/// <summary>
/// Construct.
/// </summary>
/// <param name="msMinDequeuePeriod">Minimum delay in milliseconds between dequeue events</param>
/// <param name="scriptBitrate">Bits per second available in the current Windows Media script stream</param>
public ScriptQueue(int msMinDequeuePeriod, int scriptBitrate, String baseUrl, String extent)
{
seenStudentSubmissions = new Hashtable();
rtUpdate = new RTUpdate();
mainQueue = new ArrayList();
subQueue = new ArrayList();
lastSlideTime = lastURLTime = lastScrollTime = DateTime.Now;
lastEnqueueTime = DateTime.MinValue;
lastSlideIndex = 0;
lastDeckGuid = Guid.Empty;
minDequeuePeriod = msMinDequeuePeriod;
this.scriptBitrate = scriptBitrate;
maxBytesPerSecond = scriptBitrate / 10; //theoretically we would divide by 8, but in practice we need a little extra safety factor.
bwUpdateLockObject = new object();
this.baseUrl = baseUrl;
this.extent = extent;
lastUrl = null;
scEnqueueMutex = new Mutex(false, "scEnqueue");
DequeueThread = new Thread(new ThreadStart(dequeueThread));
DequeueThread.Name = "ScriptQueue dequeue thread";
DequeueThread.SetApartmentState(ApartmentState.MTA); //Needed for WM interop
DequeueThread.Start();
LastRtUpdate = new RTUpdate();
cp3Mgr = new CP3Manager.CP3Manager();
}
/// <summary>
/// We receive this message when an instructor navigates between slides in a deck. There's also one that we
/// want to ignore that occurs when the instructor opens a new deck but before navigating to a slide in the deck.
/// </summary>
/// <param name="stdm"></param>
/// <returns></returns>
internal object AddSlideDeckTraversal(CP3Msgs.SlideDeckTraversalMessage stdm)
{
//If m.Predecessor.Child is a TOC entry, look up info for RTUPdate there.
if ((stdm.Predecessor != null) && (stdm.Predecessor.Child != null) &&
(stdm.Predecessor is CP3Msgs.SlideInformationMessage) &&
(stdm.Predecessor.Child is CP3Msgs.TableOfContentsEntryMessage) &&
(stdm.Parent != null) && (stdm.Parent is CP3Msgs.DeckInformationMessage))
{
//Debug.WriteLine(stdm.Parent.Parent.ToString(), "*****");
//We get one of these when a deck is first opened, but before the instructor navigates to it. Filter it out
//by remembering the current deck ID and ignoring messages for decks other than the current.
if ((currentDeckId == Guid.Empty) || (currentDeckId.Equals((Guid)stdm.Parent.TargetId)))
{
currentSlideId = (Guid)stdm.Predecessor.TargetId;
currentDeckId = (Guid)stdm.Parent.TargetId;
RTUpdate rtu = this.toc.GetRtUpdate((Guid)stdm.Predecessor.Child.TargetId);
return(rtu);
}
}
else
{
//No warning because this happens when a new SS deck is created upon receipt of the first submission.
Debug.WriteLine("A SlideDeckTraversal is being ignored because it lacks the expected message graph.");
}
return(null);
}
internal RTUpdate GetRtUpdate(Guid tocKey)
{
if (this.toc.ContainsKey(tocKey))
{
TocEntry entry = (TocEntry)toc[tocKey];
if (entry.DeckType == DeckTypeEnum.QuickPoll)
{
Debug.WriteLine("");
}
if (!UpdateAssociation(entry))
{
//If we failed to map a student submission to a deck it could be because the SS is on
// a whiteboard page, or it could be that we don't yet have a TOC entry for the
// original slide. For now, just treat both cases as if
// they were whiteboard.
// P2: Make a way to mark the message as SS and leave the deck association empty, and
// have that be understood as a SS on a WB. I think this requires an update to WebViewer?
