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jellyfin/MediaBrowser.MediaEncoding/Subtitles/SubtitleEditParser.cs

121 lines
4.5 KiB

using System;
using System.Collections.Generic;
using System.Globalization;
using System.IO;
using System.Linq;
using System.Reflection;
using Jellyfin.Extensions;
using MediaBrowser.Model.MediaInfo;
using Microsoft.Extensions.Logging;
using Nikse.SubtitleEdit.Core.Common;
using Nikse.SubtitleEdit.Core.SubtitleFormats;
using SubtitleFormat = Nikse.SubtitleEdit.Core.SubtitleFormats.SubtitleFormat;
namespace MediaBrowser.MediaEncoding.Subtitles
{
/// <summary>
/// SubStation Alpha subtitle parser.
/// </summary>
public class SubtitleEditParser : ISubtitleParser
{
private readonly ILogger<SubtitleEditParser> _logger;
private readonly Dictionary<string, SubtitleFormat[]> _subtitleFormats;
/// <summary>
/// Initializes a new instance of the <see cref="SubtitleEditParser"/> class.
/// </summary>
/// <param name="logger">The logger.</param>
public SubtitleEditParser(ILogger<SubtitleEditParser> logger)
{
_logger = logger;
_subtitleFormats = GetSubtitleFormats()
.Where(subtitleFormat => !string.IsNullOrEmpty(subtitleFormat.Extension))
.GroupBy(subtitleFormat => subtitleFormat.Extension.TrimStart('.'), StringComparer.OrdinalIgnoreCase)
.ToDictionary(g => g.Key, g => g.ToArray(), StringComparer.OrdinalIgnoreCase);
}
/// <inheritdoc />
public SubtitleTrackInfo Parse(Stream stream, string fileExtension)
{
var subtitle = new Subtitle();
var lines = stream.ReadAllLines().ToList();
if (!_subtitleFormats.TryGetValue(fileExtension, out var subtitleFormats))
{
throw new ArgumentException($"Unsupported file extension: {fileExtension}", nameof(fileExtension));
}
foreach (var subtitleFormat in subtitleFormats)
{
_logger.LogDebug(
"Trying to parse '{FileExtension}' subtitle using the {SubtitleFormatParser} format parser",
fileExtension,
subtitleFormat.Name);
subtitleFormat.LoadSubtitle(subtitle, lines, fileExtension);
if (subtitleFormat.ErrorCount == 0)
{
break;
}
_logger.LogError(
"{ErrorCount} errors encountered while parsing '{FileExtension}' subtitle using the {SubtitleFormatParser} format parser",
subtitleFormat.ErrorCount,
fileExtension,
subtitleFormat.Name);
}
if (subtitle.Paragraphs.Count == 0)
{
throw new ArgumentException("Unsupported format: " + fileExtension);
}
var trackInfo = new SubtitleTrackInfo();
int len = subtitle.Paragraphs.Count;
var trackEvents = new SubtitleTrackEvent[len];
for (int i = 0; i < len; i++)
{
var p = subtitle.Paragraphs[i];
trackEvents[i] = new SubtitleTrackEvent(p.Number.ToString(CultureInfo.InvariantCulture), p.Text)
{
StartPositionTicks = p.StartTime.TimeSpan.Ticks,
EndPositionTicks = p.EndTime.TimeSpan.Ticks
};
}
trackInfo.TrackEvents = trackEvents;
return trackInfo;
}
/// <inheritdoc />
public bool SupportsFileExtension(string fileExtension)
=> _subtitleFormats.ContainsKey(fileExtension);
private IEnumerable<SubtitleFormat> GetSubtitleFormats()
{
var subtitleFormats = new List<SubtitleFormat>();
var assembly = typeof(SubtitleFormat).Assembly;
foreach (var type in assembly.GetTypes())
{
if (!type.IsSubclassOf(typeof(SubtitleFormat)) || type.IsAbstract)
{
continue;
}
try
{
// It shouldn't be null, but the exception is caught if it is
var subtitleFormat = (SubtitleFormat)Activator.CreateInstance(type, true)!;
subtitleFormats.Add(subtitleFormat);
}
catch (Exception ex)
{
_logger.LogWarning(ex, "Failed to create instance of the subtitle format {SubtitleFormatType}", type.Name);
}
}
return subtitleFormats;
}
}
}