tce-load -i compiletc meson gst-plugins-base-dev ffmpeg7-dev

wget https://gstreamer.freedesktop.org/src/gst-libav/gst-libav-1.26.1.tar.xz

cd gst-libav-1.26.1

mkdir build
cd build

CC="gcc -flto -march=armv8-a+crc -mtune=cortex-a72 -Os -pipe" CXX="g++ -flto -march=armv8-a+crc -mtune=cortex-a72 -Os -pipe -fno-exceptions -fno-rtti" meson --prefix=/usr/local --localstatedir=/var --libexecdir=/usr/local/lib --buildtype=plain -Ddoc=disabled ../

ninja [0m 9.57s]
sudo ninja install

gst-libav 1.26.1

  User defined options
    buildtype    : plain
    doc          : disabled
    libexecdir   : /usr/local/lib
    localstatedir: /var
    prefix       : /usr/local