Raja Ayaz's questions

I have installed xrdp on Ubuntu 22.04 Server where I also installed ubuntu-desktop for development and testing. When one user is logged in through remote desktop, others cannot login. How to allow multiple logins (different users)?

Also, how to allow some users to login using xrdp and disable xrdp login for other users? I have four users. I want to allow accesses for two and disable access for the other two.

For ssh, it can be done using DenyUsers as answered here. Does something similar exists for xrdp?

There is one accepted answer here but I couldn't make it work.

I am required to run some video processing algorithms on IP camera stream. I don't have an IP Camera so my idea is to use a webcam as an IP cam for RTSP streaming, which the client machines can acquire and run the algorithms on. I learned that VLC can perform streaming from a webcam. I attached an old webcam to an Ubuntu machine. Here is the information.

$ v4l2-ctl --list-devices
SAMSUNG (SPC-A30M): SAMSUNG (SP (usb-0000:00:14.0-7):
    /dev/video0
    /dev/video1

$ v4l2-ctl --list-formats
ioctl: VIDIOC_ENUM_FMT
    Index       : 0
    Type        : Video Capture
    Pixel Format: 'YUYV'
    Name        : YUYV 4:2:2

Here is the driver info.

/dev/video0
Driver Info (not using libv4l2):
    Driver name   : uvcvideo
    Card type     : SAMSUNG (SPC-A30M): SAMSUNG (SP
    Bus info      : usb-0000:00:14.0-7
    Driver version: 5.3.18
    Capabilities  : 0x84A00001
            Video Capture
            Metadata Capture
            Streaming
            Extended Pix Format
            Device Capabilities
    Device Caps   : 0x04200001
            Video Capture
            Streaming
            Extended Pix Format
ioctl: VIDIOC_ENUM_FMT
    Index       : 0
    Type        : Video Capture
    Pixel Format: 'YUYV'
    Name        : YUYV 4:2:2

==========================================================
/dev/video1
Driver Info (not using libv4l2):
    Driver name   : uvcvideo
    Card type     : SAMSUNG (SPC-A30M): SAMSUNG (SP
    Bus info      : usb-0000:00:14.0-7
    Driver version: 5.3.18
    Capabilities  : 0x84A00001
            Video Capture
            Metadata Capture
            Streaming
            Extended Pix Format
            Device Capabilities
    Device Caps   : 0x04A00000
            Metadata Capture
            Streaming
            Extended Pix Format
ioctl: VIDIOC_ENUM_FMT

When i open MediaStream, do all the steps correctly, I get this error:

Your input can't be opened:
VLC is unable to open the MRL 'v4l2:///dev/video0'. Check the log for detail.

The log file contains:

-- logger module started --
main: Running vlc with the default interface. Use 'cvlc' to use vlc without interface.
main: playlist is empty
v4l2 error: cannot open device '/dev/video0': Operation not permitted
v4l2 error: cannot open device '/dev/video0': Operation not permitted
v4l2 error: cannot open device '/dev/video0': Operation not permitted
v4l2 error: cannot open device '/dev/video0': Operation not permitted

When i open Cheese, the camera is working fine and i can see the video.

For testing purpose, i set the /dev/video0 permissions to 777, still i get the same error.

This Post suggested to add the user to video group, i did that using sudo usermod -aG video ${USER} but no joy.

I also tried Motion in this post, but i couldn't get it working.

I also tried FFmpeg in this post, but i couldn't get that working as well.

I studied and tried this post, this post, this post, and many others, but nothing seems to help.

In the Driver Info section (above), i see not using libv4l2, could it be the cause of the problem? If so, how to solve this issue?

What am i doing wrong? My objective to to provide an RTSP stream form the USB Webcam attached to the Ubuntu Machine, to the client machines for processing in Java or Python. I am not bound to VLC, so i can use anything that gets the job done.

Can anyone suggest a working solution to the VLC problem or suggest any other tool that can do the job?

I tried many posts/solutions but none helped.

I have enabled root login on Ubuntu 18.10 with gnome desktop, works fine. I also have installed xrdp, and it works fine for normal users but not root. I am facing 3 issues:

1. I want to enable remote login for root. When I try to login, I get this message below

2. For users other than root, in xrdp session, I don't see complete gnome desktop as shown in the screenshot below. The sidebar is missing, and there is no Terminal in right click menu. How to fix this?

3. How to enable multi-user remote login? I want multiple users to be able to remote login at the same time.

The most important issue to fix is to enable root login via xrdp. Any help will be highly appreciated.