Visual Basic

18-Jun-09 2:57

Hi,
i got a DSP function for a media player here. The problem is that it was made for VB 6 and uses "CopyMemory".
I read the article on "CopyMemory in .Net" here but the result i got isn't working :-S
This is the original code:

Public Sub SBVocalCut32(ByVal handle As Long, ByVal channel As Long, ByVal buffer As Long, ByVal length As Long, ByVal user As Long)<br />
Dim SBVocCut32Buf() As Single, SBVocCut32CSample As Long<br />
Dim SBVocCut32DM As Single<br />
ReDim SBVocCut32Buf(length / 2) As Single<br />
<br />
Call CopyMemory(SBVocCut32Buf(0), ByVal buffer, length)<br />
    <br />
    For SBVocCut32CSample = 0 To length / 2 - 1 Step 2<br />
        SBVocCut32DM = ((0 - SBVocCut32Buf(SBVocCut32CSample)) + SBVocCut32Buf(SBVocCut32CSample + 1)) / 2<br />
        SBVocCut32Buf(SBVocCut32CSample) = SBVocCut32DM<br />
        SBVocCut32Buf(SBVocCut32CSample + 1) = SBVocCut32DM<br />
    Next SBVocCut32CSample<br />
    <br />
<br />
Call CopyMemory(ByVal buffer, SBVocCut32Buf(0), length)<br />
End Sub

Could anyone be so kind and help me out with the copymemory lines in here?

Thx!

Luc Pattyn18-Jun-09 3:34

18-Jun-09 3:34

Knight_Rider wrote:
CopyMemory in .Net

which article, there are several here on CP.

Knight_Rider wrote:
isn't working

that is really informative. Build problems? run-time problems? exceptions? what?

CopyMemory[^] seems to just copy some data in memory, something a simple for loop could do easily, provided source and destination do not overlap (if they do, the order must depend on the relative position).

Write your own copy loop and get done with it!

Smile | :)

Luc Pattyn [Forum Guidelines] [My Articles]

DISCLAIMER: this message may have been modified by others; it may no longer reflect what I intended, and may contain bad advice; use at your own risk and with extreme care.

Knight_Rider18-Jun-09 3:39

18-Jun-09 3:39

Hi,
Equivalent of CopyMemory in .NET[^] This is the article i'm refering to Wink | ;-)

Yeah i tried that with the loop already:

For i As Integer = 0 To length / 2 - 1<br />
            SBVocCut32Buf(i) = buffer.ToString(i)<br />
        Next

and

<br />
For i As Integer = 0 To SBVocCut32Buf.Length - 1<br />
    buffer += SBVocCut32Buf(i)<br />
Next<br />

But it doesn't work either because the song doesn't sound (-> Bass.NET Audio library) different after activating this function..
Thanks anyway!

BTW: There is an AccessViolationException when i use copymemory in .NET!

Luc Pattyn18-Jun-09 3:43

18-Jun-09 3:43

Hi,

that article is voted rather low, there is at least one that looks better.

Both these for loops stink; there is no ToString() and no += involved, just COPY data.

Smile | :)

Luc Pattyn [Forum Guidelines] [My Articles]

DISCLAIMER: this message may have been modified by others; it may no longer reflect what I intended, and may contain bad advice; use at your own risk and with extreme care.

Knight_Rider18-Jun-09 3:47

18-Jun-09 3:47

Well it seems i don't completely understand what copymemory does in this particular function:
This line: CopyMemory(SBVocCut32Buf(0), buffer, length) -
Will everything contained in the buffer variable be copied into SBVocCut32Buf(0)? Or is the length parameter indicating that SBVocCut32Buf will be filled as follows:
SBVocCut32Buf(0) = buffer
SBVocCut32Buf(1) = buffer
SBVocCut32Buf(2) = buffer
...? May you explain that, please? thanks Smile | :)

Luc Pattyn18-Jun-09 3:51

18-Jun-09 3:51

I don't know, I provided a link to some documentation, read that.
It sounds like the memcpy() function in C.
Maybe Array.Copy() is the .NET equivalent.
Whatever it is, it will take no more than two lines of code.

Smile | :)

Luc Pattyn [Forum Guidelines] [My Articles]

DISCLAIMER: this message may have been modified by others; it may no longer reflect what I intended, and may contain bad advice; use at your own risk and with extreme care.

Knight_Rider18-Jun-09 4:08

18-Jun-09 4:08

This is what i got so far based on the arcticle... Maybe another person may help me?

    Public Sub SBVocalCut32(ByVal handle As Long, ByVal channel As Long, ByVal buffer As Long, ByVal length As Long, ByVal user As Long)<br />
        Dim SBVocCut32Buf() As Single, SBVocCut32CSample As Long<br />
        Dim SBVocCut32DM As Single<br />
        ReDim SBVocCut32Buf(length)<br />
       <br />
 Dim MyGC As GCHandle = GCHandle.Alloc(buffer, GCHandleType.Pinned)<br />
 Dim AddofLongValue As IntPtr = MyGC.AddrOfPinnedObject()<br />
<br />
        Marshal.Copy(AddofLongValue, SBVocCut32Buf, 0, length)<br />
        ' Call CopyMemory(SBVocCut32Buf(0), buffer, length / 2)<br />
<br />
        For SBVocCut32CSample = 0 To length / 2 - 1 Step 2<br />
            SBVocCut32DM = ((0 - SBVocCut32Buf(SBVocCut32CSample)) + SBVocCut32Buf(SBVocCut32CSample + 1)) / 2<br />
            SBVocCut32Buf(SBVocCut32CSample) = SBVocCut32DM<br />
            SBVocCut32Buf(SBVocCut32CSample + 1) = SBVocCut32DM<br />
        Next SBVocCut32CSample<br />
<br />
<br />
        Marshal.Copy(SBVocCut32Buf, 0, AddofLongValue, length)<br />
        'Call CopyMemory(buffer, SBVocCut32Buf(0), length / 2)<br />
    End Sub

Henry Minute18-Jun-09 5:27

Henry Minute

18-Jun-09 5:27

Luc Pattyn wrote:
Write your own copy loop and get done with it!

