Represents a set of ordered media frames of a given type
        /// <summary>
        /// Replaces the internally-held frames with the specified new frames.
        /// </summary>
        /// <param name="newFrames">The new frames.</param>
        /// <exception cref="System.IndexOutOfRangeException">Buffer does not support the capacity of new elements</exception>
        public void Replace(FFmpegMediaFrameCache newFrames)
        {
            if (newFrames.Count > Capacity)
            {
                throw new IndexOutOfRangeException("Buffer does not support the capacity of new elements");
            }

            foreach (var frame in Frames)
            {
                frame.EnqueueRelease();
            }

            Frames.Clear();

            foreach (var frame in newFrames.Frames)
            {
                if (frame.Type != this.Type)
                {
                    this.ThrowInvalidFrameTypeException(frame.Type);
                }

                Frames.Add(frame);
            }

            RecomputeProperties();
        }
        /// <summary>
        /// Initializes a new instance of the <see cref="FFmpegMediaFrameCache"/> class.
        /// This copies all properties from an existing cache excluding frames of course.
        /// </summary>
        /// <param name="otherCache">The other cache.</param>
        public FFmpegMediaFrameCache(FFmpegMediaFrameCache otherCache)
        {
            var capacity = otherCache.Capacity;

            this.Type     = otherCache.Type;
            this.Capacity = capacity;
            RecomputeProperties();
        }
Esempio n. 3
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        /// <summary>
        /// Initializes a new instance of the <see cref="FFmpegMedia"/> class.
        /// </summary>
        /// <param name="filePath">The file path.</param>
        /// <param name="errorCallback">The error callback.</param>
        /// <exception cref="System.ArgumentException">
        /// errorCallback cannot be null
        /// or
        /// filePath cannot be null or empty
        /// </exception>
        /// <exception cref="System.Exception"></exception>
        public FFmpegMedia(string filePath, MediaErrorOccurredCallback errorCallback)
        {
            // Argument validation
            if (errorCallback == null)
            {
                throw new ArgumentException("errorCallback cannot be null");
            }

            if (string.IsNullOrWhiteSpace(filePath))
            {
                throw new ArgumentException("filePath cannot be null or empty");
            }

            // Error callback
            this.ErrorOccurredCallback = errorCallback;

            // Register the property state change handler
            this.RealtimeClock.PropertyChanged += (s, e) => { NotifyPlayStateChanged(); };

            // Make sure we registwered the library
            Helper.RegisterFFmpeg();

            // Create the audio provider and audio renderer
            this.PcmAudioProvider = new AudioBufferProvider(this);
            this.AudioRenderer    = new AudioRenderer();

            // load input, codec and output contexts
            this.InitializeMedia(filePath);

            // Setup the frames Cache
            this.VideoFramesCache = new FFmpegMediaFrameCache(this.VideoFrameRate, MediaFrameType.Video);
            this.AudioFramesCache = new FFmpegMediaFrameCache(this.AudioSampleRate / 1000M, MediaFrameType.Audio);

            // Setup the Leading and Lagging frames cache
            if (HasVideo && (HasAudio == false || InputAudioStream->index > InputVideoStream->index))
            {
                this.LeadingFramesCache = VideoFramesCache;
                this.LaggingFramesCache = AudioFramesCache;
                this.StartDts           = InputVideoStream->start_time;

                LeadingStreamType = MediaFrameType.Video;
                LaggingStreamType = HasAudio ? MediaFrameType.Audio : MediaFrameType.Unknown;
            }
            else
            {
                this.LeadingFramesCache = AudioFramesCache;
                this.LaggingFramesCache = VideoFramesCache;
                this.StartDts           = InputAudioStream->start_time;

                LeadingStreamType = MediaFrameType.Audio;
                LaggingStreamType = HasVideo ? MediaFrameType.Video : MediaFrameType.Unknown;
            }

            if (Helper.IsNoPtsValue(StartDts))
            {
                StartDts = 0;
            }

            // Setup Video Renderer and Video Frames Cache
            if (HasVideo)
            {
                this.VideoRenderer = new WriteableBitmap(this.VideoFrameWidth, this.VideoFrameHeight, 96, 96, System.Windows.Media.PixelFormats.Bgr24, null);
            }
            else
            {
                this.VideoRenderer = new WriteableBitmap(1, 1, 96, 96, System.Windows.Media.PixelFormats.Bgr24, null);
            }


