Merge branch 'master' into tonemap

3 files changed, 150 insertions, 103 deletions

diff --git a/MediaBrowser.MediaEncoding/Encoder/EncoderValidator.cs b/MediaBrowser.MediaEncoding/Encoder/EncoderValidator.cs
index 5c43fdcfa..c8bf5557b 100644
--- a/MediaBrowser.MediaEncoding/Encoder/EncoderValidator.cs
+++ b/MediaBrowser.MediaEncoding/Encoder/EncoderValidator.cs
@@ -1,8 +1,10 @@
+#pragma warning disable CS1591
+
 using System;
 using System.Collections.Generic;
 using System.Diagnostics;
+using System.Globalization;
 using System.Linq;
-using System.Text;
 using System.Text.RegularExpressions;
 using Microsoft.Extensions.Logging;
 
@@ -12,7 +14,7 @@ namespace MediaBrowser.MediaEncoding.Encoder
     {
         private const string DefaultEncoderPath = "ffmpeg";
 
-        private static readonly string[] requiredDecoders = new[]
+        private static readonly string[] _requiredDecoders = new[]
         {
             "h264",
             "hevc",
@@ -55,7 +57,7 @@ namespace MediaBrowser.MediaEncoding.Encoder
             "vc1_opencl"
         };
 
-        private static readonly string[] requiredEncoders = new[]
+        private static readonly string[] _requiredEncoders = new[]
         {
             "libx264",
             "libx265",
@@ -85,19 +87,17 @@ namespace MediaBrowser.MediaEncoding.Encoder
             "hevc_videotoolbox"
         };
 
-        // Try and use the individual library versions to determine a FFmpeg version
-        // This lookup table is to be maintained with the following command line:
-        // $ ffmpeg -version | perl -ne ' print "$1=$2.$3," if /^(lib\w+)\s+(\d+)\.\s*(\d+)/'
-        private static readonly IReadOnlyDictionary<string, Version> _ffmpegVersionMap = new Dictionary<string, Version>
+        // These are the library versions that corresponds to our minimum ffmpeg version 4.x according to the version table below
+        private static readonly IReadOnlyDictionary<string, Version> _ffmpegMinimumLibraryVersions = new Dictionary<string, Version>
         {
-            { "libavutil=56.51,libavcodec=58.91,libavformat=58.45,libavdevice=58.10,libavfilter=7.85,libswscale=5.7,libswresample=3.7,libpostproc=55.7,", new Version(4, 3) },
-            { "libavutil=56.31,libavcodec=58.54,libavformat=58.29,libavdevice=58.8,libavfilter=7.57,libswscale=5.5,libswresample=3.5,libpostproc=55.5,", new Version(4, 2) },
-            { "libavutil=56.22,libavcodec=58.35,libavformat=58.20,libavdevice=58.5,libavfilter=7.40,libswscale=5.3,libswresample=3.3,libpostproc=55.3,", new Version(4, 1) },
-            { "libavutil=56.14,libavcodec=58.18,libavformat=58.12,libavdevice=58.3,libavfilter=7.16,libswscale=5.1,libswresample=3.1,libpostproc=55.1,", new Version(4, 0) },
-            { "libavutil=55.78,libavcodec=57.107,libavformat=57.83,libavdevice=57.10,libavfilter=6.107,libswscale=4.8,libswresample=2.9,libpostproc=54.7,", new Version(3, 4) },
-            { "libavutil=55.58,libavcodec=57.89,libavformat=57.71,libavdevice=57.6,libavfilter=6.82,libswscale=4.6,libswresample=2.7,libpostproc=54.5,", new Version(3, 3) },
-            { "libavutil=55.34,libavcodec=57.64,libavformat=57.56,libavdevice=57.1,libavfilter=6.65,libswscale=4.2,libswresample=2.3,libpostproc=54.1,", new Version(3, 2) },
-            { "libavutil=54.31,libavcodec=56.60,libavformat=56.40,libavdevice=56.4,libavfilter=5.40,libswscale=3.1,libswresample=1.2,libpostproc=53.3,", new Version(2, 8) }
+            { "libavutil", new Version(56, 14) },
+            { "libavcodec", new Version(58, 18) },
+            { "libavformat", new Version(58, 12) },
+            { "libavdevice", new Version(58, 3) },
+            { "libavfilter", new Version(7, 16) },
+            { "libswscale", new Version(5, 1) },
+            { "libswresample", new Version(3, 1) },
+            { "libpostproc", new Version(55, 1) }
         };
 
