private bool InternalTextStreamSupportsExternalStream(MediaStream stream)
        {
            // These usually have styles and fonts that won't convert to text very well
            if (string.Equals(stream.Codec, "ass", StringComparison.OrdinalIgnoreCase))
            {
                return false;
            }

            return true;
        }

        private bool StreamSupportsExternalStream(MediaStream stream)
        {
            if (stream.IsExternal)
            {
                return true;
            }

            if (stream.IsTextSubtitleStream)
            {
                return true;
            }

            return false;
        }

        private bool StreamSupportsExternalStream(MediaStream stream)
        {
            if (stream.IsExternal)
            {
                return true;
            }

            if (stream.IsTextSubtitleStream)
            {
                if (string.Equals(stream.Codec, "ass", StringComparison.OrdinalIgnoreCase))
                {
                    return false;
                }
                return true;
            }

            return false;
        }

 /// <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;
 }

        private bool CanStreamCopyAudio(StreamRequest request, MediaStream audioStream, List<string> supportedAudioCodecs)
        {
            // Source and target codecs must match
            if (string.IsNullOrEmpty(audioStream.Codec) || !supportedAudioCodecs.Contains(audioStream.Codec, StringComparer.OrdinalIgnoreCase))
            {
                return false;
            }

            // Video bitrate must fall within requested value
            if (request.AudioBitRate.HasValue)
            {
                if (!audioStream.BitRate.HasValue || audioStream.BitRate.Value <= 0)
                {
                    return false;
                }
                if (audioStream.BitRate.Value > request.AudioBitRate.Value)
                {
                    return false;
                }
            }

            // Channels must fall within requested value
            var channels = request.AudioChannels ?? request.MaxAudioChannels;
            if (channels.HasValue)
            {
                if (!audioStream.Channels.HasValue || audioStream.Channels.Value <= 0)
                {
                    return false;
                }
                if (audioStream.Channels.Value > channels.Value)
                {
                    return false;
                }
            }

            // Sample rate must fall within requested value
            if (request.AudioSampleRate.HasValue)
            {
                if (!audioStream.SampleRate.HasValue || audioStream.SampleRate.Value <= 0)
                {
                    return false;
                }
                if (audioStream.SampleRate.Value > request.AudioSampleRate.Value)
                {
                    return false;
                }
            }

            return true;
        }

        private int? GetAudioBitrateParam(StreamRequest request, MediaStream audioStream)
        {
            if (request.AudioBitRate.HasValue)
            {
                // Make sure we don't request a bitrate higher than the source
                var currentBitrate = audioStream == null ? request.AudioBitRate.Value : audioStream.BitRate ?? request.AudioBitRate.Value;

                return request.AudioBitRate.Value;
                //return Math.Min(currentBitrate, request.AudioBitRate.Value);
            }

            return null;
        }

        /// <summary>
        /// Converts ffprobe stream info to our MediaStream class
        /// </summary>
        /// <param name="isAudio">if set to <c>true</c> [is audio].</param>
        /// <param name="streamInfo">The stream info.</param>
        /// <param name="formatInfo">The format info.</param>
        /// <returns>MediaStream.</returns>
        private MediaStream GetMediaStream(bool isAudio, MediaStreamInfo streamInfo, MediaFormatInfo formatInfo)
        {
            // These are mp4 chapters
            if (string.Equals(streamInfo.codec_name, "mov_text", StringComparison.OrdinalIgnoreCase))
            {
                return null;
            }

            var stream = new MediaStream
            {
                Codec = streamInfo.codec_name,
                Profile = streamInfo.profile,
                Level = streamInfo.level,
                Index = streamInfo.index,
                PixelFormat = streamInfo.pix_fmt
            };

