How do VNC clients know when to request screen updates?
I am developing a VNC-compatible server, following the RFC 6143 specs, and using UltraVNC as client.
I noticed that, although sometimes everything works pretty well, most of the times UltraVNC does not send FramebufferUpdateRequest messages. As an result, my server does not send FramebufferUpdate and the screen is stuck. Clicking the "Refresh" button, at UltraVNC's toolbar, produces a screen update normally.
I've done some tests and I discovered that, when this issue happens, UltraVNC does not send anything to my server, and the TCP traffic remains empty (the socket is not closed), unless there is some user input (mouse/keyboard) or the user clicks the "Refresh" button.
I thought about sending FramebufferUpdate regardless of the client having requested it or not, once I detected screen changes (or after user inputs). This worked well and I had a real-time screen broadcast, however it looks like UltraVNC could not handle user inputs (keyboard and mouse) anymore since the traffic was clogged up with FramebufferUpdates. Also, this seems to go against the specs, since it says that FramebufferUpdates can only be sent in response to one or more FramebufferUpdateRequests (in VNC, servers only send framebuffers when requested by clients).
So, my questions are: how do I tell the VNC client that some region of the screen was updated, "suggesting" it to send a FramebufferUpdateRequest, if this is possible? Also, what does UltraVNC takes into consideration in order to emit a FramebufferUpdateRequest? It does not look like it is interval-based, nor based in user inputs...
vnc
asked Nov 14 '18 at 23:14
Jefrey Sobreira SantosJefrey Sobreira Santos
399214
add a comment |
I am developing a VNC-compatible server, following the RFC 6143 specs, and using UltraVNC as client.
I noticed that, although sometimes everything works pretty well, most of the times UltraVNC does not send FramebufferUpdateRequest messages. As an result, my server does not send FramebufferUpdate and the screen is stuck. Clicking the "Refresh" button, at UltraVNC's toolbar, produces a screen update normally.
I've done some tests and I discovered that, when this issue happens, UltraVNC does not send anything to my server, and the TCP traffic remains empty (the socket is not closed), unless there is some user input (mouse/keyboard) or the user clicks the "Refresh" button.
I thought about sending FramebufferUpdate regardless of the client having requested it or not, once I detected screen changes (or after user inputs). This worked well and I had a real-time screen broadcast, however it looks like UltraVNC could not handle user inputs (keyboard and mouse) anymore since the traffic was clogged up with FramebufferUpdates. Also, this seems to go against the specs, since it says that FramebufferUpdates can only be sent in response to one or more FramebufferUpdateRequests (in VNC, servers only send framebuffers when requested by clients).
So, my questions are: how do I tell the VNC client that some region of the screen was updated, "suggesting" it to send a FramebufferUpdateRequest, if this is possible? Also, what does UltraVNC takes into consideration in order to emit a FramebufferUpdateRequest? It does not look like it is interval-based, nor based in user inputs...
vnc
asked Nov 14 '18 at 23:14
Jefrey Sobreira SantosJefrey Sobreira Santos
399214
add a comment |
I am developing a VNC-compatible server, following the RFC 6143 specs, and using UltraVNC as client.
I noticed that, although sometimes everything works pretty well, most of the times UltraVNC does not send FramebufferUpdateRequest messages. As an result, my server does not send FramebufferUpdate and the screen is stuck. Clicking the "Refresh" button, at UltraVNC's toolbar, produces a screen update normally.
I've done some tests and I discovered that, when this issue happens, UltraVNC does not send anything to my server, and the TCP traffic remains empty (the socket is not closed), unless there is some user input (mouse/keyboard) or the user clicks the "Refresh" button.
I thought about sending FramebufferUpdate regardless of the client having requested it or not, once I detected screen changes (or after user inputs). This worked well and I had a real-time screen broadcast, however it looks like UltraVNC could not handle user inputs (keyboard and mouse) anymore since the traffic was clogged up with FramebufferUpdates. Also, this seems to go against the specs, since it says that FramebufferUpdates can only be sent in response to one or more FramebufferUpdateRequests (in VNC, servers only send framebuffers when requested by clients).
So, my questions are: how do I tell the VNC client that some region of the screen was updated, "suggesting" it to send a FramebufferUpdateRequest, if this is possible? Also, what does UltraVNC takes into consideration in order to emit a FramebufferUpdateRequest? It does not look like it is interval-based, nor based in user inputs...
vnc
asked Nov 14 '18 at 23:14
Jefrey Sobreira SantosJefrey Sobreira Santos
399214
I am developing a VNC-compatible server, following the RFC 6143 specs, and using UltraVNC as client.
I noticed that, although sometimes everything works pretty well, most of the times UltraVNC does not send FramebufferUpdateRequest messages. As an result, my server does not send FramebufferUpdate and the screen is stuck. Clicking the "Refresh" button, at UltraVNC's toolbar, produces a screen update normally.
I've done some tests and I discovered that, when this issue happens, UltraVNC does not send anything to my server, and the TCP traffic remains empty (the socket is not closed), unless there is some user input (mouse/keyboard) or the user clicks the "Refresh" button.
I thought about sending FramebufferUpdate regardless of the client having requested it or not, once I detected screen changes (or after user inputs). This worked well and I had a real-time screen broadcast, however it looks like UltraVNC could not handle user inputs (keyboard and mouse) anymore since the traffic was clogged up with FramebufferUpdates. Also, this seems to go against the specs, since it says that FramebufferUpdates can only be sent in response to one or more FramebufferUpdateRequests (in VNC, servers only send framebuffers when requested by clients).
So, my questions are: how do I tell the VNC client that some region of the screen was updated, "suggesting" it to send a FramebufferUpdateRequest, if this is possible? Also, what does UltraVNC takes into consideration in order to emit a FramebufferUpdateRequest? It does not look like it is interval-based, nor based in user inputs...
vnc
vnc
asked Nov 14 '18 at 23:14
Jefrey Sobreira SantosJefrey Sobreira Santos
399214
asked Nov 14 '18 at 23:14
Jefrey Sobreira SantosJefrey Sobreira Santos
399214
asked Nov 14 '18 at 23:14
Jefrey Sobreira SantosJefrey Sobreira Santos
399214
asked Nov 14 '18 at 23:14
Jefrey Sobreira SantosJefrey Sobreira Santos
399214
asked Nov 14 '18 at 23:14
Jefrey Sobreira SantosJefrey Sobreira Santos
399214
399214
add a comment |
add a comment |
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