/// <summary>
/// Get the next sample from the appropriate source given the specified payload and the recompression and
/// slide stream settings for this segment.
/// </summary>
private bool getNextSample(PayloadType payload, out BufferChunk sample, out long timestamp, out bool newstream, out bool keyframe)
{
if (payload == PayloadType.dynamicAudio)
{
if (norecompression)
{
if (audiorecompression)
{
newstream = false; keyframe = false;
return(mixer.GetNextStreamSample(out sample, out timestamp));
}
else
{
keyframe = false;
return(audioStreams[0].GetNextSample(out sample, out timestamp, out newstream));
}
}
else
{
newstream = false; keyframe = false;
return(mixer.GetNextSample(out sample, out timestamp));
}
}
else if (payload == PayloadType.dynamicVideo)
{
if (norecompression)
{
if (useSlideStream)
{
newstream = false;
//unsupported:
//return slideStream.GetNextStreamSample(out sample, out timestamp, out keyframe);
}
else
{
return(videoStream.GetNextSample(out sample, out timestamp, out keyframe, out newstream));
}
}
else
{
//Note: keyframe is not relevant for uncompressed video.
if (useSlideStream)
{
newstream = false; keyframe = false;
return(slideStream.GetNextSample(out sample, out timestamp, out newstream));
}
else
{
keyframe = false;
return(videoStream.GetNextSample(out sample, out timestamp, out newstream));
}
}
}
sample = null;
timestamp = 0;
newstream = false;
keyframe = false;
return(false);
}
/// <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);
}
