Re: AVI Format using VFW

From:
"BobR" <removeBadBobR@worldnet.att.net>
Newsgroups:
comp.lang.c++
Date:
Sat, 18 Aug 2007 18:28:01 GMT
Message-ID:
<RSGxi.42544$ax1.11421@bgtnsc05-news.ops.worldnet.att.net>
Donovan Parks <donovan.parks@gmail.com> wrote in message...

VFW = Video for Windows. A widely used API for accessing data streams
(commonly AVI files).

My question is about a C++ API call for converting data in BGR, bottom
line first format (common for bitmaps in Windows) to the more standard
RGB, top line first format. Alternatively, does anyone have a fast way
to blt data in BGR format to the screen?

I would imagine this is a common problem since Windows bitmaps are
effectively reverse of what most API's expect.

Thanks.

PS: Is this form not open to all C++ programming related questions? If
not, I apology and will post somewhere else.


Standard C++. Outside libraries, APIs, platform specific, etc., are
off-topic here. Those are best answered in an NG specific to those things.

Like: I use a car to go to the doctor. Should I ask medical questions in an
automotive NG?

FAQ http://www.parashift.com/c++-faq-lite

Real ugly, but...

{ using std::cout // for NG post
unsigned int grgb( 0x00010203 ); // your GRGB

cout<<"grgb="<<std::hex<<std::setfill('0')<<std::setw(8)
     <<grgb<<std::dec<<std::endl;

unsigned char *pRev( reinterpret_cast<unsigned char*>( &grgb ) );

std::swap( pRev[0], pRev[2] ); // GRGB to GBGR

cout<<"grgb="<<std::hex<<std::setfill('0')<<std::setw(8)
     <<grgb<<std::dec<<std::endl;
}
/* -output- [win98se/iP4]
grgb=00010203
grgb=00030201
*/

I'll let you work out the 'endians' for your platform(s).

--
Bob R
POVrookie

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