| .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. |
