World (of MPP)'s Simplest note recorder!

[Lamp]

I made a very simple note recorder:

Record

var recording = [];
MPP.client.on('n', msg => {
    recording.push(msg);
});

Playback

recording.forEach(msg => {
    setTimeout(()=>{
        msg.n.forEach(n => {MPP.press(n.n, n.v)});
    }, msg.t - recording[0].t)
});

The recording part simply collects the note objects from the 'n' event into an array, and the playback part uses the timestamps of each object to play each pack of notes in sequence.
It works fairly well for how simple it is, but the result is kinda choppy and it doesn't do key releases.

The objects given by the 'n' event are actually bundles of notes, which have different delays, and the client has to take them apart and synchorize them before sending them to the piano.
If you look at the "Playing notes" part in the script.js (ctrl-f "n"), there is some more work going on. So I based on that.

Here is the second simplest note recorder, which records and plays back exactly the way you heard it!

Record

var recording = [];

MPP.client.on("n", function(msg) {

var t = msg.t - MPP.client.serverTimeOffset + 1000 - Date.now();

msg.n.forEach((note, i) => {

var ms = t + (note.d || 0);

if (ms < 0) ms = 0; else if (ms > 10000) return;

if (note.s) {

recording.push({tp:"r", ky:note.n, ts:Date.now()+ms}); // key releases

} else {

var vel = typeof note.v !== "undefined" ? parseFloat(note.v) : 0.5;

if (vel < 0) vel = 0; else if (vel > 1) vel = 1;

recording.push({tp:"p", ky:note.n, ts:Date.now()+ms, vl:vel}); // key presses

}

});

});

Playback

recording.forEach(note => {

setTimeout(()=>{

if (note.tp === "p") MPP.press(note.ky, note.vl);

if (note.tp === "r") MPP.release(note.ky);

}, note.ts - recording[0].ts);

});

http://paste.ubuntu.com/25229675/

To use it, paste the record part into your console and it'll record the notes into the "recording" array.
Then paste the playback code and it'll play back! Press backspace to release sustain pedal so key releases work.

To clear the recording, type "recording = []"

You can use JSON.stringify() to save to localStorage or to file! To save to localStorage: localStorage["name of your rec"] = JSON.stringify(recording);

Video

https://www.youtube.com/watch?v=51Bp8rSZnLQ

[SopaPlay]

That wont work, by copy and paste, if the gives error for SyntaxError
i using old chrome and windows xp. did you fix it?

[Lamp]

I made a newer version that saves much smaller data. Instead of saving to a JSON object (and then stringifying that) it appends the notes to a string, where each note is separated by a semicolon and each key by a comma. All press notes have a velocity key but release notes don't, so that's what determines its type. Also the timestamps count from the recording start time.

So here's an example of a recording:

;2337,ds4,0.859;2337,b2,0.859;2456,ds4;

Three notes here. Last one is a release note. Each note consists of keys, first is timestamp, second is key, and third is velocity if it's a press note.

So to decode this, we just split it at the semicolons, then for each item (ignoring first and last cause they're blank), split at the commas.

bla bla here's the code

http://paste.ubuntu.com/25275192/

//record
var recording = ";";
var startTime = Date.now();

MPP.client.on("n", msg => {

        var t = msg.t - MPP.client.serverTimeOffset + 1000 - Date.now();
        msg.n.forEach((note, i) => {
                var ms = t + (note.d || 0);
                if (ms < 0) ms = 0; else if (ms > 10000) return;
                if (note.s) {

                        recording += `${Date.now()+ms-startTime},${note.n};`; // key releases
                } else {
                        var vel = note.v ? parseFloat(note.v) : 0.5;

                        if (vel < 0) vel = 0; else if (vel > 1) vel = 1;

                        recording += `${Date.now()+ms-startTime},${note.n},${vel};`; // key presses
                }
        });
});

// playback
var timers = [];
recording.split(';').slice(1,-1).forEach(note => {
        var keys = note.split(',');
        timers.push(setTimeout(()=>{
                if (keys[2]) MPP.press(keys[1], Number(keys[2]));
                else MPP.release(keys[1]);
    }, keys[0]));
});

