Is this completely stupid?

wearyhacker · Sep 14, 2023

I am working on some software for an electronic concertina being constructed by a friend of mine. The instrument will look like and play like a real concertina.

He has already captured a number of samples of real concertinas of various types.

Our current workflow for producing soundfonts is as follows.

1. Record an instrument.

2. Decide which samples to use.

3. Normalise the selected samples using DAW such as Audacity.

4. Produce a soundfont using Polyphone.

5. Produce c++ source code using the soundfont decoder from
https://github.com/PaulStoffregen/Wavetable-Synthesis.git.

6. Compile and link these files into the firmware.

The following is my crazy idea.

I am thinking it would not be too difficult to write a small utility to
serialise the the static data that is defined in these files so that it
could be loaded dynamically from the sd card and then used by the
currently running firmware.

For a proof of concept we could basically link a wavetable.cpp and a wavetable.h into a simple c++ program that does the serialisation to a file. A more complex approach would be to use something like flex and bison to parse the supplied files, and then do the serialisation.

What do you think?

The structures are quite simple and we can fix the pointers at load
time.

The interface to the wavetable is passed in the following structure

Code:

struct instrument_data {
       const uint8_t sample_count;
       const uint8_t* sample_note_ranges;
       const sample_data* samples;
};

This is what this structure looks like for irish2

Code:

const AudioSynthWavetable::instrument_data irish2 = {4, irish2_ranges, irish2_samples };

The sample_count field is the number of samples(4). The
sample_note_ranges is a pointer to an array of four 8 bit numbers. I
would have to look further into the code to work out these are handled
I would assume these are treated two 4 bit numbers. The sample data
field is pointer to an array of 4 structures.

This is what this structure looks like for irish2

Code:

const AudioSynthWavetable::instrument_data irish2 = {4, irish2_ranges, irish2_samples };

The sample_count field is the number of samples(4). The
sample_note_ranges is a pointer to an array of four 8 bit numbers. I
would have to look further into the code to work out these are handled
I. would assume these are treated two 4 bit numbers. The sample data
field is pointer to an array of 4 structures.

Code:

struct sample_data {
           // SAMPLE VALUES
           const int16_t* sample;
           const bool LOOP;
           const int INDEX_BITS;
           const float PER_HERTZ_PHASE_INCREMENT;
           const uint32_t MAX_PHASE;
           const uint32_t LOOP_PHASE_END;
           const uint32_t LOOP_PHASE_LENGTH;
           const uint16_t INITIAL_ATTENUATION_SCALAR;
           // VOLUME ENVELOPE VALUES
           const uint32_t DELAY_COUNT;
           const uint32_t ATTACK_COUNT;
           const uint32_t HOLD_COUNT;
           const uint32_t DECAY_COUNT;
           const uint32_t RELEASE_COUNT;
           const int32_t SUSTAIN_MULT;
           // VIRBRATO VALUES
           const uint32_t VIBRATO_DELAY;
           const uint32_t VIBRATO_INCREMENT;
           const float VIBRATO_PITCH_COEFFICIENT_INITIAL;
           const float VIBRATO_PITCH_COEFFICIENT_SECOND;
           // MODULATION VALUES
           const uint32_t MODULATION_DELAY;
           const uint32_t MODULATION_INCREMENT;
           const float MODULATION_PITCH_COEFFICIENT_INITIAL;
           const float MODULATION_PITCH_COEFFICIENT_SECOND;
           const int32_t MODULATION_AMPLITUDE_INITIAL_GAIN;
           const int32_t MODULATION_AMPLITUDE_SECOND_GAIN;
 };

The sample_data struct in irish2 looks like this.

