Update build scripts to build single thread version

build-with-docker.sh

@@ -9,5 +9,6 @@ docker run \
   --rm \
   -v $PWD:/src \
   -v $PWD/wasm/cache:/emsdk_portable/.data/cache/wasm \
+  -e FFMPEG_ST=${FFMPEG_ST:-no} \
   emscripten/emsdk:$EM_VERSION \
   sh -c 'bash ./build.sh'

build.sh

@@ -30,10 +30,10 @@ $SCRIPT_ROOT/build-vorbis.sh
 $SCRIPT_ROOT/build-theora.sh
 # build opus
 $SCRIPT_ROOT/build-opus.sh
-# build freetype2
-$SCRIPT_ROOT/build-freetype2.sh
 # build libwebp
 $SCRIPT_ROOT/build-libwebp.sh
+# build freetype2
+$SCRIPT_ROOT/build-freetype2.sh
 # build fribidi
 $SCRIPT_ROOT/build-fribidi.sh
 # build harfbuzz

wasm/build-scripts/build-aom.sh

@@ -5,7 +5,6 @@ source $(dirname $0)/var.sh
 
 LIB_PATH=third_party/aom
 CMBUILD_DIR=cmbuild
-CFLAGS="-s USE_PTHREADS=1 $OPTIM_FLAGS"
 CM_FLAGS=(
   -DCMAKE_INSTALL_PREFIX=$BUILD_DIR             # assign lib and include install path
   -DCMAKE_TOOLCHAIN_FILE=$TOOLCHAIN_FILE        # use emscripten toolchain file

wasm/build-scripts/build-fdk-aac.sh

@@ -4,16 +4,15 @@ set -euo pipefail
 source $(dirname $0)/var.sh
 
 LIB_PATH=third_party/fdk-aac
-CFLAGS="-s USE_PTHREADS=1 $OPTIM_FLAGS"
 CONF_FLAGS=(
   --prefix=$BUILD_DIR                                 # install library in a build directory for FFmpeg to include
-  --host=i686-linux                                   # use i686 linux
+  --host=x86_64-linux
   --disable-shared                                    # disable shared library
   --disable-dependency-tracking                       # speedup one-time build
 )
 echo "CONF_FLAGS=${CONF_FLAGS[@]}"
 (cd $LIB_PATH && \
   emconfigure ./autogen.sh && \
-  CFLAGS=$CFLAGS emconfigure ./configure -C "${CONF_FLAGS[@]}")
-emmake make -C $LIB_PATH install -j
+  CFLAGS=$CFLAGS emconfigure ./configure "${CONF_FLAGS[@]}")
 emmake make -C $LIB_PATH clean
+emmake make -C $LIB_PATH install -j

