Pushing missing changes

1 files changed, 992 insertions, 0 deletions

diff --git a/MediaBrowser.Api/Streaming/BaseStreamingHandler.cs b/MediaBrowser.Api/Streaming/BaseStreamingHandler.cs
new file mode 100644
index 000000000..417f1513c
--- /dev/null
+++ b/MediaBrowser.Api/Streaming/BaseStreamingHandler.cs
@@ -0,0 +1,992 @@
+using MediaBrowser.Common.Extensions;
+using MediaBrowser.Common.IO;
+using MediaBrowser.Common.Net;
+using MediaBrowser.Common.Net.Handlers;
+using MediaBrowser.Controller;
+using MediaBrowser.Controller.Entities;
+using MediaBrowser.Controller.Entities.Audio;
+using MediaBrowser.Controller.Library;
+using MediaBrowser.Model.Drawing;
+using MediaBrowser.Model.DTO;
+using MediaBrowser.Model.Entities;
+using System;
+using System.ComponentModel;
+using System.Diagnostics;
+using System.IO;
+using System.Linq;
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace MediaBrowser.Api.Streaming
+{
+    /// <summary>
+    /// Represents a common base class for both progressive and hls streaming
+    /// </summary>
+    /// <typeparam name="TBaseItemType">The type of the T base item type.</typeparam>
+    public abstract class BaseStreamingHandler<TBaseItemType> : BaseHandler<Kernel>
+        where TBaseItemType : BaseItem, IHasMediaStreams, new()
+    {
+        /// <summary>
+        /// Gets the command line arguments.
+        /// </summary>
+        /// <param name="outputPath">The output path.</param>
+        /// <param name="isoMount">The iso mount.</param>
+        /// <returns>System.String.</returns>
+        protected abstract string GetCommandLineArguments(string outputPath, IIsoMount isoMount);
+
+        /// <summary>
+        /// Gets or sets the log file stream.
+        /// </summary>
+        /// <value>The log file stream.</value>
+        protected Stream LogFileStream { get; set; }
+
+        /// <summary>
+        /// Gets the type of the transcoding job.
+        /// </summary>
+        /// <value>The type of the transcoding job.</value>
+        protected abstract TranscodingJobType TranscodingJobType { get; }
+
+        /// <summary>
+        /// Gets the output file extension.
+        /// </summary>
+        /// <value>The output file extension.</value>
+        protected string OutputFileExtension
+        {
+            get
+            {
+                return Path.GetExtension(HttpListenerContext.Request.Url.LocalPath);
+            }
+        }
+
+        /// <summary>
+        /// Gets the output file path.
+        /// </summary>
+        /// <value>The output file path.</value>
+        protected string OutputFilePath
+        {
+            get
+            {
+                return Path.Combine(Kernel.ApplicationPaths.FFMpegStreamCachePath, GetCommandLineArguments("dummy\\dummy", null).GetMD5() + OutputFileExtension.ToLower());
+            }
+        }
+
+        /// <summary>
+        /// Gets the audio codec to endoce to.
+        /// </summary>
+        /// <value>The audio encoding format.</value>
+        protected virtual AudioCodecs? AudioCodec
+        {
+            get
+            {
+                if (string.IsNullOrEmpty(QueryString["audioCodec"]))
+                {
+                    return null;
+                }
+
+                return (AudioCodecs)Enum.Parse(typeof(AudioCodecs), QueryString["audioCodec"], true);
+            }
+        }
+
+        /// <summary>
+        /// Gets the video encoding codec.
+        /// </summary>
+        /// <value>The video codec.</value>
+        protected VideoCodecs? VideoCodec
+        {
+            get
+            {
+                if (string.IsNullOrEmpty(QueryString["videoCodec"]))
+                {
+                    return null;
+                }
+
+                return (VideoCodecs)Enum.Parse(typeof(VideoCodecs), QueryString["videoCodec"], true);
+            }
+        }
+
+        /// <summary>
+        /// Gets the time, in ticks, in which playback should start
+        /// </summary>
+        /// <value>The start time ticks.</value>
+        protected long? StartTimeTicks
+        {
+            get
+            {
+                string val = QueryString["StartTimeTicks"];
+
+                if (string.IsNullOrEmpty(val))
+                {
+                    return null;
+                }
+
+                return long.Parse(val);
+            }
+        }
+
+        /// <summary>
+        /// The fast seek offset seconds
+        /// </summary>
+        private const int FastSeekOffsetSeconds = 1;
+
+        /// <summary>
+        /// Gets the fast seek command line parameter.
