How best to receive large short array --- tcp, socket, LabVIEW, ShortBuffer

The application in question works with a LabVIEW program via Ethernet (a tcp connection). The LabVIEW program generates a large (e.g. 600x600) array of numbers (either 32-bit floats or 16-bit signed ints, whichever we choose). The question is what is the fastest, reliable, way to get those numbers? LabVIEW can send it two ways, the first is to convert the array to a string, the second is just to send the array data as-is. I believe that converting to string inflates the size of the message so much that this is not a good option. So I guess my question is how to receive the array of numbers (either as 32-bit floats or 16-bit signed ints)?
I was thinking of using a FloatBuffer or a ShortBuffer. The latter would be best since floats do not get us any extra information in this case, so I do not know why I even bothered to consider using them. I guess what happened was that I learned first of the existence of the FloatBuffer, so I sought to get LabVIEW to send floats. Now that I know there is a ShortBuffer I guess floats are out. Okay, rambling, do you think a LabVIEW array of shorts will be able to get read by a ShortBuffer on the other end of a TCP connection? Also, am I going to have to call read() multiple times in order to get all the elements of the array?

theHandOfTheKing wrote:
The application in question works with a LabVIEW program via Ethernet (a tcp connection). The LabVIEW program generates a large (e.g. 600x600) array of numbers (either 32-bit floats or 16-bit signed ints, whichever we choose). The question is what is the fastest, reliable, way to get those numbers? LabVIEW can send it two ways, the first is to convert the array to a string, the second is just to send the array data as-is. Text is more likely to be reliable as you will be able to read the data to see when something has gone wrong and have a better idea of why.
I believe that converting to string inflates the size of the message so much that this is not a good option. Why do you believe this? Do you have a bandwidth or time limit you haven't mentioned?
So I guess my question is how to receive the array of numbers (either as 32-bit floats or 16-bit signed ints)?You can optimise the data send later after you get something working.
I was thinking of using a FloatBuffer or a ShortBuffer. The latter would be best since floats do not get us any extra information in this case, so I do not know why I even bothered to consider using them. Not sure why float would have less information.
Okay, rambling, do you think a LabVIEW array of shorts will be able to get read by a ShortBuffer on the other end of a TCP connection? Provided the data is only shorts, its ideal.
Also, am I going to have to call read() multiple times in order to get all the elements of the array?yes.

Similar Messages

Need to send and receive larger byte array

I have a small WCF service, self hosted in a console app. On the same computer I have a client application. Both are running in the debugger in VS2008. The proxy code and the config file were generatred from the running service using svcutil.
In one of the service calls, the service reads a pdf file and sends the contents as a byte array. The client receives the byte array, saves it as a pdf file, and displays it.
Everything is fine for all other kinds of calls, and this one works fine also as long as the file is small (say 14K). But if the file is larger (say 84K), the client crashes (VHOST has stopped working).
Is there some kind of setting that will allow me to send and receive larger byte arrays (> 100 K)?
Thanks,
Jon Jacobs
In transmission, subatomic particles managed by professionals.
No innocent electrons were harmed.

Hi Jon,
You'll want something like this to increase the message size quotas:
<bindings>
<basicHttpBinding>
<binding name="basicHttp" allowCookies="true"
maxReceivedMessageSize="20000000"
maxBufferSize="20000000"
maxBufferPoolSize="20000000">
<readerQuotas maxDepth="32"
maxArrayLength="200000000"
maxStringContentLength="200000000"/>
</binding>
</basicHttpBinding>
</bindings>
The justification for the values is simple, they are sufficiently large to accommodate most messages. You can tune that number to fit your needs. The low default value is basically there to prevent DOS type attacks. Making it 20000000 would allow for a distributed
DOS attack to be effective, the default size of 64k would require a very large number of clients to overpower most servers these days.
If you're still getting this error message while using the WCF Test Client, it's because the client has a separate MaxBufferSize setting.
To correct the issue:
Right-Click on the Config File node at the bottom of the tree
Select Edit with SvcConfigEditor
A list of editable settings will appear, including MaxBufferSize.
Note: Auto-generated proxy clients also set MaxBufferSize to 65536 by default.
Let me know if this helped.
Regards,
Raghu

How best to receive photos from PC users?

How can I receive photos in Apple Mail from a PC user who says photos have been either attached or embedded in email? There is no evidence in his email of an attachment. Any guidance for me or that I can offer him would be appreciated. Thanks.
iMac G5 Mac OS X (10.3.9)

Hi Jim
The photos should just show up the same as if a mac user sent them. If they don't show up, it may mean either:
1 that your friend forgot to attach them
2 that your friend is behind a firewall that's been set up to strip away attachments (which is an annoying way of trying to stop the spread of viruses), or
3 that you are behind a firewall that's been set up to strip away attachments
There is one other possibility. In Apple's Mail, if the Junk filter is in training mode, and it thinks that the mail is spam, it may not automatically load the images. When you view the mail from your friend, does it have a brown stripe across the top and is there text saying something like "mail thinks this is junk mail"? If so, then there should be one button so you can mark it as "Not Junk" and another button to "Load Images".

