I am looking to create a very basic screen sharing application in C#. No remote control necessary. I just want a user to be able to broadcast their screen to a webserver.
How should I implement this? (Any pointer in the right direction will be greatly appreciated).
It does NOT need to be high FPS. Would be sufficient to even update ever 5s or so. Do you think it would be sufficient to just upload a screenshot ever 5 seconds to my web server?
I previously blogged about how remote screen sharing software works here, it is not specific to C# but it gives a good fundamental understanding on the topic. Also linked in that article is the remote frame buffer spec which you'll also probably want to read up on.
Basically you will want to take screenshots and you can transmit those screenshots and display them on the other side. You can keep the last screenshot and compare the screenshot in blocks to see which blocks of the screenshot you need to send. You would typically do some sort of compression before sending the data.
To have remote control you can track mouse movement and transmit it and set the pointer position on the other end. Also ditto about keystrokes.
As far as compression goes in C#, you can simply use JpegBitmapEncoder to create your screenshots with Jpeg compression with the quality that you want.
JpegBitmapEncoder encoder = new JpegBitmapEncoder();
encoder.QualityLevel = 40;
To compare file blocks you are probably best to create a hash on the old block and the new one, and then check to see if they are the same. You can use any hashing algorithm you want for this.
Here's code to take a screenshot, uncompressed as a bitmap:
public static Bitmap TakeScreenshot() {
Rectangle totalSize = Rectangle.Empty;
foreach (Screen s in Screen.AllScreens)
totalSize = Rectangle.Union(totalSize, s.Bounds);
Bitmap screenShotBMP = new Bitmap(totalSize.Width, totalSize.Height, PixelFormat.
Format32bppArgb);
Graphics screenShotGraphics = Graphics.FromImage(screenShotBMP);
screenShotGraphics.CopyFromScreen(totalSize.X, totalSize.Y, 0, 0, totalSize.Size,
CopyPixelOperation.SourceCopy);
screenShotGraphics.Dispose();
return screenShotBMP;
}
Now just compress it and send it over the wire, and you're done.
This code combines all screens in a multiscreen setup into one image. Tweak as needed.
Well, it can be as simple as taking screenshots, compressing them, and then sending them over the wire. However, there is existing software that already does this. Is this for practice?
I'm looking to do something similar, and I just found this up on CodeProject. I think this will help you.
http://www.codeproject.com/Articles/371955/Motion-JPEG-Streaming-Server
The key player on sharing/replicating a screen is a COM Component called: RPDViewer
Add that com component to your window form and in References as well..
and thin add this code to your form load and you will get the screen replicated in your form:
using RDPCOMAPILib;
using System;
using System.Windows.Forms;
namespace screenSharingAttempt
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
RDPSession x = new RDPSession();
private void Incoming(object Guest)
{
IRDPSRAPIAttendee MyGuest = (IRDPSRAPIAttendee)Guest;
MyGuest.ControlLevel = CTRL_LEVEL.CTRL_LEVEL_INTERACTIVE;
}
//access to COM/firewall will prompt
private void button1_Click(object sender, EventArgs e)
{
x.OnAttendeeConnected += Incoming;
x.Open();
}
//connect
private void button2_Click(object sender, EventArgs e)
{
IRDPSRAPIInvitation Invitation = x.Invitations.CreateInvitation("Trial", "MyGroup", "", 10);
textBox1.Text = Invitation.ConnectionString;
}
//Share screen
private void button4_Click(object sender, EventArgs e)
{
string Invitation = textBox1.Text;// "";// Interaction.InputBox("Insert Invitation ConnectionString", "Attention");
axRDPViewer1.Connect(Invitation, "User1", "");
}
//stop sharing
private void button5_Click(object sender, EventArgs e)
{
axRDPViewer1.Disconnect();
}
}
}
Related
I try to open an external editor during Runtime and edit an image which is currently is set to a PictureBox, edit the image and update the image after closing the editor.
For this, I have a simple c# windows application with a PictureBox two Button one to load PictureBox Image from file and another to edit the image using MS Paint.