+        /// </summary>
+        /// <value>The fast seek command line parameter.</value>
+        protected string FastSeekCommandLineParameter
+        {
+            get
+            {
+                var time = StartTimeTicks;
+
+                if (time.HasValue)
+                {
+                    var seconds = TimeSpan.FromTicks(time.Value).TotalSeconds - FastSeekOffsetSeconds;
+
+                    if (seconds > 0)
+                    {
+                        return string.Format("-ss {0}", seconds);
+                    }
+                }
+
+                return string.Empty;
+            }
+        }
+
+        /// <summary>
+        /// Gets the slow seek command line parameter.
+        /// </summary>
+        /// <value>The slow seek command line parameter.</value>
+        protected string SlowSeekCommandLineParameter
+        {
+            get
+            {
+                var time = StartTimeTicks;
+
+                if (time.HasValue)
+                {
+                    if (TimeSpan.FromTicks(time.Value).TotalSeconds - FastSeekOffsetSeconds > 0)
+                    {
+                        return string.Format(" -ss {0}", FastSeekOffsetSeconds);
+                    }
+                }
+
+                return string.Empty;
+            }
+        }
+
+        /// <summary>
+        /// Gets the map args.
+        /// </summary>
+        /// <value>The map args.</value>
+        protected virtual string MapArgs
+        {
+            get
+            {
+                var args = string.Empty;
+
+                if (VideoStream != null)
+                {
+                    args += string.Format("-map 0:{0}", VideoStream.Index);
+                }
+                else
+                {
+                    args += "-map -0:v";
+                }
+
+                if (AudioStream != null)
+                {
+                    args += string.Format(" -map 0:{0}", AudioStream.Index);
+                }
+                else
+                {
+                    args += " -map -0:a";
+                }
+
+                if (SubtitleStream == null)
+                {
+                    args += " -map -0:s";
+                }
+
+                return args;
+            }
+        }
+
+        /// <summary>
+        /// The _library item
+        /// </summary>
+        private TBaseItemType _libraryItem;
+        /// <summary>
+        /// Gets the library item that will be played, if any
+        /// </summary>
+        /// <value>The library item.</value>
+        protected TBaseItemType LibraryItem
+        {
+            get
+            {
+                return _libraryItem ?? (_libraryItem = (TBaseItemType)DtoBuilder.GetItemByClientId(QueryString["id"]));
+            }
+        }
+
+        /// <summary>
+        /// Gets or sets the iso mount.
+        /// </summary>
+        /// <value>The iso mount.</value>
+        private IIsoMount IsoMount { get; set; }
+
+        /// <summary>
+        /// The _audio stream
+        /// </summary>
+        private MediaStream _audioStream;
+        /// <summary>
+        /// Gets the audio stream.
+        /// </summary>
+        /// <value>The audio stream.</value>
+        protected MediaStream AudioStream
+        {
+            get { return _audioStream ?? (_audioStream = GetMediaStream(AudioStreamIndex, MediaStreamType.Audio)); }
+        }
+
+        /// <summary>
+        /// The _video stream
+        /// </summary>
+        private MediaStream _videoStream;
+        /// <summary>
+        /// Gets the video stream.
+        /// </summary>
+        /// <value>The video stream.</value>
+        protected MediaStream VideoStream
+        {
+            get
+            {
+                // No video streams here
+                // Need to make this check to make sure we don't pickup embedded image streams (which are listed in the file as type video)
+                if (LibraryItem is Audio)
+                {
+                    return null;
+                }
+
+                return _videoStream ?? (_videoStream = GetMediaStream(VideoStreamIndex, MediaStreamType.Video));
+            }
+        }
+
+        /// <summary>
+        /// The subtitle stream
+        /// </summary>
+        private MediaStream _subtitleStream;
+        /// <summary>
+        /// Gets the subtitle stream.