Receiving data through TCP Socket

Hi all,
I am trying to receive some data through TCP Socket from the
server using XMLSocketClass. Ther server is responding with some
data. But I can't access this data in my application. Pls tell me
the reasons for not working of handler private function
dataHandler(event:DataEvent):void .
=============================================================================
<?xml version="1.0" encoding="utf-8"?>
<mx:Application xmlns:mx="
http://www.adobe.com/2006/mxml"
layout="absolute">
<mx:Script>
<![CDATA[
import mx.controls.Alert;
import mx.collections.ArrayCollection;
import flash.display.Sprite;
import flash.events.Event;
import flash.events.DataEvent;
import flash.events.IOErrorEvent;
import flash.net.XMLSocket;
private var socket:XMLSocket;
private var nextId:int;
private var events:ArrayCollection = new ArrayCollection();
public static var host:String = "34.234.43.97";
public static var port:Number = 8002;
public var xml:XML;
private function connectToServer():void
socket = new XMLSocket();
socket.addEventListener(DataEvent.DATA, dataHandler);
configureListeners(socket);
socket.connect(host, port);
//This function is Not working
private function dataHandler(event:DataEvent):void {
Alert.show("dataHandler: " + event.data);
xml = new XML(event.data);
Alert.show(xml); }
private function
configureListeners(dispatcher:IEventDispatcher):void {
dispatcher.addEventListener(Event.CLOSE, closeHandler);
dispatcher.addEventListener(Event.CONNECT, connectHandler);
dispatcher.addEventListener(DataEvent.DATA, dataHandler);
dispatcher.addEventListener(IOErrorEvent.IO_ERROR,
ioErrorHandler);
dispatcher.addEventListener(ProgressEvent.PROGRESS,
progressHandler);
dispatcher.addEventListener(SecurityErrorEvent.SECURITY_ERROR,
securityErrorHandler);
private function closeHandler(event:Event):void {
trace("closeHandler: " + event);
private function ioErrorHandler(event:IOErrorEvent):void {
trace("ioErrorHandler: " + event);
private function progressHandler(event:ProgressEvent):void {
trace("progressHandler loaded:" + event.bytesLoaded + "
total: " + event.bytesTotal);
private function
securityErrorHandler(event:SecurityErrorEvent):void {
trace("securityErrorHandler: " + event);
/* private function dataHandler(event:DataEvent):void {
trace("dataHandler: " + event);
private function connectHandler(event:Event):void
var obj:Object = new Object();
obj.id = nextId++;
obj.eventName="connect";
obj.timestamp = new Date().valueOf();
events.addItem(obj);
private function sendData():void
var xmlvalue:String=txtData.text.toString() ;
var xmlfile:String =
"<command>SndIns<parameter1>0x06</parameter1><parameter2>0x00</parameter2><parameter3>0x7 1</parameter3><parameter4>0x0F</parameter4><parameter5>0x11</parameter5><parameter6>0xFF</ parameter6></command>";
socket.send(xmlfile);
Alert.show(xmlfile);
]]>
</mx:Script>
<mx:HBox width="80%" horizontalAlign="center">
<mx:TextInput id="txtData" name=""/>
<mx:Button id="btnConnect" label="Connect"
click="connectToServer();btnConnect.enabled = false"/>
<mx:Button id="btnSend" label="Send Data"
click="sendData()"/>

</mx:HBox>
<mx:HBox x="10" y="30" width="100%">
<mx:DataGrid width="80%" height="100%"
dataProvider="{xml}">
<mx:columns>
<mx:Array>
<mx:DataGridColumn headerText="Event Name"
dataField="eventName"/>
</mx:Array>
</mx:columns>
</mx:DataGrid>
</mx:HBox>
</mx:Application>

Hi all,
I am trying to receive some data through TCP Socket from the
server using XMLSocketClass. Ther server is responding with some
data. But I can't access this data in my application. Pls tell me
the reasons for not working of handler private function
dataHandler(event:DataEvent):void .
=============================================================================
<?xml version="1.0" encoding="utf-8"?>
<mx:Application xmlns:mx="
http://www.adobe.com/2006/mxml"
layout="absolute">
<mx:Script>
<![CDATA[
import mx.controls.Alert;
import mx.collections.ArrayCollection;
import flash.display.Sprite;
import flash.events.Event;
import flash.events.DataEvent;
import flash.events.IOErrorEvent;
import flash.net.XMLSocket;
private var socket:XMLSocket;
private var nextId:int;
private var events:ArrayCollection = new ArrayCollection();
public static var host:String = "34.234.43.97";
public static var port:Number = 8002;
public var xml:XML;
private function connectToServer():void
socket = new XMLSocket();
socket.addEventListener(DataEvent.DATA, dataHandler);
configureListeners(socket);
socket.connect(host, port);
//This function is Not working
private function dataHandler(event:DataEvent):void {
Alert.show("dataHandler: " + event.data);
xml = new XML(event.data);
Alert.show(xml); }
private function
configureListeners(dispatcher:IEventDispatcher):void {
dispatcher.addEventListener(Event.CLOSE, closeHandler);
dispatcher.addEventListener(Event.CONNECT, connectHandler);
dispatcher.addEventListener(DataEvent.DATA, dataHandler);
dispatcher.addEventListener(IOErrorEvent.IO_ERROR,
ioErrorHandler);
dispatcher.addEventListener(ProgressEvent.PROGRESS,
progressHandler);
dispatcher.addEventListener(SecurityErrorEvent.SECURITY_ERROR,
securityErrorHandler);
private function closeHandler(event:Event):void {
trace("closeHandler: " + event);
private function ioErrorHandler(event:IOErrorEvent):void {
trace("ioErrorHandler: " + event);
private function progressHandler(event:ProgressEvent):void {
trace("progressHandler loaded:" + event.bytesLoaded + "
total: " + event.bytesTotal);
private function
securityErrorHandler(event:SecurityErrorEvent):void {
trace("securityErrorHandler: " + event);
/* private function dataHandler(event:DataEvent):void {
trace("dataHandler: " + event);
private function connectHandler(event:Event):void
var obj:Object = new Object();
obj.id = nextId++;
obj.eventName="connect";
obj.timestamp = new Date().valueOf();
events.addItem(obj);
private function sendData():void
var xmlvalue:String=txtData.text.toString() ;
var xmlfile:String =
"<command>SndIns<parameter1>0x06</parameter1><parameter2>0x00</parameter2><parameter3>0x7 1</parameter3><parameter4>0x0F</parameter4><parameter5>0x11</parameter5><parameter6>0xFF</ parameter6></command>";
socket.send(xmlfile);
Alert.show(xmlfile);
]]>
</mx:Script>
<mx:HBox width="80%" horizontalAlign="center">
<mx:TextInput id="txtData" name=""/>
<mx:Button id="btnConnect" label="Connect"
click="connectToServer();btnConnect.enabled = false"/>
<mx:Button id="btnSend" label="Send Data"
click="sendData()"/>

</mx:HBox>
<mx:HBox x="10" y="30" width="100%">
<mx:DataGrid width="80%" height="100%"
dataProvider="{xml}">
<mx:columns>
<mx:Array>
<mx:DataGridColumn headerText="Event Name"
dataField="eventName"/>
</mx:Array>
</mx:columns>
</mx:DataGrid>
</mx:HBox>
</mx:Application>

Audio over TCP Socket

Hi,
I need a sample code for transmit/receive a audio over TCP socket.. can anybody help me?

You send and receive it in the same way as you handle any binary data.
Kaj

How to use tcp socket to receive a class instance

I've created a class instance c2smsg, then use PS.println(c2smsg) to send the instance to server.
But how can I receive the class and read the class members at the server side?
socket.getInputStream() can only receive String, byte[], or int...

To be clear, here is the sample code, i wrote a TestClass, and i want to send it and read it from the recieving side.
class TestClass{
String testSting = "i love you";
int port = 1024;
//send side
TestClass tc = new TestClass();
PrintWriter out=new PrintWriter(socket.getOutputStream());
out.println(tc); //i am not sure if this is right
//send side end
//receive side
BufferedReader buf =new BufferedReader(new InputStreamReader(client.getInputStream()));
//then what can i do to buf to read out TestClass members? buf.readLine()?
//receive side end

InsufficientMemoryException while sending large byte array in WCF Service callback

Hi
I have a datacontract with a large byte array that is passed by the WCF Service back to the client using a callback contract.
Until the byte array size remains below 25-30 MB, it is passed OK, but as soon as it exceeds that, an InsufficientMemoryException is thrown on the service side. I have set the max message sizes at 100 MB and using MTOM Encoder.
I am using WSDualHTTPBinding with sessions and message security - hence streaming is not an option. I know chunking channels are an option, but I want to try to tune the service and client to maximize the byte array size which can be sent over a normal channel.
Kindly advise how to tune settings to get to around 100 MB byte array size.
Binding section of web.config is given below. Same settings for sizes are used on client.
Thanks
Abhishek
<wsDualHttpBinding>
        <binding name="WSHttpBinding_IService" closeTimeout="00:01:00" openTimeout="00:01:00" receiveTimeout="00:10:00" sendTimeout="00:01:00" bypassProxyOnLocal="false"
transactionFlow="false" hostNameComparisonMode="StrongWildcard" maxBufferPoolSize="100000000" maxReceivedMessageSize="100000000" messageEncoding="Mtom" textEncoding="utf-8" useDefaultWebProxy="true">
          <readerQuotas maxArrayLength="100000000" />
          <security mode="Message">
            <message clientCredentialType="Certificate" algorithmSuite="Default" />
          </security>
        </binding>
      </wsDualHttpBinding>

Hi abhisinghal21,
>>InsufficientMemoryException while sending large byte array in WCF Service callback
First please try to increase the timeout value in the both client and service side to see if it works:
closeTimeout="00:10:00" openTimeout="00:10:00"
receiveTimeout="00:10:00" sendTimeout="00:10:00"
Then since you do not want to the use the Chunking option to help you, maybe you try to change the wsDualHttpBinding to use the binding which supports the streaming mode and supports callback.
In streaming transfer mode, the receiver can begin to process the message before it is completely delivered. And the streaming mode is useful when the information that is passed is lengthy and can be processed serially. Streaming mode is also useful when the
message is too large to be entirely buffered. So it will be better for you to use the streamed mode.
For more information, please try to check:
#How to: Enable Streaming:
http://msdn.microsoft.com/en-us/library/ms789010(v=vs.110).aspx .
Best Regards,
Amy Peng
We are trying to better understand customer views on social support experience, so your participation in this interview project would be greatly appreciated if you have time. Thanks for helping make community forums a great place.
Click
HERE to participate the survey.

