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By array of the image I mean CurImaArr() - the array I save all the pixels in. I am more comfortavle dealing with the array than with bitmaps at the moment.
I;ve already written some code that determines which frames (or, rather, which frame's array) to save. I just don't know (yet) how to actually save the array, or give the user the option of saving it or not...
My apologies if I am not using proper terminology. Also, I may be a bit confusing due to me trying to think within the limited frame of my C++ knowledge. I will endeavour to be more clear in the future.
-- modified at 13:36 Thursday 11th May, 2006
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Instead of working with your pixel data in terms of BYTE*, it would be easier to work with RGBTRIPLE*/RGBQUAD* instead.
It's ok, as long as you understand that you are not monitoring all frames (Unless the frame rate of your webcam is particularly slow). The code is polling using a timer (WM_TIMER message) set to 10 millisecs, to grab a copy of the image data currently in the VMR filter.
The call to GrabFrame() overwrites m_pFrame with the latest copy of image data from the VMR renderer. If you would like to have a copy of m_pFrame you could just do a memory copy before the next call to GrabFrame(). Look at the OnTimer handler in DXCaptureDlg.h line 191.
Your terminology is fine, it's just that with all these technical terms it can be a little ambigious sometimes.
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The reason I am using C++ for this "project" is because of the speed. It is important to monitor as many frames as possible.
Your GrabFrame() comment has clarified a little bit more, and has certainly given me ideas. For the moment I am concentrating on figuring out how to save and retrieve the array I have mentioned.
I appreciate your help. It has made my C++ start a lot smoother than it would otherwise have been.
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If you would like to monitor all the frames, then this isn't the correct approach. You should be building a filter graph with the Sample Grabber instead.
Capture Device -> Sample Grabber -> Video Renderer
The Sample Grabber filter will do a callback for every sample it receives from the upstream filter.
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is it possible to convert the RGBA from the firewire camera into a grayscale image and display it to a CStatic.SetBitmap?? can u help me?
bye
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I am afraid I can't help you with this,but I have a feeling hfry might. Good luck.
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Am I not monitoring all frames with this approach (given the initial frame is 32-bit)?
I'll be leaving for an extended trip next week, so I need to wrap this "project" up today or tomorrow, which doesn't leave me much time to "develope" a new -to me- way of doing this, hence I think I'll stick with it for the time being. I'll be using the time today and tomorrow attempting to build a save image dialogue box. Any help in this area would be welcome.
I hope to benefit from your advice again as of mid-June, when I pick this up again.
Thanks for the advice so far.
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If your webcam captures at a decent framerate, you won't get all the frames as the code is getting the frames by polling at 10 millisecond intervals. This approach isn't suitable anyway if the intent was to get all the frames.
You can just use the file dialog box provided by Windows, look at CFileDialog with bOpenFileDialog = FALSE.
http://www.functionx.com/visualc/controls/filedialog.htm[^]
If you would like to save the RGB24 image data without headers, I don't see much of a problem as the code is already there. If you would like to save it as a bitmap that other applications can read, then you would have to write the appropriate bitmap headers before writing your image data.
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A slight problem has been encountered. I tried the code with several different cameras and it doesn't work with some of them. A friend suggested it's because some do not encode in RGB but encode in IA20 or something akin to that. Any ideas?
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IA20? Are you perhaps referring to some YUV media subtype like I420?
Failed as in? Cannot create the graph? Cannot get the current image off the VMR filter? Use GraphEdit and build the graph and see if it's possible.
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Yes, I am sorry, I420 sounds more like it. The Live Video renders fine, but the Capture window is blanc. I will follow your suggestion. Thanks.
If it is YUV, how do I translate it into RGB?
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The AVI Decompressor filter can actually perform YUV to RGB conversions. My suggestion is to step through the code and see what is actually failing.
Conversion from I420 to RGB24 is actually quite straightforward. You first convert to 4:4:4 YUV and then convert that into RGB24.
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thanks for code snippet if possible
Yaron
Interface basics click here :
http://www.codeproject.com/com/COMBasics.asp
don't forget to vote 
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thanks
Interface basics click here :
http://www.codeproject.com/com/COMBasics.asp
don't forget to vote
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When we try to open the pst file when the outlook is open and accessing it, fopen itself will fail. Please let me kow what is the best way of reading the pst file contents when the file is open.
Thanks in advance
Sandeep
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How are you calling fopen()?
"Let us be thankful for the fools. But for them the rest of us could not succeed." - Mark Twain
"We will be known forever by the tracks we leave." - Native American Proverb
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fopen("pst file path", "rb");
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I can only assume that Outlook has opened the file for exclusive access. Have you considered Outlook's COM interface?
"The largest fire starts but with the smallest spark." - David Crow
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I cannot use that I belive. I am writig a backup software which can back up the files to a given medium. During this time I cannot use different menthids to backup different files I think.
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what is the difference between Dialog.DoModal and Dialog.Show.
Very junk question but any ways....
Nilesh Korpe
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Actually I failed to find such a Show function in CDialog.
- NS -
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NS17 wrote: failed to find such a Show function
It should be
CDialog::Create
and then call to
CDialog::ShowWindow
Maxwell Chen
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