+        /// </summary>
+        /// <value>The subtitle stream.</value>
+        protected MediaStream SubtitleStream
+        {
+            get
+            {
+                // No subtitle streams here
+                if (LibraryItem is Audio)
+                {
+                    return null;
+                }
+
+                return _subtitleStream ?? (_subtitleStream = GetMediaStream(SubtitleStreamIndex, MediaStreamType.Subtitle, false));
+            }
+        }
+
+        /// <summary>
+        /// Determines which stream will be used for playback
+        /// </summary>
+        /// <param name="desiredIndex">Index of the desired.</param>
+        /// <param name="type">The type.</param>
+        /// <param name="returnFirstIfNoIndex">if set to <c>true</c> [return first if no index].</param>
+        /// <returns>MediaStream.</returns>
+        private MediaStream GetMediaStream(int? desiredIndex, MediaStreamType type, bool returnFirstIfNoIndex = true)
+        {
+            var streams = LibraryItem.MediaStreams.Where(s => s.Type == type).ToList();
+
+            if (desiredIndex.HasValue)
+            {
+                var stream = streams.FirstOrDefault(s => s.Index == desiredIndex.Value);
+
+                if (stream != null)
+                {
+                    return stream;
+                }
+            }
+
+            // Just return the first one
+            return returnFirstIfNoIndex ? streams.FirstOrDefault() : null;
+        }
+
+        /// <summary>
+        /// Gets the response info.
+        /// </summary>
+        /// <returns>Task{ResponseInfo}.</returns>
+        protected override Task<ResponseInfo> GetResponseInfo()
+        {
+            var info = new ResponseInfo
+            {
+                ContentType = MimeTypes.GetMimeType(OutputFilePath),
+                CompressResponse = false
+            };
+
+            return Task.FromResult(info);
+        }
+
+        /// <summary>
+        /// Gets the client's desired audio bitrate
+        /// </summary>
+        /// <value>The audio bit rate.</value>
+        protected int? AudioBitRate
+        {
+            get
+            {
+                var val = QueryString["AudioBitRate"];
+
+                if (string.IsNullOrEmpty(val))
+                {
+                    return null;
+                }
+
+                return int.Parse(val);
+            }
+        }
+
+        /// <summary>
+        /// Gets the client's desired video bitrate
+        /// </summary>
+        /// <value>The video bit rate.</value>
+        protected int? VideoBitRate
+        {
+            get
+            {
+                var val = QueryString["VideoBitRate"];
+
+                if (string.IsNullOrEmpty(val))
+                {
+                    return null;
+                }
+
+                return int.Parse(val);
+            }
+        }
+
+        /// <summary>
+        /// Gets the desired audio stream index
+        /// </summary>
+        /// <value>The index of the audio stream.</value>
+        private int? AudioStreamIndex
+        {
+            get
+            {
+                var val = QueryString["AudioStreamIndex"];
+
+                if (string.IsNullOrEmpty(val))
+                {
+                    return null;
+                }
+
+                return int.Parse(val);
+            }
+        }
+
+        /// <summary>
+        /// Gets the desired video stream index
+        /// </summary>
+        /// <value>The index of the video stream.</value>
+        private int? VideoStreamIndex
+        {
+            get
+            {
+                var val = QueryString["VideoStreamIndex"];
+
+                if (string.IsNullOrEmpty(val))
+                {
+                    return null;
+                }
+
+                return int.Parse(val);
+            }
+        }
+
+        /// <summary>
+        /// Gets the desired subtitle stream index
+        /// </summary>
+        /// <value>The index of the subtitle stream.</value>
+        private int? SubtitleStreamIndex
+        {
+            get
+            {
+                var val = QueryString["SubtitleStreamIndex"];
+
+                if (string.IsNullOrEmpty(val))
+                {
+                    return null;
+                }
+
+                return int.Parse(val);
+            }
+        }
+
+        /// <summary>
+        /// Gets the audio channels.
+        /// </summary>
+        /// <value>The audio channels.</value>
+        public int? AudioChannels
+        {
+            get
+            {
+                var val = QueryString["audiochannels"];
+
+                if (string.IsNullOrEmpty(val))
+                {
+                    return null;
+                }
+
+                return int.Parse(val);
+            }
+        }
+
+        /// <summary>
+        /// Gets the audio sample rate.