Code:

static const AudioSynthWavetable::sample_data irish2_samples[4] = {
       {
           (int16_t*)sample_0_irish2_gfffG55, // sample
           true, // LOOP
           12, // LENGTH_BITS
           (1 << (32 - 12)) * WAVETABLE_CENTS_SHIFT(0) * 8000.0 / WAVETABLE_NOTE_TO_FREQUENCY(55) / AUDIO_SAMPLE_RATE_EXACT + 0.5, // PER_HERTZ_PHASE_INCREMENT
           ((uint32_t)2563 - 1) << (32 - 12), // MAX_PHASE
           ((uint32_t)2562 - 1) << (32 - 12), // LOOP_PHASE_END
           (((uint32_t)2562 - 1) << (32 - 12)) - (((uint32_t)1746 - 1) << (32 - 12)), // LOOP_PHASE_LENGTH
           uint16_t(UINT16_MAX * WAVETABLE_DECIBEL_SHIFT(0)), // INITIAL_ATTENUATION_SCALAR
           uint32_t(0.00 * AudioSynthWavetable::SAMPLES_PER_MSEC / AudioSynthWavetable::ENVELOPE_PERIOD + 0.5), // DELAY_COUNT
           uint32_t(1.00 * AudioSynthWavetable::SAMPLES_PER_MSEC / AudioSynthWavetable::ENVELOPE_PERIOD + 0.5), // ATTACK_COUNT
           uint32_t(0.00 * AudioSynthWavetable::SAMPLES_PER_MSEC / AudioSynthWavetable::ENVELOPE_PERIOD + 0.5), // HOLD_COUNT
           uint32_t(1.00 * AudioSynthWavetable::SAMPLES_PER_MSEC / AudioSynthWavetable::ENVELOPE_PERIOD + 0.5), // DECAY_COUNT
           uint32_t(1.00 * AudioSynthWavetable::SAMPLES_PER_MSEC / AudioSynthWavetable::ENVELOPE_PERIOD + 0.5), // RELEASE_COUNT
           int32_t((1.0 - WAVETABLE_DECIBEL_SHIFT(0.0)) * AudioSynthWavetable::UNITY_GAIN), // SUSTAIN_MULT
           uint32_t(0.00 * AudioSynthWavetable::SAMPLES_PER_MSEC / (2 * AudioSynthWavetable::LFO_PERIOD)), // VIBRATO_DELAY
           uint32_t(8.2 * AudioSynthWavetable::LFO_PERIOD * (UINT32_MAX / AUDIO_SAMPLE_RATE_EXACT)), // VIBRATO_INCREMENT
           (WAVETABLE_CENTS_SHIFT(0) - 1.0) * 4, // VIBRATO_PITCH_COEFFICIENT_INITIAL
           (1.0 - WAVETABLE_CENTS_SHIFT(0)) * 4, // VIBRATO_COEFFICIENT_SECONDARY
           uint32_t(0.00 * AudioSynthWavetable::SAMPLES_PER_MSEC / (2 * AudioSynthWavetable::LFO_PERIOD)), // MODULATION_DELAY
           uint32_t(8.2 * AudioSynthWavetable::LFO_PERIOD * (UINT32_MAX / AUDIO_SAMPLE_RATE_EXACT)), // MODULATION_INCREMENT
           (WAVETABLE_CENTS_SHIFT(0) - 1.0) * 4, // MODULATION_PITCH_COEFFICIENT_INITIAL
           (1.0 - WAVETABLE_CENTS_SHIFT(0)) * 4, // MODULATION_PITCH_COEFFICIENT_SECOND
           int32_t(UINT16_MAX * (WAVETABLE_DECIBEL_SHIFT(0) - 1.0)) * 4, // MODULATION_AMPLITUDE_INITIAL_GAIN
           int32_t(UINT16_MAX * (1.0 - WAVETABLE_DECIBEL_SHIFT(0))) * 4, // MODULATION_AMPLITUDE_FINAL_GAIN
