Re: USB HID MFC Class - C / C++ / MFC Discussion Boards

Arul Joseph16-Sep-05 23:17

16-Sep-05 23:17

Dear Members

my problem is capturing image from webcam and send it to the remote system.Now i capture the image using Windows Multimedia API.But i dont have a idea about how to send it to network.please give tips.

By
S.Arul Joseph

Re: Sending Video through Network

ThatsAlok16-Sep-05 23:35

ThatsAlok

16-Sep-05 23:35

Arul Joseph wrote:
But i dont have a idea about how to send it to network.please give tips.

Try this Link :-
http://www.codeproject.com/internet/videochat.asp[^]

"Opinions are neither right nor wrong. I cannot change your opinion. I can, however, change what influences your opinion." - David Crow

cheers,
Alok Gupta
VC Forum Q&A :- I/ IV

Re: Sending Video through Network

Alexander ^M.,17-Sep-05 11:36

Alexander ^M.,

17-Sep-05 11:36

You can also send it via RTP. There are libraries on the net that may help you.

Don't try it, just do it! Wink | ;-)

capturing web cam

ali kanju16-Sep-05 22:54

ali kanju

16-Sep-05 22:54

i want to capture the driver of my webcam using vc++.how can i do that.waiting for reply.

Re: capturing web cam

ThatsAlok16-Sep-05 23:32

ThatsAlok

16-Sep-05 23:32

These link might help
http://www.codeproject.com/audio/DXCapture.asp[^]
http://www.codeproject.com/directx/LiveVideo.asp[^]
or

Q 1.08 How to capture WEBCAM using Visual C++ or API?[^]

"Opinions are neither right nor wrong. I cannot change your opinion. I can, however, change what influences your opinion." - David Crow

cheers,
Alok Gupta
VC Forum Q&A :- I/ IV

-- modified at 5:32 Saturday 17th September, 2005

USB HID MFC Class

karmendra_js16-Sep-05 22:36

karmendra_js

16-Sep-05 22:36

hello,

Is there any class in MFC or any custom made class using MFC, which i can use to write and read from my USB HID Device. (Important: Read and Write Report should be fail safe).

Thanks

Re: USB HID MFC Class

karmendra_js16-Sep-05 23:42

karmendra_js

16-Sep-05 23:42

Mr. Alok I read an article about USB com 5 access. Can you help me with that. my question is in previous thread post.

Thanks a lot.

Re: USB HID MFC Class

ThatsAlok17-Sep-05 1:34

ThatsAlok

17-Sep-05 1:34

karmendra_js wrote:
I read an article about USB com 5 access.

Which Article..... Any links.....

karmendra_js wrote:
Can you help me with that

Will try .........

"Opinions are neither right nor wrong. I cannot change your opinion. I can, however, change what influences your opinion." - David Crow

cheers,
Alok Gupta
VC Forum Q&A :- I/ IV

Re: USB HID MFC Class

karmendra_js18-Sep-05 2:16

karmendra_js

18-Sep-05 2:16

This is from your "45 Day Series: CodeProject VC++ Forum Q&A - I"

http://www.codeproject.com/cpp/cppfaq10dec04-23jan05.asp#q103

I couldn't make out much from it how to go bout to right device drivers for my HID USB device. I had written a device driver using MFC, but it is not fail safe, means when i write to device or read from device sometimes the system hang. because write and read are blocking calls and unless they return system doesn't proceed. That should i do?

Thanks,

Best way to specify an exit code of a dialog-based MFC application.

Member 228280216-Sep-05 21:49

Member 2282802

16-Sep-05 21:49

Hi,
I am trying to specify an exit code of a dialog-based MFC application. One way I have found is to directly set the m_msgCur.wParam of the CWinApp class.

For example

BOOL CImportArinApp::InitInstance()
{
m_msgCur.wParam = 2;
return FALSE;
}

Is there a better way to specify the exit code of a dialog-based MFC application?

Thanks,
Sravan

Re: Best way to specify an exit code of a dialog-based MFC application.

ThatsAlok16-Sep-05 21:53

ThatsAlok

16-Sep-05 21:53

What about EndDialog(..) function

"Opinions are neither right nor wrong. I cannot change your opinion. I can, however, change what influences your opinion." - David Crow

cheers,
Alok Gupta
VC Forum Q&A :- I/ IV

Re: Best way to specify an exit code of a dialog-based MFC application.

benjnp17-Sep-05 3:07

benjnp

17-Sep-05 3:07

I don't know if this is the right thing to do but I tried OnDialog::OnCancel before and it worked.
Comments are welcome Smile | :)

Re: Best way to specify an exit code of a dialog-based MFC application.

ThatsAlok18-Sep-05 18:13

ThatsAlok

18-Sep-05 18:13

benjnp wrote:
I tried OnDialog::OnCancel before and it worked.

Yeap it will work and CDialog::OnOk() Work tooo ... Smile | :)

"Opinions are neither right nor wrong. I cannot change your opinion. I can, however, change what influences your opinion." - David Crow

cheers,
Alok Gupta
VC Forum Q&A :- I/ IV

Re: Best way to specify an exit code of a dialog-based MFC application.

Achim Klein17-Sep-05 5:04

Achim Klein

17-Sep-05 5:04

Hi Sravan,

CWinApp::ExitInstance

virtual int ExitInstance( );

Return Value
The application's exit code; 0 indicates no errors, and values greater than 0 indicate an error. This value is used as the return value from WinMain.

Regards
Achim Klein

We can do no great things, only small things with great love. - Mother Theresa

Multiple Zoom in One View

Member 85909616-Sep-05 21:35

Member 859096

16-Sep-05 21:35

How can I have multiple zoom in one view ? an object in CView with a zoom fact and another with its zoom fact? D'Oh! | :doh:

Read bytes from a memory mapped file

neliocc16-Sep-05 21:22

neliocc

16-Sep-05 21:22

Hi everybody. I have a problem. I have a file mapped in memory, and a pointer to section of that file, and i need to read n bytes from the file in memory begining in the pointer. If anybody can helpme i will be gratefull.

Re: Read bytes from a memory mapped file

Matt Godbolt17-Sep-05 0:22

Matt Godbolt

17-Sep-05 0:22

If the file's memory mapped, then you treat it exactly like memory - so 'reading n bytes' from the file is simply a memcpy(). If you want to emulate file-like behaviour, try something like (untested code!):

// Constants, you'll need to set these up.  Ideally you'd wrap these in a class somewhere
// and treat them like a FILE* object; this example only supports one 'open' file
const char* gFileBase = address at the beginning of your memory mapped file;
size_t gFileSize = size of the file that was memory mapped;

size_t filePtr = 0;
int memfread(void* destination, size_t numBytes)
{
    // Clamp to the end of the 'file'.
    size_t bytesRemaining = gFileSize - filePtr;
    if (numBytes > bytesRemaining)
        numBytes = bytesRemaining;

    // Copy the number of bytes requested out.
    memcpy(destination, gFileBase + filePtr, numBytes);

    // Move the virtual file pointer on.
    filePtr += numBytes;
    
    return numBytes;
}

Something like that anyway - you can hopefully see how you might implement memfseek() and so forth.

Of course, ideally you'd reap the most benefits from a memory mapped file simpply by treating it pure memory. For example, if your file was an array of Foo structures:

// Get the base of the foo array.
Foo* fooArray = reinterpret_cast<Foo*>(gFileBase);
// use fooArray as if you'd loaded them normally
// any changes you make are reflected on disk automatically.
// e.g. things like "foo[12].bar = 12;" and so forth

Matt Godbolt
Engineer, ProFactor Software
StyleManager project

-- modified at 7:06 Saturday 17th September, 2005

Re: Read bytes from a memory mapped file

Alexander ^M.,17-Sep-05 11:41

Alexander ^M.,

17-Sep-05 11:41

Create a class that has is initialized with a pointer to that section and it's size.
Every read request will increase the pointer by the amount of bytes read.
If that amount gets bigger than the section's size, the EOF is reached.

Don't try it, just do it! Wink | ;-)

DLL function calling

Ahsan Askare16-Sep-05 18:49

Ahsan Askare

16-Sep-05 18:49

Dear friends,
I want to call a function exposed by a DLL. For this purpose i am loading a DLL dynamically using LoadLibrary() and then calling GetProcAddress().

The name of the function i want to call is MSPeelerMain. I dont know about its parameters. Unfortunately the only example present in MSDN
is in VB where the function is declared as:

Function MSPeelerMain (ByVal sHtmlFile As String, ByVal sCmdOptions As String) As Integer

I want to call this function in C++ and as such i am declaring it as:

typedef int (*MYPROC)(LPTSTR, LPTSTR)

But when my program executes i am getting run time debug error:

The value of ESP was not properly saved across the function call.
This is usually a result of calling a function declared with one calling convention with a function pointer declared in other 
calling convention

Can you tell me how to solve this problem ??

Ahsan

-- modified at 0:50 Saturday 17th September, 2005

Re: DLL function calling

S. Senthil Kumar16-Sep-05 19:34

S. Senthil Kumar

16-Sep-05 19:34

Does modifying the typedef to indicate stdcall calling convention help?

typedef int (__stdcall *MYPROC)(LPTSTR, LPTSTR)

Regards
Senthil
_____________________________
My Blog | My Articles | WinMacro

Re: DLL function calling

Ahsan Askare16-Sep-05 20:58

Ahsan Askare

16-Sep-05 20:58

Yes it worked Wink | ;)

Thanks a lot.

Ahsan

Re: DLL function calling

S. Senthil Kumar16-Sep-05 21:00

S. Senthil Kumar

16-Sep-05 21:00

You'r welcome Smile | :)

Regards
Senthil
_____________________________
My Blog | My Articles | WinMacro

Re: DLL function calling

ThatsAlok16-Sep-05 19:57

ThatsAlok

16-Sep-05 19:57

Ahsan Askare wrote:
Function MSPeelerMain (ByVal sHtmlFile As String, ByVal sCmdOptions As String) As Integer

since VB -String = VC-BSTR
so you can try .....

typedef int (WINAPI *MYPROC)(BSTR, BSTR)

"Opinions are neither right nor wrong. I cannot change your opinion. I can, however, change what influences your opinion." - David Crow

cheers,
Alok Gupta
VC Forum Q&A :- I/ IV

Re: DLL function calling

ky_rerun17-Sep-05 10:25

ky_rerun

17-Sep-05 10:25

use typedef int _stdcall (*MYPROC)(LPTSTR, LPTSTR)

the prorblem has to do with who is responsible for cleaning up the stack.

a programmer traped in a thugs body

Interact with Windows Services

Laji5916-Sep-05 18:04

Laji59

16-Sep-05 18:04

Thanks;

But:
Please help me more obviously

Use Ctrl+Left/Right to switch messages, Ctrl+Up/Down to switch threads, Ctrl+Shift+Left/Right to switch pages.