Add ffmpeg mp4 scale only build script

wasm/build-scripts/build-ffmpeg.sh

@@ -16,6 +16,7 @@ FLAGS=(
   -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

wasm/build-scripts/configure-ffmpeg.mp4-scale.sh

+#!/bin/bash
+
+set -euo pipefail
+source $(dirname $0)/var.sh
+
+FLAGS=(
+  "${FFMPEG_CONFIG_FLAGS_BASE[@]}"
+  --disable-all
+  --enable-avcodec
+  --enable-avformat
+  --enable-avfilter
+  --enable-swresample
+  --enable-swscale
+  --enable-decoder=h264
+  --enable-encoder=rawvideo,libx264
+  --enable-parser=h264
+  --enable-protocol=file
+  --enable-demuxer=mov
+  --enable-muxer=rawvideo,mp4
+  --enable-filter=scale,format
+
+)
+echo "FFMPEG_CONFIG_FLAGS=${FLAGS[@]}"
+emconfigure ./configure "${FLAGS[@]}"

wasm/build-scripts/configure-ffmpeg.sh

@@ -3,33 +3,8 @@
 set -euo pipefail
 source $(dirname $0)/var.sh
 
-CFLAGS="-s USE_PTHREADS=1 -I$BUILD_DIR/include $OPTIM_FLAGS"
-LDFLAGS="$CFLAGS -L$BUILD_DIR/lib"
 FLAGS=(
-  --target-os=none        # use none to prevent any os specific configurations
-  --arch=x86_32           # use x86_32 to achieve minimal architectural optimization
-  --enable-cross-compile  # enable cross compile
-  --disable-x86asm        # disable x86 asm
-  --disable-inline-asm    # disable inline asm
-  --disable-stripping     # disable stripping
-  --disable-programs      # disable programs build (incl. ffplay, ffprobe & ffmpeg)
-  --disable-doc           # disable doc
-  --enable-gpl            # required by x264
-  --enable-libx264        # enable x264
-  --disable-debug         # disable debug info, required by closure
-  --disable-runtime-cpudetect   # disable runtime cpu detect
-  --disable-autodetect    # disable external libraries auto detect
-  --extra-cflags="$CFLAGS"
-  --extra-cxxflags="$CFLAGS"
-  --extra-ldflags="$LDFLAGS"
-  --nm="llvm-nm -g"
-  --ar=emar
-  --as=llvm-as
-  --ranlib=emranlib
-  --cc=emcc
-  --cxx=em++
-  --objcc=emcc
-  --dep-cc=emcc
+  "${FFMPEG_CONFIG_FLAGS_BASE[@]}"
 )
 echo "FFMPEG_CONFIG_FLAGS=${FLAGS[@]}"
 emconfigure ./configure "${FLAGS[@]}"

wasm/build-scripts/var.sh

@@ -10,9 +10,6 @@ OPTIM_FLAGS=(
   -O3
 )
 
-# Directory to install headers and libraries
-BUILD_DIR=$PWD/build
-
 if [[ "$OSTYPE" == "linux-gnu"* ]]; then
   # Use closure complier only in linux environment
   OPTIM_FLAGS=(
@@ -24,5 +21,37 @@ fi
 # Convert array to string
 OPTIM_FLAGS="${OPTIM_FLAGS[@]}"
 
+# Directory to install headers and libraries
+BUILD_DIR=$PWD/build
+
+CFLAGS="-s USE_PTHREADS=1 -I$BUILD_DIR/include $OPTIM_FLAGS"
+LDFLAGS="$CFLAGS -L$BUILD_DIR/lib"
+FFMPEG_CONFIG_FLAGS_BASE=(
+  --target-os=none        # use none to prevent any os specific configurations
+  --arch=x86_32           # use x86_32 to achieve minimal architectural optimization
+  --enable-cross-compile  # enable cross compile
+  --disable-x86asm        # disable x86 asm
+  --disable-inline-asm    # disable inline asm
+  --disable-stripping     # disable stripping
+  --disable-programs      # disable programs build (incl. ffplay, ffprobe & ffmpeg)
+  --disable-doc           # disable doc
+  --enable-gpl            # required by x264
+  --enable-libx264        # enable x264
+  --disable-debug         # disable debug info, required by closure
+  --disable-runtime-cpudetect   # disable runtime cpu detect
+  --disable-autodetect    # disable external libraries auto detect
+  --extra-cflags="$CFLAGS"
+  --extra-cxxflags="$CFLAGS"
+  --extra-ldflags="$LDFLAGS"
+  --nm="llvm-nm -g"
+  --ar=emar
+  --as=llvm-as
+  --ranlib=emranlib
+  --cc=emcc
+  --cxx=em++
+  --objcc=emcc
+  --dep-cc=emcc
+)
+
 echo "OPTIM_FLAGS=$OPTIM_FLAGS"
 echo "BUILD_DIR=$BUILD_DIR"