            // Filter out junk
            if (!string.IsNullOrWhiteSpace(streamInfo.codec_tag_string) && streamInfo.codec_tag_string.IndexOf("[0]", StringComparison.OrdinalIgnoreCase) == -1)
            {
                stream.CodecTag = streamInfo.codec_tag_string;
            }

            if (streamInfo.tags != null)
            {
                stream.Language = GetDictionaryValue(streamInfo.tags, "language");
            }

            if (string.Equals(streamInfo.codec_type, "audio", StringComparison.OrdinalIgnoreCase))
            {
                stream.Type = MediaStreamType.Audio;

                stream.Channels = streamInfo.channels;

                if (!string.IsNullOrEmpty(streamInfo.sample_rate))
                {
                    int value;
                    if (int.TryParse(streamInfo.sample_rate, NumberStyles.Any, _usCulture, out value))
                    {
                        stream.SampleRate = value;
                    }
                }

                stream.ChannelLayout = ParseChannelLayout(streamInfo.channel_layout);

                if (streamInfo.bits_per_sample > 0)
                {
                    stream.BitDepth = streamInfo.bits_per_sample;
                }
                else if (streamInfo.bits_per_raw_sample > 0)
                {
                    stream.BitDepth = streamInfo.bits_per_raw_sample;
                }
            }
            else if (string.Equals(streamInfo.codec_type, "subtitle", StringComparison.OrdinalIgnoreCase))
            {
                stream.Type = MediaStreamType.Subtitle;
            }
            else if (string.Equals(streamInfo.codec_type, "video", StringComparison.OrdinalIgnoreCase))
            {
                stream.Type = isAudio || string.Equals(stream.Codec, "mjpeg", StringComparison.OrdinalIgnoreCase)
                    ? MediaStreamType.EmbeddedImage
                    : MediaStreamType.Video;

                stream.Width = streamInfo.width;
                stream.Height = streamInfo.height;
                stream.AspectRatio = GetAspectRatio(streamInfo);

                stream.AverageFrameRate = GetFrameRate(streamInfo.avg_frame_rate);
                stream.RealFrameRate = GetFrameRate(streamInfo.r_frame_rate);

                if (streamInfo.bits_per_sample > 0)
                {
                    stream.BitDepth = streamInfo.bits_per_sample;
                }
                else if (streamInfo.bits_per_raw_sample > 0)
                {
                    stream.BitDepth = streamInfo.bits_per_raw_sample;
                }

                //stream.IsAnamorphic = string.Equals(streamInfo.sample_aspect_ratio, "0:1", StringComparison.OrdinalIgnoreCase) ||
                //    string.Equals(stream.AspectRatio, "2.35:1", StringComparison.OrdinalIgnoreCase) ||
                //    string.Equals(stream.AspectRatio, "2.40:1", StringComparison.OrdinalIgnoreCase);

                // http://stackoverflow.com/questions/17353387/how-to-detect-anamorphic-video-with-ffprobe
                stream.IsAnamorphic = string.Equals(streamInfo.sample_aspect_ratio, "0:1", StringComparison.OrdinalIgnoreCase);

                if (streamInfo.refs > 0)
                {
                    stream.RefFrames = streamInfo.refs;
                }
            }
            else
//.........这里部分代码省略.........

        /// <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)
        {
            var codec = stream.Codec ?? string.Empty;

            return codec.IndexOf("264", StringComparison.OrdinalIgnoreCase) != -1 ||
                   codec.IndexOf("avc", StringComparison.OrdinalIgnoreCase) != -1;
        }

        public bool? IsSecondaryAudio(MediaStream stream)
        {
            // Look for the first audio track marked as default
            foreach (MediaStream currentStream in MediaStreams)
            {
                if (currentStream.Type == MediaStreamType.Audio && currentStream.IsDefault)
                {
                    return currentStream.Index != stream.Index;
                }
            }

            // Look for the first audio track
            foreach (MediaStream currentStream in MediaStreams)
            {
                if (currentStream.Type == MediaStreamType.Audio)
                {
                    return currentStream.Index != stream.Index;
                }
            }

            return null;
        }

        private bool IsAudioDirectPlaySupported(DirectPlayProfile profile, MediaSourceInfo item, MediaStream audioStream)
        {
            if (profile.Container.Length > 0)
            {
                // Check container type
                string mediaContainer = item.Container ?? string.Empty;
                bool any = false;
                foreach (string i in profile.GetContainers())
                {
                    if (StringHelper.EqualsIgnoreCase(i, mediaContainer))
                    {
                        any = true;
                        break;
                    }
                }
                if (!any)
                {
                    return false;
                }
            }