RTUpdate rtu = entry.ToRtUpdate();
rtu.DeckType = (int)DeckTypeEnum.Whiteboard;
return(rtu);
}
return(entry.ToRtUpdate());
}
return(null);
}
private void UpdateRTUpdate(RTUpdate rtu)
{
lock (rtUpdate) {
rtUpdate = rtu;
rtUpdate.BaseUrl = baseUrl;
rtUpdate.Extent = extent;
}
}
private void enqueueMain(WorkItem wi, RTUpdate rtu)
{
lock (mainQueue)
mainQueue.Add(wi);
if (wi.Type != "URL")
{
if (OnEnqueue != null)
{
ScriptEventArgs dea = new ScriptEventArgs(Convert.ToBase64String(wi.BC.Buffer, wi.BC.Index, wi.BC.Length), wi.Type);
OnEnqueue(this, dea);
}
}
}
/// <summary>
/// Fetch image from web for Presenter 2 data
/// </summary>
/// <param name="o"></param>
private void GetWebImageThread2(object o)
{
RTUpdate rtu = (RTUpdate)o;
if ((rtu.BaseUrl == null) || (rtu.Extent == null))
{
return;
}
if (rtu.DeckGuid == Guid.Empty)
{
return;
}
System.Drawing.Image tmpImage;
string imgURL;
Guid pDeckGuid = rtu.DeckGuid;
int pSlideNumber = rtu.SlideIndex + 1;
/// Student submissions need to map to a presentation deck and slide.
if ((rtu.DeckType == (Int32)DeckTypeEnum.StudentSubmission) ||
(rtu.DeckType == (Int32)DeckTypeEnum.QuickPoll))
{
pDeckGuid = rtu.DeckAssociation;
pSlideNumber = rtu.SlideAssociation + 1;
}
//implicit assumption that rtu.BaseUrl includes the trailing '/'.
imgURL = rtu.BaseUrl + pDeckGuid.ToString() + "/slide" + pSlideNumber.ToString() + "." + rtu.Extent;
try
{
tmpImage = System.Drawing.Image.FromStream(webClient.OpenRead(imgURL));
}
catch
{
parent.LoggerWriteInvoke("Exception while opening image url: " + imgURL);
return;
}
//put the new image in the SlideDeck.
int internalIndex = slideMap.GetMapping(rtu.SlideIndex, rtu.DeckGuid);
slideDeck.SetSlide(internalIndex, new Slide(new Bitmap(tmpImage), "Slide " + internalIndex.ToString()));
// display the newly loaded slide.
DisplaySlideIndex(internalIndex); // the latter two params are not relevant here.
}
internal RTUpdate ToRtUpdate()
{
RTUpdate rtu = new RTUpdate();
rtu.DeckGuid = deckId;
rtu.SlideIndex = slideIndex;
rtu.DeckType = (int)deckType;
rtu.SlideSize = slideSize;
//background colors can be attached to any slide and deck, but they only show
//on whiteboards, or on the area around a minimized slide.
if (!backgroundColor.Equals(Color.Empty))
{
//Explicitly set slide color has top priority
rtu.BackgroundColor = backgroundColor;
}
else if ((TableOfContents.TheInstance.DeckBackgroundColors.ContainsKey(deckId)) &&
(!TableOfContents.TheInstance.DeckBackgroundColors[deckId].Equals(Color.Empty)))
{
//DeckBackground color is checked next.
rtu.BackgroundColor = TableOfContents.TheInstance.DeckBackgroundColors[deckId];
}
else
{
//If none are set, default to white.