       },
       {
           (int16_t*)sample_1_irish2_gfffF66, // sample
           true, // LOOP
           10, // LENGTH_BITS
           (1 << (32 - 10)) * WAVETABLE_CENTS_SHIFT(0) * 8000.0 / WAVETABLE_NOTE_TO_FREQUENCY(66) / AUDIO_SAMPLE_RATE_EXACT + 0.5, // PER_HERTZ_PHASE_INCREMENT
           ((uint32_t)761 - 1) << (32 - 10), // MAX_PHASE
           ((uint32_t)760 - 1) << (32 - 10), // LOOP_PHASE_END
           (((uint32_t)760 - 1) << (32 - 10)) - (((uint32_t)565 - 1) << (32 - 10)), // LOOP_PHASE_LENGTH
           uint16_t(UINT16_MAX * WAVETABLE_DECIBEL_SHIFT(0)), // INITIAL_ATTENUATION_SCALAR
           uint32_t(0.00 * AudioSynthWavetable::SAMPLES_PER_MSEC / AudioSynthWavetable::ENVELOPE_PERIOD + 0.5), // DELAY_COUNT
           uint32_t(1.00 * AudioSynthWavetable::SAMPLES_PER_MSEC / AudioSynthWavetable::ENVELOPE_PERIOD + 0.5), // ATTACK_COUNT
           uint32_t(0.00 * AudioSynthWavetable::SAMPLES_PER_MSEC / AudioSynthWavetable::ENVELOPE_PERIOD + 0.5), // HOLD_COUNT
           uint32_t(1.00 * AudioSynthWavetable::SAMPLES_PER_MSEC / AudioSynthWavetable::ENVELOPE_PERIOD + 0.5), // DECAY_COUNT
           uint32_t(1.00 * AudioSynthWavetable::SAMPLES_PER_MSEC / AudioSynthWavetable::ENVELOPE_PERIOD + 0.5), // RELEASE_COUNT
           int32_t((1.0 - WAVETABLE_DECIBEL_SHIFT(0.0)) * AudioSynthWavetable::UNITY_GAIN), // SUSTAIN_MULT
           uint32_t(0.00 * AudioSynthWavetable::SAMPLES_PER_MSEC / (2 * AudioSynthWavetable::LFO_PERIOD)), // VIBRATO_DELAY
           uint32_t(8.2 * AudioSynthWavetable::LFO_PERIOD * (UINT32_MAX / AUDIO_SAMPLE_RATE_EXACT)), // VIBRATO_INCREMENT
           (WAVETABLE_CENTS_SHIFT(0) - 1.0) * 4, // VIBRATO_PITCH_COEFFICIENT_INITIAL
           (1.0 - WAVETABLE_CENTS_SHIFT(0)) * 4, // VIBRATO_COEFFICIENT_SECONDARY
           uint32_t(0.00 * AudioSynthWavetable::SAMPLES_PER_MSEC / (2 * AudioSynthWavetable::LFO_PERIOD)), // MODULATION_DELAY
           uint32_t(8.2 * AudioSynthWavetable::LFO_PERIOD * (UINT32_MAX / AUDIO_SAMPLE_RATE_EXACT)), // MODULATION_INCREMENT
           (WAVETABLE_CENTS_SHIFT(0) - 1.0) * 4, // MODULATION_PITCH_COEFFICIENT_INITIAL
           (1.0 - WAVETABLE_CENTS_SHIFT(0)) * 4, // MODULATION_PITCH_COEFFICIENT_SECOND
           int32_t(UINT16_MAX * (WAVETABLE_DECIBEL_SHIFT(0) - 1.0)) * 4, // MODULATION_AMPLITUDE_INITIAL_GAIN
           int32_t(UINT16_MAX * (1.0 - WAVETABLE_DECIBEL_SHIFT(0))) * 4, // MODULATION_AMPLITUDE_FINAL_GAIN
