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jellyfin/MediaBrowser.MediaEncoding/Subtitles/SubtitleEncoder.cs

943 lines
33 KiB

using MediaBrowser.Common.Configuration;
using MediaBrowser.Common.Extensions;
using MediaBrowser.Common.Net;
using MediaBrowser.Controller.Entities;
using MediaBrowser.Controller.Library;
using MediaBrowser.Controller.MediaEncoding;
using MediaBrowser.Model.Entities;
using MediaBrowser.Model.Logging;
using MediaBrowser.Model.MediaInfo;
using MediaBrowser.Model.Serialization;
using System;
using System.Collections.Concurrent;
using System.Diagnostics;
using System.Globalization;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading;
using System.Threading.Tasks;
using CommonIO;
using MediaBrowser.Common.IO;
using MediaBrowser.Controller.IO;
using MediaBrowser.Model.IO;
using UniversalDetector;
namespace MediaBrowser.MediaEncoding.Subtitles
{
public class SubtitleEncoder : ISubtitleEncoder
{
private readonly ILibraryManager _libraryManager;
private readonly ILogger _logger;
private readonly IApplicationPaths _appPaths;
private readonly IFileSystem _fileSystem;
private readonly IMediaEncoder _mediaEncoder;
private readonly IJsonSerializer _json;
private readonly IHttpClient _httpClient;
private readonly IMediaSourceManager _mediaSourceManager;
private readonly IMemoryStreamProvider _memoryStreamProvider;
public SubtitleEncoder(ILibraryManager libraryManager, ILogger logger, IApplicationPaths appPaths, IFileSystem fileSystem, IMediaEncoder mediaEncoder, IJsonSerializer json, IHttpClient httpClient, IMediaSourceManager mediaSourceManager, IMemoryStreamProvider memoryStreamProvider)
{
_libraryManager = libraryManager;
_logger = logger;
_appPaths = appPaths;
_fileSystem = fileSystem;
_mediaEncoder = mediaEncoder;
_json = json;
_httpClient = httpClient;
_mediaSourceManager = mediaSourceManager;
_memoryStreamProvider = memoryStreamProvider;
}
private string SubtitleCachePath
{
get
{
return Path.Combine(_appPaths.DataPath, "subtitles");
}
}
private async Task<Stream> ConvertSubtitles(Stream stream,
string inputFormat,
string outputFormat,
long startTimeTicks,
long? endTimeTicks,
bool preserveOriginalTimestamps,
CancellationToken cancellationToken)
{
var ms = _memoryStreamProvider.CreateNew();
try
{
var reader = GetReader(inputFormat, true);
var trackInfo = reader.Parse(stream, cancellationToken);
FilterEvents(trackInfo, startTimeTicks, endTimeTicks, preserveOriginalTimestamps);
var writer = GetWriter(outputFormat);
writer.Write(trackInfo, ms, cancellationToken);
ms.Position = 0;
}
catch
{
ms.Dispose();
throw;
}
return ms;
}
private void FilterEvents(SubtitleTrackInfo track, long startPositionTicks, long? endTimeTicks, bool preserveTimestamps)
{
// Drop subs that are earlier than what we're looking for
track.TrackEvents = track.TrackEvents
.SkipWhile(i => (i.StartPositionTicks - startPositionTicks) < 0 || (i.EndPositionTicks - startPositionTicks) < 0)
.ToList();
if (endTimeTicks.HasValue)
{
var endTime = endTimeTicks.Value;
track.TrackEvents = track.TrackEvents
.TakeWhile(i => i.StartPositionTicks <= endTime)
.ToList();
}
if (!preserveTimestamps)
{
foreach (var trackEvent in track.TrackEvents)
{
trackEvent.EndPositionTicks -= startPositionTicks;
trackEvent.StartPositionTicks -= startPositionTicks;
}
}
}
public async Task<Stream> GetSubtitles(string itemId,
string mediaSourceId,
int subtitleStreamIndex,
