pmdmini

pmdmini is a C library with a simple API which can play back MDX chiptunes from the PC-98. The PC-98 was a very popular series of Japanese home computers. With its Yamaha YM2203 or YM2608 sound chip, for which many games and songs were written; the Professional Music Driver (PMD) library was a popular music library created by M. Kajihara. pmdmini allows playing back music written using PMD.

Some sample PMD music can be found at the Modland FTP and at the website of Zun (creator of the Touhou series of games).

Usage

Detailed API documentation is available in the pmdmini.h header file, but the following sample program shows how to use mdxmini to open a file, extract some metadata, and play back music:

// Initializes the library, before performing any other actions.
pmd_init();
// Check if the file is a valid PMD file before doing anything else!
int is_valid = pmd_is_pmd(path_to_file);
if (!is_valid) {
    fprintf(stderr, "Failed to open input file: %s\n", path_to_file);
    return 1;
}

// Before playback begins, call pmd_setrate to set the preferred sampling rate for generated audio.
int playback_rate = 48000;
pmd_setrate(playback_rate);

// Opens the file on disk and prepares the player for playback.
pmd_play(path_to_file, path_to_samples);

// Get the song duration, in whole seconds.
int length = pmd_length_sec();
printf("Song length: %i seconds\n", length);

// pmd_get_title allows the song's title to be fetched; this is usually encoded in Shift-JIS.
char title[1024];
pmd_get_title(title);
printf("Title: %s\n", title);
// The composer is stored separately; this is also Shift-JIS.
char compo[1024];
pmd_get_compo(compo);
printf("Composer: %s\n", title);

// For playback, define a buffer into which we'll render raw PCM data.
int buf_len = 8192;
short buf[buf_len];
// Number of channels, which we'll fetch for display later.
// This is constant for a given song, so just fetch it once.
int number_of_channels = pmd_get_tracks();
printf("Number of channels: %i\n", number_of_channels);
// A buffer into which we'll write information about the notes being played in a given frame.
int notes[32];

int position;

// Track the number of buffers played so far, which is useful to calculate the current position.
int played_buffers = 0;
int finished = 1;

// The playback loop!
while (finished == 1)
{
    // Calculate the song position based on the buffer size and frequency.
    position = played_buffers / (((playback_rate * 16 * 2) / 8) / (buf_len * 2));
    printf("Current position: %i / %i\n", position, length);

    // Render samples into the buffer
    pmd_renderer(buf, buf_len / 2);
    // Check the position against the reported duration to determine if playback is finished
    if (position >= length) {
        finished = 0;
    }

    // Do something with the calculated sample here; this is platform-dependent, so this intro will omit it.

    // Fill the note buffer with information about the notes in the current frame
    pmd_get_current_notes(notes, number_of_channels);

    for (int i = 0; i < number_of_channels; i++) {
        printf("Note for channel %i is %i\n", i, notes[i]);
    }

    // Increment the count of played buffers.
    played_buffers++;
}

// When playback is over, finalize the library's state.
pmd_stop();

Programs using pmdmini

• MDXPLAYER for Android, by BouKiCHi
• ruby-mdxplay
• Paula
• Modizer by yoyofr

Credits

• KAJIHARA Mashahiro - original author of the PMD sound driver for PC-9801
• AGAWA Koji - Maintainer of PMDXMMS, on which pmdmini was based
• PMDWin / C60 - PMD sound engine for Windows, on which PMDXMMS was based
• M88 / cisc - author of OPNA FM sound generator used by PMDWin
• PPZ8 / Ukky - author of PPZ8 PCM driver
• BouKiCHi - author of the pmdmini library, and of the Android mdxplayer
• Misty De Meo - bugfixes and improvements to mdxmini, current maintainer