         private readonly ILogger _logger;
@@ -110,6 +110,13 @@ namespace MediaBrowser.MediaEncoding.Encoder
             _encoderPath = encoderPath;
         }
 
+        private enum Codec
+        {
+            Encoder,
+            Decoder
+        }
+
+        // When changing this, also change the minimum library versions in _ffmpegMinimumLibraryVersions
         public static Version MinVersion { get; } = new Version(4, 0);
 
         public static Version MaxVersion { get; } = null;
@@ -148,32 +155,36 @@ namespace MediaBrowser.MediaEncoding.Encoder
             // Work out what the version under test is
             var version = GetFFmpegVersion(versionOutput);
 
-            _logger.LogInformation("Found ffmpeg version {0}", version != null ? version.ToString() : "unknown");
+            _logger.LogInformation("Found ffmpeg version {Version}", version != null ? version.ToString() : "unknown");
 
             if (version == null)
             {
-                if (MinVersion != null && MaxVersion != null) // Version is unknown
+                if (MaxVersion != null) // Version is unknown
                 {
                     if (MinVersion == MaxVersion)
                     {
-                        _logger.LogWarning("FFmpeg validation: We recommend ffmpeg version {0}", MinVersion);
+                        _logger.LogWarning("FFmpeg validation: We recommend version {MinVersion}", MinVersion);
                     }
                     else
                     {
-                        _logger.LogWarning("FFmpeg validation: We recommend a minimum of {0} and maximum of {1}", MinVersion, MaxVersion);
+                        _logger.LogWarning("FFmpeg validation: We recommend a minimum of {MinVersion} and maximum of {MaxVersion}", MinVersion, MaxVersion);
                     }
                 }
+                else
+                {
+                    _logger.LogWarning("FFmpeg validation: We recommend minimum version {MinVersion}", MinVersion);
+                }
 
                 return false;
             }
-            else if (MinVersion != null && version < MinVersion) // Version is below what we recommend
+            else if (version < MinVersion) // Version is below what we recommend
             {
-                _logger.LogWarning("FFmpeg validation: The minimum recommended ffmpeg version is {0}", MinVersion);
+                _logger.LogWarning("FFmpeg validation: The minimum recommended version is {MinVersion}", MinVersion);
                 return false;
             }
             else if (MaxVersion != null && version > MaxVersion) // Version is above what we recommend
             {
-                _logger.LogWarning("FFmpeg validation: The maximum recommended ffmpeg version is {0}", MaxVersion);
+                _logger.LogWarning("FFmpeg validation: The maximum recommended version is {MaxVersion}", MaxVersion);
                 return false;
             }
 
@@ -189,13 +200,12 @@ namespace MediaBrowser.MediaEncoding.Encoder
         /// <summary>
         /// Using the output from "ffmpeg -version" work out the FFmpeg version.
         /// For pre-built binaries the first line should contain a string like "ffmpeg version x.y", which is easy
-        /// to parse.  If this is not available, then we try to match known library versions to FFmpeg versions.
-        /// If that fails then we use one of the main libraries to determine if it's new/older than the latest
-        /// we have stored.
+        /// to parse. If this is not available, then we try to match known library versions to FFmpeg versions.
+        /// If that fails then we test the libraries to determine if they're newer than our minimum versions.
         /// </summary>
-        /// <param name="output"></param>
-        /// <returns></returns>
-        internal static Version GetFFmpegVersion(string output)
+        /// <param name="output">The output from "ffmpeg -version".</param>
+        /// <returns>The FFmpeg version.</returns>
+        internal Version GetFFmpegVersion(string output)
         {
             // For pre-built binaries the FFmpeg version should be mentioned at the very start of the output
             var match = Regex.Match(output, @"^ffmpeg version n?((?:[0-9]+\.?)+)");
@@ -204,45 +214,58 @@ namespace MediaBrowser.MediaEncoding.Encoder
             {
                 return new Version(match.Groups[1].Value);
             }
-            else
-            {
-                // Create a reduced version string and lookup key from dictionary
-                var reducedVersion = GetLibrariesVersionString(output);
 