string outputFormat,
long startTimeTicks,
long? endTimeTicks,
bool preserveOriginalTimestamps,
CancellationToken cancellationToken)
{
if (string.IsNullOrWhiteSpace(itemId))
{
throw new ArgumentNullException("itemId");
}
if (string.IsNullOrWhiteSpace(mediaSourceId))
{
throw new ArgumentNullException("mediaSourceId");
}
var subtitle = await GetSubtitleStream(itemId, mediaSourceId, subtitleStreamIndex, cancellationToken)
.ConfigureAwait(false);
var inputFormat = subtitle.Item2;
if (string.Equals(inputFormat, outputFormat, StringComparison.OrdinalIgnoreCase) && TryGetWriter(outputFormat) == null)
{
return subtitle.Item1;
}
using (var stream = subtitle.Item1)
{
return await ConvertSubtitles(stream, inputFormat, outputFormat, startTimeTicks, endTimeTicks, preserveOriginalTimestamps, cancellationToken).ConfigureAwait(false);
}
}
private async Task<Tuple<Stream, string>> GetSubtitleStream(string itemId,
string mediaSourceId,
int subtitleStreamIndex,
CancellationToken cancellationToken)
{
if (string.IsNullOrWhiteSpace(itemId))
{
throw new ArgumentNullException("itemId");
}
if (string.IsNullOrWhiteSpace(mediaSourceId))
{
throw new ArgumentNullException("mediaSourceId");
}
var mediaSources = await _mediaSourceManager.GetPlayackMediaSources(itemId, null, false, new[] { MediaType.Audio, MediaType.Video }, cancellationToken).ConfigureAwait(false);
var mediaSource = mediaSources
.First(i => string.Equals(i.Id, mediaSourceId, StringComparison.OrdinalIgnoreCase));
var subtitleStream = mediaSource.MediaStreams
.First(i => i.Type == MediaStreamType.Subtitle && i.Index == subtitleStreamIndex);
var inputFiles = new[] { mediaSource.Path };
if (mediaSource.VideoType.HasValue)
{
if (mediaSource.VideoType.Value == VideoType.BluRay ||
mediaSource.VideoType.Value == VideoType.Dvd)
{
var mediaSourceItem = (Video)_libraryManager.GetItemById(new Guid(mediaSourceId));
inputFiles = mediaSourceItem.GetPlayableStreamFiles().ToArray();
}
}
var fileInfo = await GetReadableFile(mediaSource.Path, inputFiles, mediaSource.Protocol, subtitleStream, cancellationToken).ConfigureAwait(false);
var stream = await GetSubtitleStream(fileInfo.Item1, subtitleStream.Language, fileInfo.Item2, fileInfo.Item4, cancellationToken).ConfigureAwait(false);
return new Tuple<Stream, string>(stream, fileInfo.Item3);
}
private async Task<Stream> GetSubtitleStream(string path, string language, MediaProtocol protocol, bool requiresCharset, CancellationToken cancellationToken)
{
if (requiresCharset)
{
var charset = await GetSubtitleFileCharacterSet(path, language, protocol, cancellationToken).ConfigureAwait(false);
if (!string.IsNullOrEmpty(charset))
{
using (var fs = await GetStream(path, protocol, cancellationToken).ConfigureAwait(false))
{
using (var reader = new StreamReader(fs, GetEncoding(charset)))
{
var text = await reader.ReadToEndAsync().ConfigureAwait(false);
var bytes = Encoding.UTF8.GetBytes(text);
return _memoryStreamProvider.CreateNew(bytes);
}
}
}
}
return _fileSystem.OpenRead(path);
}
private Encoding GetEncoding(string charset)
{
if (string.IsNullOrWhiteSpace(charset))
{
throw new ArgumentNullException("charset");
}
_logger.Debug("Getting encoding object for character set: {0}", charset);
try
{
return Encoding.GetEncoding(charset);
}
catch (ArgumentException)
{
charset = charset.Replace("-", string.Empty);
_logger.Debug("Getting encoding object for character set: {0}", charset);
