ash/webui/camera_app_ui/resources/js/lib/README.md
Follow the Emscripten Getting Started Instruction to setup the toolchain. In short:
$ git clone https://github.com/emscripten-core/emsdk.git
$ cd emsdk
$ ./emsdk install latest
$ ./emsdk activate latest
$ source ./emsdk_env.sh
You can find the current used version from the output of ./emsdk activate latest as:
Set the following tools as active:
node-14.18.2-64bit
releases-1eec24930cb2f56f6d9cd10ffcb031e27ea4157a-64bit
After the Emscripten environment is setup properly, run build_ffmpeg.sh will build ffmpeg.{js,wasm} from src/third_party/ffmpeg.
The emsdk version of the last build of this package is 3.1.31.