libjpeg is not what is currently limiting performance, but once the other performance limiting factors are removed, then libjpeg will become the main bottleneck. As shown in my earlier low-level analysis, the performance difference between libjpeg and libjpeg/SIMD is generally about 2X, so that will generally be the difference in overall performance between the accelerated and unaccelerated builds of TigerVNC.
My personal opinion-- if we really want TigerVNC to be a high-performance product, then libjpeg/SIMD should be the default in the build. We want distribution vendors to release packages that show off the best performance possible. We don't want users to have to download and build the code just to get the improved codec. At the very least, the binary packages we produce within this project need to use libjpeg/SIMD. I don't understand why anyone would not want to use the faster technology, since it is fully open source. The only reason would be if they couldn't get libjpeg/SIMD to build on their system, in which case I think that the system libjpeg should be a configure option, not the default. Pierre Ossman wrote: > On Thu, 26 Mar 2009 04:31:26 -0500 > DRC <dcomman...@users.sourceforge.net> wrote: > > >> I'm currently looking at how to add the 32-bit pixel format extensions >> to libjpeg/SIMD as well as make it run on 64-bit. The former should >> allow me to eliminate some buffer copies in the Tight encoder/decoder, >> which is step 1 of probably about 5 or 6 steps that will be required to >> optimize this. >> >> > > Most distributions will probably want to link with the system libjpeg, > so it would be a shame if this is the source of most problems. > > Did you get my quick performance hack I did yesterday? The pixel > conversion was eating a lot of CPU here and my change improved it by a > factor 20 or so. > > Rgds > ------------------------------------------------------------------------------ _______________________________________________ Tigervnc-devel mailing list Tigervnc-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/tigervnc-devel
