Dockerfile: added PyAV build and runtime deps

Dockerfile

@@ -9,8 +9,10 @@ RUN apt-get update && apt-get install -y --no-install-recommends \
         python3-venv \
         # Required to build RLE module and dbus-python (GUI)
         build-essential python3-dev \
-        libdbus-1-dev \
-        libdbus-glib-1-dev
+        libdbus-1-dev libdbus-glib-1-dev \
+        # Required to build PyAV (pyrdp-convert to MP4)
+        libavformat-dev libavcodec-dev libavdevice-dev \
+        libavutil-dev libswscale-dev libswresample-dev libavfilter-dev
 
 RUN python3 -m venv /opt/venv
 # Make sure we use the virtualenv:
@@ -34,6 +36,10 @@ RUN apt-get update && apt-get install -y --no-install-recommends python3 \
         # GUI and notifications stuff
         libgl1-mesa-glx \
         notify-osd dbus-x11 libxkbcommon-x11-0 \
+        # Runtime requirement for PyAV (pyrdp-convert to MP4)
+        libavcodec57 libavdevice57 \
+        # Runtime requirement by progressbar (required by pyrdp-convert)
+        python3-distutils \
         && rm -rf /var/lib/apt/lists/*
 
 # Copy preinstalled dependencies from compile image