return Encoding.GetEncoding(charset);
}
}
private async Task<Tuple<string, MediaProtocol, string, bool>> GetReadableFile(string mediaPath,
string[] inputFiles,
MediaProtocol protocol,
MediaStream subtitleStream,
CancellationToken cancellationToken)
{
if (!subtitleStream.IsExternal)
{
string outputFormat;
string outputCodec;
if (string.Equals(subtitleStream.Codec, "ass", StringComparison.OrdinalIgnoreCase) ||
string.Equals(subtitleStream.Codec, "ssa", StringComparison.OrdinalIgnoreCase) ||
string.Equals(subtitleStream.Codec, "srt", StringComparison.OrdinalIgnoreCase))
{
// Extract
outputCodec = "copy";
outputFormat = subtitleStream.Codec;
}
else if (string.Equals(subtitleStream.Codec, "subrip", StringComparison.OrdinalIgnoreCase))
{
// Extract
outputCodec = "copy";
outputFormat = "srt";
}
else
{
// Extract
outputCodec = "srt";
outputFormat = "srt";
}
// Extract
var outputPath = GetSubtitleCachePath(mediaPath, protocol, subtitleStream.Index, "." + outputFormat);
await ExtractTextSubtitle(inputFiles, protocol, subtitleStream.Index, outputCodec, outputPath, cancellationToken)
.ConfigureAwait(false);
return new Tuple<string, MediaProtocol, string, bool>(outputPath, MediaProtocol.File, outputFormat, false);
}
var currentFormat = (Path.GetExtension(subtitleStream.Path) ?? subtitleStream.Codec)
.TrimStart('.');
if (GetReader(currentFormat, false) == null)
{
// Convert
var outputPath = GetSubtitleCachePath(mediaPath, protocol, subtitleStream.Index, ".srt");
await ConvertTextSubtitleToSrt(subtitleStream.Path, subtitleStream.Language, protocol, outputPath, cancellationToken).ConfigureAwait(false);
return new Tuple<string, MediaProtocol, string, bool>(outputPath, MediaProtocol.File, "srt", true);
}
return new Tuple<string, MediaProtocol, string, bool>(subtitleStream.Path, protocol, currentFormat, true);
}
private ISubtitleParser GetReader(string format, bool throwIfMissing)
{
if (string.IsNullOrEmpty(format))
{
throw new ArgumentNullException("format");
}
if (string.Equals(format, SubtitleFormat.SRT, StringComparison.OrdinalIgnoreCase))
{
return new SrtParser(_logger);
}
if (string.Equals(format, SubtitleFormat.SSA, StringComparison.OrdinalIgnoreCase))
{
return new SsaParser();
}
if (string.Equals(format, SubtitleFormat.ASS, StringComparison.OrdinalIgnoreCase))
{
return new AssParser();
}
if (throwIfMissing)
{
throw new ArgumentException("Unsupported format: " + format);
}
return null;
}
private ISubtitleWriter TryGetWriter(string format)
{
if (string.IsNullOrEmpty(format))
{
throw new ArgumentNullException("format");
}
if (string.Equals(format, "json", StringComparison.OrdinalIgnoreCase))
{
return new JsonWriter(_json);
}
if (string.Equals(format, SubtitleFormat.SRT, StringComparison.OrdinalIgnoreCase))
{
return new SrtWriter();
}
if (string.Equals(format, SubtitleFormat.VTT, StringComparison.OrdinalIgnoreCase))
{
return new VttWriter();
}
if (string.Equals(format, SubtitleFormat.TTML, StringComparison.OrdinalIgnoreCase))
{
return new TtmlWriter();
}
return null;
}
private ISubtitleWriter GetWriter(string format)
{
var writer = TryGetWriter(format);
if (writer != null)
{
return writer;
}
throw new ArgumentException("Unsupported format: " + format);
}
/// <summary>
/// The _semaphoreLocks
/// </summary>
private readonly ConcurrentDictionary<string, SemaphoreSlim> _semaphoreLocks =
new ConcurrentDictionary<string, SemaphoreSlim>();
/// <summary>
/// Gets the lock.