+        /// </summary>
+        /// <value>The audio sample rate.</value>
+        public int? AudioSampleRate
+        {
+            get
+            {
+                var val = QueryString["audiosamplerate"];
+
+                if (string.IsNullOrEmpty(val))
+                {
+                    return 44100;
+                }
+
+                return int.Parse(val);
+            }
+        }
+
+        /// <summary>
+        /// If we're going to put a fixed size on the command line, this will calculate it
+        /// </summary>
+        /// <param name="outputVideoCodec">The output video codec.</param>
+        /// <returns>System.String.</returns>
+        protected string GetOutputSizeParam(string outputVideoCodec)
+        {
+            // http://sonnati.wordpress.com/2012/10/19/ffmpeg-the-swiss-army-knife-of-internet-streaming-part-vi/
+
+            var assSubtitleParam = string.Empty;
+
+            if (SubtitleStream != null)
+            {
+                if (SubtitleStream.Codec.IndexOf("srt", StringComparison.OrdinalIgnoreCase) != -1 || SubtitleStream.Codec.IndexOf("subrip", StringComparison.OrdinalIgnoreCase) != -1)
+                {
+                    assSubtitleParam = GetTextSubtitleParam(SubtitleStream);
+                }
+            }
+
+            // If fixed dimensions were supplied
+            if (Width.HasValue && Height.HasValue)
+            {
+                return string.Format(" -vf \"scale={0}:{1}{2}\"", Width.Value, Height.Value, assSubtitleParam);
+            }
+
+            var isH264Output = outputVideoCodec.Equals("libx264", StringComparison.OrdinalIgnoreCase);
+
+            // If a fixed width was requested
+            if (Width.HasValue)
+            {
+                return isH264Output ?
+                    string.Format(" -vf \"scale={0}:trunc(ow/a/2)*2{1}\"", Width.Value, assSubtitleParam) :
+                    string.Format(" -vf \"scale={0}:-1{1}\"", Width.Value, assSubtitleParam);
+            }
+
+            // If a max width was requested
+            if (MaxWidth.HasValue && !MaxHeight.HasValue)
+            {
+                return isH264Output ?
+                    string.Format(" -vf \"scale=min(iw\\,{0}):trunc(ow/a/2)*2{1}\"", MaxWidth.Value, assSubtitleParam) :
+                    string.Format(" -vf \"scale=min(iw\\,{0}):-1{1}\"", MaxWidth.Value, assSubtitleParam);
+            }
+
+            // Need to perform calculations manually
+
+            // Try to account for bad media info
+            var currentHeight = VideoStream.Height ?? MaxHeight ?? Height ?? 0;
+            var currentWidth = VideoStream.Width ?? MaxWidth ?? Width ?? 0;
+
+            var outputSize = DrawingUtils.Resize(currentWidth, currentHeight, Width, Height, MaxWidth, MaxHeight);
+
+            // If we're encoding with libx264, it can't handle odd numbered widths or heights, so we'll have to fix that
+            if (isH264Output)
+            {
+                return string.Format(" -vf \"scale=trunc({0}/2)*2:trunc({1}/2)*2{2}\"", outputSize.Width, outputSize.Height, assSubtitleParam);
+            }
+
+            // Otherwise use -vf scale since ffmpeg will ensure internally that the aspect ratio is preserved
+            return string.Format(" -vf \"scale={0}:-1{1}\"", Convert.ToInt32(outputSize.Width), assSubtitleParam);
+        }
+
+        /// <summary>
+        /// Gets the text subtitle param.
+        /// </summary>
+        /// <param name="subtitleStream">The subtitle stream.</param>
+        /// <returns>System.String.</returns>
+        protected string GetTextSubtitleParam(MediaStream subtitleStream)
+        {
+            var path = subtitleStream.IsExternal ? GetConvertedAssPath(subtitleStream) : GetExtractedAssPath(subtitleStream);
+
+            if (string.IsNullOrEmpty(path))
+            {
+                return string.Empty;
+            }
+
+            var param = string.Format(",ass={0}", path);
+
+            var time = StartTimeTicks;
+
+            if (time.HasValue)
+            {
+                var seconds = Convert.ToInt32(TimeSpan.FromTicks(time.Value).TotalSeconds);
+                param += string.Format(",setpts=PTS-{0}/TB", seconds);
+            }
+
+            return param;
+        }
+
+        /// <summary>
+        /// Gets the extracted ass path.
