SPP MSB and LSB reset to 0 after beat 1024 — not a bug, but driving me crazy! What I'm missing?

[centomila]

I'm working on a project written in Svelte (TypeScript) using the awesome WebMidi library. 😉

My project successfully receives SPP (Song Position Pointer) messages and converts them into seconds using the following function:

function sppArrayToTime(midiData: MessageEvent, bpm: number) {
    console.log('SPP message received: ', midiData.data);
    // Extract the LSB and MSB from the array
    const lsb = midiData.data[1]; // Least significant byte
    const msb = midiData.data[2]; // Most significant byte

    console.log({ lsb, msb });

    // Calculate the 14-bit SPP value from the LSB and MSB
    const sppValue = (msb << 7) | lsb; // Combine MSB and LSB to get the SPP value

    // Convert the SPP value to time in seconds
    const timeInSeconds = (sppValue * 60) / Math.round(bpm * 4);

    // Calculate hours, minutes, seconds, and milliseconds as floating-point values
    const hours = timeInSeconds / 3600;
    const minutes = (timeInSeconds % 3600) / 60;
    const seconds = timeInSeconds % 60;
    const milliseconds = (timeInSeconds % 1) * 1000;

    sppData.update((data: SPPData) => ({
        ...data,
        hours,
        minutes,
        seconds,
        milliseconds,
        seekPosition: timeInSeconds,
        secondsOnSPP: timeInSeconds
    }));

}

Everything works fine when the tempo starts from beat 0 up to 1024. However, when I try to start from beat 1025 (which is 34:08 at 120 bpm), both the LSB and MSB are 0.

I suspect this might be due to a byte size limitation, but my understanding and research have reached a dead end.

Is this a known limitation in MIDI? I haven't been able to find any information about it. I've tested with different DAWs and MIDI loop ports, but the issue persists. Is there an obvious workaround I'm missing?

[centomila]

After further research, I found that this behavior is a limitation of the MIDI protocol