            return true;
        }

        public static SubtitleProfile GetSubtitleProfile(MediaStream subtitleStream, SubtitleProfile[] subtitleProfiles, EncodingContext context)
        {
            // Look for an external profile that matches the stream type (text/graphical)
            foreach (SubtitleProfile profile in subtitleProfiles)
            {
                bool requiresConversion = !StringHelper.EqualsIgnoreCase(subtitleStream.Codec, profile.Format);

                if (!profile.SupportsLanguage(subtitleStream.Language))
                {
                    continue;
                }

                if (profile.Method == SubtitleDeliveryMethod.External && subtitleStream.IsTextSubtitleStream == MediaStream.IsTextFormat(profile.Format))
                {
                    if (!requiresConversion)
                    {
                        return profile;
                    }

                    if (subtitleStream.SupportsExternalStream)
                    {
                        return profile;
                    }

                    // For sync we can handle the longer extraction times
                    if (context == EncodingContext.Static && subtitleStream.IsTextSubtitleStream)
                    {
                        return profile;
                    }
                }
            }

            foreach (SubtitleProfile profile in subtitleProfiles)
            {
                bool requiresConversion = !StringHelper.EqualsIgnoreCase(subtitleStream.Codec, profile.Format);

                if (!profile.SupportsLanguage(subtitleStream.Language))
                {
                    continue;
                }

                if (profile.Method == SubtitleDeliveryMethod.Embed && subtitleStream.IsTextSubtitleStream == MediaStream.IsTextFormat(profile.Format))
                {
                    if (!requiresConversion)
                    {
                        return profile;
                    }

                    return profile;
                }
            }

            return new SubtitleProfile
            {
                Method = SubtitleDeliveryMethod.Encode,
                Format = subtitleStream.Codec
            };
        }

        private bool IsEligibleForDirectPlay(MediaSourceInfo item,
            int? maxBitrate,
            MediaStream subtitleStream,
            VideoOptions options)
        {
            if (subtitleStream != null)
            {
                SubtitleProfile subtitleProfile = GetSubtitleProfile(subtitleStream, options.Profile.SubtitleProfiles, options.Context);

                if (subtitleProfile.Method != SubtitleDeliveryMethod.External && subtitleProfile.Method != SubtitleDeliveryMethod.Embed)
                {
                    return false;
                }
            }

            return IsAudioEligibleForDirectPlay(item, maxBitrate);
        }

        private PlayMethod? GetVideoDirectPlayProfile(DeviceProfile profile,
            MediaSourceInfo mediaSource,
            MediaStream videoStream,
            MediaStream audioStream,
            bool isEligibleForDirectPlay,
            bool isEligibleForDirectStream)
        {
            // See if it can be direct played
            DirectPlayProfile directPlay = null;
            foreach (DirectPlayProfile i in profile.DirectPlayProfiles)
            {
                if (i.Type == DlnaProfileType.Video && IsVideoDirectPlaySupported(i, mediaSource, videoStream, audioStream))
                {
                    directPlay = i;
                    break;
                }
            }

            if (directPlay == null)
            {
                _logger.Debug("Profile: {0}, No direct play profiles found for Path: {1}",
                    profile.Name ?? "Unknown Profile",
                    mediaSource.Path ?? "Unknown path"); 
                
                return null;
            }

            string container = mediaSource.Container;

            List<ProfileCondition> conditions = new List<ProfileCondition>();
            foreach (ContainerProfile i in profile.ContainerProfiles)
            {
                if (i.Type == DlnaProfileType.Video &&
                    ListHelper.ContainsIgnoreCase(i.GetContainers(), container))
                {
                    foreach (ProfileCondition c in i.Conditions)
                    {
                        conditions.Add(c);
                    }
                }
            }