/// </summary>
/// <param name="filename">The filename.</param>
/// <returns>System.Object.</returns>
private SemaphoreSlim GetLock(string filename)
{
return _semaphoreLocks.GetOrAdd(filename, key => new SemaphoreSlim(1, 1));
}
/// <summary>
/// Converts the text subtitle to SRT.
/// </summary>
/// <param name="inputPath">The input path.</param>
/// <param name="inputProtocol">The input protocol.</param>
/// <param name="outputPath">The output path.</param>
/// <param name="cancellationToken">The cancellation token.</param>
/// <returns>Task.</returns>
private async Task ConvertTextSubtitleToSrt(string inputPath, string language, MediaProtocol inputProtocol, string outputPath, CancellationToken cancellationToken)
{
var semaphore = GetLock(outputPath);
await semaphore.WaitAsync(cancellationToken).ConfigureAwait(false);
try
{
if (!_fileSystem.FileExists(outputPath))
{
await ConvertTextSubtitleToSrtInternal(inputPath, language, inputProtocol, outputPath, cancellationToken).ConfigureAwait(false);
}
}
finally
{
semaphore.Release();
}
}
/// <summary>
/// Converts the text subtitle to SRT internal.
/// </summary>
/// <param name="inputPath">The input path.</param>
/// <param name="inputProtocol">The input protocol.</param>
/// <param name="outputPath">The output path.</param>
/// <param name="cancellationToken">The cancellation token.</param>
/// <returns>Task.</returns>
/// <exception cref="System.ArgumentNullException">
/// inputPath
/// or
/// outputPath
/// </exception>
/// <exception cref="System.ApplicationException"></exception>
private async Task ConvertTextSubtitleToSrtInternal(string inputPath, string language, MediaProtocol inputProtocol, string outputPath, CancellationToken cancellationToken)
{
if (string.IsNullOrEmpty(inputPath))
{
throw new ArgumentNullException("inputPath");
}
if (string.IsNullOrEmpty(outputPath))
{
throw new ArgumentNullException("outputPath");
}
_fileSystem.CreateDirectory(Path.GetDirectoryName(outputPath));
var encodingParam = await GetSubtitleFileCharacterSet(inputPath, language, inputProtocol, cancellationToken).ConfigureAwait(false);
if (!string.IsNullOrEmpty(encodingParam))
{
encodingParam = " -sub_charenc " + encodingParam;
}
var process = new Process
{
StartInfo = new ProcessStartInfo
{
RedirectStandardOutput = false,
RedirectStandardError = true,
RedirectStandardInput = true,
CreateNoWindow = true,
UseShellExecute = false,
FileName = _mediaEncoder.EncoderPath,
Arguments = string.Format("{0} -i \"{1}\" -c:s srt \"{2}\"", encodingParam, inputPath, outputPath),
WindowStyle = ProcessWindowStyle.Hidden,
ErrorDialog = false
}
};
_logger.Info("{0} {1}", process.StartInfo.FileName, process.StartInfo.Arguments);
var logFilePath = Path.Combine(_appPaths.LogDirectoryPath, "ffmpeg-sub-convert-" + Guid.NewGuid() + ".txt");
_fileSystem.CreateDirectory(Path.GetDirectoryName(logFilePath));
var logFileStream = _fileSystem.GetFileStream(logFilePath, FileMode.Create, FileAccess.Write, FileShare.Read,
true);
try
{
process.Start();
}
catch (Exception ex)
{
logFileStream.Dispose();
_logger.ErrorException("Error starting ffmpeg", ex);
throw;
}
var logTask = process.StandardError.BaseStream.CopyToAsync(logFileStream);
var ranToCompletion = process.WaitForExit(60000);
if (!ranToCompletion)
{
try
{
_logger.Info("Killing ffmpeg subtitle conversion process");
process.StandardInput.WriteLine("q");
process.WaitForExit(1000);
await logTask.ConfigureAwait(false);
}
catch (Exception ex)
{
_logger.ErrorException("Error killing subtitle conversion process", ex);
}
finally
{
logFileStream.Dispose();
}
}
var exitCode = ranToCompletion ? process.ExitCode : -1;
process.Dispose();
var failed = false;
if (exitCode == -1)
{
failed = true;
if (_fileSystem.FileExists(outputPath))
{
try
{
_logger.Info("Deleting converted subtitle due to failure: ", outputPath);
_fileSystem.DeleteFile(outputPath);
}
catch (IOException ex)
{
_logger.ErrorException("Error deleting converted subtitle {0}", ex, outputPath);
}
}
}
else if (!_fileSystem.FileExists(outputPath))
{
failed = true;
}
if (failed)
{
var msg = string.Format("ffmpeg subtitle converted failed for {0}", inputPath);
_logger.Error(msg);
throw new ApplicationException(msg);
}
await SetAssFont(outputPath).ConfigureAwait(false);
}
/// <summary>
/// Extracts the text subtitle.
