Getting the jdksmidi library to work with pio

PlatformIO IDE
1

I have a very specific use-case, but you can probably help me without knowing anything about this first paragraph. Using Faust, a domain specific language for DSP (https://faust.grame.fr/) I generate an audio engine that I want to run on an ESP32 with an audio codec. All of this is described in this article DSP on the ESP-32 With Faust - Faust Documentation The generated code is C++ and requires the jdksmidi library respectively this fork GitHub - thopman/jdksmidi: c++ MIDI library

Adding the github repo to the lib_deps of my platformio.ini didn’t work. I get the error src/dsp/Engine.cpp:5224:28: fatal error: jdksmidi/world.h: No such file or directory

Manually downloading the repository, removing -master from its name and putting it into the lib folder is a different story. Now I get all a ton of errors of these three kinds:

  • non-member function 'bool jdksmidi::IsSysExURT()' cannot have cv-qualifier
  • lib/jdksmidi/src/jdksmidi_msg.cpp:372:5: error: 'jdksMIDIMessage' has not been declared
  • lib/jdksmidi/src/jdksmidi_msg.cpp:409:14: error: 'status' was not declared in this scope

How can I get this library to work? What am I missing?

2

When I only try and use the library GitHub - thopman/jdksmidi: c++ MIDI library in a pure ESP-IDF project (since github page says "midi parser component for esp-idf (esp32). ") I get the same weird errors. The project has a weird include file structure in which you must be very careful regarding which file is included first. I e.g. wrote my src\main.cpp file as

#include "jdksmidi/parser.h"

and that threw a lot of errors, because one is supposed to do

#include "jdksmidi/world.h"

before that. But later, compilation fails completely in lib/jdksmidi/src/jdksmidi_msg.cpp.

The file is also different in content. Compare the original jdksmidi/jdksmidi_msg.cpp at master · jdkoftinoff/jdksmidi · GitHub version to jdksmidi/jdksmidi_msg.cpp at master · thopman/jdksmidi · GitHub – all the types were renamed from e.g. MIDIMessage to jdksMIDIMessage but I don’t find the corresponding header for it, there it’s still called MIDIMessage.

If I do a dirty hack in the platformio.ini by adding

build_flags = -DjdksMIDIMessage=MIDIMessage

a minimal example compiles.

Advanced Memory Usage is available via "PlatformIO Home > Project Inspect"
RAM:   [          ]   5.0% (used 16364 bytes from 327680 bytes)
Flash: [====      ]  37.7% (used 395152 bytes from 1048576 bytes)
esptool.py v3.0
======================== [SUCCESS] Took 51.65 seconds ========================

which feels very weird.

(standard PIO Home → Create Project → ESP-WROVER-KIT + ESP-IDF, change main.c to main.cpp with code

#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "jdksmidi/world.h"
#include "jdksmidi/parser.h"

/* entry point has to have C linkage */
extern "C" void app_main() {
    /* call test function */
    jdksmidi::MIDIParser parser {};
    jdksmidi::MIDIMessage msg {};
    
    bool parse_ok = parser.Parse(0x00, &msg);
}

and full platformio.ini

[env:esp-wrover-kit]
platform = espressif32
board = esp-wrover-kit
framework = espidf
build_flags = -DjdksMIDIMessage=MIDIMessage

)

Are you 100% sure you need that fork? Do you work with ESP-IDF or Arduino?

1 Like
3

Hi Max, thank you for your thorough answer!

I’ve been trying you the build flag and the c linkage solution, both with the regular and the hacked lib, but no luck.

I’m not 100% certain about having to use the hacked library. I asked in the Faust Slack channel and the author told me that he made the fork because of a “conflict between faust’s MIDIMessage and jsdkMIDI’s MIDIMessage”. Unfortunately, nobody there seems to be using pio which is a shame.

I am using Arduino Framework so far, but if I have to I’ll start dipping my toes into ESP-IDF.

4

Well one thing I can definitely say is that when I download the ZIP file at DSP on the ESP-32 With Faust - Faust Documentation and put it in the src/ folder of a newly-created ESP32Dev + Arduino project, it compiles without any problems or extra options.

RAM:   [          ]   4.2% (used 13780 bytes from 327680 bytes)
Flash: [==        ]  23.2% (used 304208 bytes from 1310720 bytes)
esptool.py v3.0
====================== [SUCCESS] Took 9.77 seconds ======================

and that has also 0 library dependencies to jdksmidi or anything else.

I also noticed that the article you’ve linked doesn’t mention jdskmidi.

Do you have the exact project files which don’t compile? What steps do you do / options do you set to generate the code that you’re trying to compile?

5

Yes, I’ve also managed to compile it and get it to make sound. MIDI is the problem.

Compiling my Faust like this faust2esp32 -lib -ac101 -midi -nvoices 8 Engine.dsp does result in a Engine.cpp and Engine.h which require that library. -lib is optional, -ac101 is the codec.

In Faust, MIDI is implemented by using the naming convention gate, freq and gain. I’m trying it with the additive synthesizer example.

Currently, everything in a private repository on Bitbucket. If you send me your mail via a PM I’d be happy to invite you. But it’s really just bare bones right now.

6

Hi guys, any news on this? it looks that I ran into similar problems. I try work in ESP-IDF and try to implement polyphony with midi on a TTGO TAudio board. Midi, not because I definitely need it but because I consider this as a stepping stone to other work. I also tried to get on via the #ESP32 channel on Faust Slack. Without succes yet…