-                // Try to lookup the string and return Key, otherwise if not found returns null
-                return _ffmpegVersionMap.TryGetValue(reducedVersion, out Version version) ? version : null;
+            var versionMap = GetFFmpegLibraryVersions(output);
+
+            var allVersionsValidated = true;
+
+            foreach (var minimumVersion in _ffmpegMinimumLibraryVersions)
+            {
+                if (versionMap.TryGetValue(minimumVersion.Key, out var foundVersion))
+                {
+                    if (foundVersion >= minimumVersion.Value)
+                    {
+                        _logger.LogInformation("Found {Library} version {FoundVersion} ({MinimumVersion})", minimumVersion.Key, foundVersion, minimumVersion.Value);
+                    }
+                    else
+                    {
+                        _logger.LogWarning("Found {Library} version {FoundVersion} lower than recommended version {MinimumVersion}", minimumVersion.Key, foundVersion, minimumVersion.Value);
+                        allVersionsValidated = false;
+                    }
+                }
+                else
+                {
+                    _logger.LogError("{Library} version not found", minimumVersion.Key);
+                    allVersionsValidated = false;
+                }
             }
+
+            return allVersionsValidated ? MinVersion : null;
         }
 
         /// <summary>
         /// Grabs the library names and major.minor version numbers from the 'ffmpeg -version' output
-        /// and condenses them on to one line.  Output format is "name1=major.minor,name2=major.minor,etc."
+        /// and condenses them on to one line.  Output format is "name1=major.minor,name2=major.minor,etc.".
         /// </summary>
-        /// <param name="output"></param>
-        /// <returns></returns>
-        private static string GetLibrariesVersionString(string output)
+        /// <param name="output">The 'ffmpeg -version' output.</param>
+        /// <returns>The library names and major.minor version numbers.</returns>
+        private static IReadOnlyDictionary<string, Version> GetFFmpegLibraryVersions(string output)
         {
-            var rc = new StringBuilder(144);
-            foreach (Match m in Regex.Matches(
+            var map = new Dictionary<string, Version>();
+
+            foreach (Match match in Regex.Matches(
                 output,
                 @"((?<name>lib\w+)\s+(?<major>[0-9]+)\.\s*(?<minor>[0-9]+))",
                 RegexOptions.Multiline))
             {
-                rc.Append(m.Groups["name"])
-                    .Append('=')
-                    .Append(m.Groups["major"])
-                    .Append('.')
-                    .Append(m.Groups["minor"])
-                    .Append(',');
-            }
+                var version = new Version(
+                    int.Parse(match.Groups["major"].Value, CultureInfo.InvariantCulture),
+                    int.Parse(match.Groups["minor"].Value, CultureInfo.InvariantCulture));
 
-            return rc.Length == 0 ? null : rc.ToString();
-        }
+                map.Add(match.Groups["name"].Value, version);
+            }
 
-        private enum Codec
-        {
-            Encoder,
-            Decoder
+            return map;
         }
 
         private IEnumerable<string> GetHwaccelTypes()
@@ -262,7 +285,7 @@ namespace MediaBrowser.MediaEncoding.Encoder
                 return Enumerable.Empty<string>();
             }
 