            ConditionProcessor conditionProcessor = new ConditionProcessor();

            int? width = videoStream == null ? null : videoStream.Width;
            int? height = videoStream == null ? null : videoStream.Height;
            int? bitDepth = videoStream == null ? null : videoStream.BitDepth;
            int? videoBitrate = videoStream == null ? null : videoStream.BitRate;
            double? videoLevel = videoStream == null ? null : videoStream.Level;
            string videoProfile = videoStream == null ? null : videoStream.Profile;
            float? videoFramerate = videoStream == null ? null : videoStream.AverageFrameRate ?? videoStream.AverageFrameRate;
            bool? isAnamorphic = videoStream == null ? null : videoStream.IsAnamorphic;
            bool? isCabac = videoStream == null ? null : videoStream.IsCabac;

            int? audioBitrate = audioStream == null ? null : audioStream.BitRate;
            int? audioChannels = audioStream == null ? null : audioStream.Channels;
            string audioProfile = audioStream == null ? null : audioStream.Profile;

            TransportStreamTimestamp? timestamp = videoStream == null ? TransportStreamTimestamp.None : mediaSource.Timestamp;
            int? packetLength = videoStream == null ? null : videoStream.PacketLength;
            int? refFrames = videoStream == null ? null : videoStream.RefFrames;

            int? numAudioStreams = mediaSource.GetStreamCount(MediaStreamType.Audio);
            int? numVideoStreams = mediaSource.GetStreamCount(MediaStreamType.Video);

            // Check container conditions
            foreach (ProfileCondition i in conditions)
            {
                if (!conditionProcessor.IsVideoConditionSatisfied(i, width, height, bitDepth, videoBitrate, videoProfile, videoLevel, videoFramerate, packetLength, timestamp, isAnamorphic, isCabac, refFrames, numVideoStreams, numAudioStreams))
                {
                    LogConditionFailure(profile, "VideoContainerProfile", i, mediaSource);

                    return null;
                }
            }

            string videoCodec = videoStream == null ? null : videoStream.Codec;

            if (string.IsNullOrEmpty(videoCodec))
            {
                _logger.Debug("Profile: {0}, DirectPlay=false. Reason=Unknown video codec. Path: {1}",
                    profile.Name ?? "Unknown Profile",
                    mediaSource.Path ?? "Unknown path");

                return null;
            }

            conditions = new List<ProfileCondition>();
            foreach (CodecProfile i in profile.CodecProfiles)
            {
                if (i.Type == CodecType.Video && i.ContainsCodec(videoCodec, container))
                {
                    foreach (ProfileCondition c in i.Conditions)
                    {
                        conditions.Add(c);
                    }
                }
            }

            foreach (ProfileCondition i in conditions)
//.........这里部分代码省略.........

        private int GetAudioBitrate(int? maxTotalBitrate, int? targetAudioChannels, string targetAudioCodec, MediaStream audioStream)
        {
            var defaultBitrate = 128000;

            if (targetAudioChannels.HasValue)
            {
                if (targetAudioChannels.Value >= 5 && (maxTotalBitrate ?? 0) >= 2000000)
                {
                    defaultBitrate = 320000;
                }
            }

            int encoderAudioBitrateLimit = int.MaxValue;

            if (audioStream != null)
            {
                // Seeing webm encoding failures when source has 1 audio channel and 22k bitrate. 
                // Any attempts to transcode over 64k will fail
                if (audioStream.Channels.HasValue &&
                    audioStream.Channels.Value == 1)
                {
                    if ((audioStream.BitRate ?? 0) < 64000)
                    {
                        encoderAudioBitrateLimit = 64000;
                    }
                }
            }

            return Math.Min(defaultBitrate, encoderAudioBitrateLimit);
        }

        private List<PlayMethod> GetAudioDirectPlayMethods(MediaSourceInfo item, MediaStream audioStream, AudioOptions options)
        {
            DirectPlayProfile directPlayProfile = null;
            foreach (DirectPlayProfile i in options.Profile.DirectPlayProfiles)
            {
                if (i.Type == DlnaProfileType.Audio && IsAudioDirectPlaySupported(i, item, audioStream))
                {
                    directPlayProfile = i;
                    break;
                }
            }

            List<PlayMethod> playMethods = new List<PlayMethod>();

            if (directPlayProfile != null)
            {
                // While options takes the network and other factors into account. Only applies to direct stream
                if (item.SupportsDirectStream && IsAudioEligibleForDirectPlay(item, options.GetMaxBitrate()))
                {
                    playMethods.Add(PlayMethod.DirectStream);
                }
                