+        /// </summary>
+        /// <param name="subtitleStream">The subtitle stream.</param>
+        /// <returns>System.String.</returns>
+        private string GetExtractedAssPath(MediaStream subtitleStream)
+        {
+            var video = LibraryItem as Video;
+
+            var path = Kernel.FFMpegManager.GetSubtitleCachePath(video, subtitleStream.Index, ".ass");
+
+            if (!File.Exists(path))
+            {
+                var success = Kernel.FFMpegManager.ExtractTextSubtitle(video, subtitleStream.Index, path, CancellationToken.None).Result;
+
+                if (!success)
+                {
+                    return null;
+                }
+            }
+
+            return path;
+        }
+
+        /// <summary>
+        /// Gets the converted ass path.
+        /// </summary>
+        /// <param name="subtitleStream">The subtitle stream.</param>
+        /// <returns>System.String.</returns>
+        private string GetConvertedAssPath(MediaStream subtitleStream)
+        {
+            var video = LibraryItem as Video;
+
+            var path = Kernel.FFMpegManager.GetSubtitleCachePath(video, subtitleStream.Index, ".ass");
+
+            if (!File.Exists(path))
+            {
+                var success = Kernel.FFMpegManager.ConvertTextSubtitle(subtitleStream, path, CancellationToken.None).Result;
+
+                if (!success)
+                {
+                    return null;
+                }
+            }
+
+            return path;
+        }
+
+        /// <summary>
+        /// Gets the internal graphical subtitle param.
+        /// </summary>
+        /// <param name="subtitleStream">The subtitle stream.</param>
+        /// <param name="videoCodec">The video codec.</param>
+        /// <returns>System.String.</returns>
+        protected string GetInternalGraphicalSubtitleParam(MediaStream subtitleStream, string videoCodec)
+        {
+            var outputSizeParam = string.Empty;
+
+            // Add resolution params, if specified
+            if (Width.HasValue || Height.HasValue || MaxHeight.HasValue || MaxWidth.HasValue)
+            {
+                outputSizeParam = GetOutputSizeParam(videoCodec).TrimEnd('"');
+                outputSizeParam = "," + outputSizeParam.Substring(outputSizeParam.IndexOf("scale", StringComparison.OrdinalIgnoreCase));
+            }
+
+            return string.Format(" -filter_complex \"[0:{0}]format=yuva444p,lut=u=128:v=128:y=gammaval(.3)[sub] ; [0:0] [sub] overlay{1}\"", subtitleStream.Index, outputSizeParam);
+        }
+
+        /// <summary>
+        /// Gets the fixed output video height, in pixels
+        /// </summary>
+        /// <value>The height.</value>
+        protected int? Height
+        {
+            get
+            {
+                string val = QueryString["height"];
+
+                if (string.IsNullOrEmpty(val))
+                {
+                    return null;
+                }
+
+                return int.Parse(val);
+            }
+        }
+
+        /// <summary>
+        /// Gets the fixed output video width, in pixels
+        /// </summary>
+        /// <value>The width.</value>
+        protected int? Width
+        {
+            get
+            {
+                string val = QueryString["width"];
+
+                if (string.IsNullOrEmpty(val))
+                {
+                    return null;
+                }
+
+                return int.Parse(val);
+            }
+        }
+
+        /// <summary>
+        /// Gets the maximum output video height, in pixels
+        /// </summary>
+        /// <value>The height of the max.</value>
+        protected int? MaxHeight
+        {
+            get
+            {
+                string val = QueryString["maxheight"];
+
+                if (string.IsNullOrEmpty(val))
+                {
+                    return null;
+                }
+
+                return int.Parse(val);
+            }
+        }
+
+        /// <summary>
+        /// Gets the maximum output video width, in pixels
+        /// </summary>
+        /// <value>The width of the max.</value>
+        protected int? MaxWidth
+        {
+            get
+            {
+                string val = QueryString["maxwidth"];
+
+                if (string.IsNullOrEmpty(val))
+                {
+                    return null;
+                }
+
+                return int.Parse(val);
+            }
+        }
+
+        /// <summary>
+        /// Gets the output video framerate
+        /// </summary>
+        /// <value>The max frame rate.</value>
+        protected float? FrameRate
+        {
+            get
+            {
+                string val = QueryString["framerate"];
