diff --git a/scripts/common-functions.sh b/scripts/common-functions.sh
new file mode 100755
index 0000000..045a830
--- /dev/null
+++ b/scripts/common-functions.sh
@@ -0,0 +1,33 @@
+#!/usr/bin/env bash
+
+# Function that downloads an archive with the source code by the given url,
+# extracts its files and exports a variable SOURCES_DIR_${LIBRARY_NAME}
+function downloadTarArchive() {
+  # The full name of the library
+  LIBRARY_NAME=$1
+  # The url of the source code archive
+  DOWNLOAD_URL=$2
+  # Optional. If 'true' then the function creates an extra directory for archive extraction.
+  NEED_EXTRA_DIRECTORY=$3
+
+  ARCHIVE_NAME=${DOWNLOAD_URL##*/}
+  # File name without extension
+  LIBRARY_SOURCES="${ARCHIVE_NAME%.tar.*}"
+
+  echo "Ensuring sources of ${LIBRARY_NAME} in ${LIBRARY_SOURCES}"
+
+  if [[ ! -d "$LIBRARY_SOURCES" ]]; then
+    curl -O ${DOWNLOAD_URL}
+
+    EXTRACTION_DIR="."
+    if [ "$NEED_EXTRA_DIRECTORY" = true ] ; then
+      EXTRACTION_DIR=${LIBRARY_SOURCES}
+      mkdir ${EXTRACTION_DIR}
+    fi
+
+    tar xf ${ARCHIVE_NAME} -C ${EXTRACTION_DIR}
+    rm ${ARCHIVE_NAME}
+  fi
+
+  export SOURCES_DIR_${LIBRARY_NAME}=$(pwd)/${LIBRARY_SOURCES}
+}
diff --git a/scripts/ffmpeg/download.sh b/scripts/ffmpeg/download.sh
index bdb5819..590b3fa 100755
--- a/scripts/ffmpeg/download.sh
+++ b/scripts/ffmpeg/download.sh
@@ -9,17 +9,11 @@
 # Getting sources of a particular FFmpeg release.
 # Same argument (FFmpeg version) produces the same source set.
 function ensureSourcesTar() {
-  FFMPEG_SOURCES=ffmpeg-${FFMPEG_SOURCE_VALUE}
+  source ${SCRIPTS_DIR}/common-functions.sh
 
-  if [[ ! -d "$FFMPEG_SOURCES" ]]; then
-    TARGET_FILE_NAME=ffmpeg-${FFMPEG_SOURCE_VALUE}.tar.bz2
-
-    curl https://www.ffmpeg.org/releases/${TARGET_FILE_NAME} --output ${TARGET_FILE_NAME}
-    tar xf ${TARGET_FILE_NAME} -C .
-    rm ${TARGET_FILE_NAME}
-  fi
-
-  export SOURCES_DIR_ffmpeg=$(pwd)/${FFMPEG_SOURCES}
+  downloadTarArchive \
+    "ffmpeg" \
+    "https://www.ffmpeg.org/releases/ffmpeg-${FFMPEG_SOURCE_VALUE}.tar.bz2"
 }
 
 # Getting sources of a particular branch or a tag of FFmpeg's git repository.
diff --git a/scripts/libaom/download.sh b/scripts/libaom/download.sh
index 6cbeabf..c233fba 100755
--- a/scripts/libaom/download.sh
+++ b/scripts/libaom/download.sh
@@ -1,24 +1,10 @@
 #!/usr/bin/env bash
 
-# Script to download AV1 Codec Library's source code
+source ${SCRIPTS_DIR}/common-functions.sh
 
-# Exports SOURCES_DIR_libaom - path where actual sources are stored
-
-# This 2 variables have to be changed at once.
-# The first one is produced by 'git describe' command while being in the commit represented by the second one.
 AOM_VERSION=v1.0.0-errata1-avif
-AOM_HASH=4eb1e7795b9700d532af38a2d9489458a8038233
-
-echo "Using libaom $AOM_VERSION"
-AOM_SOURCES=libaom-${AOM_VERSION}
-
-if [[ ! -d "$AOM_SOURCES" ]]; then
-  TARGET_FILE_NAME=${AOM_VERSION}.tar.gz
-
-  curl https://aomedia.googlesource.com/aom/+archive/${AOM_HASH}.tar.gz --output ${TARGET_FILE_NAME}
-  mkdir $AOM_SOURCES
-  tar xf ${TARGET_FILE_NAME} -C $AOM_SOURCES
-  rm ${TARGET_FILE_NAME}
-fi
 
