Smaller build sizes - Githubissues

i managed to do it by tweaking dockerfile, and ffmpeg.sh and ffmpeg-wasm.sh in build directory. posting it here, since it took me a while to figure it out, since i had the same problem with old guides, so it might help others.

not sure if its the correct way, but it works for me. edited the dockerfile to only take in account the flags set from ffmpeg.sh and ffmpeg-wasm.sh (except the enable-gpl, since i couldnt figure out how to remove all the flags in dockerfile for ffmpeg.sh, without failing the build, so i kept it there. instead of moving this flag to ffmpeg.sh): i kept the building of the libraries in it, since incase you do enable the flag it's easyer editing, and its cached anyway, only taking space. so proberly the only pro to removing it from the dockerfile is shorten the initial build time, and less space.

just make sure if you use --disable-all to enable the flags in ffmpeg.sh set in ffmpeg-wasm.sh or the build will fail.

not sure really how the 2 connect to each other, since its split in 2 libraries but this might help you on the way.

also if you got tips to make it even smaller for me, i'll be glad to hear.

build file size around 1 mb, it lets me remux a m4a.

ffmpeg.sh


set -euo pipefail

CONF_FLAGS=(
  --disable-all

  --enable-protocol=file
  --enable-avcodec
  --enable-avformat
  --enable-avfilter

  --enable-demuxer=mov
  --enable-parser=aac
  --enable-muxer=ipod

  --enable-filter=null,anull

  --target-os=none              # disable target specific configs
  --arch=x86_32                 # use x86_32 arch
  --enable-cross-compile        # use cross compile configs
  --disable-asm                 # disable asm
  --disable-stripping           # disable stripping as it won't work
  --disable-programs            # disable ffmpeg, ffprobe and ffplay build
  --disable-doc                 # disable doc build
  --disable-debug               # disable debug mode
  --disable-runtime-cpudetect   # disable cpu detection
  --disable-autodetect          # disable env auto detect

  # assign toolchains and extra flags
  --nm=emnm
  --ar=emar
  --ranlib=emranlib
  --cc=emcc
  --cxx=em++
  --objcc=emcc
  --dep-cc=emcc
  --extra-cflags="$CFLAGS"
  --extra-cxxflags="$CXXFLAGS"

  # disable thread when FFMPEG_ST is NOT defined
  ${FFMPEG_ST:+ --disable-pthreads --disable-w32threads --disable-os2threads}
)

emconfigure ./configure "${CONF_FLAGS[@]}" $@
emmake make -j

ffmpeg-wasm.sh:

# `-o <OUTPUT_FILE_NAME>` must be provided when using this build script.
# ex:
#     bash ffmpeg-wasm.sh -o ffmpeg.js

set -euo pipefail

EXPORT_NAME="createFFmpegCore"

CONF_FLAGS=(
  -I. 
  -I./src/fftools 
  -I$INSTALL_DIR/include 
  -L$INSTALL_DIR/lib 
  -Llibavcodec 
  -Llibavfilter 
  -Llibavformat 
  -Llibavutil 
  -lavcodec 
  -lavfilter 
  -lavformat 
  -lavutil
  -Wno-deprecated-declarations 
  $LDFLAGS 
  -sWASM_BIGINT                            # enable big int support
  -sUSE_SDL=2                              # use emscripten SDL2 lib port
  -sMODULARIZE                             # modularized to use as a library
  ${FFMPEG_MT:+ -sINITIAL_MEMORY=1024MB}   # ALLOW_MEMORY_GROWTH is not recommended when using threads, thus we use a large initial memory
  ${FFMPEG_MT:+ -sPTHREAD_POOL_SIZE=32}    # use 32 threads
  ${FFMPEG_ST:+ -sINITIAL_MEMORY=32MB -sALLOW_MEMORY_GROWTH} # Use just enough memory as memory usage can grow
  -sEXPORT_NAME="$EXPORT_NAME"             # required in browser env, so that user can access this module from window object
  -sEXPORTED_FUNCTIONS=$(node src/bind/ffmpeg/export.js) # exported functions
  -sEXPORTED_RUNTIME_METHODS=$(node src/bind/ffmpeg/export-runtime.js) # exported built-in functions
  -lworkerfs.js
  --pre-js src/bind/ffmpeg/bind.js        # extra bindings, contains most of the ffmpeg.wasm javascript code
  # ffmpeg source code
  src/fftools/cmdutils.c 
  src/fftools/ffmpeg.c 
  src/fftools/ffmpeg_filter.c 
  src/fftools/ffmpeg_hw.c 
  src/fftools/ffmpeg_mux.c 
  src/fftools/ffmpeg_opt.c 
  src/fftools/opt_common.c 
)

emcc "${CONF_FLAGS[@]}" $@

dockerfile:


# 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
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
RUN apt-get update && \
      apt-get install -y pkg-config autoconf automake libtool ragel

# Build x264
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
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
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

# Base ffmpeg image with dependencies and source code populated.
FROM emsdk-base 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=lame-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
# 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
# libraries to link
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

ffmpegwasm / ffmpeg.wasm

Smaller build sizes #569