src/udev/v4l_id/v4l_id.c

/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
 * Copyright (c) 2009 Filippo Argiolas <filippo.argiolas@gmail.com>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation; either version 2 of the
 * License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details:
 */

#include <ctype.h>
#include <errno.h>
#include <fcntl.h>
#include <getopt.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/ioctl.h>
#include <sys/time.h>
#include <sys/types.h>
#include <unistd.h>
#include <linux/videodev2.h>

#include "fd-util.h"
#include "util.h"

int main(int argc, char *argv[]) {
        static const struct option options[] = {
                { "help", no_argument, NULL, 'h' },
                {}
        };
        _cleanup_close_ int fd = -1;
        char *device;
        struct v4l2_capability v2cap;
        int c;

        while ((c = getopt_long(argc, argv, "h", options, NULL)) >= 0)

                switch (c) {
                case 'h':
                        printf("%s [-h,--help] <device file>\n\n"
                               "Video4Linux device identification.\n\n"
                               "  -h  Print this message\n",
                               program_invocation_short_name);
                        return 0;
                case '?':
                        return -EINVAL;

                default:
                        assert_not_reached("Unhandled option");
                }

        device = argv[optind];
        if (!device)
                return 2;

        fd = open(device, O_RDONLY);
        if (fd < 0)
                return 3;

        if (ioctl(fd, VIDIOC_QUERYCAP, &v2cap) == 0) {
                int capabilities;
                printf("ID_V4L_VERSION=2\n");
                printf("ID_V4L_PRODUCT=%s\n", v2cap.card);
                printf("ID_V4L_CAPABILITIES=:");
                if (v2cap.capabilities & V4L2_CAP_DEVICE_CAPS)
                        capabilities = v2cap.device_caps;
                else
                        capabilities = v2cap.capabilities;
                if ((capabilities & V4L2_CAP_VIDEO_CAPTURE) > 0 ||
                    (capabilities & V4L2_CAP_VIDEO_CAPTURE_MPLANE) > 0)
                        printf("capture:");
                if ((capabilities & V4L2_CAP_VIDEO_OUTPUT) > 0 ||
                    (capabilities & V4L2_CAP_VIDEO_OUTPUT_MPLANE) > 0)
                        printf("video_output:");
                if ((capabilities & V4L2_CAP_VIDEO_OVERLAY) > 0)
                        printf("video_overlay:");
                if ((capabilities & V4L2_CAP_AUDIO) > 0)
                        printf("audio:");
                if ((capabilities & V4L2_CAP_TUNER) > 0)
                        printf("tuner:");
                if ((capabilities & V4L2_CAP_RADIO) > 0)
                        printf("radio:");
                printf("\n");
        }

        return 0;
}