capture->set(CV_CAP_PROP_FOURCC, 0xe436eb7e); does not work due to cvRound. OpenCV2.4.3 windows x32. (Bug #2535)

Added by ippei ito over 12 years ago. Updated about 12 years ago.

Status:	Done	Start date:	2012-11-12
Priority:	Normal	Due date:
Assignee:	Andrey Kamaev	% Done:	0%
Category:	highgui-camera
Target version:	2.4.4
Affected version:	2.4.3	Operating System:
Difficulty:		HW Platform:
Pull request:	https://github.com/Itseez/opencv/pull/387

Description

CvCaptureCAM_DShow::setProperty() can't set fourcc
MEDIASUBTYPE_RGB24,MEDIASUBTYPE_RGB32,MEDIASUBTYPE_RGB555,MEDIASUBTYPE_RGB565 etc...
because these fourcc values are overflow when converted from double to int.

EX)
MEDIASUBTYPE_RGB32 fourcc value is 0xe436eb7e.
capture->set(CV_CAP_PROP_FOURCC, 0xe436eb7e);

cap_dshow.cpp
bool CvCaptureCAM_DShow::setProperty( int property_id, double value )
~_{~~
case CV_CAP_PROP_FOURCC:
// value = 0xe436eb7e = 3828804478, but fourcc = 0x80000000.
fourcc = cvRound(value);
~~}~

CV_INLINE int cvRound( double value ) {
#if (defined _MSC_VER && defined _M_X64) || (defined GNUC && defined x86_64 && defined SSE2 && !defined APPLE)
__m128d t = _mm_set_sd( value );
return _mm_cvtsd_si32(t);
#elif defined _MSC_VER && defined _M_IX86
int t;
__asm {
fld value; // value = 0xe436eb7e = 3828804478.
fistp t; // t = 0x80000000.
}
return t;