Allows the user to launch an external process on the local machine. This can be used to do transcoding when paired with applications such as LibAVConv and FFMPEG.

This function has the following parameters:

Parameter Name Mandatory Default Value Description
fullBinaryPath true null The path to the executable
keepAlive false 1 true If the process dies for any reason, the EMS will restart the external application when keepAlive is 1
arguments false zero-length string Complete list of arguments that need to be passed to the process, delimited by ESCAPED SPACES (“\ “)
groupName false if not assigned, will create a random value process_group_xxx The group name assigned to the process
$[ENV]=VALUE] false zero-length string Any number of environment variables that need to be set just before launching the process

An example of the launchProcess command is:

launchProcess fullBinaryPath=/home/ems/ffmpeg_preset.sh arguments=10fps\ Stream1\ Stream1_10fps keepAlive=1 $SAMPLE_E_VAR=MyVal

This sample command launches a script, named ffmpeg_prest.sh, which presumably contains a shell-script that will run FFMPEG with a specific set of parameters.

The arguments field passes the three values (“10fps”, “Stream1”, “Stream1_10fps”) to the ffmpeg_preset.sh script. In this example, these parameters might tell this hypothetical script to transcode Stream1 to be only 10 frames-per-second, and then name the resultant stream “Stream1_10fps”.

The final parameter is an example for setting an environment variable (SAMPLE_E_VAR set to MyVal) on the command line prior to script/binary execution.

Example:

API Call:

launchProcess fullBinaryPath=/home/ems/ffmpeg_preset.sh arguments=10fps\ Stream1\ Stream1_10fps keepAlive=1 $SAMPLE_E_VAR=MyVal

JSON Response:

{
   "data":{
      "arguments":"",
      "configId":1,
      "fullBinaryPath":"d:\\run.bat",
      "groupName":"process_group_UHBqMT6C",
      "keepAlive":true,
      "operationType":6
   },
   "description":"Process enqueued for start",
   "status":"SUCCESS"
}

The JSON response contains the following details:

  • data – The data to parse
    • arguments – Complete list of arguments that need to be passed to the process
    • configID – The configuration ID for this command
    • fullBinaryPath – Full path to the binary that needs to be launched
    • groupName - The group name assigned to the process
    • keepAlive – If keepAlive is set to 1, the server will restart the process if it exits
    • operationType – The type of operation
    • $[ENV]=[VALUE] – Any number of environment variables that need to be set just before launching the process

  • description – Describes the result of parsing/executing the command

  • status – SUCCESS if the command was parsed and executed successfully, FAIL if not