            // Setup Audio Renderer and Audio Frames Cache
            if (HasAudio)
            {
                this.StartAudioRenderer();
            }

            // Start the continuous Decoder thread that fills up our queue.
            MediaFrameExtractorThread = new Thread(ExtractMediaFramesContinuously)
            {
                IsBackground = true,
                Priority     = ThreadPriority.AboveNormal
            };

            // Begin the media extractor
            MediaFrameExtractorThread.Start();
            MediaFramesExtractedDone.Reset();
            if (MediaFramesExtractedDone.Wait(Constants.WaitForPlaybackReadyStateTimeout) == false)
            {
                throw new Exception(string.Format("Could not load sream frames in a timely manner. Timed out in {0}", Constants.WaitForPlaybackReadyStateTimeout));
            }

            // Initialize the Speed Ratio to 1.0 (Default)
            this.SpeedRatio = Constants.DefaultSpeedRatio;

            // Start the render timer on the UI thread.
            this.VideoRenderTimer.Tick     += RenderVideoImage;
            this.VideoRenderTimer.Interval  = TimeSpan.FromMilliseconds(Constants.VideoRenderTimerIntervalMillis);
            this.VideoRenderTimer.IsEnabled = true;
            this.VideoRenderTimer.Start();
        }
Esempio n. 4
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        /// <summary>
        /// Internals the seek input.
        /// </summary>
        /// <param name="renderTime">The render time.</param>
        private void InternalSeekInput(decimal renderTime)
        {
            if (IsLiveStream)
            {
                if (LeadingFramesCache.IsEmpty == false)
                {
                    RealtimeClock.Seek(LeadingFramesCache.FirstFrameTime);
                }

                return;
            }

#if DEBUG
            var seekStopwatch = new System.Diagnostics.Stopwatch();
            seekStopwatch.Start();
#endif

            if (renderTime < StartTime)
            {
                renderTime = StartTime;
            }

            RealtimeClock.Seek(renderTime);

            var allowedThreshold = Constants.SeekThresholdSeconds;
            var seekOffsetLength = Constants.SeekOffsetSeconds;

            var seekTime         = renderTime - seekOffsetLength;
            var maxSeekStartTime = seekTime - allowedThreshold;

            var bufferedLeadingFrames = new FFmpegMediaFrameCache(LeadingFramesCache);
            var bufferedLaggingFrames = new FFmpegMediaFrameCache(LaggingFramesCache);

            var outerLoopCount        = 0;
            var innerLoopCount        = 0;
            var frameReleaseCount     = 0;
            var doSeekInStream        = true;
            var doSeekByPullingFrames = true;
            var seekFlag            = 0;
            var seekFrameResult     = 0;
            var startTime           = DateTime.UtcNow;
            var lastFailedTimestamp = long.MinValue;
            var seekToLastFrame     = false;

            var seekTimeBase      = LeadingFramesCache.Type == MediaFrameType.Video ? InputVideoStream->time_base : InputAudioStream->time_base;
            var seekStreamIndex   = LeadingFramesCache.Type == MediaFrameType.Video ? InputVideoStream->index : InputAudioStream->index;
            var leadingFrameIndex = -1;

            try
            {
                while (doSeekInStream)
                {
                    outerLoopCount++;

                    if (seekTime < StartTime)
                    {
                        seekTime = StartTime;
                    }

                    if (lastFailedTimestamp == StartDts)
                    {
                        if (LeadingFramesCache.IsEmpty == false)
                        {
                            RealtimeClock.Seek(LeadingFramesCache.FirstFrameTime);
                        }

                        ErrorOccurredCallback(this, new MediaPlaybackException(MediaPlaybackErrorSources.InternalSeekInput, MediaPlaybackErrorCode.SeekFailedCritical,
                                                                               string.Format("Target Postion @ {0:0.000}s has already failed to seek. First DTS {1} also failed and will not retry.", seekTime, StartDts)));

