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author | dscho <dscho> | 2001-09-27 09:01:39 +0000 |
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committer | dscho <dscho> | 2001-09-27 09:01:39 +0000 |
commit | fb53d4812061fd0976398fc2609a5f5b4a2331a6 (patch) | |
tree | 56ecef6fd4b51c4c4d4e34a6b055d89fe03959cc /README | |
parent | 5c3eae92371309d94a5edd4e35caa71a2e481ab9 (diff) | |
download | libvncserver-fb53d4812061fd0976398fc2609a5f5b4a2331a6.zip libvncserver-fb53d4812061fd0976398fc2609a5f5b4a2331a6.tar.gz |
docu and cursors in examples.
Diffstat (limited to 'README')
-rw-r--r-- | README | 77 |
1 files changed, 74 insertions, 3 deletions
@@ -5,8 +5,9 @@ What is it? ----------- VNC is set of programs using the RFB (Remote Frame Buffer) protocol. They -are designed to "export" a frame buffer via net. It is already in wide use -for administration, but it is not that easy to make a server yourself. +are designed to "export" a frame buffer via net (if you don't know VNC, I +suggest you read "Basics" below). It is already in wide use for +administration, but it is not that easy to program a server yourself. This has been changed by LibVNCServer. @@ -175,7 +176,77 @@ History LibVNCServer is based on Tridia VNC and OSXvnc, which in turn are based on the original code from ORL/AT&T. -VNC fascinated me from t +When I began hacking with computers, my first interest was speed. So, when I +got around assembler, I programmed the floppy to do much of the work, because +it's clock rate was higher than that of my C64. This was my first experience +with client/server techniques. + +When I came around Xwindows (much later), I was at once intrigued by the +elegance of such connectedness between the different computers. I used it +a lot - not the least priority lay on games. However, when I tried it over +modem from home, it was no longer that much fun. + +When I started working with ASP (Application Service Provider) programs, I +tumbled across Tarantella and Citrix. Being a security fanatic, the idea of +running a server on windows didn't appeal to me, so Citrix went down the +basket. However, Tarantella has it's own problems (security as well as the +high price). But at the same time somebody told me about this "great little +administrator's tool" named VNC. Being used to windows programs' sizes, the +surprise was reciprocal inverse to the size of VNC! + +At the same time, the program "rdesktop" (a native Linux client for the +Terminal Services of Windows servers) came to my attention. There where even +works under way to make a protocol converter "rdp2vnc" out of this. However, +my primary goal was a slow connection and rdp2vnc could only speak RRE +encoding, which is not that funny with just 5kB/s. Tim Edmonds, the original +author of rdp2vnc, suggested that I adapt it to Hextile Encoding, which is +better. I first tried that, but had no success at all (crunchy pictures). + +Also, I liked the idea of an HTTP server included and possibly other +encodings like the Tight Encodings from Const Kaplinsky. So I started looking +for libraries implementing a VNC server where I could steal what I can't make. +I found some programs based on the demo server from AT&T, which was also the +basis for rdp2vnc (can only speak Raw and RRE encoding). There were some +rumors that GGI has a VNC backend, but I didn't find any code, so probably +there wasn't a working version anyway. + +All of a sudden, everything changed: I read on freshmeat that "OSXvnc" was +released. I looked at the code and it was not much of a problem to work out +a simple server - using every functionality there is in Xvnc. It became clear +to me that I *had* to build a library out of it, so everybody can use it. +Every change, every new feature can propagate to every user of it. + +It also makes everything easier: + You don't care about the cursor, once set (or use the standard cursor). +You don't care about those sockets. You don't care about encodings. +You just change your frame buffer and inform the library about it. Every once +in a while you call rfbProcessEvents and that's it. + +Basics +------ + +VNC (Virtual network computing) works like this: You set up a server and can +connect to it via vncviewers. The communication uses a protocol named RFB +(Remote Frame Buffer). If the server supports HTTP, you can also connect +using a java enabled browser. In this case, the server sends back a +vncviewer applet with the correct settings. + +There exist several encodings for VNC, which are used to compress the regions +which have changed before they are sent to the client. A client need not be +able to understand every encoding, but at least Raw encoding. Which encoding +it understands is negotiated by the RFB protocol. + +The following encodings are known to me: +Raw, RRE, CoRRE, Hextile, CopyRect from the original AT&T code and +Tight, ZLib, LastRect, XCursor, RichCursor from Const Kaplinsky et al. + +If you are using a modem, you want to try the "new" encodings. Especially +with my 56k modem I like ZLib or Tight with Quality 0. In my tests, it even +beats Tarantella. + +There is the possibility to set a password, which is also negotiated by the +RFB protocol, but IT IS NOT SECURE. Anybody sniffing your net can get the +password. You really should tunnel through SSH. License ------- |