I love it when you are masterful! Big Grin | :-D

Henry Minute

Do not read medical books! You could die of a misprint. - Mark Twain
Girl: (staring) "Why do you need an icy cucumber?"
“I want to report a fraud. The government is lying to us all.”

Luc Pattyn18-Jun-09 5:30

Work on Ctrl +C in PropertyGridSelectedItem

18-Jun-09 5:30

Henry Minute wrote:
I love it when you are masterful!

I thought as much.
No beating around the bush.

Smile | :)

Luc Pattyn [Forum Guidelines] [My Articles]

DISCLAIMER: this message may have been modified by others; it may no longer reflect what I intended, and may contain bad advice; use at your own risk and with extreme care.

VB 8.018-Jun-09 0:57

VB 8.0

18-Jun-09 0:57

i am having a control on a panel and their properties in the propertygrid .

How to identify the Ctrl + C in this method

Public Function PreFilterMessage(ByRef msg As Message) As Boolean Implements IMessageFilter.PreFilterMessage

    Const WM_KEYDOWN As Integer = 256
       If msg.Msg = WM_KEYDOWN Then
           Dim keyCode As Keys = (CType(CType(msg.WParam, Integer), Keys) And Keys.KeyCode)
           If pg.SelectedGridItem.PropertyDescriptor IsNot Nothing Then
               If (pg.SelectedGridItem.PropertyDescriptor.DisplayName = "Picture" Or _
                           pg.SelectedGridItem.PropertyDescriptor.DisplayName = "BackgroundPicture" _
                               And Not keyCode = Keys.Delete And Not (keyCode = Keys.Control And keyCode = Keys.C) _
                               And Not (keyCode = Keys.Control And keyCode = Keys.V) _
                               And Not (keyCode = Keys.Control And keyCode = Keys.X) _
                               And Not (keyCode = Keys.Control And keyCode = Keys.A) _
                               And Not (keyCode = Keys.Control And keyCode = Keys.Z) _
                               And Not (keyCode = Keys.Control And keyCode = Keys.Y)) Then
                   Return True
               End If
           End If
       End If
       Return False
   End Function

what i am doing is i am blocking keyboard characters and only Delete button i am allowing in the propertygrid for picture Property .

When Ctrl C , or ctrl v or ctrl x or ctrl y or ctrl z is pressed i have to work on the control to copy ,paste etc if the the propertygrid.selecteditem is picture also how can i achieve this one ??

Visual Basic

ibrahimsaa17-Jun-09 20:29

ibrahimsaa

17-Jun-09 20:29

What is vb

Rajesh Anuhya17-Jun-09 20:35

Rajesh Anuhya

17-Jun-09 20:35

see your subject line Poke tongue | ;-P

or

see this below link
waht is VB[^]

Rajesh B --> A Poor Workman Blames His Tools <--

0x3c017-Jun-09 20:47

0x3c0

17-Jun-09 20:47

Its a programming language. It comes in two flavours - legacy and normal. Legacy is obsolete, so I won't go into it here. Normal uses the .net framework, documentation for which is available on MSDN. It's easy to read, and is the beginners' language of choice (unless you like the elegant, flowing symbols of C#)

Between the idea
And the reality
Between the motion
And the act
Falls the Shadow

LCARS x3217-Jun-09 21:05

LCARS x32

17-Jun-09 21:05

Computafreak wrote:
(unless you like the elegant, flowing symbols of C#)

I think you mean "unless you like trying to figure out where the heck you're missing that curly bracket". Smile | :)

Visual Basic an excellent programming language that is popular with beginners and experts alike because it's easy to understand, and has a very English-like syntax. All while still having the power of the .NET framework at its disposal. Visual Basic is also very good for rapid application development thanks to the very well thought out Visual Studio IDE.

-Ray Phillips

0x3c017-Jun-09 23:24

0x3c0

17-Jun-09 23:24

It's probably a matter of taste (you have none Poke tongue | ;-P

). I don't like having to write out sentences to tell a computer what to do when I can just use notes (comparatively). Besides, the IDE highlights and indents brackets automatically, so it's not that big a deal

Between the idea
And the reality
Between the motion
And the act
Falls the Shadow

Netblue18-Jun-09 9:05

Netblue

18-Jun-09 9:05

Most .net is the same between the two really, the following is shorter in vb

Select Case number
Case 0
'do something
Case 1
'do something
Case 2
'do something
Case 3
'do something
End Select

I prefer the case insensitivity in vb, strSomething and strsomething should NOT be different, it is not obvious enough when your flying through the code that someone else wrote. And obvious errors are the easiest to discover.

See: http://www.joelonsoftware.com/articles/Wrong.html[^]

Proudly drinking the finest Maryland craft beer. Visiting Maryland for business? First round is on me!

dan!sh 17-Jun-09 21:25

dan!sh

17-Jun-09 21:25

Computafreak wrote:
It comes in two flavours - legacy and normal.

So can I infer:
It comes in two flavours - legacy(abnormal) and normal.

जय हिंद

0x3c017-Jun-09 23:36

0x3c0

17-Jun-09 23:36

Yes. I've tried to use VB6 for a few years; it took months to get that influence out of my system. Classes in VB6 - ugh! Dead | X|

Between the idea
And the reality
Between the motion
And the act
Falls the Shadow