                        return;
                    }

                    var targetTimestamp = Helper.SecondsToTimestamp(seekTime, seekTimeBase);
                    if (lastFailedTimestamp == targetTimestamp)
                    {
                        ErrorOccurredCallback(this, new MediaPlaybackException(MediaPlaybackErrorSources.InternalSeekInput, MediaPlaybackErrorCode.SeekFailedWillRetry,
                                                                               string.Format("Target Postion @ {0:0.000}s has already failed to seek. Target timestamp will now be First DTS {1}.", seekTime, StartDts)));

                        targetTimestamp = StartDts;
                    }

                    seekFlag = (seekTime < renderTime || seekTime <= StartTime ? (int)ffmpeg.AVSEEK_FLAG_BACKWARD : 0) | 0; // FFmpegInvoke.AVSEEK_FLAG_ANY;
                    //seekFlag = FFmpegInvoke.AVSEEK_FLAG_BACKWARD; // | FFmpegInvoke.AVSEEK_FLAG_ANY;

                    seekFrameResult = ffmpeg.av_seek_frame(InputFormatContext, seekStreamIndex, targetTimestamp, seekFlag); // significantly faster than seek_file
                    //seekFrameResult = FFmpegInvoke.avformat_seek_file(InputFormatContext, streamIndex, long.MinValue, targetTimestamp, long.MaxValue, seekFlag);
                    if (seekFrameResult < Constants.SuccessCode)
                    {
                        if (LeadingFramesCache.IsEmpty == false)
                        {
                            RealtimeClock.Seek(LeadingFramesCache.FirstFrameTime);
                        }

                        var errorMessage = Helper.GetFFmpegErrorMessage(seekFrameResult);
                        ErrorOccurredCallback(this, new MediaPlaybackException(MediaPlaybackErrorSources.InternalSeekInput, MediaPlaybackErrorCode.SeekFailedFFmpeg,
                                                                               string.Format("FFmpeg av_seek_frame @ {1:0.000}: Failed with error code {0}. {2}", seekFrameResult, seekTime, errorMessage)));

                        return;
                    }
                    else
                    {
                        if (VideoCodecContext != null)
                        {
                            ffmpeg.avcodec_flush_buffers(VideoCodecContext);
                        }

                        if (AudioCodecContext != null)
                        {
                            ffmpeg.avcodec_flush_buffers(AudioCodecContext);
                        }
                    }

                    leadingFrameIndex = -1;
                    bufferedLeadingFrames.Clear();
                    bufferedLaggingFrames.Clear();

                    doSeekInStream        = false;
                    doSeekByPullingFrames = true;

                    while (doSeekByPullingFrames)
                    {
                        innerLoopCount++;

                        var frame = this.PullMediaFrame();
                        if (frame != null)
                        {
                            if (frame.StartTime < maxSeekStartTime)
                            {
                                frame.EnqueueRelease();
                                frameReleaseCount++;
                                continue;
                            }

                            if (frame.Type == bufferedLeadingFrames.Type)
                            {
                                leadingFrameIndex++;
                                if (leadingFrameIndex == 0 && frame.Type == bufferedLeadingFrames.Type && frame.StartTime - frame.Duration > maxSeekStartTime && maxSeekStartTime > 0M)
                                {
                                    seekTime -= seekOffsetLength;
                                    frame.EnqueueRelease();
                                    doSeekInStream      = true;
                                    lastFailedTimestamp = targetTimestamp;
                                    break;
                                }

                                // We are Full minus 1 at this point. We'll stop buffering
                                if (bufferedLeadingFrames.Count >= bufferedLeadingFrames.Capacity - 1)
                                {
                                    doSeekByPullingFrames = false;
                                }

                                bufferedLeadingFrames.Add(frame);
                            }
                            else if (frame.Type == bufferedLaggingFrames.Type)
                            {
                                // add the lagging frame no matter what
                                if (bufferedLaggingFrames.IsFull)
                                {
                                    bufferedLaggingFrames.RemoveFirst();
                                }

                                bufferedLaggingFrames.Add(frame);
                            }

                            // Find out if we have the frame
                            var seekFrameIndex    = bufferedLeadingFrames.IndexOf(renderTime, true);
                            var minimumFrameCount = (seekFrameIndex - 1) * 2;

