Dockerfile

# syntax=docker/dockerfile-upstream:master-labs

# Global build arg — must be declared before the first FROM to be usable in FROM instructions.
ARG FFMPEG_TARGET=mp3

# Base emsdk image with environment variables.
FROM emscripten/emsdk:3.1.40 AS emsdk-base
ARG EXTRA_CFLAGS
ARG EXTRA_LDFLAGS
ARG FFMPEG_ST
ARG FFMPEG_MT
ARG FFMPEG_TARGET=mp3
ENV INSTALL_DIR=/opt
# We cannot upgrade to n6.0 as ffmpeg bin only supports multithread at the moment.
ENV FFMPEG_VERSION=n5.1.4
ENV CFLAGS="-I$INSTALL_DIR/include $CFLAGS $EXTRA_CFLAGS"
ENV CXXFLAGS="$CFLAGS"
ENV LDFLAGS="-L$INSTALL_DIR/lib $LDFLAGS $CFLAGS $EXTRA_LDFLAGS"
ENV EM_PKG_CONFIG_PATH=$EM_PKG_CONFIG_PATH:$INSTALL_DIR/lib/pkgconfig:/emsdk/upstream/emscripten/system/lib/pkgconfig
ENV EM_TOOLCHAIN_FILE=$EMSDK/upstream/emscripten/cmake/Modules/Platform/Emscripten.cmake
ENV PKG_CONFIG_PATH=$PKG_CONFIG_PATH:$EM_PKG_CONFIG_PATH
ENV FFMPEG_ST=$FFMPEG_ST
ENV FFMPEG_MT=$FFMPEG_MT
ENV FFMPEG_TARGET=$FFMPEG_TARGET
RUN apt-get update && \
      apt-get install -y pkg-config autoconf automake libtool ragel

# Build x264 (used by the video target)
FROM emsdk-base AS x264-builder
ENV X264_BRANCH=4-cores
ADD https://github.com/ffmpegwasm/x264.git#$X264_BRANCH /src
COPY build/x264.sh /src/build.sh
RUN bash -x /src/build.sh

# # Build x265
# FROM emsdk-base AS x265-builder
# ENV X265_BRANCH=3.4
# ADD https://github.com/ffmpegwasm/x265.git#$X265_BRANCH /src
# COPY build/x265.sh /src/build.sh
# RUN bash -x /src/build.sh

# # Build libvpx
# FROM emsdk-base AS libvpx-builder
# ENV LIBVPX_BRANCH=v1.13.1
# ADD https://github.com/ffmpegwasm/libvpx.git#$LIBVPX_BRANCH /src
# COPY build/libvpx.sh /src/build.sh
# RUN bash -x /src/build.sh

# Build lame (only used for the mp3 target)
FROM emsdk-base AS lame-builder
ENV LAME_BRANCH=master
ADD https://github.com/ffmpegwasm/lame.git#$LAME_BRANCH /src
COPY build/lame.sh /src/build.sh
RUN bash -x /src/build.sh

# # Build ogg
# FROM emsdk-base AS ogg-builder
# ENV OGG_BRANCH=v1.3.4
# ADD https://github.com/ffmpegwasm/Ogg.git#$OGG_BRANCH /src
# COPY build/ogg.sh /src/build.sh
# RUN bash -x /src/build.sh

# # Build theora
# FROM emsdk-base AS theora-builder
# COPY --from=ogg-builder $INSTALL_DIR $INSTALL_DIR
# ENV THEORA_BRANCH=v1.1.1
# ADD https://github.com/ffmpegwasm/theora.git#$THEORA_BRANCH /src
# COPY build/theora.sh /src/build.sh
# RUN bash -x /src/build.sh

# # Build opus
# FROM emsdk-base AS opus-builder
# ENV OPUS_BRANCH=v1.3.1
# ADD https://github.com/ffmpegwasm/opus.git#$OPUS_BRANCH /src
# COPY build/opus.sh /src/build.sh
# RUN bash -x /src/build.sh

# # Build vorbis
# FROM emsdk-base AS vorbis-builder
# COPY --from=ogg-builder $INSTALL_DIR $INSTALL_DIR
# ENV VORBIS_BRANCH=v1.3.3
# ADD https://github.com/ffmpegwasm/vorbis.git#$VORBIS_BRANCH /src
# COPY build/vorbis.sh /src/build.sh
# RUN bash -x /src/build.sh

# Build zlib (needed by the video target for PNG decoding)
FROM emsdk-base AS zlib-builder
ENV ZLIB_BRANCH=v1.2.11
ADD https://github.com/ffmpegwasm/zlib.git#$ZLIB_BRANCH /src
COPY build/zlib.sh /src/build.sh
RUN bash -x /src/build.sh

# # Build libwebp
# FROM emsdk-base AS libwebp-builder
# COPY --from=zlib-builder $INSTALL_DIR $INSTALL_DIR
# ENV LIBWEBP_BRANCH=v1.3.2
# ADD https://github.com/ffmpegwasm/libwebp.git#$LIBWEBP_BRANCH /src
# COPY build/libwebp.sh /src/build.sh
# RUN bash -x /src/build.sh

# # Build freetype2
# FROM emsdk-base AS freetype2-builder
# ENV FREETYPE2_BRANCH=VER-2-10-4
# ADD https://github.com/ffmpegwasm/freetype2.git#$FREETYPE2_BRANCH /src
# COPY build/freetype2.sh /src/build.sh
# RUN bash -x /src/build.sh