       },
       {
           (int16_t*)sample_2_irish2_gfffF78, // sample
           true, // LOOP
           10, // LENGTH_BITS
           (1 << (32 - 10)) * WAVETABLE_CENTS_SHIFT(0) * 8000.0 / WAVETABLE_NOTE_TO_FREQUENCY(78) / AUDIO_SAMPLE_RATE_EXACT + 0.5, // PER_HERTZ_PHASE_INCREMENT
           ((uint32_t)837 - 1) << (32 - 10), // MAX_PHASE
           ((uint32_t)836 - 1) << (32 - 10), // LOOP_PHASE_END
           (((uint32_t)836 - 1) << (32 - 10)) - (((uint32_t)544 - 1) << (32 - 10)), // LOOP_PHASE_LENGTH
           uint16_t(UINT16_MAX * WAVETABLE_DECIBEL_SHIFT(0)), // INITIAL_ATTENUATION_SCALAR
           uint32_t(0.00 * AudioSynthWavetable::SAMPLES_PER_MSEC / AudioSynthWavetable::ENVELOPE_PERIOD + 0.5), // DELAY_COUNT
           uint32_t(1.00 * AudioSynthWavetable::SAMPLES_PER_MSEC / AudioSynthWavetable::ENVELOPE_PERIOD + 0.5), // ATTACK_COUNT
           uint32_t(0.00 * AudioSynthWavetable::SAMPLES_PER_MSEC / AudioSynthWavetable::ENVELOPE_PERIOD + 0.5), // HOLD_COUNT
           uint32_t(1.00 * AudioSynthWavetable::SAMPLES_PER_MSEC / AudioSynthWavetable::ENVELOPE_PERIOD + 0.5), // DECAY_COUNT
           uint32_t(1.00 * AudioSynthWavetable::SAMPLES_PER_MSEC / AudioSynthWavetable::ENVELOPE_PERIOD + 0.5), // RELEASE_COUNT
           int32_t((1.0 - WAVETABLE_DECIBEL_SHIFT(0.0)) * AudioSynthWavetable::UNITY_GAIN), // SUSTAIN_MULT
           uint32_t(0.00 * AudioSynthWavetable::SAMPLES_PER_MSEC / (2 * AudioSynthWavetable::LFO_PERIOD)), // VIBRATO_DELAY
           uint32_t(8.2 * AudioSynthWavetable::LFO_PERIOD * (UINT32_MAX / AUDIO_SAMPLE_RATE_EXACT)), // VIBRATO_INCREMENT
           (WAVETABLE_CENTS_SHIFT(0) - 1.0) * 4, // VIBRATO_PITCH_COEFFICIENT_INITIAL
           (1.0 - WAVETABLE_CENTS_SHIFT(0)) * 4, // VIBRATO_COEFFICIENT_SECONDARY
           uint32_t(0.00 * AudioSynthWavetable::SAMPLES_PER_MSEC / (2 * AudioSynthWavetable::LFO_PERIOD)), // MODULATION_DELAY
           uint32_t(8.2 * AudioSynthWavetable::LFO_PERIOD * (UINT32_MAX / AUDIO_SAMPLE_RATE_EXACT)), // MODULATION_INCREMENT
           (WAVETABLE_CENTS_SHIFT(0) - 1.0) * 4, // MODULATION_PITCH_COEFFICIENT_INITIAL
           (1.0 - WAVETABLE_CENTS_SHIFT(0)) * 4, // MODULATION_PITCH_COEFFICIENT_SECOND
           int32_t(UINT16_MAX * (WAVETABLE_DECIBEL_SHIFT(0) - 1.0)) * 4, // MODULATION_AMPLITUDE_INITIAL_GAIN
           int32_t(UINT16_MAX * (1.0 - WAVETABLE_DECIBEL_SHIFT(0))) * 4, // MODULATION_AMPLITUDE_FINAL_GAIN