Here is the code:
public partial class Form1 : Form
{
string myImagePath = #"C:\temp\bt_logo.png";
public Form1()
{
InitializeComponent();
}
private void button1_Click(object sender, EventArgs e)
{
pictureBox1.Image = Image.FromFile(myImagePath);
}
private void button2_Click(object sender, EventArgs e)
{
System.Diagnostics.ProcessStartInfo launchEditor = new System.Diagnostics.ProcessStartInfo();
launchEditor.FileName = "mspaint";
launchEditor.Arguments = myImagePath;
launchEditor.UseShellExecute = true;
System.Diagnostics.Process.Start(launchEditor);
}
}
The Editor is openned successfully but the changes cannot be saved because of access problem:
Any idea how to solve this problem?
EDIT1:
In order to stop accessing the image when the editor is open, I modified the code of button2_Click() as follows:
pictureBox1.Image = null;
System.Diagnostics.ProcessStartInfo launchEditor = new System.Diagnostics.ProcessStartInfo();
launchEditor.FileName = "mspaint";
launchEditor.Arguments = myImagePath;
launchEditor.UseShellExecute = true;
System.Diagnostics.Process.Start(launchEditor);
pictureBox1.Image = Image.FromFile(myImagePath);
same resault. As another try, I made a copy of the image, modified it and copied it to the original image,
System.IO.File.Copy(myImagePath, myImagePath_temp, true);
System.Diagnostics.ProcessStartInfo launchEditor = new System.Diagnostics.ProcessStartInfo();
launchEditor.FileName = "mspaint";
launchEditor.Arguments = myImagePath_temp;
launchEditor.UseShellExecute = true;
System.Diagnostics.Process.Start(launchEditor);
System.IO.File.Copy(myImagePath_temp, myImagePath, true);
the same resault!
This question is essentially a duplicate of
Open Image from file, then release lock?
Image.FromFile locks the file on disk, until the image variable in your code is disposed of. You should observe the accepted answer to that question above; it provides a way to load the image data from disk, copy it inside the memory of your program, and then release the lock on the file and use the copy of the bitmap data in your picturebox
You'll find an answer on how to load your image without it being locked in the file system. I'm writing an answer instead of a comment because I wanted to give a bit of further advice to the rest of the program
Take a look at the FileSystemWatcher class; Notification when a file changes?
you can use it to detect changes to your file so the picture box can be updated when the file is saved rather than when paint is quit- this will be easier than coding to detect the app closing
Problem:
As a part of school project, I attempt to build an application that provides a guitar AMP using the NAudio library.
When i plug in the guitar it recognizes it, and everything is working properly, but there is a huge delay between the input and the output from the speakers.
Here is my source code:
private void button2_Click(object sender, EventArgs e)
{
if (sourceList.SelectedItems.Count == 0) return;
int deviceNumber = sourceList.SelectedItems[0].Index;
sourceStream = new WaveIn();
sourceStream.DeviceNumber = deviceNumber;
sourceStream.WaveFormat = new WaveFormat(44100, WaveIn.GetCapabilities(deviceNumber).Channels);
sourceStream.StartRecording();
WaveInProvider waveIn = new WaveInProvider(sourceStream);
waveOut = new DirectSoundOut();
waveOut.Init(waveIn);
waveOut.Play();
}
in this code I catch an event of a button click that uses the selected input (microphone/guitar) and converts the sound it recieves to output.
The delay between the input and the output is around ~1sec and it's a deal breaker.
How do I improve the delay, to make the application more responsive?
DirectSoundOut and WaveIn are not particularly low-latency audio APIs. For something like this, ASIO is preferable. AsioOut is unfortunately a bit more complicated to work with, but it should allow you to get much lower latencies.
everyone. I have been stuck here dealing with this bugs for days, but I still couldn't figure it out.
My guess: I think my code has some problem as I did not dispose the object properly after using it, (I'm not very familiar with these concepts of releasing resources, threading) .
