SDL::Overlay - YUV Video overlay
First import the following modules to get access to constants and functions needed for overlay.
use SDL; use SDL::Video; use SDL::Overlay;
Init the video susbsystem.
SDL::Init(SDL_INIT_VIDEO);
Create a display to use.
my $display = SDL::SetVideoMore(640, 480, 32, SDL_SWSURFACE);
Create and attach the display to a new overlay my $overlay = SDL::Overlay->new( 100, 100, SDL_YV12_OVERLAY, $display);
A SDL_Overlay
allows for video rendering on an SDL_Surface
which is a display.
The term 'overlay' is a misnomer since, unless the overlay is created in hardware, the contents for the display surface underneath the area where the overlay is shown will be overwritten when the overlay is displayed.
The constructor creates a SDL::Overlay of the specified width, height and format (see YUV_Flags
list below of available formats), for the provided display.
Note the 'display' argument needs to actually be the surface created by SDL::Video::SetVideoMode
otherwise this function will segfault.
my $overlay = SDL::Overlay->new( $width, $height, $YUV_flag, $display );
More information on YUV formats can be found at http://www.fourcc.org/indexyuv.htm .