wasm/build-scripts/build-ffmpeg.sh

@@ -3,27 +3,41 @@
 set -eo pipefail
 source $(dirname $0)/var.sh
 
-mkdir -p wasm/dist
-emmake make -j
+if [[ "$FFMPEG_ST" != "yes" ]]; then
+  mkdir -p wasm/packages/core/dist
+  EXPORTED_FUNCTIONS="[_main, _proxy_main]"
+  EXTRA_FLAGS=(
+    -pthread
+    -s USE_PTHREADS=1                             # enable pthreads support
+    -s PROXY_TO_PTHREAD=1                         # detach main() from browser/UI main thread
+    -o wasm/packages/core/dist/ffmpeg-core.js
+  )
+else
+  mkdir -p wasm/packages/core-st/dist
+  EXPORTED_FUNCTIONS="[_main]"
+  EXTRA_FLAGS=(
+    -o wasm/packages/core-st/dist/ffmpeg-core.js
+  )
+fi
 FLAGS=(
   -I. -I./fftools -I$BUILD_DIR/include
   -Llibavcodec -Llibavdevice -Llibavfilter -Llibavformat -Llibavresample -Llibavutil -Lharfbuzz -Llibass -Lfribidi -Llibpostproc -Llibswscale -Llibswresample -L$BUILD_DIR/lib
   -Wno-deprecated-declarations -Wno-pointer-sign -Wno-implicit-int-float-conversion -Wno-switch -Wno-parentheses -Qunused-arguments
-  -lavdevice -lavfilter -lavformat -lavcodec -lswresample -lswscale -lavutil -lpostproc -lm -lharfbuzz -lfribidi -llibass -lx264 -lx265 -lvpx -lwavpack -lmp3lame -lfdk-aac -lvorbis -lvorbisenc -lvorbisfile -logg -ltheora -ltheoraenc -ltheoradec -lz -lfreetype -lopus -lwebp -pthread
+  -lavdevice -lavfilter -lavformat -lavcodec -lswresample -lswscale -lavutil -lpostproc -lm -lharfbuzz -lfribidi -llibass -lx264 -lx265 -lvpx -lwavpack -lmp3lame -lfdk-aac -lvorbis -lvorbisenc -lvorbisfile -logg -ltheora -ltheoraenc -ltheoradec -lz -lfreetype -lopus -lwebp
   fftools/ffmpeg_opt.c fftools/ffmpeg_filter.c fftools/ffmpeg_hw.c fftools/cmdutils.c fftools/ffmpeg.c
   -o wasm/dist/ffmpeg-core.js
   -s USE_SDL=2                                  # use SDL2
-  -s USE_PTHREADS=1                             # enable pthreads support
-  -s PROXY_TO_PTHREAD=1                         # detach main() from browser/UI main thread
   -s INVOKE_RUN=0                               # not to run the main() in the beginning
   -s EXIT_RUNTIME=1                             # exit runtime after execution
   -s MODULARIZE=1                               # use modularized version to be more flexible
   -s EXPORT_NAME="createFFmpegCore"             # assign export name for browser
-  -s EXPORTED_FUNCTIONS="[_main, _proxy_main]"  # export main and proxy_main funcs
+  -s EXPORTED_FUNCTIONS="$EXPORTED_FUNCTIONS"  # export main and proxy_main funcs
   -s EXTRA_EXPORTED_RUNTIME_METHODS="[FS, cwrap, ccall, setValue, writeAsciiToMemory]"   # export preamble funcs
   -s INITIAL_MEMORY=2146435072                  # 64 KB * 1024 * 16 * 2047 = 2146435072 bytes ~= 2 GB
-  --post-js wasm/post-js.js
+  --post-js wasm/src/post-js.js
   $OPTIM_FLAGS
+  ${EXTRA_FLAGS[@]}
 )
 echo "FFMPEG_EM_FLAGS=${FLAGS[@]}"
+emmake make -j
 emcc "${FLAGS[@]}"

wasm/build-scripts/build-freetype2.sh

@@ -4,15 +4,17 @@ set -euo pipefail
 source $(dirname $0)/var.sh
 
 LIB_PATH=third_party/freetype2
-CFLAGS="-s USE_PTHREADS=1 $OPTIM_FLAGS"
 CONF_FLAGS=(
   --prefix=$BUILD_DIR                                 # install library in a build directory for FFmpeg to include
-  --host=i686-gnu                                     # use i686 linux
+  --host=x86_64-gnu                                   # use i686 linux
   --enable-shared=no                                  # not to build shared library
+  --without-harfbuzz
 )
 echo "CONF_FLAGS=${CONF_FLAGS[@]}"
 (cd $LIB_PATH && \
   emconfigure ./autogen.sh && \
-  CFLAGS=$CFLAGS emconfigure ./configure -C "${CONF_FLAGS[@]}")
-emmake make -C $LIB_PATH install -j
+  emconfigure ./configure "${CONF_FLAGS[@]}")
 emmake make -C $LIB_PATH clean
+# build apinames manually to prevent it built by emcc
+gcc -o third_party/freetype2/objs/apinames third_party/freetype2/src/tools/apinames.c
+emmake make -C $LIB_PATH install -j

