/// <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);
}