                            // if we have more than enough frames in the buffer or we have reached a full or end condition, stop buffering frames
                            if (seekFrameIndex > 0)
                            {
                                if (bufferedLeadingFrames.Count >= minimumFrameCount || bufferedLeadingFrames.IsFull || IsAtEndOfStream)
                                {
                                    doSeekByPullingFrames = false;
                                }
                            }
                        }

                        // We're already padt the end of the stream. Natural duration was wron for the leading frames cache.
                        if (IsAtEndOfStream && bufferedLeadingFrames.Count <= 0)
                        {
                            doSeekInStream   = true;
                            seekTime        -= seekOffsetLength;
                            maxSeekStartTime = seekTime - allowedThreshold;
                            seekToLastFrame  = true;
                        }

                        if (doSeekInStream)
                        {
                            break;
                        }

                        if (doSeekByPullingFrames == false || IsAtEndOfStream)
                        {
                            LeadingFramesCache.Replace(bufferedLeadingFrames);
                            LaggingFramesCache.Replace(bufferedLaggingFrames);

                            if (seekToLastFrame && LeadingFramesCache.Count > 0)
                            {
                                RealtimeClock.Seek(LeadingFramesCache.LastFrameTime);
                            }

                            return;
                        }
                    }
                }
            }
            finally
            {
#if DEBUG
                seekStopwatch.Stop();
                SeekTimes.Add(seekStopwatch.ElapsedMilliseconds);
                InnerLoopCounts.Add(innerLoopCount);
                System.Diagnostics.Debug.WriteLine("Seek @ {6:0.000} = Long: {0:00}\t Short: {1:000}\t Short (AVG): {2:0.000}\t Waste Count: {3:000}\t Elapsed: {4}\tElapsed (AVG): {5:0.000}",
                                                   outerLoopCount, innerLoopCount, InnerLoopCounts.Average(), frameReleaseCount, seekStopwatch.ElapsedMilliseconds, SeekTimes.Average(), renderTime);
#endif
            }
        }
Esempio n. 5
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        /// <summary>
        /// Replaces the internally-held frames with the specified new frames.
        /// </summary>
        /// <param name="newFrames">The new frames.</param>
        /// <exception cref="System.IndexOutOfRangeException">Buffer does not support the capacity of new elements</exception>
        public void Replace(FFmpegMediaFrameCache newFrames)
        {
            lock (SyncLock)
            {
                if (newFrames.Count > Capacity)
                    throw new IndexOutOfRangeException("Buffer does not support the capacity of new elements");

                foreach (var frame in Frames)
                    frame.EnqueueRelease();

                Frames.Clear();

                try
                {
                    foreach (var frame in newFrames.Frames)
                    {
                        if (frame.Type != this.Type)
                            this.ThrowInvalidFrameTypeException(frame.Type);

                        Frames.Add(frame);
                    }
                }
                finally
                {
                    RecomputeProperties();
                }
            }

        }
Esempio n. 6
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 /// <summary>
 /// Initializes a new instance of the <see cref="FFmpegMediaFrameCache"/> class.
 /// This copies all properties from an existing cache excluding frames of course.
 /// </summary>
 /// <param name="otherCache">The other cache.</param>
 public FFmpegMediaFrameCache(FFmpegMediaFrameCache otherCache)
 {
     var capacity = otherCache.Capacity;
     Type = otherCache.Type;
     Capacity = capacity;
     RecomputeProperties();
 }
Esempio n. 7
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        /// <summary>
        /// Initializes a new instance of the <see cref="FFmpegMedia" /> class.
        /// </summary>
        /// <param name="filePath">The file path.</param>
        /// <param name="errorCallback">The error callback.</param>
        /// <param name="referer">The referer. Leave null or emtpy to skip setting it.</param>
        /// <param name="userAgent">The user agent. Leave null or empty in order to skip setting a User Agent</param>
        /// <exception cref="ArgumentException">errorCallback cannot be null
        /// or
        /// filePath cannot be null or empty</exception>
        /// <exception cref="Exception"></exception>
        /// <exception cref="System.ArgumentException">errorCallback cannot be null
        /// or
        /// filePath cannot be null or empty</exception>
        /// <exception cref="System.Exception"></exception>
        public FFmpegMedia(string filePath, MediaErrorOccurredCallback errorCallback, string referer, string userAgent)
        {
            // Argument validation
            if (errorCallback == null)
                throw new ArgumentException("errorCallback cannot be null");

            if (string.IsNullOrWhiteSpace(filePath))
                throw new ArgumentException("filePath cannot be null or empty");

