Bug Tracker item #2848621, was opened at 2009-09-01 13:01 Message generated for change (Comment added) made by dcommander You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=1126848&aid=2848621&group_id=254363
Please note that this message will contain a full copy of the comment thread, including the initial issue submission, for this request, not just the latest update. Category: Windows version Group: 1.1.X Status: Open Resolution: None Priority: 5 Private: No Submitted By: Kriston Rehberg (kriston) Assigned to: Nobody/Anonymous (nobody) Summary: AutoSelect should not discard JPEG quality setting Initial Comment: When AutoSelect=1 is turned on, the JPEG quality settings are discarded and switched to "6" no matter what it is set to by the viewer when the AutoSelect routine makes its first selection after logging into a host. I cannot tell if this a Server or a Client problem. AutoSelect should be asked to leave JPEG quality alone. Better, we should be able to instruct TigerVNC which of the tuneable settings should not be changed. This is serious because out of all the tunables, JPEG is the only one that affects visual quality in non-recoverable ways. Run vncviewer with settings QualityLevel=8 AutoSelect=1 and all other defaults. Log into a host. After a short moment, we have: CConn: Throughput 1628 kbit/s - changing to quality 6 CConn: Using Tight encoding ---------------------------------------------------------------------- >Comment By: D. R. Commander (dcommander) Date: 2011-09-27 10:56 Message: JPEG quality is meaningless outside of Tight encoding, and compression level is meaningless with Hextile, so if AutoSelect is truly selecting an encoding automatically, then it doesn't make sense that compression level and quality would remain static. We are still trying to figure out the best way to do automatic encoding. The current AutoSelect feature is inherited from RealVNC, which does not support Tight encoding. Tight encoding makes ZRLE unnecessary, and I hope to eventually modify it such that Hextile is also unnecessary (I did this in TurboVNC by way of the "Lossless Tight" protocol.) I think that, eventually, the AutoSelect setting will only select Tight encoding and will modify the quality level accordingly. I am working on implementing an automatic lossless refresh feature that would work in conjunction with low JPEG quality to provide a mathematically lossless version of the screen whenever the motion stops. ---------------------------------------------------------------------- Comment By: Kriston Rehberg (kriston) Date: 2011-09-27 09:52 Message: I believe that If it's truly not supposed to be used, the option should be disabled in the GUI. The way it is working right now I would have thought that it would AutoSelect either Tight, ZRLE, Hextile while the JPEG and compression level remain static.. ---------------------------------------------------------------------- Comment By: D. R. Commander (dcommander) Date: 2011-09-26 13:51 Message: AutoSelect is actually supposed to be just that-- automatic. If you are selecting that, it means you are handing over full control of the encoding properties to the VNC viewer. The real problem is that AutoSelect is basically broken, as it stands now. It really needs to be replaced with a more sophisticated system that monitors the actual update rate and bandwidth in real time and dials in the JPEG quality based on that. As a stopgap, it should be straightforward to set up a reasonable mapping of bandwidth to quality, but if you want to specifically set the quality level, then I don't understand why you would want to specify AutoSelect=1 at the same time. Obviously if you're specifying the QualityLevel, that means that you want Tight encoding to be used. ---------------------------------------------------------------------- You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=1126848&aid=2848621&group_id=254363 ------------------------------------------------------------------------------ All the data continuously generated in your IT infrastructure contains a definitive record of customers, application performance, security threats, fraudulent activity and more. Splunk takes this data and makes sense of it. Business sense. IT sense. Common sense. http://p.sf.net/sfu/splunk-d2dcopy1 _______________________________________________ Tigervnc-devel mailing list Tigervnc-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/tigervnc-devel
