ffmpeg download script, separate build step

Dockerfile

@@ -1,5 +1,5 @@
 # multi stage to build tube archivist
-# first stage to build python wheel, copy into final image
+# build python wheel, download and extract ffmpeg, copy into final image
 
 
 # First stage to build python wheel
@@ -13,6 +13,11 @@ RUN apt-get update && apt-get install -y --no-install-recommends \
 COPY ./tubearchivist/requirements.txt /requirements.txt
 RUN pip install --user -r requirements.txt
 
+# build ffmpeg
+FROM python:3.11.3-slim-bullseye as ffmpeg-builder
+COPY docker_assets/ffmpeg_download.py ffmpeg_download.py
+RUN python ffmpeg_download.py $TARGETPLATFORM
+
 # build final image
 FROM python:3.11.3-slim-bullseye as tubearchivist
 
@@ -25,30 +30,15 @@ ENV PYTHONUNBUFFERED 1
 COPY --from=builder /root/.local /root/.local
 ENV PATH=/root/.local/bin:$PATH
 
+# copy ffmpeg
+COPY --from=ffmpeg-builder ./ffmpeg/ffmpeg /usr/bin/ffmpeg
+COPY --from=ffmpeg-builder ./ffprobe/ffprobe /usr/bin/ffprobe
+
 # install distro packages needed
 RUN apt-get clean && apt-get -y update && apt-get -y install --no-install-recommends \
     nginx \
     atomicparsley \
-    curl \
-    xz-utils && rm -rf /var/lib/apt/lists/*
-
-# install patched ffmpeg build, default to linux64
-RUN if [ "$TARGETPLATFORM" = "linux/arm64" ] ; then \
-    curl -s https://api.github.com/repos/yt-dlp/FFmpeg-Builds/releases/latest \
-        | grep browser_download_url \
-        | grep ".*master.*linuxarm64.*tar.xz" \
-        | cut -d '"' -f 4 \
-        | xargs curl -L --output ffmpeg.tar.xz ; \
-    else \
-    curl -s https://api.github.com/repos/yt-dlp/FFmpeg-Builds/releases/latest \
-        | grep browser_download_url \
-        | grep ".*master.*linux64.*tar.xz" \
-        | cut -d '"' -f 4 \
-        | xargs curl -L --output ffmpeg.tar.xz ; \
-    fi && \
-    tar -xf ffmpeg.tar.xz --strip-components=2 --no-anchored -C /usr/bin/ "ffmpeg" && \
-    tar -xf ffmpeg.tar.xz --strip-components=2 --no-anchored -C /usr/bin/ "ffprobe" && \
-    rm ffmpeg.tar.xz
+    curl && rm -rf /var/lib/apt/lists/*
 
 # install debug tools for testing environment
 RUN if [ "$INSTALL_DEBUG" ] ; then \