VideoProjector

Latest revision as of 19:26, 20 October 2014

Our new 16/9 video beamer (Aacer P7500) has some 16/9 issues as we only use a VGA (loooong) cable. So thet 16/9 laptop connected to the 16/9 projector switches to 4/3 as there seems to be no DCC signal coming through. That result in a nice 4/3 image on the 16/9 projector... pfuuuh

So here comes the xrandr,as seen on 29C3 Note that not all this will work on your laptop (e.g. the name of the display)

 # my laptop is 1366x768, so that what I use
 #xrandr       # gives the names of the displays you have
 #gtf 1366 768 60    # this gives the parameters for the next line 
 xrandr --newmode "1368x768_60.00"  85.86  1368 1440 1584 1800  768 769 772 795  -HSync +Vsync
 xrandr --addmode VGA1 1368x768_60.00
 xrandr --output VGA1 --mode 1368x768_60.00
 # mirror mode
 xrandr --output VGA1 --same-as LVDS1
 xrandr --output LVDS1 --mode 1366x768

Another setup with the recent arrival of an old acer aspire 5570Z laptop. This time side by side.

  # gtf 1920 1080 60
  xrandr --newmode "1920x1080_60.00"  172.80  1920 2040 2248 2576  1080 1081 1084 1118  -HSync +Vsync
  xrandr --addmode VGA1 1920x1080_60.00
  xrandr --output VGA1 --mode 1920x1080_60.00
  xrandr --output VGA1 --right-of LVDS1

Thanks acer to sell a 16:9 fullhd beamer which does not want to output fullhd onto the complete size of the projection. Scumbag beamer thinks: oh this is fullhd on VGA, lets just skew all that to the right and leave 20% black on the left.

But we at syn2cat are true hackers, so seeing a lower resolution using all available screen estate, a bit of testing around determined that the following makes the P7500 output the video on the whole screen without distortion.

  # gtf 1792 1008 60
  xrandr --newmode "1792x1008_60.00"  150.19  1792 1904 2096 2400  1008 1009 1012 1043  -HSync +Vsync
  xrandr --addmode VGA1 1792x1008_60.00
  xrandr --output VGA1 --mode 1792x1008_60.00
  xrandr --output VGA1 --right-of LVDS1

And here a vlc command nicely playing a video. How does it guess that it should go to the second screen? No idea, it just works.

  vlc --fullscreen --disable-screensaver --no-video-title-show --mouse-hide-timeout 100 <videofile>

Here is a script where you give the height of the screen and it calculates the resolution for an 21:9 screen

#!/bin/bash
if [ "$1" = "" ]
then
  echo "usage: $0 screenheight"
  exit
fi
h="$1"
modeline="$(gtf $((2560*h/1080)) $h 60|awk '/Modeline/{$1="";print}')"
xrandr --newmode $modeline
mode=$(echo $modeline | cut -d" " -f1)
xrandr --addmode HDMI1 $mode
xrandr --output HDMI1 --mode $mode