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Digital video

Posted on 2002-05-22
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I am writing a Windows NT application using VC++ 6.0.
I am receiving digital video data in through a HOTLink interface card.
I am required to save this digital video frame information to file.( that's the easy part)
Later, I am required to display this video frame data.  (frame by frame) or "real-time" from file.
I understand the digital video frame data format.  And can extract window size, and each pixel word data.
It seems that this will be a cumbersome task to do display all this information back to the user frame by frame, painting pixel by pixel.  
Not knowing to much about displaying video or video in general my questions are:

1) What is the file format of uncompressed video?
2) Is there a tool to display, what I am assuming is called uncompressed video?
3) Should I try to compress the video data?  
4) Will compressing the video data change the file format to JPEC or MPEG or whatever it is that will make it easier to replay this digital video?

Thanks for any help you can give.
Vida
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Question by:vpomona
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by:orange_juice
ID: 7036181
previously i built my own low speed frame grabber card with raw data.
i use DirectX DirectDraw, that enable me to directly map the entire screen to memory location. By just directly memcpy all your raw data to this memory, your video gets displayed on pc, .... as for frame, you have to some how use a way to control the timing. DirectDraw won't help

but lately there is all this DirectShow stuff which unfortunately i not quite know, if not mistaken, it support video, through some standard format

since u have raw data format, i think better to use the first approach

may i know what video card u use? is it an off the shell product?
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by:orange_juice
ID: 7036188
don't need to compress the video, or save in jpeg... just make ur thing most complex

compression is useful only at the hardware level, when it gets transfered through the cable. At software level, it adds overhead only. If u already have the raw data, i don't see any point why u want to compress it.

anyway, there are some pro, standard compressed format like jpeg, mpeg..... there exist many open source decoder works on www. u can just grab one and use, may be make ur life easier. But if u can do directdraw, why bother that??
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Author Comment

by:vpomona
ID: 7038258
I am using a Wintriss PCI HOTLink card. COTS card
I will check into using direct draw.  and get back later.
It also sounds like I do not need to compress the video data.
I am still unclear if there is a standard form for uncompressed video?  *.avi *.jpeg ????????
thanks Vida
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Accepted Solution

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orange_juice earned 400 total points
ID: 7039834
standard form for uncompressed video? I also don't know.
But for frame grabber card, normally when accessible to their buffer, the data is all raw, either RGB, YUV, or monochrome... we directly map/ BitBlt to DirectDraw surface (meaning our display card memory, e.g our monitor screen) .

   i manage to get my card working in this manner previously, can show 'slow' motion, or capture still picture. Lots of hardware issue though.

you can take a look on it at
http://www.geocities.com/cheah_wei

to see if the simple ddraw program is useful to you.
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