How to update a large (over 4 million item) List(Of Byte) quickly by altering indexes contained in a Dictionary(Of Integer, Byte) where the Dictionaries keys are the indexes in the List(Of Byte) that need to be changed to the values for those indexes?

   I'm having some difficulty with transferring images from a UDP Client to a UDP Server. The issue is receiving the bytes necessary to update an original image sent from the Client to the Server and updating the Servers List(Of Byte) with the
new bytes replacing bytes in that list. This is a simplex connection where the Sever receives and the Client sends to utilize the least amount of bandwidth for a "Remote Desktop" style application where the Server side needs image updates of whatever
occurs on the Client desktop.
   So far I can tranfer images with no issue. The images can be be any image type (.Bmp, .Gif, .JPeg, .Png, etc). I was working with sending .JPeg's as they appear to be the smallest size image when a Bitmap is saved to a memory stream as type
.JPeg. And then I am using GZip to compress that byte array again so it is much smaller. However on a loopback on my NIC the speed for sending a full size screen capture is not very fast as the Server updates fairly slowly unless the Clients screen capture
Bitmap is reduced in size to about 1/3'd of the original size. Then about 12000 bytes or less are sent for each update.
   Due to .JPeg compression I suppose there is no way to get the difference in bytes between two .JPegs and only send those when something occurs on the desktop that alters the desktop screen capture image. Therefore I went to using .Bmp's as each
.Bmp contains the same number of bytes in its array regardless of the image alterations on the desktop. So I suppose the difference in bytes from a second screen capture and an inital screen capture are what is different in the second image from the initial
image.
   What I have done so far is save an initial Bitmap of a screen capture using a memory stream and saving as type .Bmp which takes less than 93 milliseconds for 4196406 bytes. Compressing that takes less than 118 milliseconds to 197325 bytes for
the current windows on the desktop. When that is done PictureBox1 is updated from nothing to the captured image as the PictureBox's background image with image layout zoom and the PictureBox sized at 1/2 my screens width and 1/2 my screens height.
   Then I save a new Bitmap the same way which now contains different image information as the PictureBox is now displaying an image so its back color is no longer displayed (solid color Aqua) and the cursor has moved to a different location. The
second Bitmap is also 4196406 in bytes and compressed it was 315473 bytes in size.
   I also just found code from this link Converting a Bitmap to a Byte Array (and Byte Array to Bitmap) which gets a byte array
directly from a Bitmap and the size of that is 3148800 for whatever is full screen captured on my laptop. So I should be able to work with smaller byte arrays at some point.
   The issue I'm having is that once the Client sends an image of the desktop to the Server I only want to update the server with any differences occuring on the Clients desktop. So what I have done is compare the first screen captures bytes (stored
in a List(Of Byte)) to the second screen captures bytes (stored in a List(Of Byte)) by using a For/Next for 0 to 4196405 where if a byte in the first screen captures List is not equal to a byte in the second screen captures List I add the index and byte of
the second screen captures list to a Dictionary(Of Integer, Byte). The Dictionary then only contains the indexes and bytes that are different between the first screen capture and second screen capture. This takes about 125 milliseconds which I think is pretty
fast for 4196406 byte comparison using a For/Next and adding all the different bytes and indexes for each byte to a Dictionary.
    The difference in Bytes between the inital screen capture and the second screen capture is 242587 as an example which changes of course. For that amount of bytes the Dictionary contains 242587 integers as indexes and 242587 bytes as different
bytes totaling 485174 bytes for both arrays (keys, values). Compressed the indexes go from 242587 to 43489 bytes and the values go from 242587 to 34982 bytes. Which means I will have to send 78, 481 bytes from the Client to the Server to update the display
on the server. Quite smaller than the original 4196406 bytes of the second Bitmap saved to type .Bmp or the compressed size of that array which was 315473 bytes. Plus a few bytes I add as overhead so the server knows when an image array ends and how many packets
were sent for the array so it can discard complete arrays if necessary since UDP is lossfull although probably not so much in current networks like it may originally have been when the internet started.
    In reality the data from the Client to the Server will mostly be the cursor as it moves and updating the Server image with only a few hundred bytes I would imagine at a time. Or when the cursor selects a Button for example and the Buttons
color changes causing those differences in the original screen capture.
   But the problem is if I send the Dictionaries Indexes and Bytes to the Server then I need to update the original Bitmap List(Of Byte) on the server by removing the Bytes in the received informations Index locations array from the Servers Bitmap
List(Of Byte) and replacing those Bytes with the Bytes in the received informations Byte array. This takes so long using a For/Next for however many indexes are in the received informations Index array to update the Bitmap List(Of Byte) on the server using
"Bmp1Bytes.RemoveAt(Index As Integer)" followed by "Bmp1Bytes.Insert(Index As Integer, Item As Byte)" in the For/Next.
    I've tried various For/Next statements including using a new List(Of Byte) with If statements so If the the integer for the For/Next ='s the Key in a Dictionary(Of Integer, Byte) using a Counter to provide the Dictionaries Key value then
the Dictionaries byte value will be added to the List(Of Byte) and the counter will increas by one Else the List(Of Byte) adds the original "Bmp1Bytes" byte at that index to the new List(Of Byte). This takes forever also.
   I also tried the same For/Next adding to a new Dictionary(Of Integer, Byte) but that takes forever too.
   I think I could use RemoveRange and AddRange to speed things up. But I don't know how to retrieve a contiguous range of indexes in the received indexes that need to be updated in the servers "Bmp1Bytes" List(Of Byte) from the received
array of indexes and bytes which are in a Dictionary(Of Integer, Byte). But I believe this would even be slower than some realistic method for replacing all Bytes in a List(Of Byte) when I have the indexes that need to be replaced and the bytes to replace
them with.
   Even if I just used AddRange on a new List(Of Byte) to add ranges of bytes from the original "Bmp1Bytes" and the changes from the Dictionary(Of Integer, Byte) I think this would be rather slow. Although I don't know how to do that
by getting contiguous ranges of indexes from the Dictionaries keys.
   So I was wondering if there is some method perhaps using Linq or IEnumerable which I've been unable to figure anything out which could do this.
   I do have some copy and pasted code which I don't understand how it works that I am using which I would guess could be altered for doing something like this but I can't find information that provides how the code works. Or even if I did
maybe I can't understand it. Like the code below which is extremely fast.
   Dim strArray() As String = Array.ConvertAll(Of Integer, String)(BmpComparisonDict.Keys.ToArray, Function(x) x.ToString())
La vida loca