+
+                if (string.IsNullOrEmpty(val))
+                {
+                    return null;
+                }
+
+                return float.Parse(val);
+            }
+        }
+
+        /// <summary>
+        /// Gets the number of audio channels to specify on the command line
+        /// </summary>
+        /// <returns>System.Nullable{System.Int32}.</returns>
+        protected int? GetSampleRateParam()
+        {
+            // If the user requested a max value
+            if (AudioSampleRate.HasValue)
+            {
+                return AudioSampleRate.Value;
+            }
+
+            return null;
+        }
+
+        /// <summary>
+        /// Gets the number of audio channels to specify on the command line
+        /// </summary>
+        /// <param name="audioCodec">The audio codec.</param>
+        /// <returns>System.Nullable{System.Int32}.</returns>
+        protected int? GetNumAudioChannelsParam(string audioCodec)
+        {
+            if (AudioStream.Channels > 2)
+            {
+                if (audioCodec.Equals("libvo_aacenc"))
+                {
+                    // libvo_aacenc currently only supports two channel output
+                    return 2;
+                }
+                if (audioCodec.Equals("wmav2"))
+                {
+                    // wmav2 currently only supports two channel output
+                    return 2;
+                }
+            }
+
+            return GetNumAudioChannelsParam();
+        }
+
+        /// <summary>
+        /// Gets the number of audio channels to specify on the command line
+        /// </summary>
+        /// <returns>System.Nullable{System.Int32}.</returns>
+        protected int? GetNumAudioChannelsParam()
+        {
+            // If the user requested a max number of channels
+            if (AudioChannels.HasValue)
+            {
+                return AudioChannels.Value;
+            }
+
+            return null;
+        }
+
+        /// <summary>
+        /// Determines whether the specified stream is H264.
+        /// </summary>
+        /// <param name="stream">The stream.</param>
+        /// <returns><c>true</c> if the specified stream is H264; otherwise, <c>false</c>.</returns>
+        protected bool IsH264(MediaStream stream)
+        {
+            return stream.Codec.IndexOf("264", StringComparison.OrdinalIgnoreCase) != -1 ||
+                   stream.Codec.IndexOf("avc", StringComparison.OrdinalIgnoreCase) != -1;
+        }
+
+        /// <summary>
+        /// Gets the name of the output audio codec
+        /// </summary>
+        /// <returns>System.String.</returns>
+        protected string GetAudioCodec()
+        {
+            if (AudioCodec.HasValue)
+            {
+                if (AudioCodec == AudioCodecs.Aac)
+                {
+                    return "libvo_aacenc";
+                }
+                if (AudioCodec == AudioCodecs.Mp3)
+                {
+                    return "libmp3lame";
+                }
+                if (AudioCodec == AudioCodecs.Vorbis)
+                {
+                    return "libvorbis";
+                }
+                if (AudioCodec == AudioCodecs.Wma)
+                {
+                    return "wmav2";
+                }
+            }
+
+            return "copy";
+        }
+
+        /// <summary>
+        /// Gets the name of the output video codec
+        /// </summary>
+        /// <returns>System.String.</returns>
+        protected string GetVideoCodec()
+        {
+            if (VideoCodec.HasValue)
+            {
+                if (VideoCodec == VideoCodecs.H264)
+                {
+                    return "libx264";
+                }
+                if (VideoCodec == VideoCodecs.Vpx)
+                {
+                    return "libvpx";
+                }
+                if (VideoCodec == VideoCodecs.Wmv)
+                {
+                    return "wmv2";
+                }
+                if (VideoCodec == VideoCodecs.Theora)
+                {
+                    return "libtheora";
+                }
+            }
+
+            return "copy";
+        }
+
+        /// <summary>
+        /// Gets the input argument.
+        /// </summary>
+        /// <param name="isoMount">The iso mount.</param>
+        /// <returns>System.String.</returns>
+        protected string GetInputArgument(IIsoMount isoMount)
+        {
+            return isoMount == null ?
+                Kernel.FFMpegManager.GetInputArgument(LibraryItem) :
+                Kernel.FFMpegManager.GetInputArgument(LibraryItem as Video, IsoMount);
+        }
+
+        /// <summary>
+        /// Starts the FFMPEG.