/// </summary>
/// <param name="inputFiles">The input files.</param>
/// <param name="protocol">The protocol.</param>
/// <param name="subtitleStreamIndex">Index of the subtitle stream.</param>
/// <param name="outputCodec">The output codec.</param>
/// <param name="outputPath">The output path.</param>
/// <param name="cancellationToken">The cancellation token.</param>
/// <returns>Task.</returns>
/// <exception cref="System.ArgumentException">Must use inputPath list overload</exception>
private async Task ExtractTextSubtitle(string[] inputFiles, MediaProtocol protocol, int subtitleStreamIndex,
string outputCodec, string outputPath, CancellationToken cancellationToken)
{
var semaphore = GetLock(outputPath);
await semaphore.WaitAsync(cancellationToken).ConfigureAwait(false);
try
{
if (!_fileSystem.FileExists(outputPath))
{
await ExtractTextSubtitleInternal(_mediaEncoder.GetInputArgument(inputFiles, protocol), subtitleStreamIndex,
outputCodec, outputPath, cancellationToken).ConfigureAwait(false);
}
}
finally
{
semaphore.Release();
}
}
private async Task ExtractTextSubtitleInternal(string inputPath, int subtitleStreamIndex,
string outputCodec, string outputPath, CancellationToken cancellationToken)
{
if (string.IsNullOrEmpty(inputPath))
{
throw new ArgumentNullException("inputPath");
}
if (string.IsNullOrEmpty(outputPath))
{
throw new ArgumentNullException("outputPath");
}
_fileSystem.CreateDirectory(Path.GetDirectoryName(outputPath));
var processArgs = string.Format("-i {0} -map 0:{1} -an -vn -c:s {2} \"{3}\"", inputPath,
subtitleStreamIndex, outputCodec, outputPath);
var process = new Process
{
StartInfo = new ProcessStartInfo
{
CreateNoWindow = true,
UseShellExecute = false,
RedirectStandardOutput = false,
RedirectStandardError = true,
RedirectStandardInput = true,
FileName = _mediaEncoder.EncoderPath,
Arguments = processArgs,
WindowStyle = ProcessWindowStyle.Hidden,
ErrorDialog = false
}
};
_logger.Info("{0} {1}", process.StartInfo.FileName, process.StartInfo.Arguments);
var logFilePath = Path.Combine(_appPaths.LogDirectoryPath, "ffmpeg-sub-extract-" + Guid.NewGuid() + ".txt");
_fileSystem.CreateDirectory(Path.GetDirectoryName(logFilePath));
var logFileStream = _fileSystem.GetFileStream(logFilePath, FileMode.Create, FileAccess.Write, FileShare.Read,
true);
try
{
process.Start();
}
catch (Exception ex)
{
logFileStream.Dispose();
_logger.ErrorException("Error starting ffmpeg", ex);
throw;
}
// Important - don't await the log task or we won't be able to kill ffmpeg when the user stops playback
Task.Run(() => StartStreamingLog(process.StandardError.BaseStream, logFileStream));
var ranToCompletion = process.WaitForExit(300000);
if (!ranToCompletion)
{
try
{
_logger.Info("Killing ffmpeg subtitle extraction process");
process.StandardInput.WriteLine("q");
process.WaitForExit(1000);
}
catch (Exception ex)
{
_logger.ErrorException("Error killing subtitle extraction process", ex);
}
finally
{
logFileStream.Dispose();
}
}
var exitCode = ranToCompletion ? process.ExitCode : -1;
process.Dispose();
var failed = false;
if (exitCode == -1)
