Fixes video recorder ffmpeg on Centos7 and RHEL7

[zlig]

• Conditionally select different arguments for ffmpeg
• Adds meaningful error from the third party application in charge of encoding

[christopherhesse]

Should we instead depend on imageio-ffmpeg to get a consistent binary across different platforms? We could use imageio_ffmpeg.get_ffmpeg_exe() instead of relying on system ffmpeg. @pzhokhov

[pzhokhov]

yeah, I like imageio-ffmpeg python package path better too

[zlig]

Are you suggesting to replace distutils.spawn.find_executable() by imageio_ffmpeg.get_ffmpeg_exe(), such as the following?

250         if "avconv" in os.path.split(imageio_ffmpeg.get_ffmpeg_exe())[-1]:
251             self.backend = 'avconv'
252         elif "ffmpeg" in os.path.split(imageio_ffmpeg.get_ffmpeg_exe())[-1]:
253             self.backend = 'ffmpeg'
254         else:
255             raise error.DependencyNotInstalled("""Found neither the ffmpeg nor avconv executables. On OS X, you can install ffmpeg via `brew install ffmpeg`. On most Ubuntu variants, `sudo apt-get install ff    mpeg` should do it. On Ubuntu 14.04, however, you'll need to install avconv with `sudo apt-get install libav-tools`.""")

Not sure if it is an improvement question readability, but having new dependencies in the requirements for imageio and imageio_ffmpeg will probably resolve other install issues.

[christopherhesse]

Sort of, I think we could forget "avconv" entirely, add imageio_ffmpeg to the dependencies, and then always assume that imageio's ffmpeg works and accepts the options we are giving it. Does that package work fine on centos?

[vwxyzjn]

Hey following up with this issue. @zlig could you create a Dockerfile based on Centos7 or RHEL7? This would greatly help us understand and test the PR.

[zlig]

Hi @vwxyzjn

Actually, the RHEL/CentOS 7 systems aren't supported anymore.

Provided the following CentOS 8 Dockerfile into the PR 2400, if there is an issue number you need me to attach against. It is still work-in-progress as I'm still getting 15x failing tests at the moment...

# A Dockerfile based on CentOS 8 that sets up a full Gym install with test dependencies
FROM centos:8
ARG PYTHON_VERSION
ENV PYTHON_VERSION=${PYTHON_VERSION:-36}

# Install pre-requisites
RUN dnf clean all 
RUN dnf install -y epel-release
RUN dnf install -y --enablerepo=powertools wget unzip cmake gcc patchelf \
                python$PYTHON_VERSION python$PYTHON_VERSION-devel python3-pyopengl freeglut-devel \
                mesa-libOSMesa-devel mesa-libOSMesa mesa-libGL-devel glfw-devel xorg-x11-server-Xvfb
RUN rm -rf /var/cache/dnf

# Download and install mujoco
RUN mkdir /root/.mujoco && \
    cd /root/.mujoco  && \
    curl -O https://www.roboti.us/download/mujoco200_linux.zip && \
    unzip mujoco200_linux.zip && \
    mv /root/.mujoco/mujoco200_linux/ /root/.mujoco/mujoco200/ && \
    echo DUMMY_KEY > /root/.mujoco/mjkey.txt

ENV LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/root/.mujoco/mujoco200/bin

COPY . /usr/local/gym/
WORKDIR /usr/local/gym/

# Set Python 3 as default interpreter
RUN ln -s /usr/bin/python3 /usr/bin/python
RUN ln -s /usr/bin/pip3 /usr/bin/pip
RUN python --version

# Install required Python modules
RUN pip install pyglet && pip install ffmpeg && pip install -U 'mujoco-py<2.1,>=2.0' && pip install -r test_requirements.txt

# Execution
ENTRYPOINT ["/usr/local/gym/bin/docker_entrypoint"]

Also, just for reference, this is a CentOS 7 Dockerfile, but I need to spend a bit more time on it :

# A Dockerfile that sets up a full Gym install with test dependencies
ARG PYTHON_VERSION
FROM centos:7
#RUN apt-get -y update && apt-get install -y unzip libglu1-mesa-dev libgl1-mesa-dev libosmesa6-dev xvfb patchelf ffmpeg cmake swig
RUN yum clean all 
RUN yum install -y epel-release
RUN yum install -y wget unzip cmake gcc 
RUN yum install -y python36 python36-devel
RUN yum install -y glfw-devel mesa-libOSMesa-devel mesa-libGL-devel patchelf python-xvfbwrapper

# Download mujoco
RUN mkdir /root/.mujoco && \
    cd /root/.mujoco  && \
    curl -O https://www.roboti.us/download/mjpro150_linux.zip && \
    unzip mjpro150_linux.zip && \
    echo DUMMY_KEY > /root/.mujoco/mjkey.txt

ENV LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/root/.mujoco/mjpro150/bin

COPY . /usr/local/gym/
WORKDIR /usr/local/gym/

RUN echo 'alias python="python3"' >> ~/.bashrc
RUN echo 'alias pip="pip3"' >> ~/.bashrc
RUN source ~/.bashrc
RUN python --version

RUN pip3 install ffmpeg && pip3 install -U 'mujoco-py<1.50.2,>=1.50.1' && pip3 install -r test_requirements.txt

ENTRYPOINT ["/usr/local/gym/bin/docker_entrypoint"]