       },
       {
           (int16_t*)sample_3_irish2_gfffF90, // sample
           true, // LOOP
           9, // LENGTH_BITS
           (1 << (32 - 9)) * WAVETABLE_CENTS_SHIFT(0) * 8000.0 / WAVETABLE_NOTE_TO_FREQUENCY(90) / AUDIO_SAMPLE_RATE_EXACT + 0.5, // PER_HERTZ_PHASE_INCREMENT
           ((uint32_t)460 - 1) << (32 - 9), // MAX_PHASE
           ((uint32_t)459 - 1) << (32 - 9), // LOOP_PHASE_END
           (((uint32_t)459 - 1) << (32 - 9)) - (((uint32_t)367 - 1) << (32 - 9)), // LOOP_PHASE_LENGTH
           uint16_t(UINT16_MAX * WAVETABLE_DECIBEL_SHIFT(0)), // INITIAL_ATTENUATION_SCALAR
           uint32_t(0.00 * AudioSynthWavetable::SAMPLES_PER_MSEC / AudioSynthWavetable::ENVELOPE_PERIOD + 0.5), // DELAY_COUNT
           uint32_t(1.00 * AudioSynthWavetable::SAMPLES_PER_MSEC / AudioSynthWavetable::ENVELOPE_PERIOD + 0.5), // ATTACK_COUNT
           uint32_t(0.00 * AudioSynthWavetable::SAMPLES_PER_MSEC / AudioSynthWavetable::ENVELOPE_PERIOD + 0.5), // HOLD_COUNT
           uint32_t(1.00 * AudioSynthWavetable::SAMPLES_PER_MSEC / AudioSynthWavetable::ENVELOPE_PERIOD + 0.5), // DECAY_COUNT
           uint32_t(1.00 * AudioSynthWavetable::SAMPLES_PER_MSEC / AudioSynthWavetable::ENVELOPE_PERIOD + 0.5), // RELEASE_COUNT
           int32_t((1.0 - WAVETABLE_DECIBEL_SHIFT(0.0)) * AudioSynthWavetable::UNITY_GAIN), // SUSTAIN_MULT
           uint32_t(0.00 * AudioSynthWavetable::SAMPLES_PER_MSEC / (2 * AudioSynthWavetable::LFO_PERIOD)), // VIBRATO_DELAY
           uint32_t(8.2 * AudioSynthWavetable::LFO_PERIOD * (UINT32_MAX / AUDIO_SAMPLE_RATE_EXACT)), // VIBRATO_INCREMENT
           (WAVETABLE_CENTS_SHIFT(0) - 1.0) * 4, // VIBRATO_PITCH_COEFFICIENT_INITIAL
           (1.0 - WAVETABLE_CENTS_SHIFT(0)) * 4, // VIBRATO_COEFFICIENT_SECONDARY
           uint32_t(0.00 * AudioSynthWavetable::SAMPLES_PER_MSEC / (2 * AudioSynthWavetable::LFO_PERIOD)), // MODULATION_DELAY
           uint32_t(8.2 * AudioSynthWavetable::LFO_PERIOD * (UINT32_MAX / AUDIO_SAMPLE_RATE_EXACT)), // MODULATION_INCREMENT
           (WAVETABLE_CENTS_SHIFT(0) - 1.0) * 4, // MODULATION_PITCH_COEFFICIENT_INITIAL
           (1.0 - WAVETABLE_CENTS_SHIFT(0)) * 4, // MODULATION_PITCH_COEFFICIENT_SECOND
           int32_t(UINT16_MAX * (WAVETABLE_DECIBEL_SHIFT(0) - 1.0)) * 4, // MODULATION_AMPLITUDE_INITIAL_GAIN
           int32_t(UINT16_MAX * (1.0 - WAVETABLE_DECIBEL_SHIFT(0))) * 4, // MODULATION_AMPLITUDE_FINAL_GAIN
       },
 };

