40 lines
1.1 KiB
Groff
40 lines
1.1 KiB
Groff
.TH VIDEO 3 "3 March 2001"
|
|
.SH NAME
|
|
im_video_v4l1 \- various image grabbers
|
|
|
|
.SH SYNOPSIS
|
|
.B #include <vips/vips.h>
|
|
|
|
.B int
|
|
.B im_video_v4l1( IMAGE *im, const char *device, int channel,
|
|
.B int brightness, int colour, int contrast, int hue,
|
|
.B int ngrabs )
|
|
|
|
.SH DESCRIPTION
|
|
These functions grab single video frames from various devices. Which of these
|
|
functions work depends upon how your VIPS has been configured and compiled,
|
|
and your platform. As a result, they are far from portable ... you want a
|
|
layer on top of these functions.
|
|
|
|
.B im_video_v4l1(3)
|
|
grabs a frame using Video4Linux. It grabs a 24-bit RGB colour image, at the
|
|
maximum resolution your card allows.
|
|
|
|
.B device
|
|
should typically be "/dev/video".
|
|
.B channel
|
|
selects the channel to acquire: usually 0 is TV, and 1 is composite video.
|
|
.B brightness,
|
|
.B colour,
|
|
.B contrast
|
|
and
|
|
.B hue
|
|
set grab parameters. Each should be in the range (0 - 32768). 32768 is usually
|
|
the value you want.
|
|
.B ngrabs
|
|
sets the number of frames the card should average. Higher values are slower,
|
|
but typically less noisy (and slightly softer).
|
|
|
|
.SH RETURN VALUE
|
|
All functions return 0 on success and -1 on error.
|