{
failed = true;
try
{
_logger.Info("Deleting extracted subtitle due to failure: {0}", outputPath);
_fileSystem.DeleteFile(outputPath);
}
catch (FileNotFoundException)
{
}
catch (DirectoryNotFoundException)
{
}
catch (IOException ex)
{
_logger.ErrorException("Error deleting extracted subtitle {0}", ex, outputPath);
}
}
else if (!_fileSystem.FileExists(outputPath))
{
failed = true;
}
if (failed)
{
var msg = string.Format("ffmpeg subtitle extraction failed for {0} to {1}", inputPath, outputPath);
_logger.Error(msg);
throw new ApplicationException(msg);
}
else
{
var msg = string.Format("ffmpeg subtitle extraction completed for {0} to {1}", inputPath, outputPath);
_logger.Info(msg);
}
if (string.Equals(outputCodec, "ass", StringComparison.OrdinalIgnoreCase))
{
await SetAssFont(outputPath).ConfigureAwait(false);
}
}
private async Task StartStreamingLog(Stream source, Stream target)
{
try
{
using (var reader = new StreamReader(source))
{
while (!reader.EndOfStream)
{
var line = await reader.ReadLineAsync().ConfigureAwait(false);
var bytes = Encoding.UTF8.GetBytes(Environment.NewLine + line);
await target.WriteAsync(bytes, 0, bytes.Length).ConfigureAwait(false);
await target.FlushAsync().ConfigureAwait(false);
}
}
}
catch (ObjectDisposedException)
{
// Don't spam the log. This doesn't seem to throw in windows, but sometimes under linux
}
catch (Exception ex)
{
_logger.ErrorException("Error reading ffmpeg log", ex);
}
}
/// <summary>
/// Sets the ass font.
/// </summary>
/// <param name="file">The file.</param>
/// <returns>Task.</returns>
private async Task SetAssFont(string file)
{
_logger.Info("Setting ass font within {0}", file);
string text;
Encoding encoding;
using (var reader = new StreamReader(file, true))
{
encoding = reader.CurrentEncoding;
text = await reader.ReadToEndAsync().ConfigureAwait(false);
}
var newText = text.Replace(",Arial,", ",Arial Unicode MS,");
if (!string.Equals(text, newText))
{
using (var writer = new StreamWriter(file, false, encoding))
{
writer.Write(newText);
}
}
}
private string GetSubtitleCachePath(string mediaPath, MediaProtocol protocol, int subtitleStreamIndex, string outputSubtitleExtension)
{
if (protocol == MediaProtocol.File)
{
var ticksParam = string.Empty;
var date = _fileSystem.GetLastWriteTimeUtc(mediaPath);
var filename = (mediaPath + "_" + subtitleStreamIndex.ToString(CultureInfo.InvariantCulture) + "_" + date.Ticks.ToString(CultureInfo.InvariantCulture) + ticksParam).GetMD5() + outputSubtitleExtension;
var prefix = filename.Substring(0, 1);
return Path.Combine(SubtitleCachePath, prefix, filename);
}
else
{
var filename = (mediaPath + "_" + subtitleStreamIndex.ToString(CultureInfo.InvariantCulture)).GetMD5() + outputSubtitleExtension;
var prefix = filename.Substring(0, 1);
return Path.Combine(SubtitleCachePath, prefix, filename);
}
}
public async Task<string> GetSubtitleFileCharacterSet(string path, string language, MediaProtocol protocol, CancellationToken cancellationToken)
{
if (protocol == MediaProtocol.File)
{
if (GetFileEncoding(path).Equals(Encoding.UTF8))
{
return string.Empty;