                // The profile describes what the device supports
                // If device requirements are satisfied then allow both direct stream and direct play
                if (item.SupportsDirectPlay && IsAudioEligibleForDirectPlay(item, GetBitrateForDirectPlayCheck(item, options)))
                {
                    playMethods.Add(PlayMethod.DirectPlay);
                }
            }

            return playMethods;
        }

        /// <summary>
        /// Adds the video stream.
        /// </summary>
        /// <param name="streams">The streams.</param>
        /// <param name="videoStream">The video stream.</param>
        private void AddVideoStream(List<MediaStream> streams, TSVideoStream videoStream)
        {
            var mediaStream = new MediaStream
            {
                BitRate = Convert.ToInt32(videoStream.BitRate),
                Width = videoStream.Width,
                Height = videoStream.Height,
                Codec = videoStream.CodecShortName,
                ScanType = videoStream.IsInterlaced ? "interlaced" : "progressive",
                Type = MediaStreamType.Video,
                Index = streams.Count
            };

            if (videoStream.FrameRateDenominator > 0)
            {
                float frameRateEnumerator = videoStream.FrameRateEnumerator;
                float frameRateDenominator = videoStream.FrameRateDenominator;

                mediaStream.AverageFrameRate = mediaStream.RealFrameRate = frameRateEnumerator / frameRateDenominator;
            }

            streams.Add(mediaStream);
        }

        private void UpdateFromMediaInfo(MediaSourceInfo video, MediaStream videoStream)
        {
            if (video.Protocol == MediaProtocol.File)
            {
                if (videoStream != null)
                {
                    try
                    {
                        _logger.Debug("Running MediaInfo against {0}", video.Path);

                        var result = new MediaInfoLib().GetVideoInfo(video.Path);

                        videoStream.IsCabac = result.IsCabac ?? videoStream.IsCabac;
                        videoStream.IsInterlaced = result.IsInterlaced ?? videoStream.IsInterlaced;
                        videoStream.BitDepth = result.BitDepth ?? videoStream.BitDepth;
                        videoStream.RefFrames = result.RefFrames;
                    }
                    catch (Exception ex)
                    {
                        _logger.ErrorException("Error running MediaInfo on {0}", ex, video.Path);
                    }
                }
            }
        }

        private bool IsVideoDirectPlaySupported(DirectPlayProfile profile, MediaSourceInfo item, MediaStream videoStream, MediaStream audioStream)
        {
            if (profile.Container.Length > 0)
            {
                // Check container type
                string mediaContainer = item.Container ?? string.Empty;
                bool any = false;
                foreach (string i in profile.GetContainers())
                {
                    if (StringHelper.EqualsIgnoreCase(i, mediaContainer))
                    {
                        any = true;
                        break;
                    }
                }
                if (!any)
                {
                    return false;
                }
            }

            // Check video codec
            List<string> videoCodecs = profile.GetVideoCodecs();
            if (videoCodecs.Count > 0)
            {
                string videoCodec = videoStream == null ? null : videoStream.Codec;
                if (string.IsNullOrEmpty(videoCodec) || !ListHelper.ContainsIgnoreCase(videoCodecs, videoCodec))
                {
                    return false;
                }
            }

            List<string> audioCodecs = profile.GetAudioCodecs();
            if (audioCodecs.Count > 0)
            {
                // Check audio codecs
                string audioCodec = audioStream == null ? null : audioStream.Codec;
                if (string.IsNullOrEmpty(audioCodec) || !ListHelper.ContainsIgnoreCase(audioCodecs, audioCodec))
                {
                    return false;
                }
            }

            return true;
        }

        /// <summary>
        /// Gets the number of audio channels to specify on the command line
        /// </summary>
        /// <param name="request">The request.</param>
        /// <param name="audioStream">The audio stream.</param>
        /// <param name="outputAudioCodec">The output audio codec.</param>
        /// <returns>System.Nullable{System.Int32}.</returns>
        private int? GetNumAudioChannelsParam(EncodingJobOptions request, MediaStream audioStream, string outputAudioCodec)
        {
            var inputChannels = audioStream == null
                            ? null
                            : audioStream.Channels;

