jellyfin/MediaBrowser.Providers/MediaInfo/AudioResolver.cs

using System;
using System.Collections.Generic;
using System.Globalization;
using System.IO;
using System.Linq;
using System.Runtime.CompilerServices;
using System.Threading;
using System.Threading.Tasks;
using Emby.Naming.Audio;
using Emby.Naming.Common;
using MediaBrowser.Controller.Entities;
using MediaBrowser.Controller.MediaEncoding;
using MediaBrowser.Controller.Providers;
using MediaBrowser.Model.Dlna;
using MediaBrowser.Model.Dto;
using MediaBrowser.Model.Entities;
using MediaBrowser.Model.Globalization;
using MediaBrowser.Model.MediaInfo;

namespace MediaBrowser.Providers.MediaInfo
{
    /// <summary>
    /// Resolves external audios for videos.
    /// </summary>
    public class AudioResolver
    {
        private readonly ILocalizationManager _localizationManager;
        private readonly IMediaEncoder _mediaEncoder;
        private readonly NamingOptions _namingOptions;
        private readonly ExternalAudioFilePathParser _externalAudioFilePathParser;
        private readonly CompareInfo _compareInfo = CultureInfo.InvariantCulture.CompareInfo;
        private const CompareOptions CompareOptions = System.Globalization.CompareOptions.IgnoreCase | System.Globalization.CompareOptions.IgnoreNonSpace | System.Globalization.CompareOptions.IgnoreSymbols;

        /// <summary>
        /// Initializes a new instance of the <see cref="AudioResolver"/> class.
        /// </summary>
        /// <param name="localizationManager">The localization manager.</param>
        /// <param name="mediaEncoder">The media encoder.</param>
        /// <param name="namingOptions">The naming options.</param>
        public AudioResolver(
            ILocalizationManager localizationManager,
            IMediaEncoder mediaEncoder,
            NamingOptions namingOptions)
        {
            _localizationManager = localizationManager;
            _mediaEncoder = mediaEncoder;
            _namingOptions = namingOptions;
            _externalAudioFilePathParser = new ExternalAudioFilePathParser(_namingOptions);
        }

        /// <summary>
        /// Returns the audio streams found in the external audio files for the given video.
        /// </summary>
        /// <param name="video">The video to get the external audio streams from.</param>
        /// <param name="startIndex">The stream index to start adding audio streams at.</param>
        /// <param name="directoryService">The directory service to search for files.</param>
        /// <param name="clearCache">True if the directory service cache should be cleared before searching.</param>
        /// <param name="cancellationToken">The cancellation token to cancel operation.</param>
        /// <returns>A list of external audio streams.</returns>
        public async IAsyncEnumerable<MediaStream> GetExternalAudioStreams(
            Video video,
            int startIndex,
            IDirectoryService directoryService,
            bool clearCache,
            [EnumeratorCancellation] CancellationToken cancellationToken)
        {
            cancellationToken.ThrowIfCancellationRequested();

            if (!video.IsFileProtocol)
            {
                yield break;
            }

            string videoFileNameWithoutExtension = Path.GetFileNameWithoutExtension(video.Path);

            var externalAudioFileInfos = GetExternalAudioFiles(video, directoryService, clearCache);
            foreach (var externalAudioFileInfo in externalAudioFileInfos)
            {
                string fileName = Path.GetFileName(externalAudioFileInfo.Path);
                string fileNameWithoutExtension = Path.GetFileNameWithoutExtension(externalAudioFileInfo.Path);
                Model.MediaInfo.MediaInfo mediaInfo = await GetMediaInfo(externalAudioFileInfo.Path, cancellationToken).ConfigureAwait(false);

                if (mediaInfo.MediaStreams.Count == 1)
                {
                    MediaStream mediaStream = mediaInfo.MediaStreams.First();
                    mediaStream.Index = startIndex++;
                    mediaStream.Type = MediaStreamType.Audio;
                    mediaStream.IsExternal = true;
                    mediaStream.Path = externalAudioFileInfo.Path;
                    mediaStream.IsDefault = externalAudioFileInfo.IsDefault || mediaStream.IsDefault;
                    mediaStream.IsForced = externalAudioFileInfo.IsForced || mediaStream.IsForced;

