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Hi
yet again me...
Thanks all for your patience.
I'm building a wav builder software for my firm. I have completed the program at 95% and only one bug remains.
The program has variable sampleRate, bits/second,frequency,duration.
My algorithm for building the sine wave works, but calculating how many samples would it take for a provided duration (ms) is buggy...
It goes something like this
dblFrequency = Frequency
dblWaveTime = 1 / dblFrequency
dblSampleTime = 1 / CDbl(lngSampleRate)
dblDataSlice = (2 * PI) / (dblWaveTime / dblSampleTime)
If intBits = 8 Then
lngLimit = 127
lngSamples = CDbl(lngSampleRate) * duration / 1000
Else
lngLimit = 32767
lngSamples =cdbl(lngsamplerate) * duration * 2 / 1000 'because it is 16 bit, 2 bytes is written, thus * 2
End If
This algorithm creates problems...
I have an array() as byte, in which the results are filled... They are calculated as math.sine...
But the problem is here in the upper code...
so, for example the duration is 323 ms, i need to calculate how many samples does it take for the duration.
Any help is greatly appreciated.
Thank you!
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The calculation is really simple, you just multiply the time with the number of samples per time unit. Example:
time = 0.323 ' duration in seconds<br />
frequency = 44100 ' samples per second (44.1 kHz)<br />
bytes = 2 ' sample size (16 bit mono)<br />
<br />
samples = frequency * time<br />
size = samples * bytes
(That is pseudo code, of course. You have to apply appropriate type conversions.)
---
single minded; short sighted; long gone;
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I have a situation where i need to create a Crystalreport with a subreport.
I don't know is possible on vb.net.?
the situation is :
Have 3 tables : Students Finance Score
Each student have sone registration on table1 and some registration on table2.
(the tables are related)
I want to display on the report :
Name of student1
All the registration for this student on Finance
All the registration for this student on Score
-------
Name of Student2
All the registration for this student on Finance
All the registration for this student on Score
----------
....... for all the students
i think to do this with report-subreport?
Any idea ?
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Imports CrystalDecisions.CrystalReports.Engine
Imports CrystalDecisions.Shared
Public SubReport As ReportDocument
SubReport = New ReportDocument
SubReport = Report.OpenSubreport(SubReportName)
SubReport.SetDataSource(datasource)
Now use this SubReport object to solve the problem
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I have swann webcam Mac IP cam network camera.......its connected to the RJ-45 connector....I want to capture images after every 10 sec. from this and save it in to sql database..............can you guys help me out
you can have a look abt my cam on this link
http://www.swann.com.au/webfiles/download/445SW-C-IPC_Manual_ENG_v2.pdf
Thanx in advance
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You will use DirectShow to connect to the camera. Plenty of examples on the web, and even articles on this site.
Christian Graus - Microsoft MVP - C++
"I am working on a project that will convert a FORTRAN code to corresponding C++ code.I am not aware of FORTRAN syntax" ( spotted in the C++/CLI forum )
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It' an IP webcam. It doesn't look like there's any possibility to connect it to the machine directly.
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You're first move should be to find out if the manufacturer has an SDK for the webcam. If so, then it'll come with documentation on using the SDK to talk to the cam and get images.
If there isn't one, you've options are very limited. You're either going to have to setup the cam to automatically post the image to an FTP server or you've going to have to download a webpage from the camera that's got the image in it, parse the page and get the URL of the image, then download that image using the HttpWebRequest/Response classes.
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Try Video.ocx, it may solve your problem, do a search on google write just video.ocx and you will find the website.
Be a part of solution, rather then be a part of problem
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Video.OCX only works with Video For Windows compatible cameras. Unless he's got VFW drivers for an IP-based camera (highly doubtful!), it won't work with this camera.
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I was following the example in code project
"Calling a DLL C++ function from a VC++ application" posted by Hans Dietrich
I am using Visual Studio 2005 for this example. It works fine.
Now I want the same application to run on different machines which DOES NOT have Visual Studio 2005 installed on them.
I copied all the dll files and vb application's .EXE files on all machine2 but its not working. It gives me an error saying the dll's are not synchronized properly.
What exactly is the procedure of making an application run independently on all machines.
Can someone PLEASE HELP ME in solving this problem.
Thanks
Jyothi
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jyothim wrote: It gives me an error saying the dll's are not synchronized properly.
This isn't the error message. It would help if you posted the EXACT error being shown.
