Dockerized Midi2Mp3

REST API for converting MIDI files to MP3 audio files - Provided as Docker container for easy usage.

Upload a JSON with base64 encoded Midi data and get a JSON including the base64 encoded Mp3 file. All details see below.

This is a stateless microservice without volumes. The microservice runs forever and accepts http requests on the specified port.

Setup and run

You need to have installed:

• docker
• docker-compose
• make

Running the container

Run the container using the prebuild image from Dockerhub:

docker run -p 8094:80 midi2mp3

Building the container

You can build the image and start it up with make and docker-compose

make build up ps

There are more commands in the Makefile, try

make

API Usage

Endpoint http://[docker-machine]/info

Request

• Verb : GET
• No parameter

Response

• Content-Type : Application/json

{
  "apiName": "midi2mp3",
  "version": {
    "api": "1.0"
  },
  "description": "midi to mp3 audio files cnverter"
}

Endpoint http://[docker-machine]/convert

Request

• Verb : POST
• Content-Type : Application/json
• Parameters : -- midiData : Base64 encoded MIDI-Data (see test section for an example)

Response

• Content-Type : Application/json

{
  "statusCode": "OK|ERROR",
  "message": "Information on error",
  "base64MidiData": "....",
  "logs": []
}

Test from command line

Or make the test from inside the container:

    make bash

and build a request file:

    echo -n "{\"midiData\":\"" > /tmp/test.json
    cat /tmp/elton.mid | base64 --wrap=0 >> /tmp/test.json
    echo "\"}" >> /tmp/test.json

or as a one liner:

    { echo -n "{\"midiData\":\""; echo -n "`base64 --wrap=0 /tmp/elton.mid`"; echo "\"}"; } > /tmp/test.json

then execute the conversion

    curl -X POST -H "Content-Type: application/json" --data "@/tmp/test.json" localhost/convert | jq .

You should get a json output containing the base64 encoded mp3 file as

    {
        "statusCode": "OK",
        "message": "",
        "base64Mp3Data": ".......",
        "logs": []
    }

You can test the microservice from outside the container (this is more complicated since you need the tools installed in your os):

    curl -X POST -H "Content-Type: application/json" --data "@test.json" localhost:8094/convert | jq .

To extract the mp3 file out of the result on the command line, use

    curl -X POST -H "Content-Type: application/json" --data "@/tmp/test.json" localhost/convert | jq -r .base64Mp3Data | base64 -d > /tmp/elton.mp3

Credits

This repo was inspired by

• https://github.com/GGracieux/lilypond-api
• https://github.com/mikechernev/midi2mp3-docker

Author

[email protected]

(C) Copyright, 2020