questions about vnc and audio and video

[Corné Beerse]

Me ...... wrote:

> Hi there....i have a couple of questions: firstly, what technical 
> reasons are behind VNC not supporting audio (sound)?...and the second is 

The reasons I can trace back to include (but are not limited to):
- Not defined in the rfb protocol
- Not implemented
- Not available on a lot of systems
- Audio consumes a lot of bandwidth to transmit (network bandwidth) or compress 
(cpu bandwidth).
- VNC only services a kvm-kind of service.

Keep in mind that vnc is origionally pointed at unix machines in a time most 
computers had only "beep" as audio.

On the other hand, there appear to be vnc-implementations that are currently 
implementing audio and other stuff. With that, hooking both viewer and server to 
the same platform (M$Windows).


> does VNC support video?....because while im testing vnc on two windows 
> machines and i played video on the server in a webcam and on the viewer 
> i could see the video clearly so what are the problems VNC face with 
> Video?....thaaaaaanks for any1s help.

For video, I can say that vnc IS video. However, I recognize that your question 
should read 'streaming video'.

VNC Does video in a verry limited way and is server-side dependent:
- Xvnc (linux, unix) handles video the way it goes, provided it can hanlde and 
process the video stream with the available cpu and network bandwidth. In the 
end, no suitable process.
- winvnc (M$Windows) handles video that is NOT using any hardware acceleration: 
It polls the window with video and transmits the contents it finds in the video 
memory. Since polling is used, the frequency is limited: many frames will be 
skipped between poll-s. Since hardare-accelerated video is not stored in the 
video memory, that is not sent.

In the end, there are other protocols that are better suited for streaming audio 
and video.



CBee

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