Monkeyboy,
That was quite a bit to read, but still a bit unclear. Could you put a specific list of goals/questions, asked in the smallest possible form?
It seems like either you're making a program that monitors activity on your computer, or you're writing some kind of remote pc app.
When you do get your bytes from using lockbits, keep in mind all the files header info would be lost. I think retaining the header info is worth the extra bytes.
The other, thing: I'm not sure if you're taking 32bpp screen shots, but also keep in mind that the "whole desktop" is the final destination for blended graphics, if that makes sense. What I mean is that there is no need to capture an "alpha"
channel for a desktop screenshot, as alpha would always be 255, this could save you 1 byte per pixel captured... Theres nothing "behind" the desktop, therefore no alpha, and every window shown above the desktop is already blended. I suggest using
24Bpp for a full screen capture.
Your X,Y information for the mouse could be stored as UINT16, this would save you a measly 2 bytes per location update/save.
When you update your byte arrays, maybe you can turn the array into a stream and write to whatever index, however many bytes, that should prevent a "Shift" of bytes, and instead overwrite any bytes that "get in the way".
ex
Dim example As String = "This is an example."
Dim insertString As String = "was"
Dim insertBytes As Byte() = System.Text.Encoding.ASCII.GetBytes(insertString)
Dim bytes As Byte() = System.Text.Encoding.ASCII.GetBytes(example)
Dim modifiedBytes As Byte() = {}
Using ms As New System.IO.MemoryStream(bytes)
ms.Position = 5
ms.Write(insertBytes, 0, 3)
modifiedBytes = ms.ToArray
End Using
Dim newString As String = System.Text.Encoding.ASCII.GetString(modifiedBytes)
'Notice how below there isn't the word "is" anymore, and that there isn't a
'space.
'This demonstrates that you overwrite existing data, versus shifting everything to
'the right.
'Returns: This wasan example.
MsgBox(newString)
“If you want something you've never had, you need to do something you've never done.”
Don't forget to mark
helpful posts and answers
! Answer an interesting question? Write a
new article
about it! My Articles
*This post does not reflect the opinion of Microsoft, or its employees.
Well it's too much to read. I was really tired when I wrote it. Even the below is too much to read but perhaps gets the point across of what I would like to do which I think
Joel Engineer may have answered but I'm not sure. As I'm still too tired to understand that yet and research what he said in order to figure it out yet.
But maybe the code below can provide the concept of the operation with the comments in it. But seeing as how I'm still tired it may be confused.
Option Strict On
Imports System.Windows.Forms
Imports System.IO
Imports System.IO.Compression
Imports System.Drawing.Imaging
Imports System.Runtime.InteropServices
Public Class Form1
Dim Bmp1Bytes As New List(Of Byte)
Dim Bmp1BytesCompressed As New List(Of Byte)
Dim Bmp2Bytes As New List(Of Byte)
Dim BmpComparisonDict As New Dictionary(Of Integer, Byte)
Dim BmpDifferenceIndexesCompressed As New List(Of Byte)
Dim BmpDifferenceBytesCompressed As New List(Of Byte)
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
SomeSub()
End Sub
Private Sub SomeSub()
' Pretend this code is in UDP Client app. A screen capture is performed of the desktop. Takes about 90 milliseconds.
Bmp1Bytes.Clear()
Using BMP1 As New Bitmap(Screen.PrimaryScreen.Bounds.Width, Screen.PrimaryScreen.Bounds.Height)
Using g1 As Graphics = Graphics.FromImage(BMP1)
g1.CopyFromScreen(0, 0, 0, 0, BMP1.Size)
Cursor.Draw(g1, New Rectangle(Cursor.Position.X, Cursor.Position.Y, Cursor.Size.Width, Cursor.Size.Height))
Using MS As New MemoryStream
BMP1.Save(MS, System.Drawing.Imaging.ImageFormat.Bmp)
Bmp1Bytes.AddRange(MS.ToArray)
End Using
End Using
End Using
Bmp1BytesCompressed.AddRange(Compress(Bmp1Bytes.ToArray))
' UDP Client app sends Bmp1BytesCompressed.ToArray to UDP Server which is the entire image of the desktop that the UDP
' Client is on. This image takes awhile to send since compressed it is about 177000 bytes from over 4000000 bytes.
' I will be using different code just to get the bytes from the actual Bitmap in the future. That is not important for now.
' Pretend the UDP Server has received the bytes, decompressed the array received into a List(Of Byte) and is displaying
