rfbproxy is a program for recording, playback, and video conversion of Virtual Network Computing (VNC) screen sessions.

The heart of VNC is the RFB protocol, a simple network protocol to transmit an image of a computer's display, update the images as changes occur, and relay mouse and keyboard events. A VNC server maintains a desktop, which may correspond to a real physical computer display, or may be completely virtual, existing only in the computer's memory. VNC clients connecting to the VNC server can use this display as if it was their own, even though it may exist on another computer over the network. In this way, VNC is similar to Microsoft's Remote Desktop or Symantic's PCanywhere.

Yet the simple, open design of the RFB protocol, combined with VNC's support for multiple simultaneous clients, allows a client to unobtrusively connect to a VNC server and record the changing contents of its screen to a file, independent of any other activity on the desktop. This is the function of rfbproxy:

Since VNC server support is available for both X Windows and Microsoft Windows, this means you can use VNC and rfbproxy to record a UNIX X Windows or Microsoft Windows screen session, then either play it back or convert it to a MPEG, DivX, or Theora video. Since almost all computers also have soundcards, only a few more steps are required to couple audio with your video.

Links

• Get the latest rfbproxy from its Sourceforge Download Page
• rfbproxy's usage is documented on its man page
• Mailing lists
• Sourceforge Project Page

• www.realvnc.com

Gallery

Here are some sample videos I created using rfbproxy. Linux users can use ffplay to decode and display both MPEG-4 and Ogg/Vorbis files. Microsoft users can display MPEG-4 videos using either the DivX or Xvid codecs. The Makefile in the rfbproxy source distribution contains rules for building DVD, MPEG-4, and Ogg/Vorbis videos from recorded rfbproxy sessions.

• Maxima demo (1:57 duration)
  • maxima.avi - 1024x768 MPEG-4 (DivX); 5.6 MB
  • maxima-720x480.avi - 720x480 MPEG-4 (DivX); 3.1 MB
  • maxima-720x480.ogg - 720x480 Ogg/Vorbis; 3.8 MB

• Hydraulic ram theory (4:46 duration)
  • theory1.avi - 1024x768 MPEG-4 (DivX); 26.1 MB
  • theory1-720x480.avi - 720x480 MPEG-4 (DivX); 15.8 MB
  • theory1-720x480.ogg - 720x480 Ogg/Vorbis; 11.5 MB

Requests for Assistance

There is always plenty of work to be done with any computer project. rfbproxy is no exception. Here are a few ideas:

• Double-check the usage options in the README file. In particular, I haven't had the chance to verify the XFree86 instructions.

• Port/compile for Windows, probably using the MSYS tools

• It'd be nice to have a turn-key solution for Windows users who want to record their desktop with audio and convert it to video. ffmpeg is available for Windows, so this would require rfbproxy for Windows and some kind of audio tool.

• Add an option to export PPM frames only within a range of timestamps, perhaps something like --time=05:00-06:00 to just get a minute of video starting from the five minute mark

Credits

VNC was developed at Olivetti Research Labs, Cambridge (now AT&T Laboratories, Cambridge) by Tristan Richardson, Ken Wood, James Weatherall, Andy Harter, Charlie McLachlan, Paul Webster, Quentin Stafford-Fraser and others.

Tim Waugh wrote the original version of rfbproxy.

Brent Baccala added the video export capability to rfbproxy.