unfmt.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "synth.h"

/* unfmt: convert integers on stdin to internal float format */

static int monosrc; /* convert from mono? */
static void conv_u8(void);
static void conv_s8(void);
static void conv_16(void);
static void conv_24(void);
static void conv_32(void);

#define PERCHANNEL(code) (code); if (monosrc) { (code); }

int main(int argc, char *argv[])
{
	int fmt = 2;
	int i;

	/* read options */
	for (i = 1; i < argc; i++)
	{
		     if (!strcmp(argv[i], "-u8")) fmt = 0; /* 8-bit unsigned */
		else if (!strcmp(argv[i], "-s8")) fmt = 1; /* 8-bit signed */
		else if (!strcmp(argv[i], "-16")) fmt = 2; /* 16-bit signed */
		else if (!strcmp(argv[i], "-24")) fmt = 3; /* 24-bit signed */
		else if (!strcmp(argv[i], "-32")) fmt = 4; /* 32-bit signed */
		else if (!strcmp(argv[i], "-mono")) monosrc = 1;
		else if (!strcmp(argv[i], "-help"))
		{
			fprintf(stderr, "options: -u8, -s8, -16, -24, -32, "
				"-mono\n");
			exit(0);
		}
	}

	SET_BINARY_MODE
	if (fmt == 0)
		conv_u8();
	else if (fmt == 1)
		conv_s8();
	else if (fmt == 2)
		conv_16();
	else if (fmt == 3)
		conv_24();
	else if (fmt == 4)
		conv_32();

	return 0;
}

static void conv_u8(void)
{
	float f;
	unsigned char s;
	int c;

	while ((c = getchar()) != EOF)
	{
		s = (unsigned char)c;
		f = s;

		/* Move range from [0, 255] to [-128, 127]. */
		f -= 128.0f;

		/* Squish from [-128, 127] to [-1, 1). */
		f /= 128.0f;

		PERCHANNEL(fwrite(&f, sizeof f, 1, stdout))
	}
}

static void conv_s8(void)
{
	float f;
	signed char s;
	int c;

	while ((c = getchar()) != EOF)
	{
		s = (signed char)c;
		f = s;

		/* Squish from [-128, 127] to [-1, 1). */
		f /= 128.0f;

		PERCHANNEL(fwrite(&f, sizeof f, 1, stdout))
	}
}

static void conv_16(void)
{
	float f;
	short s;

	while (fread(&s, sizeof s, 1, stdin) == 1)
	{
		f = s;

		/* Squish from [-32768, 32767] to [-1, 1). */
		f /= 32768.0f;

		PERCHANNEL(fwrite(&f, sizeof f, 1, stdout))
	}
}

static void conv_24(void)
{
	float f;
	double d;
	int s;
	unsigned char *sr;
	int c;

	sr = (unsigned char *)&s;

	for (;;)
	{
#if !WORDS_BIGENDIAN
		if ((c = getchar()) == EOF) return;
		sr[0] = c;
#endif
		if ((c = getchar()) == EOF) return;
		sr[1] = c;
		if ((c = getchar()) == EOF) return;
		sr[2] = c;
#if WORDS_BIGENDIAN
		if ((c = getchar()) == EOF) return;
		sr[3] = c;
		sr[0] = (sr[1] & 0x80) ? 0xff : 0;
#else
		sr[3] = (sr[2] & 0x80) ? 0xff : 0;
#endif

		d = (double)s;

		/* Squish from [-8388608, 8388607] to [-1, 1). */
		d /= 8388608.0f;

		f = (float)d;

		PERCHANNEL(fwrite(&f, sizeof f, 1, stdout))
	}
}

static void conv_32(void)
{
	float f;
	double d;
	int s;

	while (fread(&s, sizeof s, 1, stdin) == 1)
	{
		d = (double)s;

		/* Squish from [-2147483648, 2147483647] to [-1, 1). */
		d /= 2147483648.0f;

		f = (float)d;

		PERCHANNEL(fwrite(&f, sizeof f, 1, stdout))
	}
}