-            var found = output.Split(new char[] {'\r','\n'}, StringSplitOptions.RemoveEmptyEntries).Skip(1).Distinct().ToList();
+            var found = output.Split(new char[] { '\r', '\n' }, StringSplitOptions.RemoveEmptyEntries).Skip(1).Distinct().ToList();
             _logger.LogInformation("Available hwaccel types: {Types}", found);
 
             return found;
@@ -286,7 +309,7 @@ namespace MediaBrowser.MediaEncoding.Encoder
                 return Enumerable.Empty<string>();
             }
 
-            var required = codec == Codec.Encoder ? requiredEncoders : requiredDecoders;
+            var required = codec == Codec.Encoder ? _requiredEncoders : _requiredDecoders;
 
             var found = Regex
                 .Matches(output, @"^\s\S{6}\s(?<codec>[\w|-]+)\s+.+$", RegexOptions.Multiline)
diff --git a/MediaBrowser.MediaEncoding/Encoder/EncodingUtils.cs b/MediaBrowser.MediaEncoding/Encoder/EncodingUtils.cs
index d4aede572..63310fdf6 100644
--- a/MediaBrowser.MediaEncoding/Encoder/EncodingUtils.cs
+++ b/MediaBrowser.MediaEncoding/Encoder/EncodingUtils.cs
@@ -1,4 +1,8 @@
+#pragma warning disable CS1591
+
+using System;
 using System.Collections.Generic;
+using System.Globalization;
 using System.Linq;
 using MediaBrowser.Model.MediaInfo;
 
@@ -12,7 +16,7 @@ namespace MediaBrowser.MediaEncoding.Encoder
             {
                 var url = inputFiles[0];
 
-                return string.Format("\"{0}\"", url);
+                return string.Format(CultureInfo.InvariantCulture, "\"{0}\"", url);
             }
 
             return GetConcatInputArgument(inputFiles);
@@ -31,7 +35,7 @@ namespace MediaBrowser.MediaEncoding.Encoder
             {
                 var files = string.Join("|", inputFiles.Select(NormalizePath));
 
-                return string.Format("concat:\"{0}\"", files);
+                return string.Format(CultureInfo.InvariantCulture, "concat:\"{0}\"", files);
             }
 
             // Determine the input path for video files
@@ -45,15 +49,15 @@ namespace MediaBrowser.MediaEncoding.Encoder
         /// <returns>System.String.</returns>
         private static string GetFileInputArgument(string path)
         {
-            if (path.IndexOf("://") != -1)
+            if (path.IndexOf("://", StringComparison.Ordinal) != -1)
             {
-                return string.Format("\"{0}\"", path);
+                return string.Format(CultureInfo.InvariantCulture, "\"{0}\"", path);
             }
 
             // Quotes are valid path characters in linux and they need to be escaped here with a leading \
             path = NormalizePath(path);
 
-            return string.Format("file:\"{0}\"", path);
+            return string.Format(CultureInfo.InvariantCulture, "file:\"{0}\"", path);
         }
 
         /// <summary>
@@ -64,7 +68,7 @@ namespace MediaBrowser.MediaEncoding.Encoder
         private static string NormalizePath(string path)
         {
             // Quotes are valid path characters in linux and they need to be escaped here with a leading \
-            return path.Replace("\"", "\\\"");
+            return path.Replace("\"", "\\\"", StringComparison.Ordinal);
         }
     }
 }
diff --git a/MediaBrowser.MediaEncoding/Encoder/MediaEncoder.cs b/MediaBrowser.MediaEncoding/Encoder/MediaEncoder.cs
index 62fdbc618..5a3a9185d 100644
--- a/MediaBrowser.MediaEncoding/Encoder/MediaEncoder.cs
+++ b/MediaBrowser.MediaEncoding/Encoder/MediaEncoder.cs
@@ -1,5 +1,8 @@
+#pragma warning disable CS1591
+
 using System;
 using System.Collections.Generic;
+using System.Diagnostics;
 using System.Globalization;
 using System.IO;
 using System.Linq;
@@ -9,6 +12,7 @@ using System.Threading;
 using System.Threading.Tasks;
 using MediaBrowser.Common.Configuration;
 using MediaBrowser.Common.Extensions;
+using MediaBrowser.Common.Json;
 using MediaBrowser.Controller.Configuration;
 using MediaBrowser.Controller.MediaEncoding;
 using MediaBrowser.MediaEncoding.Probing;
@@ -19,9 +23,8 @@ using MediaBrowser.Model.Globalization;
 using MediaBrowser.Model.IO;
 using MediaBrowser.Model.MediaInfo;
 using MediaBrowser.Model.System;
-using Microsoft.Extensions.Logging;
-using System.Diagnostics;
 using Microsoft.Extensions.Configuration;
+using Microsoft.Extensions.Logging;
 