You can see that each one point to a different block of bit bit audio
samples.

It should not be to difficult to load the dumps of all this from a file
and modify the fields in a instrument_data structure to point to the the
relevant arrays of structures. Then modify the sample pointer in each of
sample_data structure to point to the correct block of raw sample data.

What do you guys think?

Am I being completely stupid?

There is a similar approach suggested here.

h4yn0nnym0u5e · Sep 14, 2023

Doesn't sound stupid to me. I had much the same idea a few weeks back while musing on how to use the AudioSynthWavetable object in my "dynamic" branch of the audio ecosystem. At a glance it looks like most of the data structure is position-independent, with just a few pointers needing to be set once loaded from the filesystem of your choice. I've never used the AudioSynthWavetable so it's not been a high priority, but I'll definitely keep an eye on your progress!

wearyhacker · Sep 15, 2023

Progress report. I have created a repo on github https://github.com/rogerjames99/sf2bin.git. This contains the source of a c++ program that instantiates the wavetable data. The next step is to write this out to a file.

The changes to the sample data were trivial.

wearyhacker · Sep 15, 2023

The changes are a little more complex than first thought.

I need to get hold of the actual sizes of the raw sample data arrays. The easiest way to do this would be a small mod to decoder.py in the Wavetable-Synthesis library to add a count field to sample metadata.

Code:

struct sample_data {
	// SAMPLE VALUES
	const int16_t* sample;
        const int sample_count;  // !!!! This bit added
	const bool LOOP;
	const int INDEX_BITS;
	const float PER_HERTZ_PHASE_INCREMENT;
	const uint32_t MAX_PHASE;
	const uint32_t LOOP_PHASE_END;
	const uint32_t LOOP_PHASE_LENGTH;
	const uint16_t INITIAL_ATTENUATION_SCALAR;
	
	// VOLUME ENVELOPE VALUES
	const uint32_t DELAY_COUNT;
	const uint32_t ATTACK_COUNT;
	const uint32_t HOLD_COUNT;
	const uint32_t DECAY_COUNT;
	const uint32_t RELEASE_COUNT;
	const int32_t SUSTAIN_MULT;

	// VIRBRATO VALUES
	const uint32_t VIBRATO_DELAY;
	const uint32_t VIBRATO_INCREMENT;
	const float VIBRATO_PITCH_COEFFICIENT_INITIAL;
	const float VIBRATO_PITCH_COEFFICIENT_SECOND;

	// MODULATION VALUES
	const uint32_t MODULATION_DELAY;
	const uint32_t MODULATION_INCREMENT;
	const float MODULATION_PITCH_COEFFICIENT_INITIAL;
	const float MODULATION_PITCH_COEFFICIENT_SECOND;
	const int32_t MODULATION_AMPLITUDE_INITIAL_GAIN;
	const int32_t MODULATION_AMPLITUDE_SECOND_GAIN;
};

This would need a small mod to the decoder.py script in the Wavetable-Synthesis library to put the the value the generated .cpp file.

Any volunteers. I will hack it in manually for the time being.

wearyhacker · Sep 15, 2023

Just pushed up a version of sf2bin that actually outputs sonething that looks useful. Feel free to fork and improve.

wearyhacker · Sep 16, 2023

The binary data I produce is an aligned and padded version for a PC. The next step is to read in the file in a teensy sketch and see if there is a match between the alignments and padding on my PC and on an arm m7.

wearyhacker · Oct 5, 2023

Modifying sample_data.h is giving some downstream problems in platformio as the sketch keeps picking up the version from the teensy package framework.

I have decided to work on the a cleaner approach using the cppparser library to parse the files. I am currently struggling to get the dependencies correct to use the library in my sf2bin program.

wearyhacker · Nov 11, 2023

Belated update. I have abandoned the cpp parser approach. I am now a using shell script to preprocess the source file. sf2bin then needs to be recompiled with the newly generated instrument_samples.cpp and instrument_samples.h files. sft2bin produces a binary data file that can be read in from teensy sd card at run time. The example code to to read in the file and and apply the instrument sample data to an AudioSynthWavetable object is in the platformio directory of the repository.