-export SOURCES_DIR_libaom=$(pwd)/${AOM_SOURCES}
+downloadTarArchive \
+  "libaom" \
+  "https://aomedia.googlesource.com/aom/+archive/${AOM_VERSION}.tar.gz" \
+  true
diff --git a/scripts/libdav1d/download.sh b/scripts/libdav1d/download.sh
index ec0a7c5..9697551 100755
--- a/scripts/libdav1d/download.sh
+++ b/scripts/libdav1d/download.sh
@@ -1,19 +1,9 @@
 #!/usr/bin/env bash
 
-# Script to download Dav1d's source code
-
-# Exports SOURCES_DIR_libdav1d - path where actual sources are stored
+source ${SCRIPTS_DIR}/common-functions.sh
 
 DAV1D_VERSION=0.6.0
-echo "Using libdav1d $DAV1D_VERSION"
-DAV1D_SOURCES=dav1d-${DAV1D_VERSION}
-
-if [[ ! -d "$DAV1D_SOURCES" ]]; then
-  TARGET_FILE_NAME=dav1d-${DAV1D_VERSION}.tar.gz
-
-  curl https://code.videolan.org/videolan/dav1d/-/archive/${DAV1D_VERSION}/dav1d-${DAV1D_VERSION}.tar.gz --output ${TARGET_FILE_NAME}
-  tar xf ${TARGET_FILE_NAME} -C .
-  rm ${TARGET_FILE_NAME}
-fi
 
-export SOURCES_DIR_libdav1d=$(pwd)/${DAV1D_SOURCES}
+downloadTarArchive \
+  "libdav1d" \
+  "https://code.videolan.org/videolan/dav1d/-/archive/${DAV1D_VERSION}/dav1d-${DAV1D_VERSION}.tar.gz"
diff --git a/scripts/libmp3lame/download.sh b/scripts/libmp3lame/download.sh
index 46cf5d6..fe58d48 100755
--- a/scripts/libmp3lame/download.sh
+++ b/scripts/libmp3lame/download.sh
@@ -1,19 +1,9 @@
 #!/usr/bin/env bash
 
-# Script to download Lame's source code
-
-# Exports SOURCES_DIR_libmp3lame - path where actual sources are stored
+source ${SCRIPTS_DIR}/common-functions.sh
 
 LAME_VERSION=3.100
-echo "Using libmp3lame $LAME_VERSION"
-LAME_SOURCES=lame-${LAME_VERSION}
-
-if [[ ! -d "$LAME_SOURCES" ]]; then
-  TARGET_FILE_NAME=lame-${LAME_VERSION}.tar.gz
-
-  curl http://downloads.videolan.org/pub/contrib/lame/${TARGET_FILE_NAME} --output ${TARGET_FILE_NAME}
-  tar xf ${TARGET_FILE_NAME} -C .
-  rm ${TARGET_FILE_NAME}
-fi
 
-export SOURCES_DIR_libmp3lame=$(pwd)/${LAME_SOURCES}
+downloadTarArchive \
+  "libmp3lame" \
+  "http://downloads.videolan.org/pub/contrib/lame/lame-${LAME_VERSION}.tar.gz"
diff --git a/scripts/parse-arguments.sh b/scripts/parse-arguments.sh
index 56ce7cb..ae4520b 100755
--- a/scripts/parse-arguments.sh
+++ b/scripts/parse-arguments.sh
@@ -73,7 +73,7 @@ for argument in "$@"; do
     --enable-libdav1d|-dav1d)
       EXTERNAL_LIBRARIES+=( "libdav1d" )
     ;;
-    --enable-libmp3lame|-mp3lame)
+    --enable-libmp3lame|-mp3lame|-lame)
       EXTERNAL_LIBRARIES+=( "libmp3lame" )
     ;;
     --enable-libopus|-opus)