 namespace MediaBrowser.MediaEncoding.Encoder
 {
@@ -35,6 +38,11 @@ namespace MediaBrowser.MediaEncoding.Encoder
         /// </summary>
         internal const int DefaultImageExtractionTimeout = 5000;
 
+        /// <summary>
+        /// The us culture.
+        /// </summary>
+        private readonly CultureInfo _usCulture = new CultureInfo("en-US");
+
         private readonly ILogger<MediaEncoder> _logger;
         private readonly IServerConfigurationManager _configurationManager;
         private readonly IFileSystem _fileSystem;
@@ -47,6 +55,13 @@ namespace MediaBrowser.MediaEncoding.Encoder
         private readonly object _runningProcessesLock = new object();
         private readonly List<ProcessWrapper> _runningProcesses = new List<ProcessWrapper>();
 
+        // MediaEncoder is registered as a Singleton
+        private readonly JsonSerializerOptions _jsonSerializerOptions;
+
+        private List<string> _encoders = new List<string>();
+        private List<string> _decoders = new List<string>();
+        private List<string> _hwaccels = new List<string>();
+
         private string _ffmpegPath = string.Empty;
         private string _ffprobePath;
 
@@ -64,6 +79,7 @@ namespace MediaBrowser.MediaEncoding.Encoder
             _localization = localization;
             _encodingHelperFactory = encodingHelperFactory;
             _startupOptionFFmpegPath = config.GetValue<string>(Controller.Extensions.ConfigurationExtensions.FfmpegPathKey) ?? string.Empty;
+            _jsonSerializerOptions = JsonDefaults.GetOptions();
         }
 
         private EncodingHelper EncodingHelper => _encodingHelperFactory.Value;
@@ -77,7 +93,7 @@ namespace MediaBrowser.MediaEncoding.Encoder
         /// <summary>
         /// Run at startup or if the user removes a Custom path from transcode page.
         /// Sets global variables FFmpegPath.
-        /// Precedence is: Config > CLI > $PATH
+        /// Precedence is: Config > CLI > $PATH.
         /// </summary>
         public void SetFFmpegPath()
         {
@@ -122,8 +138,8 @@ namespace MediaBrowser.MediaEncoding.Encoder
         /// Triggered from the Settings > Transcoding UI page when users submits Custom FFmpeg path to use.
         /// Only write the new path to xml if it exists.  Do not perform validation checks on ffmpeg here.
         /// </summary>
-        /// <param name="path"></param>
-        /// <param name="pathType"></param>
+        /// <param name="path">The path.</param>
+        /// <param name="pathType">The path type.</param>
         public void UpdateEncoderPath(string path, string pathType)
         {
             string newPath;
@@ -168,8 +184,8 @@ namespace MediaBrowser.MediaEncoding.Encoder
         /// If checks pass, global variable FFmpegPath and EncoderLocation are updated.
         /// </summary>
         /// <param name="path">FQPN to test.</param>
-        /// <param name="location">Location (External, Custom, System) of tool</param>
-        /// <returns></returns>
+        /// <param name="location">Location (External, Custom, System) of tool.</param>
+        /// <returns><c>true</c> if the version validation succeeded; otherwise, <c>false</c>.</returns>
         private bool ValidatePath(string path, FFmpegLocation location)
         {
             bool rc = false;
@@ -185,9 +201,6 @@ namespace MediaBrowser.MediaEncoding.Encoder
                         _logger.LogWarning("FFmpeg: {Location}: Failed version check: {Path}", location, path);
                     }
 
