A tool can remux flv to mp4 written by Node.js.
Prerequisites: Node.js (>=7.x) and Git.
$ npm install -g https://github.com/houxinjie/flv_to_mp4$ ftom4 -i <inputFile> -o <outFile>Example:
$ ftom4 -i data/test.flv -o data/test.mp4$ git clone https://github.com/houxinjie/flv_to_mp4
$ cd flv_to_mp4
$ npm install && npm run build