' the image of the UDP Clients desktop in a PictureBox.
' Now the image on the UDP Clients desktop changes due to the mouse cursor moving as an example. Therefore a new Bitmap
' is created from a screen capture. This takes about 90 milliseconds.
Bmp2Bytes.Clear()
Using BMP2 As New Bitmap(Screen.PrimaryScreen.Bounds.Width, Screen.PrimaryScreen.Bounds.Height)
Using g1 As Graphics = Graphics.FromImage(BMP2)
g1.CopyFromScreen(0, 0, 0, 0, BMP2.Size)
Cursor.Draw(g1, New Rectangle(Cursor.Position.X, Cursor.Position.Y, Cursor.Size.Width, Cursor.Size.Height))
Using MS As New MemoryStream
BMP2.Save(MS, System.Drawing.Imaging.ImageFormat.Bmp)
Bmp2Bytes.AddRange(MS.ToArray)
End Using
End Using
End Using
' Now I have the original images bytes in Bmp1Bytes and the new images bytes in Bmp2Bytes on the UDP Client. But I don't
' want to send all of the bytes in Bmp2Bytes to the UDP Server. Just the indexes of and the bytes that are different in
' Bmp2Bytes from Bmp1Bytes.
' This takes less than 100 milliseconds for what I've tested so far where over 500000 bytes in Bmp2Bytes are different
' than the bytes in Bmp1Bytes. Usually that amount would be much less. But during testing I was displaying the image
' from Bmp1 bytes in a PictureBox so a large amount of data would change between the first screen shot, the PictureBox
' then displaying an image on the same PC and then the second screen shot.
BmpComparisonDict.Clear()
For i = 0 To Bmp1Bytes.Count - 1
If Bmp1Bytes(i) <> Bmp2Bytes(i) Then
BmpComparisonDict.Add(i, Bmp2Bytes(i))
End If
Next
' So now I have all the difference bytes and their indexes from Bmp2Bytes in the BmpComparisonDict. So I compress
' the indexes into on List and the Bytes into another List.
BmpDifferenceIndexesCompressed.Clear()
BmpDifferenceBytesCompressed.Clear()
BmpDifferenceIndexesCompressed.AddRange(Compress(BmpComparisonDict.Keys.SelectMany(Function(d) BitConverter.GetBytes(d)).ToArray()))
BmpDifferenceBytesCompressed.AddRange(Compress(BmpComparisonDict.Values.ToArray))
' Now pretend the UDP Client has sent both those arrays to the UDP Server which has added both decompressed arrays
' to a Dictionary(Of Integer, Byte). And the server has the original image decompressed bytes received in a List
' called Bmp1Bytes also.
' This is where I am stuck. The UDP Server has the Dictionary. That part was fast. However there is no
' fast method I have found for creating a new List(Of Byte) where bytes in the originally received List(Of Byte) that
' do not have to be altered are placed into a new List(Of Byte) except for the indexes listed in the
' Dictionary(Of Integer, Byte) that need to be placed into the appropriate index locations of the new List(Of Byte).
' The below example for doing so is exceptionally slow. Pretend UpdateDictionary has all of the decompressed indexes
' and bytes received by the UDP Server for the update contained within it.
Dim UpdateDictionary As New Dictionary(Of Integer, Byte)
Dim UpdatedBytes As New List(Of Byte)
Dim Counter As Integer = 0
For i = 0 To Bmp1Bytes.Count - 1
If i = UpdateDictionary.Keys(Counter) Then ' Provides the index contained in the Keys for the Dictionary
UpdatedBytes.Add(UpdateDictionary.Values(Counter))
Counter += 1
If Counter > UpdateDictionary.Count - 1 Then Counter = 0
Else
UpdatedBytes.Add(Bmp1Bytes(i))
End If
Next
' So what I'm trying to do is find an extremely fast method for performing something similar to what the
' above operation performs.
End Sub
Private Function Compress(BytesToCompress() As Byte) As List(Of Byte)
Dim BytesCompressed As New List(Of Byte)
Using compressedStream = New MemoryStream()
Using zipStream = New GZipStream(compressedStream, CompressionMode.Compress)
zipStream.Write(BytesToCompress, 0, BytesToCompress.Count)
zipStream.Close()
BytesCompressed.AddRange(compressedStream.ToArray)
End Using
End Using
Return BytesCompressed
End Function
Private Function Decompress(BytesToDecompress() As Byte) As List(Of Byte)
Dim BytesDecompressed As New List(Of Byte)
Using DecompressedStream = New MemoryStream()
Using zipStream = New GZipStream(DecompressedStream, CompressionMode.Decompress)
zipStream.Write(BytesToDecompress, 0, BytesToDecompress.Count)
zipStream.Close()
BytesDecompressed.AddRange(DecompressedStream.ToArray)
End Using
End Using
Return BytesDecompressed
End Function
End Class
La vida loca

