Build FFmpeg for LibreElec RPi5 with static x264 codec to fix Jellyfin transcoding issue

Dockerfile

FROM ubuntu:focal AS build

ARG DEBIAN_FRONTEND=noninteractive

RUN apt-get update \
 && apt-get dist-upgrade -y \
 && apt-get install -y locales sudo \
 && rm -rf /var/lib/apt/lists/*

RUN locale-gen en_US.UTF-8 \
 && update-locale LANG=en_US.UTF-8 LANGUAGE=en_US:en
ENV LANG=en_US.UTF-8 \
    LANGUAGE=en_US:en \
    LC_ALL=en_US.UTF-8

RUN adduser --disabled-password --gecos '' docker \
 && adduser docker sudo \
 && echo '%sudo ALL=(ALL) NOPASSWD:ALL' >> /etc/sudoers

RUN apt-get update && apt-get install -y \
    curl bash bc gcc-10 sed patch patchutils tar bzip2 gzip xz-utils zstd perl gawk gperf zip \
      unzip diffutils lzop make file g++-10 xfonts-utils xsltproc default-jre-headless python3 \
      libc6-dev libncurses5-dev libjson-perl libxml-parser-perl libparse-yapp-perl \
      golang-1.18-go git openssh-client rsync \
      pkg-config \
    --no-install-recommends \
 && ln -s /usr/lib/go-1.18 /usr/lib/go \
 && rm -rf /var/lib/apt/lists/*

RUN update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-10 100 \
    --slave /usr/bin/cpp cpp /usr/bin/cpp-10 \
    --slave /usr/bin/g++ g++ /usr/bin/g++-10 \
    --slave /usr/bin/gcov gcov /usr/bin/gcov-10
RUN update-alternatives --config gcc

WORKDIR /building
RUN git clone https://code.videolan.org/videolan/x264.git \
    && cd x264 \
    && ./configure --enable-static --disable-shared \
    && make -j$(nproc) \
    && make install

WORKDIR /building
RUN git clone https://github.com/FFmpeg/FFmpeg.git \
    && cd FFmpeg \
    && ./configure \
        --enable-gpl \
        --enable-libx264 \
        --enable-static \
        --disable-shared \
        --extra-cflags="-I/usr/local/include" \
        --extra-ldflags="-L/usr/local/lib" \
    && make -j$(nproc) \
    && mkdir /app/ \
    && cp ffmpeg ffprobe /app

FROM scratch
COPY --from=build /app /app
CMD ["/app/ffmpeg"]

Fixes Jellyfin issue with ffmpeg when transcoding; Unrecognized option 'preset'.

• Build using: docker build -t buildffmpeg .
• Obtain binaries:

docker create --name buildffmpeg buildffmpeg
docker cp buildffmpeg:/app .
docker rm buildffmpeg