# # Build fribidi
# FROM emsdk-base AS fribidi-builder
# ENV FRIBIDI_BRANCH=v1.0.9
# ADD https://github.com/fribidi/fribidi.git#$FRIBIDI_BRANCH /src
# COPY build/fribidi.sh /src/build.sh
# RUN bash -x /src/build.sh

# # Build harfbuzz
# FROM emsdk-base AS harfbuzz-builder
# ENV HARFBUZZ_BRANCH=5.2.0
# ADD https://github.com/harfbuzz/harfbuzz.git#$HARFBUZZ_BRANCH /src
# COPY build/harfbuzz.sh /src/build.sh
# RUN bash -x /src/build.sh

# # Build libass
# FROM emsdk-base AS libass-builder
# COPY --from=freetype2-builder $INSTALL_DIR $INSTALL_DIR
# COPY --from=fribidi-builder $INSTALL_DIR $INSTALL_DIR
# COPY --from=harfbuzz-builder $INSTALL_DIR $INSTALL_DIR
# ENV LIBASS_BRANCH=0.15.0
# ADD https://github.com/libass/libass.git#$LIBASS_BRANCH /src
# COPY build/libass.sh /src/build.sh
# RUN bash -x /src/build.sh

# # Build zimg
# FROM emsdk-base AS zimg-builder
# ENV ZIMG_BRANCH=release-3.0.5
# RUN apt-get update && apt-get install -y git
# RUN git clone --recursive -b $ZIMG_BRANCH https://github.com/sekrit-twc/zimg.git /src
# COPY build/zimg.sh /src/build.sh
# RUN bash -x /src/build.sh

# Dependency selector stages: choose external codec libraries based on FFMPEG_TARGET.
# mp3 target requires libmp3lame; video target relies only on FFmpeg's built-in codecs.
FROM emsdk-base AS deps-mp3
COPY --from=lame-builder $INSTALL_DIR $INSTALL_DIR

FROM emsdk-base AS deps-m4b
# no external libs needed: mp3 decoder and aac encoder are both built into FFmpeg

FROM emsdk-base AS deps-video
# zlib: needed by FFmpeg's PNG decoder
COPY --from=zlib-builder $INSTALL_DIR $INSTALL_DIR
# x264: H.264 encoder
COPY --from=x264-builder $INSTALL_DIR $INSTALL_DIR

# Select the right deps stage based on FFMPEG_TARGET (ARG declared before first FROM, so
# it is available here for use in the FROM instruction).
FROM deps-${FFMPEG_TARGET} AS codec-deps

# Base ffmpeg image: SDL2 + FFmpeg source on top of the selected codec deps.
FROM codec-deps AS ffmpeg-base
RUN embuilder build sdl2 sdl2-mt
ADD https://github.com/FFmpeg/FFmpeg.git#$FFMPEG_VERSION /src
# COPY --from=x264-builder $INSTALL_DIR $INSTALL_DIR
# COPY --from=x265-builder $INSTALL_DIR $INSTALL_DIR
# COPY --from=libvpx-builder $INSTALL_DIR $INSTALL_DIR
# COPY --from=opus-builder $INSTALL_DIR $INSTALL_DIR
# COPY --from=theora-builder $INSTALL_DIR $INSTALL_DIR
# COPY --from=vorbis-builder $INSTALL_DIR $INSTALL_DIR
# COPY --from=libwebp-builder $INSTALL_DIR $INSTALL_DIR
# COPY --from=libass-builder $INSTALL_DIR $INSTALL_DIR
# COPY --from=zimg-builder $INSTALL_DIR $INSTALL_DIR

# Build ffmpeg
FROM ffmpeg-base AS ffmpeg-builder
COPY build/ffmpeg.sh /src/build.sh
RUN bash -x /src/build.sh \
      --enable-gpl
      # Target-specific codec flags (--enable-libmp3lame etc.) are handled inside
      # ffmpeg.sh based on $FFMPEG_TARGET, so only the GPL license flag is needed here.
      # --enable-libx264 \
      # --enable-libx265 \
      # --enable-libvpx \
      # --enable-libtheora \
      # --enable-libvorbis \
      # --enable-libopus \
      # --enable-zlib \
      # --enable-libwebp \
      # --enable-libfreetype \
      # --enable-libfribidi \
      # --enable-libass \
      # --enable-libzimg

# Build ffmpeg.wasm
FROM ffmpeg-builder AS ffmpeg-wasm-builder
COPY src/bind /src/src/bind
COPY src/fftools /src/src/fftools
COPY build/ffmpeg-wasm.sh build.sh
# External library linking and swscale (video target) are handled inside ffmpeg-wasm.sh
# based on $FFMPEG_TARGET, so no FFMPEG_LIBS env var is needed here.
RUN mkdir -p /src/dist/umd && bash -x /src/build.sh \
      -o dist/umd/ffmpeg-core.js
RUN mkdir -p /src/dist/esm && bash -x /src/build.sh \
      -sEXPORT_ES6 \
      -o dist/esm/ffmpeg-core.js

# Export ffmpeg-core.wasm to dist/, use `docker buildx build -o . .` to get assets
FROM scratch AS exportor
COPY --from=ffmpeg-wasm-builder /src/dist /dist