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"deriving from the interface" and "implementing the interface" are basically the same, the only subtle difference is that you usually say "implement" (but "derive" or "extend" are also okay) when the base class is an interface - the only exception is when both the subclass and the base class are interfaces because in this case documentations use "extend" or "derive". This because evident after reading some documentation about C# or java where there is sharp distinction between classes and interfaces, the VS __interface keyword is also something that mimics the behavior of C# interfaces.
What do you mean on "virtualness" of the class that implements the interface?
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pasztorpisti wrote: What do you mean on "virtualness" of the class that implements the interface?
Sorry, just meaning that once declared virtual in base class, a method is virtual for all "derived" classes.
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Excellent answer, better than mine. +5 for yours...
--
Harvey
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Hi to all,
I am trying to implement Brian Gladman's AES Encryption in my program. But as i am new to Encryption, please guide which mode is good to use.
AES_RETURN aes_ecb_encrypt(const unsigned char *ibuf, unsigned char *obuf,
int len, const aes_encrypt_ctx cx[1]);
AES_RETURN aes_cbc_encrypt(const unsigned char *ibuf, unsigned char *obuf,
int len, unsigned char *iv, const aes_encrypt_ctx cx[1]);
AES_RETURN aes_mode_reset(aes_encrypt_ctx cx[1]);
AES_RETURN aes_cfb_encrypt(const unsigned char *ibuf, unsigned char *obuf,
int len, unsigned char *iv, aes_encrypt_ctx cx[1]);
#define aes_ofb_encrypt aes_ofb_crypt
AES_RETURN aes_ofb_crypt(const unsigned char *ibuf, unsigned char *obuf,
and i am confused on *iv what is this? I had to encrypt files as well as strings.  
Regards,
Vishal
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Try asking Brian Gladman, we cannot guess which of the above is the right choice.
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perhaps you had not understand my question, my question was related to modes and iv. Anyways thanks. 
Regards,
Vishal
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vishalgpt wrote: perhaps you had not understand my question, my question was related to modes and iv.
I understand your question perfectly well. The problem is that you are referring to someone else's code and we do not have access to it, so how can we tell you which function to use? Those function definitions on their own provide no useful information. All I can tell you is that iv is a pointer to a character string, but how that fits in with these functions is anyone's guess.
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well first hello :
i would like to know how to learn kernel programming ?
Does any one know where should i start what books should i read ,if any one know books , websites,forums ,let me know them ,and i know C++ ,Java ,i have been programming since 1 year and half
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well i tried google but i wish if i could learn from members experience
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This is a technical forum, you cannot expect to get full tutorials on something as wide and complex as this subject. You have not even stated which platform you are planning to work on.
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linux platform,well i'm not asking for tutorial i know that this forum is full of programmers , well anyway Thank you.
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OmarSH wrote: linux platform
Then I suggest you do a Google search and you will find lots of useful references.
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OSR online is a very good resource.
Book wise you need Walter Oneys book on kernel programming.
Other than that you need 2 machines, the WDK, windbg, a firewire or serial x over cable and start putting code into the kernel.
PS, I have been doing windows kernel for about 16 years. It is fun, but complex, very very complex, but if you can stick at it for about 2 years you should know enough to be able to write useful code. (And use Verifier, a lot)
==============================
Nothing to say.
modified 8-Feb-13 8:24am.
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You'll probably want to get really familiar and comfortable with C. It may also be helpful to experiment with Linux drivers since you can browse all the existent code to see what other people are doing (although that may confuse you at first, specially if you're not comfortable with C). A lot of people try to dive right in without reading documentation, I'd recommend going over the documentation first, it might not make sense while you're reading it but when you finally dive in, things will start to make sense.
One thing you can do is take an existent driver from Linux and see if you can modify it to do something different. That should get you comfortable with it.
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Hi,
Until now I used MCI to playback my videos directly from memory. I used this trick, because my avi's where inside a huge file archive, so I read them directly without any extraction.