rtu.BackgroundColor = Color.White;
}
if ((deckType == DeckTypeEnum.StudentSubmission) ||
(deckType == DeckTypeEnum.QuickPoll))
{
rtu.DeckAssociation = deckAssociation;
rtu.SlideAssociation = slideAssociation;
rtu.DeckTypeAssociation = (int)deckTypeAssociation;
}
return(rtu);
}
public static void CopyRtUpdate(RTUpdate from, ref RTUpdate to)
{
if (from == null)
{
return;
}
if (to == null)
{
return;
}
to.BackgroundColor = from.BackgroundColor;
to.BaseUrl = from.BaseUrl;
to.DeckAssociation = from.DeckAssociation;
to.DeckGuid = from.DeckGuid;
to.DeckType = from.DeckType;
to.Extent = from.Extent;
to.ScrollExtent = from.ScrollExtent;
to.ScrollPosition = from.ScrollPosition;
to.SlideAssociation = from.SlideAssociation;
to.SlideIndex = from.SlideIndex;
to.SlideSize = from.SlideSize;
}
public static bool RtUpdatesEqual(RTUpdate rtu1, RTUpdate rtu2)
{
if ((rtu1 == null) || (rtu2 == null))
{
return(false);
}
if ((rtu1.BackgroundColor != rtu2.BackgroundColor) ||
(rtu1.BaseUrl != rtu2.BaseUrl) ||
(rtu1.DeckAssociation != rtu2.DeckAssociation) ||
(rtu1.DeckGuid != rtu2.DeckGuid) ||
(rtu1.DeckType != rtu2.DeckType) ||
(rtu1.Extent != rtu2.Extent) ||
(rtu1.ScrollExtent != rtu2.ScrollExtent) ||
(rtu1.ScrollPosition != rtu2.ScrollPosition) ||
(rtu1.SlideAssociation != rtu2.SlideAssociation) ||
(rtu1.SlideIndex != rtu2.SlideIndex) ||
(rtu1.SlideSize != rtu2.SlideSize))
{
return(false);
}
return(true);
}
/// <summary>
/// This is a message used in the beacon, and it is also the message that indicates when
/// an instructor navigates to an initial slide in a newly opened deck.
/// </summary>
/// <param name="icdtcm"></param>
/// <returns></returns>
/// This is the beacon message graph we expect:
/// {InstructorMessage;
/// child={InstructorCurrentDeckTraversalChangedMessage;
/// pred={SlideInformationMessage;
/// pred={InstructorCurrentPresentationChangedMessage;};
/// child={TableOfContentsEntryMessage;};};};}
internal List <object> AddInstructorCurrentDeckTraversalChanged(UW.ClassroomPresenter.Network.Messages.Network.InstructorCurrentDeckTraversalChangedMessage icdtcm)
{
//If m.Predecessor.Child is a TOC entry, return a RTUPdate.
List <object> outputMessages = null;
if ((icdtcm.Predecessor != null) && (icdtcm.Predecessor.Child != null) &&
(icdtcm.Predecessor is CP3Msgs.SlideInformationMessage) &&
(icdtcm.Predecessor.Child is CP3Msgs.TableOfContentsEntryMessage))
{
if (icdtcm.Predecessor.Predecessor == null) //This effectively filters out the beacon messages.
//In some late-joiner scenarios, we may not have the TOC entry.
{
if (!toc.ContainsEntry((Guid)icdtcm.Predecessor.Child.TargetId))
{
string err;
Guid slideId = toc.AddTableOfContentsEntry((CP3Msgs.TableOfContentsEntryMessage)icdtcm.Predecessor.Child,
icdtcm.DeckId, icdtcm.Dispositon, out err);
if (err != null)
{
Debug.WriteLine(err);
}
else if (!slideId.Equals(Guid.Empty))
{
outputMessages = this.getCachedStrokes(slideId);
}
}
if (currentDeckId.Equals(icdtcm.DeckId) && currentSlideId.Equals((Guid)icdtcm.Predecessor.TargetId))
{
Debug.WriteLine("***Ignoring InstructorCurrentDeckTraversalChanged because it matches the current slide and deck");
return(outputMessages);
}
RTUpdate rtu = this.toc.GetRtUpdate((Guid)icdtcm.Predecessor.Child.TargetId);
if (rtu != null)
{
currentDeckId = icdtcm.DeckId;
currentSlideId = (Guid)icdtcm.Predecessor.TargetId;
}
else
{
Debug.WriteLine("Warning: Navigation failure.");
}
if (outputMessages == null)
{
outputMessages = new List <object>();
}
outputMessages.Add(rtu);
return(outputMessages);
}
else
{
//The beacon also causes navigation in some cases, eg. the initial slide after we join.
