When i do presentation i have this workflow: I connect the beamer on my notebook so i have dualscreen. On my notebook screen i have all icons/windows i need. The things i want to show i move to the 2. desktopscreen (the beamer). If i want to be independent of the cable-end of the beamer i do this: i connect a second monitor to my notebook and i stream the screen of the 2. monitor with ffmpeg / ffserver (installed on my notebook). a other device eg notebook, which is connect to beamer, show my stream on the beamer. Very nice solution for me :). I want to extend the solution that i dont need a monitor connected to my notebook. I dont know how can i get a second desktop is useable like a dualscreen. Greetings Joey Am 2016-01-19 16:57, schrieb Mark Haney:> I'm curious as to what exactly you are needing what appears to be a > second > monitor without an actual second monitor? For what purpose do you > think > you need such a setup? Maybe there's another method to get what you > want > if you can give us more detail. > > > On Tue, Jan 19, 2016 at 10:53 AM, Joey <forum at r5d.de> wrote: > >> Am 2016-01-19 02:01, schrieb Mark LaPierre: >> >>> On 01/17/16 11:42, Joey wrote: >>> >>>> Hello List, >>>> >>>> i want to use a Dual-Screen Solution without connected a second >>>> Monitor. >>>> >>>> Its a solution available, that a physical monitor/Device is >>>> simulated? I >>>> want to use it on KDE. >>>> >>>> Thank you. >>>> >>>> Joey >>>> >>> >>> Hey Joey, >>> >>> Does your current physical monitor support multiple connections? >>> Most >>> modern monitors do. If it does then you can connect a second video >>> cable from your computer to your monitor. There you have it. A duel >>> monitor connection. >>> >> >> Hey, >> >> thx for this tricky idea! Unfortunately i need it for notebooks .. >> >> _______________________________________________ >> CentOS mailing list >> CentOS at centos.org >> https://lists.centos.org/mailman/listinfo/centos >> > > > > -- > > Mark Haney ::: Senior Systems Engineer > *VIF* International Education > P.O. Box 3566 ::: Chapel Hill, N.C. 27515 ::: USA > 919-265-5006 office > > Global learning for all. > www.vifprogram.com > <http://www.vifprogram.com/?utm_source=signature&utm_medium=email&utm_campaign=VIF> > Find VIF on Facebook <http://facebook.com/VIFInternationalEducation> | > Twitter <https://twitter.com/vifglobaled> | LinkedIn > <http://www.linkedin.com/company/vif-international-education> > > Recognized as a ?Best for the World? > <http://bestfortheworld.bcorporation.net/> B Corp! > _______________________________________________ > CentOS mailing list > CentOS at centos.org > https://lists.centos.org/mailman/listinfo/centos
On Tue, Jan 19, 2016 at 05:11:22PM +0100, Joey wrote:> i connect a second monitor to my notebook and i stream the screen of the 2. > monitor with ffmpeg / ffserver (installed on my notebook). a other device eg > notebook, which is connect to beamer, show my stream on the beamer. > > Very nice solution for me :). I want to extend the solution that i dont need > a monitor connected to my notebook. I dont know how can i get a second > desktop is useable like a dualscreen.Could you use Xephyr (xorg-x11-server-Xephyr package in centos7) as a nested X environment for the streaming screen? -- Jonathan Billings <billings at negate.org>
IIRC, back when I did presentations regularly there was a way to screen share a second virtual desktop and leave the primary on the display itself. But that was 5 years ago and I"ve slept since then. On Tue, Jan 19, 2016 at 11:11 AM, Joey <forum at r5d.de> wrote:> When i do presentation i have this workflow: > > I connect the beamer on my notebook so i have dualscreen. On my notebook > screen i have all icons/windows i need. The things i want to show i move to > the 2. desktopscreen (the beamer). > > If i want to be independent of the cable-end of the beamer i do this: > > i connect a second monitor to my notebook and i stream the screen of the > 2. monitor with ffmpeg / ffserver (installed on my notebook). a other > device eg notebook, which is connect to beamer, show my stream on the > beamer. > > Very nice solution for me :). I want to extend the solution that i dont > need a monitor connected to my notebook. I dont know how can i get a second > desktop is useable like a dualscreen. > > Greetings Joey > > > > Am 2016-01-19 16:57, schrieb Mark Haney: > >> I'm curious as to what exactly you are needing what appears to be a second >> monitor without an actual second monitor? For what purpose do you think >> you need such a setup? Maybe there's another method to get what you want >> if you can give us more detail. >> >> >> On Tue, Jan 19, 2016 at 10:53 AM, Joey <forum at r5d.de> wrote: >> >> Am 2016-01-19 02:01, schrieb Mark LaPierre: >>> >>> On 01/17/16 11:42, Joey wrote: >>>> >>>> Hello List, >>>>> >>>>> i want to use a Dual-Screen Solution without connected a second >>>>> Monitor. >>>>> >>>>> Its a solution available, that a physical monitor/Device is simulated? >>>>> I >>>>> want to use it on KDE. >>>>> >>>>> Thank you. >>>>> >>>>> Joey >>>>> >>>>> >>>> Hey Joey, >>>> >>>> Does your current physical monitor support multiple connections? Most >>>> modern monitors do. If it does then you can connect a second video >>>> cable from your computer to your monitor. There you have it. A duel >>>> monitor connection. >>>> >>>> >>> Hey, >>> >>> thx for this tricky idea! Unfortunately i need it for notebooks .. >>> >>> _______________________________________________ >>> CentOS mailing list >>> CentOS at centos.org >>> https://lists.centos.org/mailman/listinfo/centos >>> >>> >> >> >> -- >> >> Mark Haney ::: Senior Systems Engineer >> *VIF* International Education >> P.O. Box 3566 ::: Chapel Hill, N.C. 27515 ::: USA >> 919-265-5006 office >> >> Global learning for all. >> www.vifprogram.com >> < >> http://www.vifprogram.com/?utm_source=signature&utm_medium=email&utm_campaign=VIF >> > >> Find VIF on Facebook <http://facebook.com/VIFInternationalEducation> | >> Twitter <https://twitter.com/vifglobaled> | LinkedIn >> <http://www.linkedin.com/company/vif-international-education> >> >> Recognized as a ?Best for the World? >> <http://bestfortheworld.bcorporation.net/> B Corp! >> _______________________________________________ >> CentOS mailing list >> CentOS at centos.org >> https://lists.centos.org/mailman/listinfo/centos >> > > _______________________________________________ > CentOS mailing list > CentOS at centos.org > https://lists.centos.org/mailman/listinfo/centos >-- Mark Haney ::: Senior Systems Engineer *VIF* International Education P.O. Box 3566 ::: Chapel Hill, N.C. 27515 ::: USA 919-265-5006 office Global learning for all. www.vifprogram.com <http://www.vifprogram.com/?utm_source=signature&utm_medium=email&utm_campaign=VIF> Find VIF on Facebook <http://facebook.com/VIFInternationalEducation> | Twitter <https://twitter.com/vifglobaled> | LinkedIn <http://www.linkedin.com/company/vif-international-education> Recognized as a ?Best for the World? <http://bestfortheworld.bcorporation.net/> B Corp!
Am 2016-01-19 20:28, schrieb Jonathan Billings:> On Tue, Jan 19, 2016 at 05:11:22PM +0100, Joey wrote: >> i connect a second monitor to my notebook and i stream the screen of >> the 2. >> monitor with ffmpeg / ffserver (installed on my notebook). a other >> device eg >> notebook, which is connect to beamer, show my stream on the beamer. >> >> Very nice solution for me :). I want to extend the solution that i >> dont need >> a monitor connected to my notebook. I dont know how can i get a second >> desktop is useable like a dualscreen. > > Could you use Xephyr (xorg-x11-server-Xephyr package in centos7) as a > nested X environment for the streaming screen?i try xephyr/xnest, but i dont recognize how i can use a nested display like a second screen.
On Jan 19, 2016, at 9:11 AM, Joey <forum at r5d.de> wrote:> > i stream the screen of the 2. monitor with ffmpeg / ffserverThat?s an inherently problematic way of approaching the problem. Wifi is a terrible medium for transmitting live video, or in fact any realtime data. It?s subject to frequent timeouts, which are fine for web pages or email, where most of your time is spent reading what you downloaded, not pulling live data. And, a bit of delay is fine there, too. The common solutions to that problem, used by the likes of YouTube and Netfix, are high compression rates and buffering. Neither solution is really open to you here. First, high compression rates take too much CPU. (Just curious: what codec and encoding parameters are you currently using?) Second, the lag from buffering directly fights your wish for a realtime solution. You really don?t want lags of half a second or more between mouse movements and the resulting action appearing on the projector. And half a second of buffering is on the short side of typical for such applications. Wifi security camera buffering is often more like 3 seconds, for example. Even when all of this works, your single stream will suck up a huge chunk of the whole network?s capacity, since wifi is inherently a broadcast medium. You might be nearly monopolizing it, in many cases. (e.g. 802.11g with ?54? Mbit/sec, which ends up maybe 11 Mbit/sec at the computers, which is about the data rate you should be using for screen-res video.) If I had this problem, I?d just use a wireless HDMI transceiver pair: https://www.google.com/webhp?q=wireless%20hdmi Then you?re not fighting for bandwidth with other wifi users, and it?s going to be geared for near-instant transmission. Plus, the transceiver pair is smaller and cheaper than the second notebook. :)