            // Error callback
            this.ErrorOccurredCallback = errorCallback;

            // Register the property state change handler
            this.RealtimeClock.PropertyChanged += (s, e) => { NotifyPlayStateChanged(); };

            // Make sure we registwered the library            
            Helper.RegisterFFmpeg();

            // Create the audio provider and audio renderer
            this.PcmAudioProvider = new AudioBufferProvider(this);
            this.AudioRenderer = new AudioRenderer();

            // load input, codec and output contexts
            this.InitializeMedia(filePath, null, referer, userAgent);

            // Setup the frames Cache
            this.VideoFramesCache = new FFmpegMediaFrameCache(this.VideoFrameRate * (int)FramesCacheLength.TotalSeconds, MediaFrameType.Video);
            this.AudioFramesCache = new FFmpegMediaFrameCache(this.AudioSampleRate / (int)FramesCacheLength.TotalMilliseconds, MediaFrameType.Audio);

            // Setup the Leading and Lagging frames cache
            if (HasVideo && (HasAudio == false || InputAudioStream->index > InputVideoStream->index))
            {
                this.PrimaryFramesCache = VideoFramesCache;
                this.SecondaryFramesCache = AudioFramesCache;
                this.StartDts = InputVideoStream->start_time;

                LeadingStreamType = MediaFrameType.Video;
                LaggingStreamType = HasAudio ? MediaFrameType.Audio : MediaFrameType.Unknown;
            }
            else
            {
                this.PrimaryFramesCache = AudioFramesCache;
                this.SecondaryFramesCache = VideoFramesCache;
                this.StartDts = InputAudioStream->start_time;

                LeadingStreamType = MediaFrameType.Audio;
                LaggingStreamType = HasVideo ? MediaFrameType.Video : MediaFrameType.Unknown;
            }

            if (Helper.IsNoPtsValue(StartDts))
                StartDts = 0;

            // Setup Video Renderer and Video Frames Cache
            if (HasVideo)
                this.VideoRenderer = new WriteableBitmap(this.VideoFrameWidth, this.VideoFrameHeight, 96, 96, System.Windows.Media.PixelFormats.Bgr24, null);
            else
                this.VideoRenderer = new WriteableBitmap(1, 1, 96, 96, System.Windows.Media.PixelFormats.Bgr24, null);


            // Setup Audio Renderer and Audio Frames Cache
            if (HasAudio)
            {
                this.StartAudioRenderer();
            }

            // Start the continuous Decoder thread that fills up our queue.
            MediaFrameExtractorThread = new Thread(ExtractMediaFramesContinuously)
            {
                IsBackground = true,
                Priority = ThreadPriority.AboveNormal
            };

            // Begin the media extractor
            MediaFrameExtractorThread.Start();
            MediaFramesExtractedDone.Reset();
            if (MediaFramesExtractedDone.Wait(Constants.WaitForPlaybackReadyStateTimeout) == false)
            {
                throw new Exception(string.Format("Could not load sream frames in a timely manner. Timed out in {0}", Constants.WaitForPlaybackReadyStateTimeout));
            }

            // Initialize the Speed Ratio to 1.0 (Default)
            this.SpeedRatio = Constants.DefaultSpeedRatio;

            // Start the render timer on the UI thread.
            this.VideoRenderTimer.Tick += RenderVideoImage;
            this.VideoRenderTimer.Interval = TimeSpan.FromMilliseconds(Constants.VideoRenderTimerIntervalMillis);
            this.VideoRenderTimer.IsEnabled = true;
            this.VideoRenderTimer.Start();
        }
Esempio n. 8
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        /// <summary>
        /// Internals the seek input.
        /// </summary>
        /// <param name="renderTime">The render time.</param>
        private void InternalSeekInput(decimal renderTime)
        {
            if (IsLiveStream)
            {
                if (PrimaryFramesCache.IsEmpty == false)
                    RealtimeClock.Seek(PrimaryFramesCache.FirstFrameTime);

                return;
            }

#if DEBUG
            var seekStopwatch = new System.Diagnostics.Stopwatch();
            seekStopwatch.Start();
#endif

            if (renderTime < StartTime)
                renderTime = StartTime;

