[vlc-devel] RGB capture issues in DirectShow

[Rémi Denis-Courmont]

Le lauantaina 11. helmikuuta 2017, 20.06.41 EET Rémi Denis-Courmont a écrit :
> 	Hello,
> 
> Le lauantaina 11. helmikuuta 2017, 19.17.23 EET Salah-Eddin Shaban a écrit :
> > The orientation issue is that frames are bottom to top, and should be
> > flipped before rendering. But the statement in line 720 of dshow.cpp
> > 
> > fmt.video.orientation = ORIENT_BOTTOM_LEFT;
> 
> I made VLC use the EXIF orientation syntax as reference because it
> unambiguous. The first term is where the top field goes, the second is where
> the left field goes. So Bottom-Left means that the image is flipped around
> the horizontal axis.

To be clear, it´s where the physical top line and the physical left column are 
stored in the decoded picture. It is not the other way. The distinction only 
matters for bottom-right and left-bottom though; the other orientations are 
involutive, including bottom-left.

-- 
雷米‧德尼-库尔蒙
https://www.remlab.net/