gasman/jasmid

UNMAINTAINED. A MIDI file reader and synthesiser in Javascript

jasmid's Issues

update README, this supports webkitAudio too

Your README undersells this library.
Sound output is via the Mozilla Audio Data API, with a Flash fallback

but audio.js will use webkitAudio in Chromium, without falling back to Flash.

How to know the instrument if there is no instrumentName or trackName?

Most midi files has tracks with instrument labelled in the trackName with the same track number. But some don't. Is the information stored somewhere? Also, is there a way to obtain the instrument code, where 1 corresponds to Acoustic Grand Piano, etc.?

How to play single notes

Hi!

I am trying to figure out how to build a project in which I need to play single notes. Those notes would be defined from javascript, say playNote("a") or playNote("g")

Could it be achieved using jasmid? What is the best approach to build it?

Performance issues on mobile CPUs

Hi,

I'm using jasmid along with MIDI.js to play some midi files inside the browser. I've ran into a strange issue. Playback deteriorates when I play a bit longer midi file on mobile CPUs (smartphones, tables). I'm trying with iPhone 5s, Nexus 5x, Nexus 7. These devices are not that bad generally.

It seem like it is influenced by the number of events a track inside midi file has. When I limit events to like 100 everything is great.

Any idea what might be the cause?

Add more instruments

Add more instruments from WebAudioFont

see example
https://surikov.github.io/webaudiofont/examples/midiplayer.html
300 drums + 1500 tone samples

stream.js array buffer ajax

IO.PrimitiveReader = function (data) {
var arr = Array.from(new Uint8Array(data));
var fn = {};
var position = 0;

    fn.read = function (length) {
        var result = arr.slice(position, position + length);
        position += length;
        return result;
    };

    /* read a big-endian 32-bit integer */
    fn.readInt32 = function () {
        var result = (
                (arr[position] << 24)
                + (arr[position + 1] << 16)
                + (arr[position + 2] << 8)
                + arr[position + 3]);
        position += 4;
        return result;
    }

    /* read a big-endian 16-bit integer */
    fn.readInt16 = function () {
        var result = (
                (arr[position] << 8)
                + arr[position + 1]);
        position += 2;
        return result;
    }

    /* read an 8-bit integer */
    fn.readInt8 = function (signed) {
        var result = arr[position];
        if (signed && result > 127)
            result -= 256;
        position += 1;
        return result;
    }

    fn.eof = function () {
        return position >= arr.length;
    }

    fn.readVarInt = function () {
        var result = 0;
        while (true) {
            var b = fn.readInt8();
            if (b & 0x80) {
                result += (b & 0x7f);
                result <<= 7;
            } else {
                /* b is the last byte */
                return result + b;
            }
        }
    };
    return fn;

};

Parsing tempo event results in invalid microsecondsPerBeat

This code

case 0x51:
    event.subtype = 'setTempo';
    if (length != 3) throw "Expected length for setTempo event is 3, got " + length;
    event.microsecondsPerBeat = (
        (stream.readInt8() << 16)
        + (stream.readInt8() << 8)
        + stream.readInt8()
        )
    return event;

will sometimes result in a microsecondsPerBeat of zero which results in a beatsPerMinute of Infinity, and a secondsToGenerate of 0, resulting in a perceived MIDI file length of 0.

See mudcube/MIDI.js#134

event subtype error

noteoff appears well on chrome and firefox.but On IE I got "noteAftertouch",and the note also get disorted.

Uncaught TypeError: undefined is not a function (context.createJavaScriptNode)

Tried playing from the demos page, but got an error

navigator.appVersion - "5.0 (X11; CrOS x86_64 5978.80.0) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/37.0.2062.119 Safari/537.36"

add support for loop

some way to loop would be nice

and jhohertz https://github.com/jhohertz/jasmid/tree/sidengine seem to have done lots of work on the jasmid

and this is perfect for 8 bit song in midi format :D

it would be a lot better if it's possible to loop though.

A440 == Midi Number 69?

in synth.js, looks like A440 is used on midi number 57.

should it be

var frequency = 440 * Math.pow(2, (note-69)/12);

instead of

var frequency = 440 * Math.pow(2, (note-57)/12);

but according to http://www.phys.unsw.edu.au/jw/notes.html its number 69. Just wondering if this is intentional before submitting a pull request. but btw, awesome library! :)

How to get key signature

I wanna be able to get key signature of midi file. How do I do so?

index.html

when I click on the links nothing happens (Mac OS X 10.8.4). Sandbox seems to work but the midi player does not.

Thanks

Unable to play a midi correctly.

Hi Matt,

Thanks for your effort to bring midi squencer/syth to web, I'm thinking to use jasmid in my project, however I find it can't play one of our midi correctly. but it do work with other sequencer without problem.

http://69.195.73.224/tcmm070000603.mid.

Can you kindly take a look?

Thanks,
Rick

Why not using jQuery

I notice there is extra code in this project to avoid a dependency on jQuery. I can understand that at one level, but the reality is that when using jQuery there is more JS than there needs to be.

Is this still an objective of the project?

Lyrics with unicode, handling meta events and stopping

hi,
firstly, thanks for this nice framework.

i wanted to also display lyrics in devnagari(indian script) and found that currently it won't work as it is,
due to the x-user-defined charset. so i had to add some conversion code. i also tried another approach with a different version of loadRemote() in index.html, using the arrayBuffer type. then i had to change stream.js accordingly, which i have saved as stream1.js. i think this is a better approach, as to-from encoding conversions are reduced. the "b102_Bhairavi_*.mid file i have used is the test-file for unicode lyrics.
Of course we also need to read and propagate lyrics events in replayer, and i have done it using the handleMidiMetaEvent().

i have also added a stop button by calling the audioplayer.stop().it works, but i wonder if some other clean-up needs to be done.

have attached my change files to this issue.

regards,
manoj

jasmid_fix.zip

Stop playback

How to implement stop playback after playing MIDI file?