            RealtimeClock.Seek(renderTime);

            var allowedThreshold = Constants.SeekThresholdSeconds;
            var seekOffsetLength = Constants.SeekOffsetSeconds;

            var seekTime = renderTime - seekOffsetLength;
            var maxSeekStartTime = seekTime - allowedThreshold;

            var bufferedLeadingFrames = new FFmpegMediaFrameCache(PrimaryFramesCache);
            var bufferedLaggingFrames = new FFmpegMediaFrameCache(SecondaryFramesCache);

            var outerLoopCount = 0;
            var innerLoopCount = 0;
            var frameReleaseCount = 0;
            var doSeekInStream = true;
            var doSeekByPullingFrames = true;
            var seekFlag = 0;
            var seekFrameResult = 0;
            var startTime = DateTime.UtcNow;
            var lastFailedTimestamp = long.MinValue;
            var seekToLastFrame = false;

            var seekTimeBase = PrimaryFramesCache.Type == MediaFrameType.Video ? InputVideoStream->time_base : InputAudioStream->time_base;
            var seekStreamIndex = PrimaryFramesCache.Type == MediaFrameType.Video ? InputVideoStream->index : InputAudioStream->index;
            var leadingFrameIndex = -1;

            try
            {
                while (doSeekInStream)
                {
                    outerLoopCount++;

                    if (seekTime < StartTime) seekTime = StartTime;

                    if (lastFailedTimestamp == StartDts)
                    {
                        if (PrimaryFramesCache.IsEmpty == false)
                            RealtimeClock.Seek(PrimaryFramesCache.FirstFrameTime);

                        ErrorOccurredCallback(this, new MediaPlaybackException(MediaPlaybackErrorSources.InternalSeekInput, MediaPlaybackErrorCode.SeekFailedCritical,
                            string.Format("Target Postion @ {0:0.000}s has already failed to seek. First DTS {1} also failed and will not retry.", seekTime, StartDts)));

                        return;
                    }

                    var targetTimestamp = Helper.SecondsToTimestamp(seekTime, seekTimeBase);
                    if (lastFailedTimestamp == targetTimestamp)
                    {
                        ErrorOccurredCallback(this, new MediaPlaybackException(MediaPlaybackErrorSources.InternalSeekInput, MediaPlaybackErrorCode.SeekFailedWillRetry,
                            string.Format("Target Postion @ {0:0.000}s has already failed to seek. Target timestamp will now be First DTS {1}.", seekTime, StartDts)));

                        targetTimestamp = StartDts;
                    }

                    seekFlag = (seekTime < renderTime || seekTime <= StartTime ? (int)ffmpeg.AVSEEK_FLAG_BACKWARD : 0) | 0; // FFmpegInvoke.AVSEEK_FLAG_ANY;
                    //seekFlag = ffmpeg.AVSEEK_FLAG_BACKWARD; // | ffmpeg.AVSEEK_FLAG_ANY;
                    
                    seekFrameResult = ffmpeg.av_seek_frame(InputFormatContext, seekStreamIndex, targetTimestamp, seekFlag); // significantly faster than seek_file
                    //seekFrameResult = ffmpeg.avformat_seek_file(InputFormatContext, seekStreamIndex, targetTimestamp - 2, targetTimestamp, targetTimestamp + 2, seekFlag);
                    if (seekFrameResult < Constants.SuccessCode)
                    {
                        if (PrimaryFramesCache.IsEmpty == false)
                            RealtimeClock.Seek(PrimaryFramesCache.FirstFrameTime);

                        var errorMessage = Helper.GetFFmpegErrorMessage(seekFrameResult);
                        ErrorOccurredCallback(this, new MediaPlaybackException(MediaPlaybackErrorSources.InternalSeekInput, MediaPlaybackErrorCode.SeekFailedFFmpeg,
                            string.Format("FFmpeg av_seek_frame @ {1:0.000}: Failed with error code {0}. {2}", seekFrameResult, seekTime, errorMessage)));