How Best To Install Snow Leopard For A Non-Techy?

What is the best route to go down to install Snow Leopard please? I received my copy on Saturday but I'm apprehensive at installing it!
When I installed Leopard I ended up with a lot of problems, some of which are still not resolved, such as the non-recognition of log-in passwords etc. I still have to provide a password when switching back and forth between users and in order to close down I have to log out all users individually!
As a keen Mac-user (but by no means a technical expert) I would like my Snow Leopard experience to be as painless as possible, so how best to install it please and at the same time eliminate my old Leopard problems outlined above?
Message was edited by: Julian Brown

Julian Brown wrote:
As a keen Mac-user (but by no means a technical expert) I would like my Snow Leopard experience to be as painless as possible, so how best to install it please and at the same time eliminate my old Leopard problems outlined above?
For the most painless upgrade possible, I suggest you just follow the instructions under the heading "Upgrading Mac OS X" in the Snow Leopard Installation Instructions document.
As a precaution, you may want to run Disk Utility's "Repair Disk" step first. You can also run the "Repair Permissions" step if you want but I doubt that is necessary.
Your 'old problems' aren't problems, AFAIK. You must always provide a password to change accounts & all accounts must be logged out to shut down or restart the computer. These steps insure the privacy of each user's account & make sure each user has a chance to save any open documents before the computer shuts down. IOW, they are desirable features, not problems!

How do I handle large resultsets in CRXI without a performance issue?

Hello -
Problem Definition
I have a performance problem displaying large/huge resultset of data on a crystal report. The report takes about 4 minutes or more depending on the resultset size.
How do you handle large resultsets in Crystal Reports without a performance issue?
Environment
Crystal Reports XI
Apache WebSvr 2.X, Jboss 4.2.3, Struts
Java Reporting Component (JRC),Crystal Report Viewer (CRV)
Firefox
DETAILS
I use the CRXI thick client to build my report (.rpt) and then use it in my webapplication (webapp) under Jboss.
User specifies the filter criteria to generate a report (date range etc) and submits the request to the webapp. Webapp queries the database, gets a "resultset".
I initialize the JRC and CRV according to all the specifications and finally call the "processHttpRequest" method of Crystal Report Viewer to display the report on browser.
So.....
- Request received to generate a report with a filter criteria
- Query DB to get resultset
- Initialize JRC and CRV
- finally display the report by calling
reportViewer.processHttpRequest(request, response, request.getSession().getServletContext(), null);
The performance problem is within the last step. I put logs everywhere and noticed that database query doesnt take too long to return resultset. Everything processes pretty quickly till I call the processHttpRequest of CRV. This method just hangs for a long time before displaying the report on browser.
CRV runs pretty fast when the resultset is smaller, but for large resultset it takes a long long time.
I do have subreports and use Crystal report formulas on the reports. Some of them are used for grouping also. But I dont think Subreports is the real culprit here. Because I have some other reports that dont have any subreports, and they too get really slow displaying large resultsets.
Solutions?
So obviously I need a good solution to this generic problem of "How do you handle large resultsets in Crystal Reports?"
I have thought of some half baked ideas.
A) Use external pagination and fetch data only for the current page being displayed. But for this, CRXI must allow me to create my own buttons (previous, next, last), so I can control the click event and fetch data accordingly. I tried capturing events by registering event handler "addToolbarCommandEventListener" of CRV. But my listener gets invoked "after" processHttpRequest method completes, which doesnt help.
Some how I need to be able to control the UI by adding my own previous page, next page, last page buttons and controlling it's click events.
B) Automagically have CRXI use a javascript functionality, to allow browser side page navigation. So maybe the first time it'll take 5 mins to display the report, but once it's displayed, user can go to any page without sending the request back to server.
C) Try using Crystal Reports 2008. I'm open to using this version, but I couldnt figureout if it has any features that can help me do external pagination or anything that can handle large resultsets.
D) Will using the Crystal Reports Servers like cache server/application server etc help in any way? I read a little on the Crystal Page Viewer, Interactive Viewer, Part Viewer etc....but I'm not sure if any of these things are going to solve the issue.
I'd appreciate it if someone can point me in the right direction.

Essentialy the answer is use smaller resultsets or pull from the database directly instead of using resultsets.

How can I copy a short video from iPad to DVD

How can I copy a short video from Mini iPad to DVD via my laptop please?

You can try some free DVD burners like Wondershare, Pavtube Free DVD creator or so. Here is a list for some:
http://www.techsupportalert.com/best-free-cd-dvd-burning-software.htm

Limit in Mail on receiving large attachments?

Noticed someone else had a problem with receiving large attachments in Mail and my friend and I also have it now.
My question is if anyone knows of a limit to size for recieving attachments in Mail. I noticed that Apple has set a default 10 MB limit on their server versions and thought maybe this is so also in ordinary OS X Mail? If so -- how do I change this in OS X?
(It is really ridiculous that one should not be able to send a small 15 MB file with e-mail any longer -- it is not like we are all getting slower connections, less hard drive space and slower processors all the time, so why does things like this happen?)
Yes, I know the problem is not releated to ISPs, Mail Servers, Firewalls as I have tested for that in most respects. (No problem sending such a file nor downloading it via web mail, etc.) It could be related to IMAP and Apple Mail.
/Jerry (in Sweden where you cannot specify decimals on paper sizes under Mac OS X ... )

Yes, I know the problem is not releated to ISPs, Mail Servers,
Firewalls as I have tested for that in most respects.
Yes it is related since this is not a limitation or problem with the Mail.app or with any email client.
Most ISPs and email account providers have limits on overall message size for received and sent messages similar to the .Mac account message size limit for received and sent messages.
Your ISP or email account provider may not have such a limit (which is unusual) but the recipient's ISP or email account provider may impose a limit.
Have you checked with your ISP or email account provider for this account regarding a message size limit imposed for received and sent messages?
In case you aren't aware, message attachments must be encoded before being sent. The Mail.app uses MIME 1.0 for attachment encoding which is the internet standard. The pre-encoded size of the attachment is increased by 50% or so after the encoding process. A 15MB file will be roughly 22.5MB after the encoding process.
Check What is the maximum size of email attachments? for information on the attachment encoding process.

