TurboVNC project is a spin-off of TightVNC and differs from its parent project in the following ways:
· TurboVNC provides only two forms of image encoding: Tight JPEG encoding and Raw encoding of 24-bit pixels. The Tight encoding algorithm is accelerated using TurboJPEG (the same JPEG codec used by the VGL Image Transport) and is tuned to provide high frame rates at the expense of using a bit more network bandwidth. TightVNC spends a lot of CPU time reducing the color depth of certain blocks, which can improve performance on very low-bandwidth networks (e.g. dial-up) but will generally cause the performance to be CPU-limited on broadband and faster connections. · TurboVNC does not bother to perform any color depth analysis on the blocks when using Tight encoding. It simply encodes them all as 24-bit JPEG.
· TurboVNC provides more fine-grained control over the JPEG image quality.
· TurboVNC provides (optional) double buffering on the client side to alleviate tearing artifacts in 3D and video applications.
· TurboVNC provides protocol tweaks which allow some stages of the VNC pipeline to be executed in parallel. This improves performance on high-latency networks.
· TurboVNC provides a "lossless refresh" feature, which sends a Zlib-encoded RGB copy of the current screen image when you press a certain hotkey. This is useful in situations where image quality is critical but the network is too slow to support high-quality JPEG or Raw image encoding.
· TurboVNC is built and tested thoroughly on Solaris platforms (client and server) and on Intel-based Macs (client only.)
TurboVNC, when used with VirtualGL's X11 Image Transport, is the fastest solution for remotely displaying 3D applications across a wide-area network. TurboVNC performs about the same as the VGL Image Transport when used on a local-area network, but TurboVNC requires the user to interact with the entire remote desktop in a single window and thus does not provide a completely seamless experience.
TurboVNC is capable of sending nearly 20 Megapixels/second over a 100 Megabit/second local area network with perceptually lossless image quality. TurboVNC can deliver between 10 and 12 Megapixels/second over a 3 Megabit/second broadband connection at reduced (but usable) image quality.
The TurboVNC server is backward compatible with other VNC distributions. RealVNC and TightVNC clients can connect to the TurboVNC server (with reduced performance.) TurboVNC can be installed onto the same system as another VNC distribution without interference.
What's New in This Release:
Added a new preset to all VNC viewers which allows the user to select both the
WAN protocol optimizations and perceptually lossless image quality.
Added '-list' option to vncserver which lists all VNC sessions (not just
TurboVNC sessions) running under the current user account on the current
machine. This new option is documented in the VGL/TVNC docs as well as the
TurboVNC man pages.
vncserver will no longer fail if the USER environment variable is unset. That
environment variable is unused in the script, so checking for its presence was
apparently a vestigial feature.
Modified Windows build to embed a proper version number in TurboVNC.exe.
Changed the fallback logic in the default ~/.vnc/xstartup file so that Gnome is
used as the window manager on Solaris if it is available and if
~/.dt/sessions/lastsession doesn't exist. Otherwise, CDE is used.
Fixed an issue whereby Gnome would fail to start in TurboVNC if TurboVNC was
launched from within another X session.