Cross compile WebRTC for Raspberry Pi

• Install Toolchain :

   sudo git clone https://chromium.googlesource.com/chromium/tools/depot_tools.git /opt/depot_tools
   echo "export PATH=/opt/depot_tools:\$PATH" | sudo tee /etc/profile.d/depot_tools.sh
  
   sudo git clone https://github.com/raspberrypi/tools.git /opt/rpi_tools
  
   echo "export PATH=/opt/rpi_tools/arm-bcm2708/gcc-linaro-arm-linux-gnueabihf-raspbian-x64/bin:\$PATH" | sudo tee /etc/profile.d/rpi_tools.sh
   source /etc/profile
  

• Download WebRTC :

   export GYP_CROSSCOMPILE=1
   export GYP_DEFINES="target_arch=arm arm_float_abi=hard"
   fetch --no-history webrtc
  

• Build :

   gn gen out/arm/Release --args='is_debug=false rtc_use_h264=true ffmpeg_branding="Chrome" rtc_include_tests=false is_clang=false target_cpu="arm" treat_warnings_as_errors=false'
   ninja -C src/out/arm/Release