                        return;
                    }
                    else
                    {
                        if (VideoCodecContext != null)
                            ffmpeg.avcodec_flush_buffers(VideoCodecContext);

                        if (AudioCodecContext != null)
                            ffmpeg.avcodec_flush_buffers(AudioCodecContext);
                    }

                    leadingFrameIndex = -1;
                    bufferedLeadingFrames.Clear();
                    bufferedLaggingFrames.Clear();

                    doSeekInStream = false;
                    doSeekByPullingFrames = true;

                    while (doSeekByPullingFrames)
                    {
                        innerLoopCount++;

                        var frame = this.PullMediaFrame();
                        if (frame != null)
                        {
                            if (frame.StartTime < maxSeekStartTime)
                            {
                                frame.EnqueueRelease();
                                frameReleaseCount++;
                                continue;
                            }

                            if (frame.Type == bufferedLeadingFrames.Type)
                            {
                                leadingFrameIndex++;
                                if (leadingFrameIndex == 0 && frame.Type == bufferedLeadingFrames.Type && frame.StartTime - frame.Duration > maxSeekStartTime && maxSeekStartTime > 0M)
                                {
                                    seekTime -= seekOffsetLength;
                                    frame.EnqueueRelease();
                                    doSeekInStream = true;
                                    lastFailedTimestamp = targetTimestamp;
                                    break;
                                }

                                // We are Full minus 1 at this point. We'll stop buffering
                                if (bufferedLeadingFrames.Count >= bufferedLeadingFrames.Capacity - 1)
                                    doSeekByPullingFrames = false;

                                bufferedLeadingFrames.Add(frame);
                            }
                            else if (frame.Type == bufferedLaggingFrames.Type)
                            {
                                // add the lagging frame no matter what
                                if (bufferedLaggingFrames.IsFull)
                                    bufferedLaggingFrames.RemoveFirst();

                                bufferedLaggingFrames.Add(frame);
                            }

                            // Find out if we have the frame
                            var seekFrameIndex = bufferedLeadingFrames.IndexOf(renderTime, true);
                            var minimumFrameCount = (seekFrameIndex - 1) * 2;

                            // if we have more than enough frames in the buffer or we have reached a full or end condition, stop buffering frames
                            if (seekFrameIndex > 0)
                                if (bufferedLeadingFrames.Count >= minimumFrameCount || bufferedLeadingFrames.IsFull || IsAtEndOfStream)
                                    doSeekByPullingFrames = false;

                        }

                        // We're already padt the end of the stream. Natural duration was wron for the leading frames cache.
                        if (IsAtEndOfStream && bufferedLeadingFrames.Count <= 0)
                        {
                            doSeekInStream = true;
                            seekTime -= seekOffsetLength;
                            maxSeekStartTime = seekTime - allowedThreshold;
                            seekToLastFrame = true;
                        }

                        if (doSeekInStream)
                            break;

                        if (doSeekByPullingFrames == false || IsAtEndOfStream)
                        {
                            PrimaryFramesCache.Replace(bufferedLeadingFrames);
                            SecondaryFramesCache.Replace(bufferedLaggingFrames);

                            if (seekToLastFrame && PrimaryFramesCache.Count > 0)
                                RealtimeClock.Seek(PrimaryFramesCache.LastFrameTime);

                            return;
                        }
                    }
                }
            }
            finally
            {
#if DEBUG
                seekStopwatch.Stop();
                SeekTimes.Add(seekStopwatch.ElapsedMilliseconds);
                InnerLoopCounts.Add(innerLoopCount);
                System.Diagnostics.Debug.WriteLine("Seek @ {6:0.000} = Long: {0:00}\t Short: {1:000}\t Short (AVG): {2:0.000}\t Waste Count: {3:000}\t Elapsed: {4}\tElapsed (AVG): {5:0.000}",
                    outerLoopCount, innerLoopCount, InnerLoopCounts.Average(), frameReleaseCount, seekStopwatch.ElapsedMilliseconds, SeekTimes.Average(), renderTime);
#endif
            }

        }