I have got as far as testing the code, but I get no audio output. I think I have missed something that I need to do the the WaveTable object recognise a change to the sample data once the audio subsystem has been started,

All help gratefully received.

dbhale1943 · Feb 25, 2024

I just now found your post by searching for sample_data.h. I can not find this file anywhere.
I've even searched the complete Teensy libraries.
Could you tell me where it resides?

Moreover, perhaps I can help you out... I JUST finished a method to record Teensy wavetable samples by a sketch which runs on a Teensy 4.1 populated with at least an 8 MB EXTMEM chip soldered on. I'll abbreviate Wavetable as WT. I name my WT files using the 8.3 name method. The extension I use is ".w1". The sketch actually uses pointer access to the WT code which resides in T41's Flash, (including Instrument names of up to 15 characters in the same order of pointers to all WTs) copies it to EXTMEM. The .w1 file is a binary file including a header which defines the number of WTs. (I picture in the future of having additional text in the header which could contain the WT source, etc.) The number of WTs included in a file in this case is limited by the Flash memory size of the T41. (8 MB - the sketch, so I made one limited sketch with only one WT so some play back can be used to confirm the WTs work. The WT files can be loaded starting at a flexible offset based on EE variable in sequence until the end of EXTMEM. I have made various WT files and loaded many combinations into an 8 MB EXTMEM almost completely filling RAM and playing selected WTs by a WebMIDI keyboard (one note at a time. (For my initial tests I wanted to limit my file sizes to under 4 MB because I wanted to compare two WT images in my 8 MB RAM so I have not made a WT file close to 8 MB yet.

I think there's a lot to explain, but I'll write it up soon and perhaps show my WebMIDI app as well on a video.

h4yn0nnym0u5e mentioned, a few pointers needing to be set once loaded.

This is of done once the file is loaded.

wearyhacker · Feb 26, 2024

Where I eventually ended up in this journey can be found in the following threads. To summarise I store the soundfonts as JSON.

https://forum.pjrc.com/index.php?th...-by-jannick-manickens-soundfontdecoder.74003/

https://forum.pjrc.com/index.php?th...nstrument_data-to-and-from-a-json-file.74073/

https://forum.pjrc.com/index.php?th...json2asw-platformio-first-full-release.74205/

wearyhacker · Feb 26, 2024

dbhale1943 said:
I just now found your post by searching for sample_data.h. I can not find this file anywhere.
I've even searched the complete Teensy libraries.
Could you tell me where it resides?

The standalone standalone sample_data.h comes from the original "General repository for Wavetable Synthesis Capstone project at Portland State, Fall 2016 - Winter 2017".

https://github.com/TeensyAudio/Wavetable-Synthesis/blob/master/sample_data.h

I don't think it exists any more as a separate file as Paul has moved the sample_data definition inside the AudioSynthWavetable class. Unfortunately the definition is const so you cannot use it to create a sample_data structure at runtime.

I have vague recollection of the file existing in the teensy cores library for a while.

dbhale1943 · Feb 26, 2024

Thank you for your quick replies, wearyhacker. Glad you found a solution. I see you are using a different environment - platformio instead of Arduino. And I have seen many references to JSON, but I haven't looked into it , yet.

Just a couple questions regarding the file sizes - Are they quit efficient in packing the WT data ?
Actually, maybe I can answer this myself. I see your instrument.cpp. Maybe I'll try platformio and see if I can try this.

Maybe I'll look up some concertina samples to add as well.

Thanks, again, and good luck with your project.

Is this completely stupid?

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h4yn0nnym0u5e mentioned, a few pointers needing to be set once loaded.

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Is this completely stupid?

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h4yn0nnym0u5e mentioned, a few pointers needing to be set once loaded.​

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h4yn0nnym0u5e mentioned, a few pointers needing to be set once loaded.