26.05.2015, 18:47, "Matthew Woehlke" <mw_tr...@users.sourceforge.net>: > On 2015-05-23 13:50, René J.V. Bertin wrote: >> On Saturday May 23 2015 19:06:47 Allan Sandfeld Jensen wrote: >>> The bug for replacing lbjpeg with libjpeg-turbo is >>> https://bugreports.qt.io/browse/QTBUG-40091 - Feel free to take it over :) >> Funny how that focuses on a performance difference which is >> apparently not due to using libjpeg-turbo vs. the regular version. > > Hmm... > > Performance is *exactly* why we switched to building our own > libjpeg-turbo and then building Qt against that, rather than using the > bundled libjpeg. > > We have an application that deals with what is effectively MJPEG video, > but we are handling the "M" part of it ourselves, and using Qt to read > and write frames. We ran into problems with HD video; it worked fine on > Linux, but had serious issues on Windows. After tracking it down to the > time spent reading/writing the frames, we realized that on Windows, Qt > was using a bundled libjpeg, while Linux of course was using > libjpeg-turbo. Building Qt on Windows against an externally built > libjpeg-turbo fixed the problem.
FWIW, MJPEG is by far not the best codec choice for HD video. -- Regards, Konstantin _______________________________________________ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest
