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When streaming video over the internet, witch way is the best/fastest way to do it?
Send frame by frame?
Send from a avi-stream?
I have a program witch captures frames/video from a webcamera. The picture (bitmap) size is 160*120*24bit
This gives me a buffer size of 57600 bytes (160*120*3) which is too much to data to send.
The upload speed is 256 kilobits/s. which is 32000 bytes/s (256000/8 = 32000)
This give me ~ a half picture/s 
How can I compress this buffer (without the use of 3-party components)?
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You have two choices:
1) Code the compression/decompression on your own (called a "codec") and suffer with nearly zero support from other people.
2) Use codecs that are already written, "industry standard", and supported by others.
The choice is up to you. If it were me, I'd skip writing my own codec...
RageInTheMachine9532
"...a pungent, ghastly, stinky piece of cheese!" -- The Roaming Gnome
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I agree... but: should the stream be frame by frame or avi stream???
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That's not as straight forward as it would seem. There are many methods for compressing a video stream into a data stream and sending it. It sould like your talking about both using the same terms. AVI is just a compressed video stream format.
You can compress the video stream using either a full frame compression technique, or partial frames with key frames, or several frames at once. There are dozens of different techniques that fall under each of these categories.
Sending the data can be done over TCP, UDP, or Multicast IP. The choice is up to you.
But unless you writing code to explore these techniques and come up with your own format, you'd be MUCH better off using third party components that follow industry standards for video compression and transmission. The Microsoft Windows Media SDK[^] would be a good place to start.
RageInTheMachine9532
"...a pungent, ghastly, stinky piece of cheese!" -- The Roaming Gnome
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Hi,
I need to dynamically add table rows and text boxes. When the user clicks "add" , on postback i am adding new and textboxes.
The problem is the page moves up and the newly added textboxes are out of sight. the user has to scroll down and find where the new row is added. I have different sections to which new rows can be added.
Any clues how I can find the position of the newly added textbox and move the page up to that location. I am using vb.net
thanks,
Soujanya
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Hi! I really need some's help who has extensive experience working with FileSystemWatcher object in vb.net. I've a production application I've written that monitors local and network files for creation/changes. My problem is that the FSW seems to be very inconsistent in picking up files. I've done extensive research and tried several methods, but overall I still have problems getting it work my way. I only monitor a handfull (10-12) files so it's not an overload of events issue. I know many of you would want to have more details before attempting to help, but I'd rather if someone who's willing to spend a bit of time to review my code in general and give me a suggestion or 2 would contact me. Any help is appreciated. I'm including the basic logic of what my application is trying to do below:
1) Service runs every 30 minutes
2) checks database for any records for files to watch
3) locates those records, creates 1 FSW object for each record with
File Name and Path pointing to the info in database, wires up OnChanged,
OnRenamed, OnCreated, and OnDeleted events to their handlers
4) Adds the instance of the FSW object to global shared Hashtable
5) Updates SQL status for this file to 2, meaning that FSW created, waiting
for the file to be generated/updated.
6) OnChanged event contains the code that reacts on 2 types of events
OnChanged and OnCreated. When it fires, it checks that the instance of FSW
that raised the event is contained in global hashtable. If so, it connects to
database and gets the XML options for this specific file (such as FTP file,
email it, back it up, etc...)
7) In OnChanged event there's loop inside of which it keeps trying to rename
the file that has raised the event to a new name (just appends one to the
end of the file name). This is done so that if the file is very large it would not
try to work with it (FTP or something else) until it's fully written.
Once it's able to rename it, it means the system no longer has a lock on the
file. It then renames the file to its original name and kicks off the
function that process the XML actions associated with this file.
8) Upon completion of all the actions or in case of failure the SQL status
for this file is updated (1 for success, 3 for failure.
9) The reference for this FSW object is removed from global hashtable.
10) Same thing is done for any other files that have been picked up by the service
when it ran initially with same logic.
11) Service runs once again in 30 minutes.
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Hi,
I need to write a Add function within a class to add to complex Numbers,
So far I have two variables in a class called ComplexNo
Private frealpart As single
Private fimagpart As Single
Representing the real part and imaginary part of the complex Number
A variable in the form event. I.e. ocomplex as new ocomplexNo (4,5)
Returns the values to the Variables in the class 4 real and 5 imaginary
File constructor in the class is ….
Sub New ( fpart as single, ipart as single)
frealpart = fpart
fimagpart = fipart
End sub
I need to create a new variable called ocomplex2 as new (4,6) and use a function to add these values to the class variables above.
I would like to
ocomplex.Add(ocomplex2) thus returning the values to the class.
Hope this makes sense to someone
Thank you in Advance
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Hi!