            if (inputChannels <= 0)
            {
                inputChannels = null;
            }

            var codec = outputAudioCodec ?? string.Empty;

            if (codec.IndexOf("wma", StringComparison.OrdinalIgnoreCase) != -1)
            {
                // wmav2 currently only supports two channel output
                return Math.Min(2, inputChannels ?? 2);
            }

            if (request.MaxAudioChannels.HasValue)
            {
                if (inputChannels.HasValue)
                {
                    return Math.Min(request.MaxAudioChannels.Value, inputChannels.Value);
                }

                var channelLimit = codec.IndexOf("mp3", StringComparison.OrdinalIgnoreCase) != -1
                    ? 2
                    : 6;

                // If we don't have any media info then limit it to 5 to prevent encoding errors due to asking for too many channels
                return Math.Min(request.MaxAudioChannels.Value, channelLimit);
            }

            return request.AudioChannels;
        }

        /// <summary>
        /// Converts ffprobe stream info to our MediaStream class
        /// </summary>
        /// <param name="streamInfo">The stream info.</param>
        /// <param name="formatInfo">The format info.</param>
        /// <returns>MediaStream.</returns>
        private static MediaStream GetMediaStream(MediaStreamInfo streamInfo, MediaFormatInfo formatInfo)
        {
            var stream = new MediaStream
            {
                Codec = streamInfo.codec_name,
                Profile = streamInfo.profile,
                Level = streamInfo.level,
                Index = streamInfo.index
            };

            if (streamInfo.tags != null)
            {
                stream.Language = GetDictionaryValue(streamInfo.tags, "language");
            }

            if (string.Equals(streamInfo.codec_type, "audio", StringComparison.OrdinalIgnoreCase))
            {
                stream.Type = MediaStreamType.Audio;

                stream.Channels = streamInfo.channels;

                if (!string.IsNullOrEmpty(streamInfo.sample_rate))
                {
                    stream.SampleRate = int.Parse(streamInfo.sample_rate, UsCulture);
                }

                stream.ChannelLayout = ParseChannelLayout(streamInfo.channel_layout);
            }
            else if (string.Equals(streamInfo.codec_type, "subtitle", StringComparison.OrdinalIgnoreCase))
            {
                stream.Type = MediaStreamType.Subtitle;
            }
            else if (string.Equals(streamInfo.codec_type, "video", StringComparison.OrdinalIgnoreCase))
            {
                stream.Type = MediaStreamType.Video;

                stream.Width = streamInfo.width;
                stream.Height = streamInfo.height;
                stream.AspectRatio = GetAspectRatio(streamInfo);

                stream.AverageFrameRate = GetFrameRate(streamInfo.avg_frame_rate);
                stream.RealFrameRate = GetFrameRate(streamInfo.r_frame_rate);
            }
            else
            {
                return null;
            }

            // Get stream bitrate
            if (stream.Type != MediaStreamType.Subtitle)
            {
                var bitrate = 0;

                if (!string.IsNullOrEmpty(streamInfo.bit_rate))
                {
                    bitrate = int.Parse(streamInfo.bit_rate, UsCulture);
                }
                else if (formatInfo != null && !string.IsNullOrEmpty(formatInfo.bit_rate))
                {
                    // If the stream info doesn't have a bitrate get the value from the media format info
                    bitrate = int.Parse(formatInfo.bit_rate, UsCulture);
                }

                if (bitrate > 0)
                {
                    stream.BitRate = bitrate;
                }
            }

            if (streamInfo.disposition != null)
            {
                var isDefault = GetDictionaryValue(streamInfo.disposition, "default");
                var isForced = GetDictionaryValue(streamInfo.disposition, "forced");

                stream.IsDefault = string.Equals(isDefault, "1", StringComparison.OrdinalIgnoreCase);

                stream.IsForced = string.Equals(isForced, "1", StringComparison.OrdinalIgnoreCase);
            }

            return stream;
        }