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diff --git a/x11vnc/misc/turbovnc/README b/x11vnc/misc/turbovnc/README new file mode 100644 index 0000000..b8e0ac9 --- /dev/null +++ b/x11vnc/misc/turbovnc/README @@ -0,0 +1,147 @@ +INTRO: +------ + +This is a "patch" to make x11vnc/libvncserver work with TurboVNC: + + http://www.virtualgl.org/About/TurboVNC + +It is very experimental/kludgy. Not all TurboVNC features may be enabled. +We are currently evaluating whether TurboVNC support should be officially +put into x11vnc/libvncserver. + +TurboVNC is an optimized VNC for fast refresh rates on fast networks. + +It does pretty well on good broadband as well. But it is not as fast +as regular TightVNC on slow links. + + +TURBOJPEG: +--------- + +TurboVNC uses the TurboJPEG library based on a fast proprietary JPEG +implementation. You will need to download it from the VirtualGL +sourceforge site: + + http://sourceforge.net/project/showfiles.php?group_id=117509&package_id=166100 + +Either install it or simply unpack the .deb or .rpm file into a directory. + +N.B. you can unpack a .deb via 'ar x package.deb' and the extracting +from the data.tar.gz file. rpm2cpio can be used to unpack .rpm's. + + +QUICK-START: +------------ + +For those in a hurry: + + cd x11vnc-x.y.z/x11vnc/misc/turbovnc + ./apply_turbovnc + cd ../../.. + env LDFLAGS='-L/DIR -Xlinker --rpath=/DIR' ./configure + make AM_LDFLAGS='-lturbojpeg' + +where you replace /DIR with your directory containing libturbojpeg.so. + + +PATCHING AND BUILDING: +---------------------- + +After unpacking your x11vnc-x.y.z.tar.gz tarball cd to the +x11vnc-x.y.z/x11vnc/misc/turbovnc (where this README file is) and from +that directory run: + + ./apply_turbovnc + +that will modify files in the libvncserver and x11vnc directories above +this directory. (To undo these changes run: ./undo_turbovnc) The input +sources, tight.c and turbojpeg.h are from the TurboVNC source package. + +After applying, go back to the top level source directory and run: + + env LDFLAGS='-L/path/to/turbojpeg -Xlinker --rpath=/path/to/turbojpeg' ./configure + +where the turbojpeg library is: + + /path/to/turbojpeg/libturbojpeg.so + +(change /path/to/turbojpeg to the directory where you installed or +unpacked it.) + +If you are not using gnu gcc and gnu linker the options may be a little +different (e.g. -R instead of -Xlinker --rpath). + +If you need additional ./configure options or env. var. settings, +add them too. + + +Next, run this make command: + + make AM_LDFLAGS='-lturbojpeg' + +This is a hack and may not always work, if it doesn't edit x11vnc/Makefile +and add '-lturbojpeg' to the LIBS variable. + +This should create a binary: + + ./x11vnc/x11vnc + +that supports VirtualGL's TurboVNC. + +You will need a TurboVNC viewer, you can get one here: + + http://sourceforge.net/project/showfiles.php?group_id=117509&package_id=128130 + +Let us know how it goes. + + +PERFORMANCE: +------------ + +Note that x11vnc has to read the display's screen pixels from the +graphics card memory. This can be slow, e.g. 10 MB/sec. + +There is not a big need for graphics card manufacturers to optimize the +read rate; the write rate is the one they optimize greatly. + + http://www.karlrunge.com/x11vnc/#limitations + +If you run x11vnc and see lines like this: + + 28/02/2009 00:52:07 Autoprobing selected port 5900 + 28/02/2009 00:52:07 fb read rate: 10 MB/sec + 28/02/2009 00:52:07 screen setup finished. + +you have a typical slow one. + +Whereas if you see this: + + 28/02/2009 00:54:46 Autoprobing selected port 5900 + 28/02/2009 00:54:46 fb read rate: 321 MB/sec + 28/02/2009 00:54:46 fast read: reset wait ms to: 10 + 28/02/2009 00:54:46 fast read: reset defer ms to: 10 + 28/02/2009 00:54:46 screen setup finished. + +that is very fast. + +We have only seen it this fast on Linux by using the nvidia proprietary +graphics drivers. The Xorg drivers are typically slow 10 MB/sec. + +It will also be fast if the X server is virtual: Xvfb or Xdummy +since the screen pixels are stored in RAM: + + http://www.karlrunge.com/x11vnc/faq.html#faq-xvfb + +And it will be fast if the ShadowFB xorg.conf option is enabled (if the +card supports it.) + + +The point we are trying to make is that even though TurboVNC uses a +wicked fast JPEG implementation, and cuts out overhead in its attempt to +pump out as many frames per second as it can, if it is slow for x11vnc +to read the screen pixels in the first place then you might not even +notice the TurboVNC speedup. + +So TurboVNC+x11vnc will be faster than TightVNC+x11vnc, but if there is +a large overhead/bottleneck from reading the graphics card framebuffer, +then the speedup will be marginal. |