I got these code by taking reference of what people did on youtube, but despite me doing exactly the same thing, my code didn't work out nicely.
SITUATION:
I have two picture boxes, left one can take video of me, right one take the snapshot, if you press button1 , you will start the video, clone_button will copy a image i.e. take a snapshot, and save_image should save it to the path reference, however, i get a generic error occured in GDI+ again and again while I'm trying to save it. Also, my debugger seemed to get crazy (i.e. failed to terminate the vshost.exe ) once I ran this program, I have to restart the computer to get my code running again, which is bleak and frustrating.
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.IO;
using System.Drawing.Imaging;
//AForge.Video dll
using AForge.Video;
using AForge.Video.DirectShow;
using AForge.Imaging;
using AForge.Imaging.Filters;
using AForge;
namespace WebCameraCapture
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
private FilterInfoCollection CaptureDevice; // list of webcam
private VideoCaptureDevice FinalFrame;
private void Form1_Load(object sender, EventArgs e)
{
CaptureDevice = new FilterInfoCollection(FilterCategory.VideoInputDevice);//constructor
foreach (FilterInfo Device in CaptureDevice)
{
comboBox1.Items.Add(Device.Name);
}
comboBox1.SelectedIndex = 0; // default
FinalFrame = new VideoCaptureDevice();
}
private void button1_Click(object sender, EventArgs e)
{
FinalFrame = new VideoCaptureDevice(CaptureDevice[comboBox1.SelectedIndex].MonikerString);// specified web cam and its filter moniker string
FinalFrame.NewFrame += new NewFrameEventHandler(FinalFrame_NewFrame);// click button event is fired,
FinalFrame.Start();
}
void FinalFrame_NewFrame(object sender, NewFrameEventArgs eventArgs) // must be void so that it can be accessed everywhere.
// New Frame Event Args is an constructor of a class
{
pictureBox1.Image = (Bitmap)eventArgs.Frame.Clone();// clone the bitmap
}
private void From1_CLosing(object sender, EventArgs e)
{
if (FinalFrame.IsRunning==true) FinalFrame.Stop();
}
private void save_Click(object sender, EventArgs e)
{
if (pictureBox2.Image != null)
{
Bitmap varBmp = new Bitmap(pictureBox2.Image);
Bitmap newBitmap = new Bitmap(varBmp);
varBmp.Dispose();
varBmp = null;
varBmp.Save(#"C:\a.png", ImageFormat.Png);
}
else
{ MessageBox.Show("null exception"); }
}
private void clone_Click(object sender, EventArgs e)
{
pictureBox2.Image = (Bitmap)pictureBox1.Image.Clone();
}
}
}
Any AForge.net user can just PRESS the LINK below and try it out. Thanks!
SAMPLE
After having a look at your code, to me it appears that you are disposing of your image right before you save it. Meaning that your program can't save the image, because it doesn't exist anymore. Actually it reads that you've essentially removed the captured image twice, once on dispose, the second when you set it as null.
So if you move the two code segments after the save, it should be working. Granted without using a dialog box to change the name of the file, you'll surely receive an error unless you remove that file after each time it has been created.
private void save_Click(object sender, EventArgs e)
{
if (pictureBox2.Image != null)
{
//Save First
Bitmap varBmp = new Bitmap(pictureBox2.Image);
Bitmap newBitmap = new Bitmap(varBmp);
varBmp.Save(#"C:\a.png", ImageFormat.Png);
//Now Dispose to free the memory
varBmp.Dispose();
varBmp = null;
}
else
{ MessageBox.Show("null exception"); }
}
If you open the task manager, you can watch how much memory your program is soaking up.
Disposing of the memory after you're done using it, gives it back to the system.
You don't have a dispose inside your FinalFrame_NewFrame thread, so when the camera is reading images,
you should see the memory usage continue to climb until you stop the program.
I've added dispose to my thread, putting the memory usage under control, but now I'm debugging my image saves. Because I'm disposing, I can't save the image lol. My program ends up trying to save a null image file and throws the appropriate error.