Because you're using a VB.NET app, any machine running this app MUST have the .NET Framework 2.0 installed on it.
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Thank you very much it solved my problem
Jyothi
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hi everyone.
I am quite new to vb.net 2005 and I have been trying to connect my database programmatically to my sql server database. I have moved from one error to the next and I have followed the steps highlighted in the msdn walk through on crystal reports. Every time I run my code, I am getting an error message that states that the load report event has failed. and the object reference has not been set to an instance of the object.
I have tried this several times and I don't know what to do. If anyone can help me I would be most greatful. The code I have been trying to use is as follows.
Imports CrystalDecisions.CrystalReports.Engine
Imports CrystalDecisions.Shared
Public Class Form1
Private Sub ConfigureCrystalReports()
Dim myConnectionInfo As ConnectionInfo = New ConnectionInfo()
myConnectionInfo.DatabaseName = "Northwind"
myConnectionInfo.UserID = "user"
myConnectionInfo.Password = "bob123"
myConnectionInfo.ServerName = "chiko-shumba"
Dim reportPath As String = Application.StartupPath & "\" & "NorthwindCustomers.rpt"
myCrystalReportViewer.ReportSource = reportPath
SetDBLogonForReport(myConnectionInfo)
End Sub
Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
ConfigureCrystalReports()
End Sub
Private Sub SetDBLogonForReport(ByVal myConnectionInfo As ConnectionInfo)
Dim myTableLogOnInfos As TableLogOnInfos = myCrystalReportViewer.LogOnInfo
For Each myTableLogOnInfo As TableLogOnInfo In myTableLogOnInfos
myTableLogOnInfo.ConnectionInfo = myConnectionInfo
Next
End Sub
Private Sub myCrystalReportViewer_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles myCrystalReportViewer.Load
End Sub
End Class
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Hi there,
I just want to ask if is it possible to put calculations in a datagridview? in such a way that the column2 = column1 * 30%...
if it is possible, can you help on how to work on it?
I'm realy new in vb.net eh..
thanks in advance!
ange(",)8
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Nope. You cannot put expressions in the DGV. Putting them into a strongly typed dataset/datatable on the other hand, yes. Then you bind the DGV to that dataset/datatable.
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Thank you sir for replying..
the DGV is already binded with the dataset/datatable.
What shall I do now?
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You don't have a choice. You either rework your strongly typed dataset or you add support code for going through each record in the table and doing the calculation and putting the result in a column in the table.
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Thanks. You gave me an idea for my work.
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I have a dotnet control that i load into a page in the browser. It uses tcp and system.diagnostics(for launching) to communicate with an exe on the PC. The exe can be started up via browser(hidden mode) or a shortcut(visible mode) on the user's pc. If the exe is already started in hidden mode and the user clicks on the shortcut (which would obviously try and start a new instance of the exe), I want the new exe to check if the first exe is running and if running tell the first one to change it's mode and then the new one will just shutdown.
What's the best course of action to get the exes to talk to each other (tcp/api/etc)?
Thanks,
Nathan
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This was just covered a couple of days ago. You're looking for the Mutex class. Search the articles for "single instance" and you'll find examples.
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thanks dave...must of missed it.
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newbie to programming here...  I have an Access database that I am binding a TextBox text property to. I would like to have data that is coming in from the database post to the textbox in the (###) ###-#### phone format (in access it is saved as a text type without formatting). I created an event handler for the format and parse event to handle the binding (a copy of which is below). The data is now posting to the textbox as (###) ### - #### without the data (every phone record is filled with the pound sign).
Private Sub PhoneNumberFormat(ByVal sender As Object, ByVal cevent As ConvertEventArgs)
cevent.Value = Format(cevent.Value, "(###) ### - ####")
End Sub
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sabr49 wrote: The data is now posting to the textbox as (###) ### - #### without the data (every phone record is filled with the pound sign).
That's because the format string you've come up with only works with numbers. Since you're storing the phone number as a string, you've going to have to parse that string and insert the characters in the correct place to make a whole new formatted string.
A regular expression might help you in this case.
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Greatly appreciate. Had never used a regular expression b/4 and got it with this regular expression in a jiffy.. Powerful stuff!
Private Sub PhoneNumberFormat(ByVal sender As Object, ByVal cevent As ConvertEventArgs)
Dim strFormatted As String
strFormatted = Regex.Replace(cevent.Value, "(\d{3})(\d{3})(\d{4})", "($1) $2-$3")
cevent.Value = strFormatted
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