Now I want to update my code to use DirectShow for video playback, but it lacks a callback functionality like mmioInstallIOProc. Is there any approach in my situation ?
Regards,
George
sdancer75
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1. Google for DirectShow input filters that can read from memory
OR
2. try writing your own filter to stream data from memory
> The problem with computers is that they do what you tell them to do and not what you want them to do. <
> If it doesn't matter, it's antimatter.<
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Yes, i suppose this is what I am gonna do.....
I just wished to avoid time and effort in case there was something already out there that did the trick.
sdancer75
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That's understandable, i tried googling around some too but didn't really find anything readymade either. I can think of two alternatives to writing your own source filter:
1. Extract your videos into some temporary files and play those from the file system, this can be a bit costy in both time and resource wise (you need time to extract the videos to temp files and you will need extra disk space for the videos) but i supose this is quite a straightforward solution. Alternatively you might try using a named pipe and specifying that as the source for the file reader filter, no idea if that would work or not, never tried, but i kinda suspect it wouldn't work.
2. Implement a "small" HTTP server in your application that can stream the video from your big file and try to render the stream with DirectShow like "http:\\localhost:12345\a.avi" or somesuch. This might be more work than just writing the filter though.
Good luck.
> The problem with computers is that they do what you tell them to do and not what you want them to do. <
> If it doesn't matter, it's antimatter.<
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Thanks for the reply.
I already thought both of your solutions you suggest. The 1st is abandoned from the very beggining since the archive file is delivered in retail-DVD and as you can imagine the time needed to extract it in the hard disk is critical. The 2nd solution is also rejected, since this is a retail product and the configuration of end computer is unknown, any anti-virus or general other protection software may block my application to work as it expected. So I think a custom filter in my case is more than imperative.
Thanks anyway,
sdancer75
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I want to display my image on window without saving it.
When data is received window size changes but there is no display
on window.
My Code is:
int iBufferLength;
int iEnd;
int iSpaceRemaining;
int i;
iBufferLength = iSpaceRemaining = sizeof(chIncomingDataBuffer);
iEnd = 0;
iSpaceRemaining -= iEnd;
iBytesRead = recv(Socket, chIncomingDataBuffer+iEnd, iSpaceRemaining, 0);
iEnd+=iBytesRead;
if (iBytesRead == SOCKET_ERROR)
MessageBox(hWnd,
"Socket Error",
"Connection strt",
MB_ICONINFORMATION|MB_OK);
chIncomingDataBuffer[iEnd] = '\0';
if (lstrlen(chIncomingDataBuffer) != 0)
{
GetWindowRect(hWnd, &rect);
SetWindowPos(hWnd, NULL, rect.left, rect.top, cBitmap.bmWidth, cBitmap.bmHeight, 0);
HDC ThisDC = GetDC(hWnd);
DeleteDC(RemoteDC);
RemoteDC = CreateCompatibleDC(ThisDC);
DeleteObject(hbitmap);
hbitmap= CreateCompatibleBitmap(ThisDC, cBitmap.bmWidth, cBitmap.bmHeight);
SelectObject(RemoteDC, hbitmap);
ReleaseDC(hWnd, ThisDC);
BITMAPINFO bi;
HBITMAP hbmap;
int bisize = sizeof(BITMAPINFO);
memcpy(&bi, chIncomingDataBuffer+iEnd, bisize );
SetDIBits(RemoteDC, hbitmap, 0, cBitmap.bmHeight, chIncomingDataBuffer+iEnd+bisize, &bi, DIB_RGB_COLORS);
InvalidateRect(hWnd, NULL, false);
can anyone tell me..where I am wrong?
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Quote: memcpy(&bi, chIncomingDataBuffer+iEnd, bisize );
for instance, what are you doing in the above line?
Veni, vidi, vici.
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toms from newdelhi wrote: can anyone tell me..where I am wrong?
Yes, the same as I told you before. You are not checking that you have read all the data from the client so you have no way of being sure that you have a valid image. You are using sizeof and lstrlen to find the length of the data, neither of which will give you a valid answer.
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