man display-file (Conventions) - display-file : Render display into image file
NAME
display-file : Render display into image file
SYNOPSIS
display-file: [-flushcmd=<command>] [-flushframe=<n>] [-flushtime=<t>] <filename>
DESCRIPTION
Renders an image into a file. The file can be a framebuffer device (e.g. /dev/fb0), in which case a reasonable representation of the image will be drawn on the console so long as the program's mode matches the framebuffer's mode. Note: This target generates no input. The display-multi target can be used in order to see (and control) what the program does (using a normal target) and then generate a snapshot when the program exits.
OPTIONS
filename is the file to render the images to. If the filename is a PPM file (has the extension .ppm), then the image will be generated at ggiClose time. Otherwise the file is a custom GGIFILE format and is generated continuously.
The display-file target can be used to generate movies from running LibGGI applications. To do this, set -flushcmd to a shell command to execute at the times given by one of the two other parameters. This looks typically like:
ppmtogif foo.ppm > foo.%04d.gif
The command is passed through a printf(3) which has the current count of saved frames as an argument (or rather as 10 arguments to allow a few more complex commands).
This shell command is either executed at every n-th invocation of ggiFlush or every t seconds, where t can have fractional components (specified as decimal).
Note, that the invocation of the shell command will slow down the program, so make sure you use a reasonable value, if you use the -flushtime argument.
The primary file is updated before every invocation of the shell command.
FEATURES
- •
- DirectBuffer always available.
- •
- Unaccelerated.