I'm using a 2nd picurebox just as you are, but using for example, pbox2.image = pbox1.image, doesn't copy the data, it copies the memory location with the image data, so when I dispose pbox1 to free memory, the image data disappears with the memory location.
So, I had the same issue, and it was resolved one, by moving the dispose method, and two, I had to change the path, it didnt want to save to C:, so I put it on my desktop, you may not have had this issue if you were running as admin but I did so for anyone else who sees this, dont save to the root of C:.
I am trying to change the code http://sites.google.com/site/webcamlibrarydotnet/winfrom-and-csharp-sample-code-and-download from picture box to image or bitmap as I dont want to display any image or plan to display, all I want is that it will output the image to file.
I have tried changing the webcam.cs from PictureBox _FrameImage to Bitmap _FrameImage and PictureBox ImageControl to Bitmap ImageControl and casting (Bitmap) at e.WebCamImage
As well as changing it on the main form:
private void bWebcam_Click(object sender, EventArgs e)
{
WebCam webcam = new WebCam();
Bitmap image = null;
webcam.InitializeWebCam(ref image);
webcam.Start();
webcam.Stop();
FileStream fstream = new FileStream("testWebcam.jpg", FileMode.Create);
image.Save(fstream, System.Drawing.Imaging.ImageFormat.Jpeg);
fstream.Close();
}
Unhappyly it doesnt seem to work so
how could I change it from picture
box to Bitmap or Image or similar
storage before saving it to a file or
save it to file directly ?
The source code I am using is:
http://sites.google.com/site/webcamlibrarydotnet/winfrom-and-csharp-sample-code-and-download
Instead of using the WebCam class, why not just use the WebCamCapture class directly (since you are not displaying this in a form) and handle the ImageCapture event directly. The event argument for the event contains the Image. You could, in the event handler save the image to disk. Alternately, if you want to use the sample and the WebCam class, and you have a form. Use a PictureBox but leave it hidden (set Visible to false) and then just copy the image from there and save to disk when you need to.
Here is some sample code of using the WebCamCapture class instead of the WebCam class. It should be noted that this code is based on the sample code from the link provided in the question. I have kept the style of the sample so that code lines up.
Edit: Adding example of using WebCamCapture instead of WebCam class. This code should be used to modify Form1.cs in the sample code.
// Instead of having WebCam as member variable, have WemCamCapture
WebCamCapture webCam;
// Change the mainWinForm_Load function
private void mainWinForm_Load(object sender, EventArgs e)
{
webCam = new WebCamCapture();
webCam.FrameNumber = ((ulong)(0ul));
webCam.TimeToCapture_milliseconds = 30;
webCam.ImageCaptured += webcam_ImageCaptured;
}
// Add the webcam Image Captured handler to the main form
private void webcam_ImageCaptured(object source, WebcamEventArgs e)
{
Image imageCaptured = e.WebCamImage;
// You can now stop the camera if you only want 1 image
// webCam.Stop();
// Add code here to save image to disk
}
// Adjust the code in bntStart_Click
// (yes I know there is a type there, but to make code lineup I am not fixing it)
private void bntStart_Click(object sender, Event Args e)
{
webCam.Start(0);
}
Using reflector you can see that internally the WebCam class uses a timer to simulate a framerate. Therefore calling start and stop right after each other will never generate an image since the application doesnt handle application events (and therefore the timer tick event) in between starting and stopping. You should register on the ImageChanged event and call stop in there.
