video_capture_start :: Quanser C Functions

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video_capture_start

Start video capture on a session.

Description

The video_capture_start function starts video capture on a session. This function should be called from the same thread as video_capture_read. Once video capture has been started, images will be captured from the device in the background at the requested frame rate. The images are retrieved using the video_capture_read function.

Prototype

t_error
video_capture_start(t_video_capture capture);

Parameters

t_video_capture capture

A handle to the video capture session, as returned by video_capture_open.

Return value

The return value is 0 if the video capture session is started successfully. Otherwise a negative error code is returned. Error codes are defined in quanser_errors.h. A suitable error message may be retrieved using msg_get_error_message.

Error codes

QERR_INVALID_ARGUMENT

An invalid capture session was passed as an argument. Once a capture session has been closed using video_capture_start the session handle is invalid.

Requirements

Include Files	Libraries
quanser_video.h	quanser_media.lib;quanser_communications.lib;quanser_runtime.lib;quanser_common.lib

Examples

result = video_capture_start(capture);
if (result >= 0) {
    result = video_capture_read(capture, image);
    if (result > 0) {
        ... process image ...
    }
    video_capture_stop(capture);
}