How to add a large number of keywords to the e-mail filter?

Hello.
I would like to know how to add a large number of keywords to a filter.
The thing I want to accomplish, is it to add around 4000 e-mail addresses to a filter list, which checks the body of incoming e-mails, which get forwarded to me.
I don't want to outright delete them, but I would love it if it detects that the forwarded message contains one of the e-mail addresses, it would add a tag to the message.
Is it in any way possible to make a filter like this, which doesn't slow Thunderbird down to ass-crawl speed?
I tried to copy the whole list into the small filter tab, but It had no discernible effect on my messages, since some of the previously received ones, which I was sure contained the keywords, were not tagged. All it did was make the program super slow and I was forced to delete the filter.

You can look at creating a exclusion crawl rule:
http://technet.microsoft.com/en-us/library/jj219686(v=office.15).aspx
You can also modify your content source starting addresses and remove onedrive:
http://technet.microsoft.com/en-us/library/jj219808(v=office.15).aspx
Blog | SharePoint Field Notes Dev Tools |
SPFastDeploy | SPRemoteAPIExplorer

Large string array in 6.1 is extremely slow

Good day all,
While this is in to tech support at NI, I wanted to see if anyone else has encountered it.
I am upgrading from 6.0.2 to 6.1. Several large (2500 rows by 250 columns or larger) string arrays are used as inputs into subvi's. Under 6.0.2, these functions run in tenths of seconds, while under the converted 6.1 vi's they run in 20 seconds or more!
Tracing back using probes, the problem is occurring at the point of the input. It is appears that the array is taking many seconds to copy from the input to the wire on the diagram.
Array controls generated in 6.1 (not converted from 6.0.2) seem to function just fine. Using a save with options... to convert back to 6.0.2, the vi's again function in tenths of
seconds.
Anyone have any ideas?
Thanks!

I hear what you're saying about legacy code...
Something you might want to be looking at for the future is migrating to a structure where the data is stored in a 1D array, where each element is a cluster contain the data that's now in a single row. This would be the most straight-forward change, but could make getting at the data tricky, depending on how you need to be able to search it.
Alternately, you could have a cluster containing arrays of each of the row values.In this structure element 0 of all the arrays is the first "row", element 1 of the arrays is the second "row" and so on. This structure at first blush looks more complicated, but it's really not, plus it would allow you to use any value (or combination of
values) to search for a specific row without a lot of parsing.
If the data that is in the example VIs you posted is typical, either of these changes would be advantagous because it looks like there is a lot of reptative data that might be able to be encoded in an enum. Plus storing numbers as numbers often reduces the memory required and produces a predictable memory footprint (an I32 will always take-up 4 bytes per value regardless of how large of small the number is). My sense is that the variability of the string size is what's killing you.
One thing that would make this sort of dramatic change somewhat easier is that because you are changing the basic datatype of the interface, you aren't going to have to worry about finding all the places the change will effect--the wires will be broken.
If you ever decide to take this on, give a hollar.
Mike...
Certified Professional Instructor
Certified LabVIEW Architect
LabVIEW Champion
"... after all, He's not a tame lion..."
Be thinking ahead and mark your dance card for NI Week 2015 now: TS 6139 - Object Oriented First Steps

Question on Sequences and how best to use them

Hi all,
I am used to Premiere Pro v6 and I have recently moved to CS4.1.
Could you explain to me how best and why to use multiple sequences for a single project in Premiere Pro CS4.1? I understand that you can have different formats on each, but I was wondering if there was a technique for using multiple sequences for a large project, eg a wedding where each scene could have a different sequence. Am I on the right track.
If so, then how does one preview edited footage that spans multiple sequences?
Your help and advice would be appreciated.
Cheers

It all depends on your workflow, but personally when doing large projects, I prefer to work on smaller pieces first. Your example of a wedding could easily be broken down into sequences like intro, preparation, ceremony, reception, party and background material. Then make a master sequence where you combine all the sequences into this master sequence. It also makes it easy to place chapter markers at the beginning of each smaller sequence and it makes the overview of the project a lot easier. It also makes it easier to maintain a semblance of organization in the project bins.
When I did a sailing movie last year (http://vimeo.com/1122531) I had different sequences for St. Maarten, Jost van Dijke, Virgin Gorda, The Baths, The Bitter End, Saba and again St. Maarten, plus the intro and the end sequence. When all of these parts were finished, it was simply a matter of putting all in a master sequence and go to Encore.

How best to receive large short array --- tcp, socket, LabVIEW, ShortBuffer

Similar Messages

Maybe you are looking for