudiobookResume { get; set; } = 5;
+    public int MinAudiobookResume { get; set; } = 0;
 
     /// <summary>
     /// Gets or sets the remaining minutes of a book that can be played while still saving playstate. If this percentage is crossed playstate will be reset to the beginning and the item will be marked watched.
     /// </summary>
     /// <value>The remaining time in minutes.</value>
-    public int MaxAudiobookResume { get; set; } = 5;
+    public int MaxAudiobookResume { get; set; } = 1;
 
     /// <summary>
     /// Gets or sets the threshold in minutes after a inactive session gets closed automatically.