Good luck
** Edit: the start logic **
public void Start(ulong FrameNum)
{
try
{
this.Stop();
this.mCapHwnd = capCreateCaptureWindowA("WebCap", 0, 0, 0, this.m_Width, this.m_Height, base.Handle.ToInt32(), 0);
Application.DoEvents();
SendMessage(this.mCapHwnd, 0x40a, 0, 0);
SendMessage(this.mCapHwnd, 0x432, 0, 0);
this.m_FrameNumber = FrameNum;
this.timer1.Interval = this.m_TimeToCapture_milliseconds;
this.bStopped = false;
this.timer1.Start();
}
catch (Exception exception)
{
MessageBox.Show("An error ocurred while starting the video capture. Check that your webcamera is connected properly and turned on.\r\n\n" + exception.Message);
this.Stop();
}
}
In WebCam.cs you have:
public void InitializeWebCam(ref System.Windows.Forms.PictureBox ImageControl)
{
webcam = new WebCamCapture();
webcam.FrameNumber = ((ulong)(0ul));
webcam.TimeToCapture_milliseconds = FrameNumber;
webcam.ImageCaptured += new WebCamCapture.WebCamEventHandler(webcam_ImageCaptured);
_FrameImage = ImageControl;
}
void webcam_ImageCaptured(object source, WebcamEventArgs e)
{
_FrameImage.Image = e.WebCamImage;
}
If you modify the ImageCaptured code you can do what you want: e.WebCamImage is an Image.
for example you could change/add constructor to accept a file name and, in the ImageCaptured event, you could save image to file.
I develop a Winform Application with the framlework .NET 3.5 in C#.
I would like to allow the user to drag&drop a picture from Word 2007. Basically the user open the docx, select a picture and drag&drop them to my PictureBox.
I've already done the same process with picture files from my desktop and from Internet pages but I can't go through my problem with my Metafile. I've done few researches but I didn't find any solutions solving my issue.
Here is what I've done on my Drag&Drop event :
private void PictureBox_DragDrop(object sender, DragEventArgs e)
{
if (e.Data.GetDataPresent(DataFormats.MetafilePict)){
Image image = new Metafile((Stream)e.Data.GetData(DataFormats.MetafilePict));
}
}
I can obtain a stream with this code : (Stream)e.Data.GetData(DataFormats.MetafilePict) but I don't know how to convert it into a Metafile or better an Image object.
If you have any idea or solution, I'll be glad to read it.
Thanks,
Here is a working example of Drag n Drop from Word (not for PowerPoint and Excel):
static Metafile GetMetafile(System.Windows.Forms.IDataObject obj)
{
var iobj = (System.Runtime.InteropServices.ComTypes.IDataObject)obj;
var etc = iobj.EnumFormatEtc(System.Runtime.InteropServices.ComTypes.DATADIR.DATADIR_GET);
var pceltFetched = new int[1];
var fmtetc = new System.Runtime.InteropServices.ComTypes.FORMATETC[1];
while (0 == etc.Next(1, fmtetc, pceltFetched) && pceltFetched[0] == 1)
{
var et = fmtetc[0];
var fmt = DataFormats.GetFormat(et.cfFormat);
if (fmt.Name != "EnhancedMetafile")
{
continue;
}
System.Runtime.InteropServices.ComTypes.STGMEDIUM medium;
iobj.GetData(ref et, out medium);
return new Metafile(medium.unionmember, true);
}
return null;
}
private void Panel_DragDrop(object sender, DragEventArgs e)
{
if (e.Data.GetDataPresent(DataFormats.EnhancedMetafile) & e.Data.GetDataPresent(DataFormats.MetafilePict))
{
Metafile meta = GetMetafile(e.Data);
Image image = meta;
}
}
After this you can use image.Save to save picture or you can use it on picturebox or other control.
I think you need to call new Metafile(stream) as there is no method .FromStream in Metafile.
I'm still digging into he web to try different way to solve my issue.
Hopefully I've found this unanswered thread talking about my problem but without any response :
Get Drag & Drop MS Word image + DataFormats.EnhancedMetafile & MetafilePict :
http://www.codeguru.com/forum/showthread.php?t=456722
I work around with another io be able to copy floating Image (Image stored in Shape and not InlineShape) with Word 2003 and pasting into my winform. I can't paste the link of the second source (because of my low reputation on this website) but I'll do if someone request.
So apparently there are a common issue with the fact that you cannot access to your Metafile stored in the Clipboard and by Drag&Drop.
I still need to understand how to get my Metafile by Drag&Drop.