//If the beacon has a toc entry we don't already have, add it.
if (!toc.ContainsEntry((Guid)icdtcm.Predecessor.Child.TargetId))
{
string err;
Guid slideId = toc.AddTableOfContentsEntry((CP3Msgs.TableOfContentsEntryMessage)icdtcm.Predecessor.Child,
icdtcm.DeckId, icdtcm.Dispositon, out err);
if (err != null)
{
Debug.WriteLine(err);
}
else if (!slideId.Equals(Guid.Empty))
{
outputMessages = this.getCachedStrokes(slideId);
}
}
//if the beacon indicates a slide other than the current slide, navigate there.
if ((!currentSlideId.Equals((Guid)icdtcm.Predecessor.TargetId)) ||
(!currentDeckId.Equals(icdtcm.DeckId)))
{
currentSlideId = (Guid)icdtcm.Predecessor.TargetId;
RTUpdate rtu = this.toc.GetRtUpdate((Guid)icdtcm.Predecessor.Child.TargetId);
currentDeckId = (Guid)icdtcm.DeckId;
currentSlideId = (Guid)icdtcm.Predecessor.TargetId;
if (outputMessages == null)
{
outputMessages = new List <object>();
}
outputMessages.Add(rtu);
return(outputMessages);
}
}
}
else
{
warning += "Warning: Found InstructorCurrentDeckTraversalChangedMessage message without a TOC Entry. ";
}
return(outputMessages);
}
/// <summary>
/// Filter the contents of the existing tempdir using the specified
/// difference threshold. Rewrite tempdir, metadata and differenceMetrics.
/// </summary>
/// <param name="threshold"></param>
internal void Refilter(double threshold)
{
//Make an imageFilter instance and configure with the new threshold.
ImageFilter.ImageFilter imgFilter = null;
try {
imgFilter = new ImageFilter.ImageFilter();
imgFilter.DifferenceThreshold = threshold;
}
catch {
return;
}
Console.WriteLine("Refiltering framegrabs using threshold: " + threshold.ToString());
List <double> newDifferenceMetrics = new List <double>();
List <PresentationMgr.DataItem> newMetadata = new List <PresentationMgr.DataItem>();
RTUpdate rtu = new RTUpdate();
this.deckGuid = Guid.NewGuid();
rtu.DeckGuid = this.deckGuid;
rtu.SlideSize = 1.0;
rtu.DeckType = (Int32)DeckTypeEnum.Presentation;
string filebase = "slide";
string extent = ".jpg";
int fileindex = 1;
try {
string newDir = Utility.GetTempDir();
Directory.CreateDirectory(newDir);
string[] files = Directory.GetFiles(this.tempdir, "*.jpg");
Array.Sort(files, new PMPComparer());
string previous = null;
for (int i = 0; i < files.Length; i++)
{
string file = files[i];
string msg;
bool error = false;
double metric;
if (imgFilter.ImagesDiffer(previous, file, out msg, out error, out metric))
{
string newFilename = filebase + fileindex.ToString() + extent;
File.Copy(file, Path.Combine(newDir, newFilename));
rtu.SlideIndex = fileindex - 1; // This is a zero-based index
newMetadata.Add(new PresentationMgr.DataItem(metadata[i].Timestamp, PresentationMgr.CopyRTUpdate(rtu)));
newDifferenceMetrics.Add(metric);
DateTime t = new DateTime(metadata[i].Timestamp);
Console.WriteLine("Refilter keeping old index: " + (i + 1).ToString() +
"; new index: " + fileindex.ToString() +
"; difference: " + metric.ToString() + "; time: " + t.ToString());
fileindex++;
previous = file;
}
}
this.metadata = newMetadata;
this.differenceMetrics = newDifferenceMetrics;
Directory.Delete(this.tempdir, true);
this.tempdir = newDir;
}
catch (Exception) {
return;
}
}
/// <summary>
/// Capture stills from the video stream. Create a temporary directory and save the images there.