I have an app that does async. reads from a networkStrem.When i do BeginRead() i pass an object(which is kept in a collection) that includes info about the connection and the networkstream.When the application enters the callback method the object has changed(the network stream already contains the info?) or does it change only after the EndRead() when i read data from the networkStream? Is the EndRead method Thread-safe?I ask this because if it isn't thread-safe then the collection is changing without any sync. method and i use synclock whenever i'm accessing the collection... Thanks in advance.
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:->1) Resource transformation for file "tgif_resx" failed. type is not resolved for member Crystaldecisions.ReportAppServer.InternalEnterpriseLogonInfo.CrystalDecisions.CrystalReports.Engine, Version=10.0.3300.0, culture=Neutral,PublicKey Token=692fbea5521e1304
2) D:\CTC\ctc\TGIIMS 041213a\TGIIMS 041213a code\tgif_Report.vb(46): 'FileName' is not a member of 'CrystalDecisions.CrystalReports.Engine.ReportDocument'.
Regards
Abhijeet
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How To Stretch Picture Box Manually at Run Time in VB.Net. its Urgent.
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I'd like to use 2 comboboxes in my application that views Crystal Reports. My report is a inventory of available material at different warehouse locations. The report needs 2 parameters (from location) and (to location). Essentially I can query inventory from a location (from New York to New York).
My combo boxes alone work fine with the Crystal report viewer but when used together only the second combo box works (to location). As a result I'm promted to add the value for the (to location) a second time.
I want the have my program pass both of the "to" and "from" information from the combo boxes directly into the Crystal report viewer.
Here's the code that I have thus far.
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click<br />
<br />
Dim myParameterFields As New ParameterFields<br />
Dim myParameterField As New ParameterField<br />
Dim myDiscreteValue As New ParameterDiscreteValue<br />
<br />
myParameterField.ParameterFieldName = "location_from"<br />
myDiscreteValue.Value = ComboBox1.Text<br />
myParameterField.CurrentValues.Add(myDiscreteValue)<br />
<br />
myParameterField.ParameterFieldName = "location_to"<br />
myDiscreteValue.Value = ComboBox2.Text<br />
myParameterField.CurrentValues.Add(myDiscreteValue)<br />
<br />
myParameterFields.Add(myParameterField)<br />
<br />
CrystalReportViewer1.ParameterFieldInfo = myParameterFields<br />
<br />
CrystalReportViewer1.ReportSource = New Lager_best_XL<br />
CrystalReportViewer1.Refresh()<br />
<br />
<br />
End Sub
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i didn't check it coz i didn't have dotnet Installed currently. but i think it will slove ur problem
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Dim myParameterFields As New ParameterFields
Dim myParameterField As New ParameterField
Dim myDiscreteValue As New ParameterDiscreteValue
myParameterField.ParameterFieldName = "location_from"
myDiscreteValue.Value = ComboBox1.Text
myParameterField.CurrentValues.Add(myDiscreteValue)
myParameterFields.Add(myParameterField) // Add This line of Code
myParameterField.ParameterFieldName = "location_to"
myDiscreteValue.Value = ComboBox2.Text
myParameterField.CurrentValues.Add(myDiscreteValue)
myParameterFields.Add(myParameterField)
CrystalReportViewer1.ParameterFieldInfo = myParameterFields
CrystalReportViewer1.ReportSource = New Lager_best_XL
CrystalReportViewer1.Refresh()
End Sub
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Thanks I tried out your suggestion of adding in the extra line of code (myParameterFields.Add(myParameterField) after the first combo box definition but the same problem still persists. No debugging problems were created with the new line of code.
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It May Not seem a good awnser but its the best i can give without testing.
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Dim myParameterFields As New ParameterFields
Dim myParameterField As New ParameterField
Dim myParameterField1 As New ParameterField
// the value for location_from is seem to be replaced by location_to and it can
//be tested by saving there values into two different objects.
Dim myDiscreteValue As New ParameterDiscreteValue
Dim myDiscreteValue1 As New ParameterDiscreteValue
myParameterField.ParameterFieldName = "location_from"
myDiscreteValue.Value = ComboBox1.Text
myParameterField.CurrentValues.Add(myDiscreteValue)
myParameterFields.Add(myParameterField) // Add This line of Code
myParameterField1.ParameterFieldName = "location_to"
myDiscreteValue1.Value = ComboBox2.Text
myParameterField1.CurrentValues.Add(myDiscreteValue1)
myParameterFields.Add(myParameterField1)
CrystalReportViewer1.ParameterFieldInfo = myParameterFields
// also its has been a while since i did it but i remember there is a way to pass
//the string to CrystalReportViewer or New Lager_best_XL directly like this
//New Lager_best_XL.METHODNAME="Location_from>='' and Location_to = <=" //etc...
