fastfetch/src/detection/camera/camera_linux.c

#include "camera.h"
#include "common/io.h"

#include <unistd.h>
#include <fcntl.h>
#include <sys/ioctl.h>

#if FF_HAVE_LINUX_VIDEODEV2
    #include <linux/videodev2.h>
#elif __has_include(<sys/videoio.h>) // OpenBSD
    #include <sys/videoio.h>
    #define FF_HAVE_LINUX_VIDEODEV2 1
#endif

const char* ffDetectCamera(FFlist* result) {
#if FF_HAVE_LINUX_VIDEODEV2
    char path[] = "/dev/videoN";

    for (uint32_t i = 0; i <= 9; ++i) {
        path[ARRAY_SIZE(path) - 2] = (char) (i + '0');
        FF_AUTO_CLOSE_FD int fd = open(path, O_RDONLY | O_CLOEXEC);
        if (fd < 0) {
            if (errno == ENOENT) {
                break;
            }
            if (errno == ENXIO) {
                continue;
            }
            return "Failed to open /dev/videoN";
        }

        struct v4l2_capability cap = {};
        if (ioctl(fd, VIDIOC_QUERYCAP, &cap) < 0 || !(cap.capabilities & V4L2_CAP_VIDEO_CAPTURE)) {
            continue;
        }

        struct v4l2_format fmt = { .type = V4L2_BUF_TYPE_VIDEO_CAPTURE };
        if (ioctl(fd, VIDIOC_G_FMT, &fmt) < 0) {
            continue;
        }

        FFCameraResult* camera = FF_LIST_ADD(FFCameraResult, *result);
        ffStrbufInitS(&camera->name, (const char*) cap.card);
        ffStrbufInit(&camera->vendor);
        ffStrbufInitS(&camera->id, (const char*) cap.bus_info);
        switch (fmt.fmt.pix.colorspace) {
            case V4L2_COLORSPACE_SMPTE170M:
                ffStrbufInitStatic(&camera->colorspace, "SMPTE 170M");
                break;
            case V4L2_COLORSPACE_SMPTE240M:
                ffStrbufInitStatic(&camera->colorspace, "SMPTE 240M");
                break;
            case V4L2_COLORSPACE_BT878:
                ffStrbufInitStatic(&camera->colorspace, "BT.878");
                break;
            case V4L2_COLORSPACE_470_SYSTEM_M:
                ffStrbufInitStatic(&camera->colorspace, "NTSC");
                break;
            case V4L2_COLORSPACE_470_SYSTEM_BG:
                ffStrbufInitStatic(&camera->colorspace, "EBU 3213");
                break;
            case V4L2_COLORSPACE_JPEG:
                ffStrbufInitStatic(&camera->colorspace, "JPEG");
                break;
            case V4L2_COLORSPACE_REC709:
            case V4L2_COLORSPACE_SRGB:
                ffStrbufInitStatic(&camera->colorspace, "sRGB");
                break;
            case 9 /* V4L2_COLORSPACE_OPRGB */:
                ffStrbufInitStatic(&camera->colorspace, "Adobe RGB");
                break;
            case 10 /* V4L2_COLORSPACE_BT2020 */:
                ffStrbufInitStatic(&camera->colorspace, "BT.2020");
                break;
            case 11 /* V4L2_COLORSPACE_RAW */:
                ffStrbufInitStatic(&camera->colorspace, "RAW");
                break;
            case 12 /* V4L2_COLORSPACE_DCI_P3 */:
                ffStrbufInitStatic(&camera->colorspace, "DCI-P3");
                break;
            default:
                ffStrbufInit(&camera->colorspace);
                break;
        }
        camera->width = fmt.fmt.pix.width;
        camera->height = fmt.fmt.pix.height;
    }

    return NULL;
#else
    FF_UNUSED(result);
    return "Fastfetch was compiled without <linux/videodev2.h>";
#endif
}