/// Compile a list of DataItem objects to indicate when the slide transitions should take place.
/// </summary>
/// <returns></returns>
public string Process()
{
ImageFilter.ImageFilter imgFilter = null;
try {
imgFilter = new ImageFilter.ImageFilter();
imgFilter.DifferenceThreshold = this.differenceThreshold;
}
catch {
this.errorLog.Append("Video capture images in the presentation will not be filtered probably " +
"because ImageMagick is not available in the configuration.\r\n");
}
this.differenceMetrics = new List <double>();
metadata = new List <PresentationMgr.DataItem>();
RTUpdate rtu = new RTUpdate();
this.deckGuid = Guid.NewGuid();
rtu.DeckGuid = this.deckGuid;
rtu.SlideSize = 1.0;
rtu.DeckType = (Int32)DeckTypeEnum.Presentation;
this.videoStream = new StreamMgr(videoDescriptor.VideoCname, videoDescriptor.VideoName, new DateTime(this.start), new DateTime(this.end), false, PayloadType.dynamicVideo);
this.videoStream.ToRawWMFile(this.progressTracker);
MediaTypeVideoInfo mtvi = videoStream.GetUncompressedVideoMediaType();
this.tempdir = Utility.GetTempDir();
Directory.CreateDirectory(this.tempdir);
string filebase = "slide";
string extent = ".jpg";
int fileindex = 1;
BufferChunk bc;
long time;
bool newStream;
string previousFile = null;
this.stopNow = false;
while ((!stopNow) && (videoStream.GetNextSample(out bc, out time, out newStream)))
{
if ((time - lastFramegrab) >= (long)(this.frameGrabIntervalMs * Constants.TicksPerMs))
{
DateTime dt = new DateTime(time);
Debug.WriteLine("time=" + dt.ToString() + ";length=" + bc.Length.ToString());
lastFramegrab = time;
string filepath = Path.Combine(tempdir, filebase + fileindex.ToString() + extent);
PixelFormat pixelFormat = subtypeToPixelFormat(mtvi.SubType);
Bitmap bm = new Bitmap(mtvi.VideoInfo.BitmapInfo.Width, mtvi.VideoInfo.BitmapInfo.Height, pixelFormat);
BitmapData bd = bm.LockBits(new Rectangle(0, 0, mtvi.VideoInfo.BitmapInfo.Width, mtvi.VideoInfo.BitmapInfo.Height), ImageLockMode.ReadWrite, pixelFormat);
Marshal.Copy(bc.Buffer, 0, bd.Scan0, bc.Length);
bm.UnlockBits(bd);
bm.RotateFlip(RotateFlipType.RotateNoneFlipY);
if ((SCALE) && (mtvi.VideoInfo.BitmapInfo.Width >= 1280))
{
int w = mtvi.VideoInfo.BitmapInfo.Width / 2;
int h = mtvi.VideoInfo.BitmapInfo.Height / 2;
Bitmap scaled = new Bitmap(bm, new Size(w, h));
scaled.Save(filepath, ImageFormat.Jpeg);
}
else
{
bm.Save(filepath, ImageFormat.Jpeg);
}
if (imgFilter != null)
{
string filterMsg;
bool filterError;
double metric;
bool differ = imgFilter.ImagesDiffer(filepath, previousFile, out filterMsg, out filterError, out metric);
if (filterError)
{
//this.errorLog.Append(filterMsg);
Console.WriteLine(filterMsg);
}
if (!differ)
{
continue;
}
this.differenceMetrics.Add(metric);
Console.WriteLine("Framegrab slide index: " + fileindex.ToString() +
"; difference: " + metric.ToString() + "; time: " + dt.ToString());
}
rtu.SlideIndex = fileindex - 1; // This is a zero-based index
metadata.Add(new PresentationMgr.DataItem(time - this.offset, PresentationMgr.CopyRTUpdate(rtu)));
fileindex++;
previousFile = filepath;
}
}
return(null);
}