//or
//CrystalReportViewer.METHODNAME="Location_from>='' and Location_to = <=" //etc...
//i don't remember the method name coz it has been a while but at that time i used it
//to get a report inbetween two dates.
CrystalReportViewer1.ReportSource = New Lager_best_XL
CrystalReportViewer1.Refresh()
End Sub
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I tried your suggestion of sending the outputs from the combo boxes to different objects. I inserted a second crystal report viewer and a second button. I have the (location from) combo box sent to the new report viewer. The (location to) combo box still uses the original report viewer.
As predicted when running the using the original report viewer I'm prompted for the for (location from) information. Likewise when I use the new report viewer I'm prompted for (location to) information.
The combo boxes are both doing their jobs it's just that the last passed value is taken or the first value is over witten from the second either way same result.
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well i didn't say u use two different report viewer i said u use two different myParameterField Object Then Add Them To myParameterFields The Code Will Look Like This
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Dim myParameterFields As New ParameterFields
Dim myParameterField As New ParameterField
Dim myParameterField1 As New ParameterField
Dim myDiscreteValue As New ParameterDiscreteValue
Dim myDiscreteValue1 As New ParameterDiscreteValue
myParameterField.ParameterFieldName = "location_from"
myDiscreteValue.Value = ComboBox1.Text
myParameterField.CurrentValues.Add(myDiscreteValue)
myParameterFields.Add(myParameterField)
myParameterField1.ParameterFieldName = "location_to"
myDiscreteValue1.Value = ComboBox2.Text
myParameterField1.CurrentValues.Add(myDiscreteValue1)
myParameterFields.Add(myParameterField1)
CrystalReportViewer1.ParameterFieldInfo = myParameterFields
CrystalReportViewer1.ReportSource = New Lager_best_XL
CrystalReportViewer1.Refresh()
End Sub
Hope Fully It Will Work
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Here's a copy of what I added:
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click<br />
<br />
Dim myParameterFields As New ParameterFields<br />
Dim myParameterField As New ParameterField<br />
Dim myParameterField1 As New ParameterField<br />
<br />
Dim myDiscreteValue As New ParameterDiscreteValue<br />
Dim myDiscreteValue1 As New ParameterDiscreteValue<br />
<br />
myParameterField.ParameterFieldName = "Lagerort_von"<br />
myDiscreteValue.Value = ComboBox1.Text<br />
myParameterField.CurrentValues.Add(myDiscreteValue)<br />
<br />
myParameterFields.Add(myParameterField)<br />
<br />
myParameterField.ParameterFieldName = "Lagerort_bis"<br />
myDiscreteValue.Value = ComboBox2.Text<br />
myParameterField1.CurrentValues.Add(myDiscreteValue1)<br />
<br />
myParameterFields.Add(myParameterField1)<br />
<br />
CrystalReportViewer1.ParameterFieldInfo = myParameterFields<br />
CrystalReportViewer1.ReportSource = New Lager_best_XL<br />
CrystalReportViewer1.Refresh()<br />
<br />
<br />
End Sub
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If your printing raw text, then you'll have to consult with the printers manual and send the appropriate ESC codes to the printer, just like you do text, to get it to change the font, bold, italics, size, ...
RageInTheMachine9532
"...a pungent, ghastly, stinky piece of cheese!" -- The Roaming Gnome
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hi
i wish to add a value to date
example
1/1/2005 add 4 days ahead
so the date will be 5/1/2005
may i know how to do this by code?
i try this way
dim a as date
a= today +4
but there is an error here state that + cannot be done by date n integer
may i know how to add it to date?
thank you in advance
Gary
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You can add DateTime and TimeSpan:
<br />
DateTime nowPlusFourHours = DateTime.Now + new TimeSpan(4, 0, 0, 0)<br />
You can also substract one DateTime from another one and get a TimeSpan back.
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hi robert
i dont understand......
DateTime?
i try typing it
it say here
DateTime is a type and cannot be used as an expression
so i try this way
Dim a As Date<br />
a = DateTime.Now + New TimeSpan(4, 0, 0, 0)
but ending up it say
operator "+" is not define for "Date" and "TimeSpan"
can please explain in more detail?
im using vb.net
thanks
Gary
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You are right, sorry. Sometimes I mix up C# and VB.Net 
You should use:
<br />
Dim a As Date<br />
a = DateTime.Now.Add(New TimeSpan(4, 0, 0, 0))<br />
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There is also
DateTime.Now.AddDays(4)
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