wasm/build-scripts/build-fribidi.sh

@@ -4,10 +4,9 @@ set -euo pipefail
 source $(dirname $0)/var.sh
 
 LIB_PATH=third_party/fribidi
-CFLAGS="-s USE_PTHREADS=1 $OPTIM_FLAGS"
 CONF_FLAGS=(
   --prefix=$BUILD_DIR                                 # install library in a build directory for FFmpeg to include
-  --host=i686-gnu                                     # use i686 linux
+  --host=x86_64-linux
   --enable-shared=no                                  # not to build shared library
   --enable-static=yes
   --disable-dependency-tracking
@@ -15,8 +14,7 @@ CONF_FLAGS=(
 )
 echo "CONF_FLAGS=${CONF_FLAGS[@]}"
 (cd $LIB_PATH && \
-  emconfigure ./autogen.sh && \
-  CFLAGS=$CFLAGS emconfigure ./configure -C "${CONF_FLAGS[@]}")
+  emconfigure ./autogen.sh "${CONF_FLAGS[@]}")
+emmake make -C $LIB_PATH clean
 emmake make -C $LIB_PATH install -j || true
 cp $LIB_PATH/fribidi.pc $BUILD_DIR/lib/pkgconfig
-emmake make -C $LIB_PATH clean

wasm/build-scripts/build-harfbuzz.sh

@@ -4,7 +4,6 @@ set -euo pipefail
 source $(dirname $0)/var.sh
 
 LIB_PATH=third_party/harfbuzz
-CFLAGS="-s USE_PTHREADS=1 $OPTIM_FLAGS"
 CONF_FLAGS=(
   --prefix=$BUILD_DIR                                 # install library in a build directory for FFmpeg to include
   --host=i686-gnu                                     # use i686 linux
@@ -13,7 +12,6 @@ CONF_FLAGS=(
 )
 echo "CONF_FLAGS=${CONF_FLAGS[@]}"
 (cd $LIB_PATH && \
-  emconfigure ./autogen.sh && \
-  CFLAGS=$CFLAGS emconfigure ./configure -C "${CONF_FLAGS[@]}")
-emmake make -C $LIB_PATH install -j
+  emconfigure ./autogen.sh "${CONF_FLAGS[@]}")
 emmake make -C $LIB_PATH clean
+emmake make -C $LIB_PATH install -j

wasm/build-scripts/build-lame.sh

@@ -4,7 +4,6 @@ set -euo pipefail
 source $(dirname $0)/var.sh
 
 LIB_PATH=third_party/lame
-CFLAGS="-s USE_PTHREADS=1 $OPTIM_FLAGS"
 CONF_FLAGS=(
   --prefix=$BUILD_DIR                                 # install library in a build directory for FFmpeg to include
   --host=i686-linux                                   # use i686 linux
@@ -16,5 +15,5 @@ CONF_FLAGS=(
 )
 echo "CONF_FLAGS=${CONF_FLAGS[@]}"
 (cd $LIB_PATH && CFLAGS=$CFLAGS emconfigure ./configure "${CONF_FLAGS[@]}")
-emmake make -C $LIB_PATH install -j
 emmake make -C $LIB_PATH clean
+emmake make -C $LIB_PATH install -j

wasm/build-scripts/build-libass.sh

@@ -14,6 +14,6 @@ CONF_FLAGS=(
   --disable-require-system-font-provider
 )
 echo "CONF_FLAGS=${CONF_FLAGS[@]}"
-(cd $LIB_PATH && ./autogen.sh && EM_PKG_CONFIG_PATH=$EM_PKG_CONFIG_PATH emconfigure ./configure -C "${CONF_FLAGS[@]}")
-emmake make -C $LIB_PATH install -j
+(cd $LIB_PATH && ./autogen.sh && emconfigure ./configure "${CONF_FLAGS[@]}")
 emmake make -C $LIB_PATH clean
+emmake make -C $LIB_PATH install -j

