transmux from h.264/aac/mp4 => h.264/aac/flv

request.json

{
  "test": true,
  "input": "http://s3.amazonaws.com/zencodertesting/test.mov",
  "outputs": [
    {
      "label": "mp4_output"
    },
    {
      "source": "mp4_output",
      "copy_audio": true,
      "copy_video": true,
      "video_codec": "h264",
      "audio_codec": "aac",
      "format": "flv"
    }
  ]
}