Above is for the interest of people who understand Javascript, but if you're not that high, I made something a little more user friendly:

http://paste.ubuntu.com/25275195/

// Basic note recorder for use in web console, made by Lamp
// To use, paste into console, then control with the following functions (type into console)
// record(), stopRecord(), playRecording(), stopPlayingRecording(), saveRecording("name"), loadRecording("name"), and resetRecording()

var recording = ";";
var isRecording = false;
var startTime;
var timers = [];

MPP.client.on("n", msg => {

        if (!isRecording) return;

        var t = msg.t - MPP.client.serverTimeOffset + 1000 - Date.now();
        msg.n.forEach((note, i) => {
                var ms = t + (note.d || 0);
                if (ms < 0) ms = 0; else if (ms > 10000) return;
                if (note.s) {

                        recording += `${Date.now()+ms-startTime},${note.n};`; // key releases
                } else {
                        var vel = note.v ? parseFloat(note.v) : 0.5;

                        if (vel < 0) vel = 0; else if (vel > 1) vel = 1;

                        recording += `${Date.now()+ms-startTime},${note.n},${vel};`; // key presses
                }
        });
});
function record() {
        startTime = Date.now();
        isRecording = true;
}
function stopRecord() {
        isRecording = false;
}
function playRecording() {
        recording.split(';').slice(1,-1).forEach(note => {
                var keys = note.split(',');
                timers.push(setTimeout(()=>{
                        if (keys[2]) MPP.press(keys[1], Number(keys[2]));
                        else MPP.release(keys[1]);
                }, keys[0]));
        });
}
function stopPlayingRecording() {
        timers.forEach(timer => {clearTimeout(timer)});
        timers = [];
}
function saveRecording(name) {
        localStorage[name] = recording;
}
function loadRecording(name) {
        recording = localStorage[name];
}
function resetRecording() {
        recording = ";";
}

You can just paste all that into console, then call the functions to control it.

A fully-featured user-friendly userscript is todo

[LGPvS]

how to fix bug if its dont records yourself notes???

[Lamp]

On Tuesday, May 22, 2018 at 4:49:58 AM UTC-7, LGPvS wrote:

how to fix bug if its dont records yourself notes???

 hmm, you know what, instead of listening and parsing "n" events, you could just modify the gPiano.play() and gPiano.stop() functions to collect notes, since those are the functions that make the piano simply play. They're the final destionations of both the built-in "n" event listener, and the press() and release() functions that are used for your own notes. That would be even simpler and work perfectly!!

[Lamp]

// record
var recording = new Array();
MPP.piano._play = MPP.piano.play;
MPP.piano._stop = MPP.piano.stop;
MPP.piano.play = function (note, vol, participant, delay_ms) {
    recording.push([note, vol, Date.now() + delay_ms]);
    MPP.piano._play(note, vol, participant, delay_ms);
};
MPP.piano.stop = function (note, participant, delay_ms) {
    recording.push([note, null, Date.now() + delay_ms]);
    MPP.piano._stop(note, participant, delay_ms);
};


// playback
for (let note of recording) {
    setTimeout(()=>{
        if (note[1]) MPP.press(note[0], note[1]);
        else MPP.release(note[0]);
    }, note[2] - recording[0][2]);
}

[Lamp]

here is another playback method for the above example, using a recursing function:

(function playback(i = 0){
    var note = recording[i];

    if (note[1]) MPP.press(note[0], note[1]);
    else MPP.release(note[0]);

    setTimeout(playback, note[2] - recording[i-1][2], i);
})()

This keeps on playing as the recorder records so you have a loop

I can't seem to get it working right though

[LGPvS]

how to make its record only your notes?

[Lamp]

you'd have to modify the press() and release() functions in the script.js; they represent your own key presses and releases. Unfortunately you can't just assign to MPP.press and MPP.release because of the way function assignments work (assigning a function makes a copy of that function, while assigning an object makes a reference to the same object, hence why we can assign to MPP.piano.play and have the internal gPiano.play use the same function; MPP.piano and internal gPiano are the same object; MPP object references the piano object. But MPP.press is just a copy of the internal press function so assigning a new function to MPP.press won't affect the internal `press`)

[LGPvS]

How to record notes by _id?

[Lamp]

The piano .play and .stop functions have a `participant` argument so you can just include `participant._id` into your recording.

[LGPvS]

Give script that records notes of specified player