wasm/build-scripts/build-libvpx.sh

@@ -4,7 +4,13 @@ set -euo pipefail
 source $(dirname $0)/var.sh
 
 LIB_PATH=third_party/libvpx
-FLAGS="-c -s USE_PTHREADS=1 $OPTIM_FLAGS"
+
+if [[ "$FFMPEG_ST" == "yes" ]]; then
+  EXTRA_CONF_FLAGS=(
+    --disable-multithread
+  )
+fi
+
 CONF_FLAGS=(
   --prefix=$BUILD_DIR                                # install library in a build directory for FFmpeg to include
   --target=generic-gnu                               # target with miminal features
@@ -14,10 +20,11 @@ CONF_FLAGS=(
   --disable-docs                                     # not to build docs
   --disable-unit-tests                               # not to do unit tests
   --disable-dependency-tracking                      # speed up one-time build
-  --extra-cflags="$FLAGS"                            # flags to use pthread and code optimization
-  --extra-cxxflags="$FLAGS"                          # flags to use pthread and code optimization
+  --extra-cflags="$CFLAGS"                           # flags to use pthread and code optimization
+  --extra-cxxflags="$CXXFLAGS"                       # flags to use pthread and code optimization
+  ${EXTRA_CONF_FLAGS-}
 )
 echo "CONF_FLAGS=${CONF_FLAGS[@]}"
-(cd $LIB_PATH && LDFLAGS="$FLAGS" STRIP="llvm-strip" emconfigure ./configure "${CONF_FLAGS[@]}")
-emmake make -C $LIB_PATH install -j
+(cd $LIB_PATH && emconfigure ./configure "${CONF_FLAGS[@]}")
 emmake make -C $LIB_PATH clean
+emmake make -C $LIB_PATH install -j

wasm/build-scripts/build-libwebp.sh

@@ -4,7 +4,6 @@ set -euo pipefail
 source $(dirname $0)/var.sh
 
 LIB_PATH=third_party/libwebp
-CXXFLAGS="-s USE_PTHREADS=1 $OPTIM_FLAGS"
 CM_FLAGS=(
   -DCMAKE_INSTALL_PREFIX=$BUILD_DIR
   -DCMAKE_TOOLCHAIN_FILE=$TOOLCHAIN_FILE
@@ -28,6 +27,6 @@ cd $LIB_PATH
 mkdir -p build
 cd build
 emmake cmake .. -DCMAKE_C_FLAGS="$CXXFLAGS" ${CM_FLAGS[@]}
-emmake make install
 emmake make clean
+emmake make install
 cd $ROOT_DIR

wasm/build-scripts/build-ogg.sh

@@ -4,7 +4,6 @@ set -euo pipefail
 source $(dirname $0)/var.sh
 
 LIB_PATH=third_party/Ogg
-CFLAGS="-s USE_PTHREADS=1 $OPTIM_FLAGS"
 CONF_FLAGS=(
   --prefix=$BUILD_DIR                                 # install library in a build directory for FFmpeg to include
   --host=i686-linux                                   # use i686 linux
@@ -15,6 +14,6 @@ CONF_FLAGS=(
 echo "CONF_FLAGS=${CONF_FLAGS[@]}"
 (cd $LIB_PATH && \
   emconfigure ./autogen.sh && \
-  CFLAGS=$CFLAGS emconfigure ./configure -C "${CONF_FLAGS[@]}")
-emmake make -C $LIB_PATH install -j
+  emconfigure ./configure "${CONF_FLAGS[@]}")
 emmake make -C $LIB_PATH clean
+emmake make -C $LIB_PATH install -j

