sample2413.c

/*============================================================

  Test code for emu2413.c

    Write 2 seconds of the piano tone into temp.wav

  gcc -Wall -lm sample2413.c emu2413.c
  (The author had tried to compile on Solaris7 with gcc 2.8.1)

=============================================================*/
#include "emu2413.h"
#include <stdio.h>
#include <time.h>

/*
 * Standard clock = MSX clock
 */
#define MSX_CLK 3579545

#define SAMPLERATE 44100
#define DATALENGTH (SAMPLERATE * 8)

static void WORD(char *buf, uint32_t data) {

  buf[0] = data & 0xff;
  buf[1] = (data & 0xff00) >> 8;
}

static void DWORD(char *buf, uint32_t data) {

  buf[0] = data & 0xff;
  buf[1] = (data & 0xff00) >> 8;
  buf[2] = (data & 0xff0000) >> 16;
  buf[3] = (data & 0xff000000) >> 24;
}

static void chunkID(char *buf, char id[4]) {

  buf[0] = id[0];
  buf[1] = id[1];
  buf[2] = id[2];
  buf[3] = id[3];
}

int main(void) {

  static char wave[DATALENGTH * 2];
  char filename[16] = "temp.wav";
  char header[46];
  int i;
  clock_t start, finish;

  FILE *fp;
  OPLL *opll;

  /*
   * Create WAVE header
   */
  chunkID(header, "RIFF");
  DWORD(header + 4, DATALENGTH * 2 + 36);
  chunkID(header + 8, "WAVE");
  chunkID(header + 12, "fmt ");
  DWORD(header + 16, 16);
  WORD(header + 20, 1);               /* WAVE_FORMAT_PCM */
  WORD(header + 22, 1);               /* channel 1=mono,2=stereo */
  DWORD(header + 24, SAMPLERATE);     /* samplesPerSec */
  DWORD(header + 28, 2 * SAMPLERATE); /* bytesPerSec */
  WORD(header + 32, 2);               /* blockSize */
  WORD(header + 34, 16);              /* bitsPerSample */
  chunkID(header + 36, "data");
  DWORD(header + 40, 2 * DATALENGTH);

  opll = OPLL_new(MSX_CLK, SAMPLERATE);
  OPLL_reset(opll);
  OPLL_writeReg(opll, 0x30, 0x30); /* select PIANO Voice to ch1. */
  OPLL_writeReg(opll, 0x10, 0x80); /* set F-Number(L). */
  OPLL_writeReg(opll, 0x20, 0x15); /* set BLK & F-Number(H) and
                                    * keyon. */

  start = clock();

  i = 0;

  for (i = 0; i < DATALENGTH; i++) {
    WORD(wave + i * 2, OPLL_calc(opll));
  }

  finish = clock();
  OPLL_delete(opll);

  printf("It has been %f sec to calc %d waves.\n", (double)(finish - start) / CLOCKS_PER_SEC, DATALENGTH);
  printf("%f times faster than real YM2413.\n",
         ((double)DATALENGTH / SAMPLERATE) / ((double)(finish - start) / CLOCKS_PER_SEC));

  fp = fopen(filename, "wb");

  if (fp == NULL)
    return 1;

  fwrite(header, 46, 1, fp);
  fwrite(wave, DATALENGTH, 2, fp);

  fclose(fp);

  printf("Wrote : %s\n", filename);

  return 0;
}