-                    // ToDo - Enable the ffmpeg validator.  At the moment any version can be used.
-                    rc = true;
-
                     _ffmpegPath = path;
                     EncoderLocation = location;
                 }
@@ -221,8 +234,8 @@ namespace MediaBrowser.MediaEncoding.Encoder
         /// <summary>
         /// Search the system $PATH environment variable looking for given filename.
         /// </summary>
-        /// <param name="fileName"></param>
-        /// <returns></returns>
+        /// <param name="fileName">The filename.</param>
+        /// <returns>The full path to the file.</returns>
         private string ExistsOnSystemPath(string fileName)
         {
             var inJellyfinPath = GetEncoderPathFromDirectory(AppContext.BaseDirectory, fileName, recursive: true);
@@ -246,25 +259,19 @@ namespace MediaBrowser.MediaEncoding.Encoder
             return null;
         }
 
-        private List<string> _encoders = new List<string>();
         public void SetAvailableEncoders(IEnumerable<string> list)
         {
             _encoders = list.ToList();
-            // _logger.Info("Supported encoders: {0}", string.Join(",", list.ToArray()));
         }
 
-        private List<string> _decoders = new List<string>();
         public void SetAvailableDecoders(IEnumerable<string> list)
         {
             _decoders = list.ToList();
-            // _logger.Info("Supported decoders: {0}", string.Join(",", list.ToArray()));
         }
 
-        private List<string> _hwaccels = new List<string>();
         public void SetAvailableHwaccels(IEnumerable<string> list)
         {
             _hwaccels = list.ToList();
-            //_logger.Info("Supported hwaccels: {0}", string.Join(",", list.ToArray()));
         }
 
         public bool SupportsEncoder(string encoder)
@@ -332,8 +339,16 @@ namespace MediaBrowser.MediaEncoding.Encoder
 
             var forceEnableLogging = request.MediaSource.Protocol != MediaProtocol.File;
 
-            return GetMediaInfoInternal(GetInputArgument(inputFiles, request.MediaSource.Protocol), request.MediaSource.Path, request.MediaSource.Protocol, extractChapters,
-                probeSize, request.MediaType == DlnaProfileType.Audio, request.MediaSource.VideoType, forceEnableLogging, cancellationToken);
+            return GetMediaInfoInternal(
+                GetInputArgument(inputFiles, request.MediaSource.Protocol),
+                request.MediaSource.Path,
+                request.MediaSource.Protocol,
+                extractChapters,
+                probeSize,
+                request.MediaType == DlnaProfileType.Audio,
+                request.MediaSource.VideoType,
+                forceEnableLogging,
+                cancellationToken);
         }
 
         /// <summary>
@@ -342,7 +357,7 @@ namespace MediaBrowser.MediaEncoding.Encoder
         /// <param name="inputFiles">The input files.</param>
         /// <param name="protocol">The protocol.</param>
         /// <returns>System.String.</returns>
-        /// <exception cref="ArgumentException">Unrecognized InputType</exception>
+        /// <exception cref="ArgumentException">Unrecognized InputType.</exception>
         public string GetInputArgument(IReadOnlyList<string> inputFiles, MediaProtocol protocol)
             => EncodingUtils.GetInputArgument(inputFiles, protocol);
 
@@ -350,7 +365,8 @@ namespace MediaBrowser.MediaEncoding.Encoder
         /// Gets the media info internal.
         /// </summary>
         /// <returns>Task{MediaInfoResult}.</returns>
-        private async Task<MediaInfo> GetMediaInfoInternal(string inputPath,
+        private async Task<MediaInfo> GetMediaInfoInternal(
+            string inputPath,
             string primaryPath,
             MediaProtocol protocol,
             bool extractChapters,
@@ -363,7 +379,7 @@ namespace MediaBrowser.MediaEncoding.Encoder
             var args = extractChapters
                 ? "{0} -i {1} -threads 0 -v warning -print_format json -show_streams -show_chapters -show_format"
                 : "{0} -i {1} -threads 0 -v warning -print_format json -show_streams -show_format";
-            args = string.Format(args, probeSizeArgument, inputPath).Trim();
+            args = string.Format(CultureInfo.InvariantCulture, args, probeSizeArgument, inputPath).Trim();
 
             var process = new Process
             {
@@ -378,7 +394,6 @@ namespace MediaBrowser.MediaEncoding.Encoder
                     FileName = _ffprobePath,
                     Arguments = args,
 