wasm/build-scripts/build-opus.sh

@@ -4,7 +4,6 @@ set -euo pipefail
 source $(dirname $0)/var.sh
 
 LIB_PATH=third_party/opus
-CFLAGS="-s USE_PTHREADS=1 $OPTIM_FLAGS"
 CONF_FLAGS=(
   --prefix=$BUILD_DIR                                 # install library in a build directory for FFmpeg to include
   --host=i686-gnu                                     # use i686 linux
@@ -18,6 +17,6 @@ CONF_FLAGS=(
 echo "CONF_FLAGS=${CONF_FLAGS[@]}"
 (cd $LIB_PATH && \
   emconfigure ./autogen.sh && \
-  CFLAGS=$CFLAGS emconfigure ./configure -C "${CONF_FLAGS[@]}")
-emmake make -C $LIB_PATH install -j
+  CFLAGS=$CFLAGS emconfigure ./configure "${CONF_FLAGS[@]}")
 emmake make -C $LIB_PATH clean
+emmake make -C $LIB_PATH install -j

wasm/build-scripts/build-theora.sh

@@ -4,8 +4,6 @@ set -euo pipefail
 source $(dirname $0)/var.sh
 
 LIB_PATH=third_party/theora
-CFLAGS="-s USE_PTHREADS=1 $OPTIM_FLAGS -I$BUILD_DIR/include"
-LDFLAGS="-L$BUILD_DIR/lib"
 CONF_FLAGS=(
   --prefix=$BUILD_DIR                                 # install library in a build directory for FFmpeg to include
   --host=i686-linux                                   # use i686 linux
@@ -21,6 +19,6 @@ CONF_FLAGS=(
 )
 echo "CONF_FLAGS=${CONF_FLAGS[@]}"
 (cd $LIB_PATH && \
-  CFLAGS=$CFLAGS LDFLAGS=$LDFLAGS emconfigure ./autogen.sh -C "${CONF_FLAGS[@]}")
-emmake make -C $LIB_PATH install -j
+  emconfigure ./autogen.sh "${CONF_FLAGS[@]}")
 emmake make -C $LIB_PATH clean
+emmake make -C $LIB_PATH install -j

wasm/build-scripts/build-vorbis.sh

@@ -4,8 +4,6 @@ set -euo pipefail
 source $(dirname $0)/var.sh
 
 LIB_PATH=third_party/vorbis
-CFLAGS="-s USE_PTHREADS=1 $OPTIM_FLAGS -I$BUILD_DIR/include"
-LDFLAGS="-L$BUILD_DIR/lib"
 CONF_FLAGS=(
   --prefix=$BUILD_DIR                                 # install library in a build directory for FFmpeg to include
   --host=i686-linux                                   # use i686 linux
@@ -19,6 +17,6 @@ CONF_FLAGS=(
 echo "CONF_FLAGS=${CONF_FLAGS[@]}"
 (cd $LIB_PATH && \
   emconfigure ./autogen.sh && \
-  CFLAGS=$CFLAGS LDFLAGS=$LDFLAGS emconfigure ./configure -C "${CONF_FLAGS[@]}")
-emmake make -C $LIB_PATH install -j
+  emconfigure ./configure "${CONF_FLAGS[@]}")
 emmake make -C $LIB_PATH clean
+emmake make -C $LIB_PATH install -j

wasm/build-scripts/build-wavpack.sh

@@ -4,7 +4,6 @@ set -euo pipefail
 source $(dirname $0)/var.sh
 
 LIB_PATH=third_party/WavPack
-CFLAGS="-s USE_PTHREADS=1 $OPTIM_FLAGS"
 CONF_FLAGS=(
   --prefix=$BUILD_DIR                                  # install library in a build directory for FFmpeg to include
   --host=x86-linux-gnu                                 # use x86 linux as host
@@ -19,6 +18,6 @@ CONF_FLAGS=(
   --disable-maintainer-mode
 )
 echo "CONF_FLAGS=${CONF_FLAGS[@]}"
-(cd $LIB_PATH && CFLAGS=$CFLAGS emconfigure ./autogen.sh -C "${CONF_FLAGS[@]}")
-emmake make -C $LIB_PATH install -j
+(cd $LIB_PATH && CFLAGS=$CFLAGS emconfigure ./autogen.sh "${CONF_FLAGS[@]}")
 emmake make -C $LIB_PATH clean
+emmake make -C $LIB_PATH install -j