                    yield return DetectLanguage(mediaStream, fileNameWithoutExtension, videoFileNameWithoutExtension);
                }
                else
                {
                    foreach (MediaStream mediaStream in mediaInfo.MediaStreams)
                    {
                        mediaStream.Index = startIndex++;
                        mediaStream.Type = MediaStreamType.Audio;
                        mediaStream.IsExternal = true;
                        mediaStream.Path = externalAudioFileInfo.Path;

                        yield return DetectLanguage(mediaStream, fileNameWithoutExtension, videoFileNameWithoutExtension);
                    }
                }
            }
        }

        /// <summary>
        /// Returns the external audio file paths for the given video.
        /// </summary>
        /// <param name="video">The video to get the external audio file paths from.</param>
        /// <param name="directoryService">The directory service to search for files.</param>
        /// <param name="clearCache">True if the directory service cache should be cleared before searching.</param>
        /// <returns>A list of external audio file paths.</returns>
        public IEnumerable<ExternalAudioFileInfo> GetExternalAudioFiles(
            Video video,
            IDirectoryService directoryService,
            bool clearCache)
        {
            if (!video.IsFileProtocol)
            {
                yield break;
            }

            // Check if video folder exists
            string folder = video.ContainingFolderPath;
            if (!Directory.Exists(folder))
            {
                yield break;
            }

            var videoFileNameWithoutExtension = Path.GetFileNameWithoutExtension(video.Path);

            var files = directoryService.GetFilePaths(folder, clearCache, true);
            for (int i = 0; i < files.Count; i++)
            {
                var subtitleFileInfo = _externalAudioFilePathParser.ParseFile(files[i]);

                if (subtitleFileInfo == null)
                {
                    continue;
                }

                yield return subtitleFileInfo;
            }
        }

        /// <summary>
        /// Returns the media info of the given audio file.
        /// </summary>
        /// <param name="path">The path to the audio file.</param>
        /// <param name="cancellationToken">The cancellation token to cancel operation.</param>
        /// <returns>The media info for the given audio file.</returns>
        private Task<Model.MediaInfo.MediaInfo> GetMediaInfo(string path, CancellationToken cancellationToken)
        {
            cancellationToken.ThrowIfCancellationRequested();

            return _mediaEncoder.GetMediaInfo(
                new MediaInfoRequest
                {
                    MediaType = DlnaProfileType.Audio,
                    MediaSource = new MediaSourceInfo
                    {
                        Path = path,
                        Protocol = MediaProtocol.File
                    }
                },
                cancellationToken);
        }

        private MediaStream DetectLanguage(MediaStream mediaStream, string fileNameWithoutExtension, string videoFileNameWithoutExtension)
        {
            // Support xbmc naming conventions - 300.spanish.srt
            var languageString = fileNameWithoutExtension;
            while (languageString.Length > 0)
            {
                var lastDot = languageString.LastIndexOf('.');
                if (lastDot < videoFileNameWithoutExtension.Length)
                {
                    break;
                }

                var currentSlice = languageString[lastDot..];
                languageString = languageString[..lastDot];

                if (currentSlice.Equals(".default", StringComparison.OrdinalIgnoreCase)
                    || currentSlice.Equals(".forced", StringComparison.OrdinalIgnoreCase)
                    || currentSlice.Equals(".foreign", StringComparison.OrdinalIgnoreCase))
                {
                    continue;
                }

                var currentSliceString = currentSlice[1..];

                // Try to translate to three character code
                var culture = _localizationManager.FindLanguageInfo(currentSliceString);

                if (culture == null || mediaStream.Language != null)
                {
                    if (mediaStream.Title == null)
                    {
                        mediaStream.Title = currentSliceString;
                    }
                }
                else
                {
                    mediaStream.Language = culture.ThreeLetterISOLanguageName;
                }
            }

            return mediaStream;
        }
    }
}