-
                     WindowStyle = ProcessWindowStyle.Hidden,
                     ErrorDialog = false,
                 },
@@ -404,6 +419,7 @@ namespace MediaBrowser.MediaEncoding.Encoder
                 {
                     result = await JsonSerializer.DeserializeAsync<InternalMediaInfoResult>(
                                         process.StandardOutput.BaseStream,
+                                        _jsonSerializerOptions,
                                         cancellationToken: cancellationToken).ConfigureAwait(false);
                 }
                 catch
@@ -439,11 +455,6 @@ namespace MediaBrowser.MediaEncoding.Encoder
             }
         }
 
-        /// <summary>
-        /// The us culture.
-        /// </summary>
-        protected readonly CultureInfo UsCulture = new CultureInfo("en-US");
-
         public Task<string> ExtractAudioImage(string path, int? imageStreamIndex, CancellationToken cancellationToken)
         {
             return ExtractImage(new[] { path }, null, null, imageStreamIndex, MediaProtocol.File, true, null, null, cancellationToken);
@@ -459,8 +470,16 @@ namespace MediaBrowser.MediaEncoding.Encoder
             return ExtractImage(inputFiles, container, imageStream, imageStreamIndex, protocol, false, null, null, cancellationToken);
         }
 
-        private async Task<string> ExtractImage(string[] inputFiles, string container, MediaStream videoStream, int? imageStreamIndex, MediaProtocol protocol, bool isAudio,
-            Video3DFormat? threedFormat, TimeSpan? offset, CancellationToken cancellationToken)
+        private async Task<string> ExtractImage(
+            string[] inputFiles,
+            string container,
+            MediaStream videoStream,
+            int? imageStreamIndex,
+            MediaProtocol protocol,
+            bool isAudio,
+            Video3DFormat? threedFormat,
+            TimeSpan? offset,
+            CancellationToken cancellationToken)
         {
             var inputArgument = GetInputArgument(inputFiles, protocol);
 
@@ -536,8 +555,8 @@ namespace MediaBrowser.MediaEncoding.Encoder
             // Use ffmpeg to sample 100 (we can drop this if required using thumbnail=50 for 50 frames) frames and pick the best thumbnail. Have a fall back just in case.
             var thumbnail = enableThumbnail ? ",thumbnail=24" : string.Empty;
 
-            var args = useIFrame ? string.Format("-i {0}{3} -threads 0 -v quiet -vframes 1 -vf \"{2}{4}\" -f image2 \"{1}\"", inputPath, tempExtractPath, vf, mapArg, thumbnail) :
-                string.Format("-i {0}{3} -threads 0 -v quiet -vframes 1 -vf \"{2}\" -f image2 \"{1}\"", inputPath, tempExtractPath, vf, mapArg);
+            var args = useIFrame ? string.Format(CultureInfo.InvariantCulture, "-i {0}{3} -threads 0 -v quiet -vframes 1 -vf \"{2}{4}\" -f image2 \"{1}\"", inputPath, tempExtractPath, vf, mapArg, thumbnail) :
+                string.Format(CultureInfo.InvariantCulture, "-i {0}{3} -threads 0 -v quiet -vframes 1 -vf \"{2}\" -f image2 \"{1}\"", inputPath, tempExtractPath, vf, mapArg);
 
             var probeSizeArgument = EncodingHelper.GetProbeSizeArgument(1);
             var analyzeDurationArgument = EncodingHelper.GetAnalyzeDurationArgument(1);
@@ -554,7 +573,7 @@ namespace MediaBrowser.MediaEncoding.Encoder
 
