v4l2loopback.h

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/* SPDX-License-Identifier: GPL-2.0+ WITH Linux-syscall-note */
/*
 * v4l2loopback.h
 *
 * Written by IOhannes m zmölnig, 7/1/20.
 *
 * Copyright 2020 by IOhannes m zmölnig.  Redistribution of this file is
 * permitted under the GNU General Public License.
 */
#ifndef _V4L2LOOPBACK_H
#define _V4L2LOOPBACK_H
 
#define V4L2LOOPBACK_VERSION_MAJOR 0
#define V4L2LOOPBACK_VERSION_MINOR 13
#define V4L2LOOPBACK_VERSION_BUGFIX 2
 
/* /dev/v4l2loopback interface */
 
struct v4l2_loopback_config {
    int output_nr;
    int unused; /*capture_nr;*/
 
    char card_label[32];
 
    unsigned int min_width;
    unsigned int max_width;
    unsigned int min_height;
    unsigned int max_height;
 
    int max_buffers;
 
    int max_openers;
 
    int debug;
 
    int announce_all_caps;
};
 
/* a pointer to a (struct v4l2_loopback_config) that has all values you wish to impose on the
 * to-be-created device set.
 * if the ptr is NULL, a new device is created with default values at the driver's discretion.
 *
 * returns the device_nr of the OUTPUT device (which can be used with V4L2LOOPBACK_CTL_QUERY,
 * to get more information on the device)
 */
#define V4L2LOOPBACK_CTL_ADD 0x4C80
 
/* a pointer to a (struct v4l2_loopback_config) that has output_nr and/or capture_nr set
 * (the two values must either refer to video-devices associated with the same loopback device
 *  or exactly one of them must be <0
 */
#define V4L2LOOPBACK_CTL_QUERY 0x4C82
 
/* the device-number (either CAPTURE or OUTPUT) associated with the loopback-device */
#define V4L2LOOPBACK_CTL_REMOVE 0x4C81
 
#endif /* _V4L2LOOPBACK_H */