CreateWave

Borland C++ Compiler 5.5

CreateWave

#include <math.h>
#include <stdio.h>
#include <windows.h>
#include <mmsystem.h>

// プロトタイプ宣言
int WriteWaveFile(const char *pcFile);
int CreateWave(void);

// グローバル変数
static WAVEFORMATEX	g_wf;
static DWORD		g_dwSampleLength;
static u_char		*g_pucWaveformData = NULL;

int main(int argc, char **argv)
{
	if (argc != 2) {
		fprintf(stderr, "Usage: CreateWave.c file-out\n");
		return 1;
	}

if (CreateWave() != 0) {
		return 1;
	}

WriteWaveFile(argv[1]);

if (g_pucWaveformData != NULL) {
		free(g_pucWaveformData);
	}

return 0;
}

int WriteWaveFile(const char *pcFile)
{
	HMMIO		hmmio;
	MMCKINFO	ckParent;
	MMCKINFO	ckSub;

// Open
	hmmio = mmioOpen((LPSTR)pcFile, NULL, MMIO_WRITE | MMIO_CREATE);
	if (hmmio == NULL) {
		fprintf(stderr, "mmioOpen\n");
		return -1;
	}

// RIFFチャンク
	ckParent.cksize		= 0;	// ダミー
	ckParent.fccType	= mmioFOURCC('W', 'A', 'V', 'E');
	mmioCreateChunk(hmmio, &ckParent, MMIO_CREATERIFF);

// fmtチャンク
	ckSub.ckid	= mmioFOURCC('f', 'm', 't', ' ');
	ckSub.cksize	= sizeof(WAVEFORMATEX);
	mmioCreateChunk(hmmio, &ckSub, 0);

mmioWrite(hmmio, (char *)&g_wf, sizeof(WAVEFORMATEX));
	mmioAscend(hmmio, &ckSub, 0);

// factチャンク
	ckSub.ckid	= mmioFOURCC('f', 'a', 'c', 't');
	ckSub.cksize	= sizeof(DWORD);
	mmioCreateChunk(hmmio, &ckSub, 0);

mmioWrite(hmmio, (char *)&g_dwSampleLength, sizeof(DWORD));
	mmioAscend(hmmio, &ckSub, 0);

// dataチャンク
	ckSub.ckid	= mmioFOURCC('d', 'a', 't', 'a');
	ckSub.cksize	= 0;	// ダミー
	mmioCreateChunk(hmmio, &ckSub, 0);

mmioWrite(hmmio, g_pucWaveformData, g_dwSampleLength);
	mmioAscend(hmmio, &ckSub, 0);

// RIFFチャンク
	mmioAscend(hmmio, &ckParent, 0);

// Close
	mmioFlush(hmmio, 0);
	mmioClose(hmmio, 0);

return 0;
}

int CreateWave(void)
{
	DWORD	dwSamplesPerSec = 8000;	// サンプリングレート
	int	aiScale[] = {0, 2, 3, 5, 7, 8, 10, 12, 14, 15};	// 音階
	int	iScale;
	int	i;
	double	dVol = 64.0;	// ボリューム
	double	dFreq;		// 周波数(Hz)

g_wf.wFormatTag		= WAVE_FORMAT_PCM;
	g_wf.nChannels		= 1;
	g_wf.nSamplesPerSec	= dwSamplesPerSec;
	g_wf.nAvgBytesPerSec	= dwSamplesPerSec * 1 * 1;
	g_wf.nBlockAlign	= 1 * 1;
	g_wf.wBitsPerSample	= 8;
	g_wf.cbSize		= 0;

g_dwSampleLength = 8 * 4000;
	g_pucWaveformData = malloc(g_dwSampleLength);
	if (g_pucWaveformData == NULL) {
		fprintf(stderr, "Error: malloc\n");
		return -1;
	}

for (iScale = 0; iScale < 8; iScale++) {
		dFreq = 440.0 * pow(2.0, aiScale[2 + iScale] / 12.0);
		printf("%f\n", dFreq);
		for (i = 0; i < 4000; i++) {
			g_pucWaveformData[iScale * 4000 + i] = 128 + dVol *
				sin(i * 2.0 * M_PI * dFreq / dwSamplesPerSec);
		}
	}

return 0;
}