             if (offset.HasValue)
             {
-                args = string.Format("-ss {0} ", GetTimeParameter(offset.Value)) + args;
+                args = string.Format(CultureInfo.InvariantCulture, "-ss {0} ", GetTimeParameter(offset.Value)) + args;
             }
 
             if (videoStream != null)
@@ -625,7 +644,7 @@ namespace MediaBrowser.MediaEncoding.Encoder
 
                 if (exitCode == -1 || !file.Exists || file.Length == 0)
                 {
-                    var msg = string.Format("ffmpeg image extraction failed for {0}", inputPath);
+                    var msg = string.Format(CultureInfo.InvariantCulture, "ffmpeg image extraction failed for {0}", inputPath);
 
                     _logger.LogError(msg);
 
@@ -645,7 +664,7 @@ namespace MediaBrowser.MediaEncoding.Encoder
 
         public string GetTimeParameter(TimeSpan time)
         {
-            return time.ToString(@"hh\:mm\:ss\.fff", UsCulture);
+            return time.ToString(@"hh\:mm\:ss\.fff", _usCulture);
         }
 
         public async Task ExtractVideoImagesOnInterval(
@@ -662,19 +681,19 @@ namespace MediaBrowser.MediaEncoding.Encoder
         {
             var inputArgument = GetInputArgument(inputFiles, protocol);
 
-            var vf = "fps=fps=1/" + interval.TotalSeconds.ToString(UsCulture);
+            var vf = "fps=fps=1/" + interval.TotalSeconds.ToString(_usCulture);
 
             if (maxWidth.HasValue)
             {
-                var maxWidthParam = maxWidth.Value.ToString(UsCulture);
+                var maxWidthParam = maxWidth.Value.ToString(_usCulture);
 
-                vf += string.Format(",scale=min(iw\\,{0}):trunc(ow/dar/2)*2", maxWidthParam);
+                vf += string.Format(CultureInfo.InvariantCulture, ",scale=min(iw\\,{0}):trunc(ow/dar/2)*2", maxWidthParam);
             }
 
             Directory.CreateDirectory(targetDirectory);
             var outputPath = Path.Combine(targetDirectory, filenamePrefix + "%05d.jpg");
 
-            var args = string.Format("-i {0} -threads 0 -v quiet -vf \"{2}\" -f image2 \"{1}\"", inputArgument, outputPath, vf);
+            var args = string.Format(CultureInfo.InvariantCulture, "-i {0} -threads 0 -v quiet -vf \"{2}\" -f image2 \"{1}\"", inputArgument, outputPath, vf);
 
             var probeSizeArgument = EncodingHelper.GetProbeSizeArgument(1);
             var analyzeDurationArgument = EncodingHelper.GetAnalyzeDurationArgument(1);
@@ -774,7 +793,7 @@ namespace MediaBrowser.MediaEncoding.Encoder
 
                 if (exitCode == -1)
                 {
-                    var msg = string.Format("ffmpeg image extraction failed for {0}", inputArgument);
+                    var msg = string.Format(CultureInfo.InvariantCulture, "ffmpeg image extraction failed for {0}", inputArgument);
 
                     _logger.LogError(msg);
 
@@ -840,7 +859,7 @@ namespace MediaBrowser.MediaEncoding.Encoder
             // https://ffmpeg.org/ffmpeg-filters.html#Notes-on-filtergraph-escaping
             // We need to double escape
 
-            return path.Replace('\\', '/').Replace(":", "\\:").Replace("'", "'\\\\\\''");
+            return path.Replace('\\', '/').Replace(":", "\\:", StringComparison.Ordinal).Replace("'", "'\\\\\\''", StringComparison.Ordinal);
         }
 
         /// <inheritdoc />
@@ -859,6 +878,7 @@ namespace MediaBrowser.MediaEncoding.Encoder
             if (dispose)
             {
                 StopProcesses();
+                _thumbnailResourcePool.Dispose();
             }
         }