wasm/build-scripts/build-x264.sh

@@ -4,15 +4,23 @@ set -euo pipefail
 source $(dirname $0)/var.sh
 
 LIB_PATH=third_party/x264
+
+if [[ "$FFMPEG_ST" == "yes" ]]; then
+  EXTRA_CONF_FLAGS=(
+    --disable-thread
+  )
+fi
+
 CONF_FLAGS=(
   --prefix=$BUILD_DIR           # install library in a build directory for FFmpeg to include
   --host=i686-gnu               # use i686 linux
   --enable-static               # enable building static library
   --disable-cli                 # disable cli tools
   --disable-asm                 # disable asm optimization
-  --extra-cflags="-c -s USE_PTHREADS=1 $OPTIM_FLAGS"  # flags to use pthread and code optimization
+  --extra-cflags="$CFLAGS"      # flags to use pthread and code optimization
+  ${EXTRA_CONF_FLAGS-}
 )
 echo "CONF_FLAGS=${CONF_FLAGS[@]}"
-(cd $LIB_PATH && emconfigure ./configure -C "${CONF_FLAGS[@]}")
-emmake make -C $LIB_PATH install-lib-static -j
+(cd $LIB_PATH && emconfigure ./configure "${CONF_FLAGS[@]}")
 emmake make -C $LIB_PATH clean
+emmake make -C $LIB_PATH install-lib-static -j

wasm/build-scripts/build-x265.sh

@@ -4,7 +4,6 @@ set -euo pipefail
 source $(dirname $0)/var.sh
 
 LIB_PATH=third_party/x265/source
-CXXFLAGS="-s USE_PTHREADS=1 $OPTIM_FLAGS"
 BASE_FLAGS=(
   -DCMAKE_TOOLCHAIN_FILE=$TOOLCHAIN_FILE
   -DENABLE_LIBNUMA=OFF
@@ -42,16 +41,19 @@ mkdir -p main 10bit 12bit
 
 cd 12bit
 emmake cmake ../.. -DCMAKE_CXX_FLAGS="$CXXFLAGS" ${FLAGS_12BIT[@]}
+emmake make clean
 emmake make -j
 
 cd ../10bit 
 emmake cmake ../.. -DCMAKE_CXX_FLAGS="$CXXFLAGS" ${FLAGS_10BIT[@]}
+emmake make clean
 emmake make -j
 
 cd ../main
 ln -sf ../10bit/libx265.a libx265_main10.a
 ln -sf ../12bit/libx265.a libx265_main12.a
 emmake cmake ../.. -DCMAKE_CXX_FLAGS="$CXXFLAGS" ${FLAGS_MAIN[@]}
+emmake make clean
 emmake make install -j
 
 mv libx265.a libx265_main.a
@@ -68,8 +70,4 @@ EOF
 
 cp libx265.a $BUILD_DIR/lib
 
-emmake make -C . clean
-emmake make -C ../10bit clean
-emmake make -C ../12bit clean
-
 cd $ROOT_DIR

wasm/build-scripts/build-zlib.sh

@@ -4,7 +4,6 @@ set -euo pipefail
 source $(dirname $0)/var.sh
 
 LIB_PATH=third_party/zlib
-CXXFLAGS="-s USE_PTHREADS=1 $OPTIM_FLAGS"
 CM_FLAGS=(
   -DCMAKE_INSTALL_PREFIX=$BUILD_DIR
   -DCMAKE_TOOLCHAIN_FILE=$TOOLCHAIN_FILE
@@ -18,6 +17,6 @@ rm -rf build zconf.h
 mkdir -p build
 cd build
 emmake cmake .. -DCMAKE_C_FLAGS="$CXXFLAGS" ${CM_FLAGS[@]}
-emmake make install
 emmake make clean
+emmake make install
 cd $ROOT_DIR

