cross-compile

app/deps/.gitignore

@@ -0,0 +1,2 @@
+/data
+/target-*

app/deps/src/build-ffmpeg.sh

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+#!/usr/bin/env bash
+. init_deps
+
+VERSION=5.0.1
+FILENAME=ffmpeg-$VERSION.tar.xz
+
+URL=http://ffmpeg.org/releases/ffmpeg-$VERSION.tar.xz
+SHA256SUM=ef2efae259ce80a240de48ec85ecb062cecca26e4352ffb3fda562c21a93007b
+
+DEP_DIR="$DATA_DIR/ffmpeg-$VERSION-$SHA256SUM"
+
+if [[ ! -d "$DEP_DIR" ]]
+then
+    get_file "$URL" "$FILENAME" "$SHA256SUM"
+
+    mkdir "$DEP_DIR"
+    cd "$DEP_DIR"
+
+    tar xvf "../$FILENAME"
+else
+    echo "$DEP_DIR found"
+    cd "$DEP_DIR"
+fi
+
+cd "ffmpeg-$VERSION"
+rm -rf "build-$HOST"
+mkdir "build-$HOST"
+cd "build-$HOST"
+
+params=(
+    --prefix="$INSTALL_DIR"
+    --arch="$ARCH"
+    --disable-autodetect
+    --disable-programs
+    --disable-everything
+    --disable-doc
+    --disable-swresample
+    --disable-swscale
+    --disable-avfilter
+    --disable-postproc
+    --disable-static
+    --enable-shared
+    --enable-decoder=h264
+    --enable-decoder=png
+    --enable-muxer=mp4
+    --enable-muxer=matroska
+)
+
+case "$HOST_SYSTEM" in
+    linux)
+        params+=(--enable-libv4l2)
+        ;;
+    windows)
+        params+=(--target-os=mingw32)
+        params+=(--cross-prefix="$HOST-")
+        ;;
+    *)
+        fail "Unsupported platform: $HOST"
+        ;;
+esac
+
+../configure "${params[@]}"
+make -j $NJOBS
+make install

app/deps/src/init_deps

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+set -e
+
+# The caller must set the following environment variable
+#  - $HOST (e.g. "x86_64-linux-gnu")
+#  - $HOST_SYSTEM ("linux", "windows", "apple"), for scripts convenience
+
+fail() {
+    echo "$1" >&2
+    exit 1
+}
+
+[[ -z "$HOST" ]] && fail '$HOST not defined'
+
+if [[ "$HOST" == *linux* ]]
+then
+    HOST_SYSTEM='linux'
+elif [[ "$HOST" == *mingw* ]]
+then
+    HOST_SYSTEM='windows'
+else
+    fail "Host system could not be deduced from '$HOST'"
+fi
+
+ARCH="${HOST%%-*}"
+[[ -z "$ARCH" ]] && fail "Arch could not be deduced from '$HOST'"
+
+DIR=$(dirname ${BASH_SOURCE[0]})
+cd "$DIR"
+
+DATA_DIR=$(realpath ../data)
+INSTALL_DIR=$(realpath ../target-"$HOST")
+NJOBS=$(grep -c ^processor /proc/cpuinfo)
+
+mkdir -p "$DATA_DIR"
+cd "$DATA_DIR"
+
+checksum() {
+    local file="$1"
+    local sum="$2"
+    echo "$file: verifying checksum..."
+    echo "$sum  $file" | sha256sum -c
+}
+
+get_file() {
+    local url="$1"
+    local file="$2"
+    local sum="$3"
+    if [[ -f "$file" ]]
+    then
+        echo "$file: found"
+    else
+        echo "$file: not found, downloading..."
+        wget "$url" -O "$file"
+    fi
+    checksum "$file" "$sum"
+}