Apologies for the delay, had a few busy work days again.
Argh, the av conversion stuff always changes. You are receiving that warning because you need to install the package libavresample-dev. Even if you install this however openlase needs to be patched yet again for this to start working again. Yes, as you have seen KamalMostafa's has made some changes to allow it to work. I think those are sufficient but since this is a tangental problem lets just comment out that build step so the rest of OpenLase compiles. The qplayvid allows videos to be displayed on the laser projector by edge tracing if you wre curious.
To disable it, change to the tools/qplayvid directory and open the CMakeLists.txt file and change this line:
if(QT4_FOUND AND FFMPEG_FOUND AND SWSCALE_FOUND AND BUILD_TRACER)
to this:
if(FALSE AND QT4_FOUND AND FFMPEG_FOUND AND SWSCALE_FOUND AND BUILD_TRACER)
sudo apt-get install libavresample-dev