wasm/build-scripts/configure-ffmpeg.sh

@@ -24,4 +24,4 @@ FLAGS=(
   # --enable-libaom         # enable libaom
 )
 echo "FFMPEG_CONFIG_FLAGS=${FLAGS[@]}"
-EM_PKG_CONFIG_PATH=${EM_PKG_CONFIG_PATH} emconfigure ./configure "${FLAGS[@]}"
+emconfigure ./configure "${FLAGS[@]}"

wasm/build-scripts/var.sh

@@ -7,6 +7,23 @@ set -euo pipefail
 # Include llvm binaries
 export PATH=$PATH:$EMSDK/upstream/bin
 
+# if yes, we are building a single thread version of
+# ffmpeg.wasm-core, which is slow but compatible with
+# most browsers as there is no SharedArrayBuffer.
+FFMPEG_ST=${FFMPEG_ST:-no}
+
+# Root directory
+ROOT_DIR=$PWD
+
+# Directory to install headers and libraries
+BUILD_DIR=$ROOT_DIR/build
+
+# Directory to look for pkgconfig files
+EM_PKG_CONFIG_PATH=$BUILD_DIR/lib/pkgconfig
+
+# Toolchain file path for cmake
+TOOLCHAIN_FILE=$EMSDK/upstream/emscripten/cmake/Modules/Platform/Emscripten.cmake
+
 # Flags for code optimization, focus on speed instead
 # of size
 OPTIM_FLAGS=(
@@ -24,20 +41,22 @@ fi
 # Convert array to string
 OPTIM_FLAGS="${OPTIM_FLAGS[@]}"
 
-# Root directory
-ROOT_DIR=$PWD
-
-# Directory to install headers and libraries
-BUILD_DIR=$ROOT_DIR/build
+CFLAGS_BASE="-I$BUILD_DIR/include $OPTIM_FLAGS"
+CFLAGS="$CFLAGS_BASE -s USE_PTHREADS=1"
 
-# Directory to look for pkgconfig files
-EM_PKG_CONFIG_PATH=$BUILD_DIR/lib/pkgconfig
+if [[ "$FFMPEG_ST" == "yes" ]]; then
+  CFLAGS="$CFLAGS_BASE -s USE_PTHREADS=0"
+  EXTRA_FFMPEG_CONF_FLAGS=(
+    --disable-pthreads
+  )
+fi
 
-# Toolchain file path for cmake
-TOOLCHAIN_FILE=$EMSDK/upstream/emscripten/cmake/Modules/Platform/Emscripten.cmake
+export CFLAGS=$CFLAGS
+export CXXFLAGS=$CFLAGS
+export LDFLAGS="$CFLAGS -L$BUILD_DIR/lib"
+export STRIP="llvm-strip"
+export EM_PKG_CONFIG_PATH=$EM_PKG_CONFIG_PATH
 
-CFLAGS="-s USE_PTHREADS=1 -I$BUILD_DIR/include $OPTIM_FLAGS"
-LDFLAGS="$CFLAGS -L$BUILD_DIR/lib"
 FFMPEG_CONFIG_FLAGS_BASE=(
   --target-os=none        # use none to prevent any os specific configurations
   --arch=x86_32           # use x86_32 to achieve minimal architectural optimization
@@ -61,8 +80,10 @@ FFMPEG_CONFIG_FLAGS_BASE=(
   --cxx=em++
   --objcc=emcc
   --dep-cc=emcc
+  ${EXTRA_FFMPEG_CONF_FLAGS-}
 )
 
 echo "EMSDK=$EMSDK"
-echo "OPTIM_FLAGS=$OPTIM_FLAGS"
+echo "FFMPEG_ST=$FFMPEG_ST"
+echo "CFLAGS(CXXFLAGS)=$CFLAGS"
 echo "BUILD_DIR=$BUILD_DIR"