On Wed, Mar 11, 2009 at 03:55:11PM +0100, Pierre Ossman wrote: > On Wed, 11 Mar 2009 15:35:29 +0100 > Adam Tkac <at...@redhat.com> wrote: > > > > > If non-SIMD JPEG is not so slower than raw encoding we can prefer > > Tight JPEG encoding all the time. Otherwise we can use JPEG on low and > > medium bandwidth nets and raw on high bandwidth nets. I think that > > current algorithm which is currently in CConn.cxx will be reused. > > > > We should always send "second preferred" encoding to server in case > > that server doesn't support JPEG. So, in theory, existing code will be > > improved this way: > > > > for speeds >= 16Mbps client sends "Raw, JPEG, hextile, zrle" > > for speeds < 16Mbps client sends "JPEG, zrle, hextile" > > > > (Note: with JPEG I mean Tight encoding, of course) > > > > I'm not convinced we should ever put Raw at the top. The bandwidth > detection is flaky and often over-estimates the bandwidth. > > And raw isn't even used today, so we wouldn't be worse off by not > adding it. > > A more fair comparison would be between Hextile (the current high > bandwidth option), and JPEG. JPEG and Hextile have about the same CPU > usage at a "perceptually lossless" JPEG setting, but JPEG consumes a > tenth of the bandwidth. > > And the bandwidth can be an issue, even on a LAN. Playing some video > easily saturates a 100 Mbps link with raw, whilst with JPEG I get a > very pleasurable experience at around 10 Mbps (and this is without > SIMD!). Hextile is better than raw, but still easily fills 100 Mbps. > > IMO, raw and hextile are not acceptable choices until you have at > least a gigabit network. >
Ok, then I vote for Tight-JPEG as default encoding and for zrle as fallback. Adam -- Adam Tkac, Red Hat, Inc. ------------------------------------------------------------------------------ Apps built with the Adobe(R) Flex(R) framework and Flex Builder(TM) are powering Web 2.0 with engaging, cross-platform capabilities. Quickly and easily build your RIAs with Flex Builder, the Eclipse(TM)based development software that enables intelligent coding and step-through debugging. Download the free 60 day trial. http://p.sf.net/sfu/www-adobe-com _______________________________________________ Tigervnc-devel mailing list Tigervnc-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/tigervnc-devel