}
}
var charset = await DetectCharset(path, language, protocol, cancellationToken).ConfigureAwait(false);
if (!string.IsNullOrWhiteSpace(charset))
{
if (string.Equals(charset, "utf-8", StringComparison.OrdinalIgnoreCase))
{
return null;
}
return charset;
}
if (!string.IsNullOrWhiteSpace(language))
{
return GetSubtitleFileCharacterSetFromLanguage(language);
}
return null;
}
public string GetSubtitleFileCharacterSetFromLanguage(string language)
{
// https://developer.xamarin.com/api/type/System.Text.Encoding/
switch (language.ToLower())
{
case "hun":
return "windows-1252";
case "pol":
case "cze":
case "ces":
case "slo":
case "slk":
case "slv":
case "srp":
case "hrv":
case "rum":
case "ron":
case "rup":
case "alb":
case "sqi":
return "windows-1250";
case "ara":
return "windows-1256";
case "heb":
return "windows-1255";
case "grc":
case "gre":
return "windows-1253";
case "crh":
case "ota":
case "tur":
return "windows-1254";
case "rus":
return "windows-1251";
case "vie":
return "windows-1258";
case "kor":
return "cp949";
default:
return "windows-1252";
}
}
private async Task<string> DetectCharset(string path, string language, MediaProtocol protocol, CancellationToken cancellationToken)
{
try
{
using (var file = await GetStream(path, protocol, cancellationToken).ConfigureAwait(false))
{
var detector = new CharsetDetector();
detector.Feed(file);
detector.DataEnd();
var charset = detector.Charset;
if (!string.IsNullOrWhiteSpace(charset))
{
_logger.Info("UniversalDetector detected charset {0} for {1}", charset, path);
}
// This is often incorrectly indetected. If this happens, try to use other techniques instead
if (string.Equals("x-mac-cyrillic", charset, StringComparison.OrdinalIgnoreCase))
{
if (!string.IsNullOrWhiteSpace(language))
{
return null;
}
}
return charset;
}
}
catch (IOException ex)
{
_logger.ErrorException("Error attempting to determine subtitle charset from {0}", ex, path);
}
return null;
}
private Encoding GetFileEncoding(string srcFile)
{
// *** Detect byte order mark if any - otherwise assume default
var buffer = new byte[5];
using (var file = _fileSystem.GetFileStream(srcFile, FileMode.Open, FileAccess.Read, FileShare.ReadWrite))
{
file.Read(buffer, 0, 5);
}
if (buffer[0] == 0xef && buffer[1] == 0xbb && buffer[2] == 0xbf)
return Encoding.UTF8;
if (buffer[0] == 0xfe && buffer[1] == 0xff)
return Encoding.Unicode;
if (buffer[0] == 0 && buffer[1] == 0 && buffer[2] == 0xfe && buffer[3] == 0xff)
return Encoding.UTF32;
if (buffer[0] == 0x2b && buffer[1] == 0x2f && buffer[2] == 0x76)
return Encoding.UTF7;
// It's ok - anything aside from utf is ok since that's what we're looking for
return Encoding.Default;
}
private async Task<Stream> GetStream(string path, MediaProtocol protocol, CancellationToken cancellationToken)
{
if (protocol == MediaProtocol.Http)
{
return await _httpClient.Get(path, cancellationToken).ConfigureAwait(false);
}
if (protocol == MediaProtocol.File)
{
return _fileSystem.GetFileStream(path, FileMode.Open, FileAccess.Read, FileShare.ReadWrite);
}
throw new ArgumentOutOfRangeException("protocol");
}
}
}