+        /// </summary>
+        /// <param name="outputPath">The output path.</param>
+        /// <returns>Task.</returns>
+        protected async Task StartFFMpeg(string outputPath)
+        {
+            var video = LibraryItem as Video;
+
+            if (video != null && video.VideoType == VideoType.Iso &&
+                video.IsoType.HasValue && Kernel.IsoManager.CanMount(video.Path))
+            {
+                IsoMount = await Kernel.IsoManager.Mount(video.Path, CancellationToken.None).ConfigureAwait(false);
+            }
+
+            var process = new Process
+            {
+                StartInfo = new ProcessStartInfo
+                {
+                    CreateNoWindow = true,
+                    UseShellExecute = false,
+
+                    // Must consume both stdout and stderr or deadlocks may occur
+                    RedirectStandardOutput = true,
+                    RedirectStandardError = true,
+
+                    FileName = Kernel.FFMpegManager.FFMpegPath,
+                    WorkingDirectory = Path.GetDirectoryName(Kernel.FFMpegManager.FFMpegPath),
+                    Arguments = GetCommandLineArguments(outputPath, IsoMount),
+
+                    WindowStyle = ProcessWindowStyle.Hidden,
+                    ErrorDialog = false
+                },
+
+                EnableRaisingEvents = true
+            };
+
+            Plugin.Instance.OnTranscodeBeginning(outputPath, TranscodingJobType, process);
+
+            Logger.Info(process.StartInfo.FileName + " " + process.StartInfo.Arguments);
+
+            var logFilePath = Path.Combine(Kernel.ApplicationPaths.LogDirectoryPath, "ffmpeg-" + Guid.NewGuid() + ".txt");
+
+            // FFMpeg writes debug/error info to stderr. This is useful when debugging so let's put it in the log directory.
+            LogFileStream = new FileStream(logFilePath, FileMode.Create, FileAccess.Write, FileShare.Read, StreamDefaults.DefaultFileStreamBufferSize, FileOptions.Asynchronous);
+
+            process.Exited += OnFFMpegProcessExited;
+
+            try
+            {
+                process.Start();
+            }
+            catch (Win32Exception ex)
+            {
+                Logger.ErrorException("Error starting ffmpeg", ex);
+
+                Plugin.Instance.OnTranscodeFailedToStart(outputPath, TranscodingJobType);
+
+                process.Exited -= OnFFMpegProcessExited;
+                LogFileStream.Dispose();
+
+                throw;
+            }
+
+            // MUST read both stdout and stderr asynchronously or a deadlock may occurr
+            process.BeginOutputReadLine();
+
+            // Important - don't await the log task or we won't be able to kill ffmpeg when the user stops playback
+            process.StandardError.BaseStream.CopyToAsync(LogFileStream);
+
+            // Wait for the file to exist before proceeeding
+            while (!File.Exists(outputPath))
+            {
+                await Task.Delay(100).ConfigureAwait(false);
+            }
+        }
+
+        /// <summary>
+        /// Processes the exited.
+        /// </summary>
+        /// <param name="sender">The sender.</param>
+        /// <param name="e">The <see cref="EventArgs" /> instance containing the event data.</param>
+        protected void OnFFMpegProcessExited(object sender, EventArgs e)
+        {
+            if (IsoMount != null)
+            {
+                IsoMount.Dispose();
+                IsoMount = null;
+            }
+
+            var outputFilePath = OutputFilePath;
+
+            LogFileStream.Dispose();
+
+            var process = (Process)sender;
+
+            process.Exited -= OnFFMpegProcessExited;
+
+            int? exitCode = null;
+
+            try
+            {
+                exitCode = process.ExitCode;
+                Logger.Info("FFMpeg exited with code {0} for {1}", exitCode.Value, outputFilePath);
+            }
+            catch
+            {
+                Logger.Info("FFMpeg exited with an error for {0}", outputFilePath);
+            }
+
+            process.Dispose();
+
+            Plugin.Instance.OnTranscodingFinished(outputFilePath, TranscodingJobType);
+
+            if (!exitCode.HasValue || exitCode.Value != 0)
+            {
+                Logger.Info("Deleting partial stream file(s) {0}", outputFilePath);
+
+                try
+                {
+                    DeletePartialStreamFiles(outputFilePath);
+                }
+                catch (IOException ex)
+                {
+                    Logger.ErrorException("Error deleting partial stream file(s) {0}", ex, outputFilePath);
+                }
+            }
+            else
+            {
+                Logger.Info("FFMpeg completed and exited normally for {0}", outputFilePath);
+            }
+        }
+
+        /// <summary>
+        /// Deletes the partial stream files.
+        /// </summary>
+        /// <param name="outputFilePath">The output file path.</param>
+        protected abstract void DeletePartialStreamFiles(string outputFilePath);
+    }
+}