anchor.diff:      --extra-ldflags="-L/tmp${PREFIX}/lib" \
       --extra-libs="-lpthread -lm" \
       --bindir="/usr/local/bin/"  \
  -    && make && make install && make distclean && hash -r && rm -rf /tmp/* && \
  +    && make -j4 && make install && make distclean && hash -r && rm -rf /tmp/* && \
   echo "---- COMPILE SANDREAS MP4V2 ----" \
       && cd /tmp/ \
       && wget https://github.com/sandreas/mp4v2/archive/master.zip \
       && unzip master.zip \
       && rm master.zip \
       && cd mp4v2-master \
  -    && ./configure && make && make install && make distclean && rm -rf /tmp/* && \
  +    && ./configure && make -j4 && make install && make distclean && rm -rf /tmp/* && \
   echo "---- COMPILE FDKAAC ----" \
       && cd /tmp/ \
       && wget https://github.com/nu774/fdkaac/archive/1.0.0.tar.gz \
       && tar xzf 1.0.0.tar.gz \
       && rm 1.0.0.tar.gz \
       && cd fdkaac-1.0.0 \
  -    && autoreconf -i && ./configure && make && make install && rm -rf /tmp/* && \
  +    && autoreconf -i && ./configure && make -j4 && make install && rm -rf /tmp/* && \
   echo "---- REMOVE BUILD DEPENDENCIES ----" \
       && apk del --purge build-dependencies
   
  +ARG M4B_TOOL_DOWNLOAD_LINK="https://github.com/sandreas/m4b-tool/releases/latest/download/m4b-tool.tar.gz"
  +
   # workaround to copy a local m4b-tool.phar IF it exists
  -ADD ./Dockerfile ./dist/m4b-tool.phar* /tmp/
  +#ADD ./Dockerfile ./dist/m4b-tool.phar* /tmp/
   RUN echo "---- INSTALL M4B-TOOL ----" \
  -    && if [ ! -f /tmp/m4b-tool.phar ]; then wget "${M4B_TOOL_DOWNLOAD_LINK}" -O /tmp/m4b-tool.phar ; fi \
  +    && if [ ! -f /tmp/m4b-tool.phar ]; then \
  +            cd /tmp/ && \
  +            wget "${M4B_TOOL_DOWNLOAD_LINK}" && \
  +            if [ ! -f /tmp/m4b-tool.phar ]; then \
  +                tar xzf m4b-tool*.tar.gz && rm m4b-tool*.tar.gz ;\
  +            fi && \
  +            cd - ; \
  +       fi \
       && mv /tmp/m4b-tool.phar /usr/local/bin/m4b-tool \
       && chmod +x /usr/local/bin/m4b-tool
   
  
positive.code: FROM alpine:3.9.2
  
  ENV WORKDIR /mnt
  ARG M4B_TOOL_DOWNLOAD_LINK="https://github.com/sandreas/m4b-tool/releases/latest/download/m4b-tool.phar"
  ARG FFMPEG_VERSION=4.1
  ARG PREFIX=/ffmpeg_build
  
  
negative.code:     openssl-dev \
      opus-dev \
      git \
      wget && \
  echo "---- INSTALL RUNTIME PACKAGES ----" \
      && apk add --no-cache --update --upgrade bzip2 \
  