anchor.diff:  			SDL-devel \
   			freeglut-devel
   
  -RUN 	curl -fsSL https://github.com/gpac/gpac/archive/v0.5.2.tar.gz -o gpac.tar.gz && \
  -		tar -xzf gpac.tar.gz && cd gpac-0.5.2/ && \
  +ENV		MP4Box_Version	0.6.0
  +RUN 	curl -fsSL https://github.com/gpac/gpac/archive/v${MP4Box_Version}.tar.gz -o gpac.tar.gz && \
  +		tar -xzf gpac.tar.gz && cd gpac-${MP4Box_Version}/ && \
   			./configure --static-mp4box --use-zlib=no && \
   		make -j4 && make install && \	
   		ln -s /usr/local/bin/MP4Box /usr/bin/MP4Box && \
  -		cd .. && rm -rf gpac && rm gpac.tar.gz && rm -rf gpac-0.5.2
  +		cd .. && rm -rf gpac && rm gpac.tar.gz && rm -rf gpac-${MP4Box_Version}
   
   # install nodejs (version 0.11.0)
   RUN 	curl -sL https://rpm.nodesource.com/setup | bash - && \
  
positive.code: # install prerequisites
  RUN		npm install --quiet -g install grunt-cli bower
  
  # Set /zoomable as pwd and copy all files to this container's directory
  WORKDIR	/zoomable
  ADD		.	/zoomable				
  
  # install npm packages
  RUN		npm install && \
  	 	bower install --quiet --allow-root --config.interactive=false
  
  # cleanup
  RUN 	npm cache clean
negative.code: # Pre-existing docker image with ffmpeg preloaded (Centos)
  # To build: sudo docker build -t <your-username>/<repository-name> .
  # To run: sudo docker run -it -p 1337:1337 --entrypoint='bash' <your-username>/<repository-name> 
  FROM	jrottenberg/ffmpeg
  
  # install utilities
  RUN 	yum -y update && yum -y install curl make gcc gcc-c++ git bzip2
  
  # install MP4Box (GPAC)
  RUN		yum -y install \
  