On 11/28/16, in commit 88c0c9 (and a related commit 0cbea6), Leslie Zhai commented out the contents of K3b::addTranscodePrograms (in ./libk3b/core/k3bdefaultexternalprograms.cpp), declaring the "transcode" program as deprecated.  Unfortunately, K3b::VideoDVDRippingView::reloadMedium (in ./src/rip/videodvd/k3bvideodvdrippingview.cpp) explicitly calls k3bcore->externalBinManager()->foundBin("transcode") to see if it should enable the "Start ripping" option when a video DVD is set to be ripped.  The effect of the change is that K3B can no longer rip DVDs, since the button to begin is disabled and K3B pops up a dialog that says "K3b uses transcode to rip Video DVDs. Please make sure it is installed", even though it is installed.

Uncommenting the commented-out code and recompiling and installing libk3b7 allows K3B to rip DVDs again.

did:
    
      sudo apt-get build-dep k3b
      apt-get source k3b
      cd k3b-2.0.3a+git20170325
      find . -type f | xs grep Deprecated
      vi libk3b/core/k3bdefaultexternalprograms.cpp
      dpkg-buildpackage -rfakeroot -uc -b
      sudo dpkg -i ../libk3b7_2.0.3a+git20170325-0ubuntu2_amd64.deb