apex-mix/wav_convert.c

#include "wav_convert.h"

typedef union wav_u
{
	uint8_t u8[4];
	uint16_t u16[2];
	uint32_t u32;
} wav_u;

uint32_t endian_swap32(uint32_t in)
{
	wav_u un;
	uint8_t u8[4];

	un.u32 = in;
	for (int i = 0; i < 4; ++i)
	{
		u8[i] = un.u8[3 - i];
	}

	for (int i = 0; i < 4; ++i)
	{
		un.u8[i] = u8[i];
	}

	return un.u32;
}

uint16_t endian_swap16(uint16_t in)
{
	wav_u un;
	uint8_t u8[2];

	un.u16[0] = in;
	for (int i = 0; i < 2; ++i)
	{
		u8[i] = un.u8[1 - i];
	}

	for (int i = 0; i < 2; ++i)
	{
		un.u8[i] = u8[i];
	}

	return un.u16[0];
}

void wavtoh32(uint8_t* in, uint32_t* out, uint8_t is_be)
{
	wav_u un;
	for (int i = 0; i < 4; ++i)
	{
		un.u8[i] = in[i];
	}

	if (0 == is_be)
	{
		*out = un.u32;
	}
	else
	{
		*out = endian_swap32(un.u32);
	}
}

void wavtoh24(uint8_t* in, uint32_t* out, uint8_t is_be)
{
	wav_u un;
	int adjust;

	if (0 == is_be)
	{
		adjust = 0;
		un.u8[3] = 0;
	}
	else
	{
		adjust = 1;
		un.u8[0] = 0;
	}

	for (int i = 0; i < 3; ++i)
	{
		un.u8[i + adjust] = in[i];
	}

	if (0 == is_be)
	{
		*out = un.u32;
	}
	else
	{
		*out = endian_swap32(un.u32);
	}
}

void wavtoh16(uint8_t* in, uint16_t* out, uint8_t is_be)
{
	wav_u un;
	for (int i = 0; i < 2; ++i)
	{
		un.u8[i] = in[i];
	}

	if (0 == is_be)
	{
		*out = un.u16[0];
	}
	else
	{
		*out = endian_swap16(un.u16[0]);
	}
}

void htowav32(uint32_t* in, uint8_t* out, uint8_t is_be)
{
	wav_u un;
	if (0 == is_be)
	{
		un.u32 = *in;
	}
	else
	{
		un.u32 = endian_swap32(*in);
	}

	for (int i = 0; i < 4; ++i)
	{
		out[i] = un.u8[i];
	}
}

void htowav24(uint32_t* in, uint8_t* out, uint8_t is_be)
{
	wav_u un;
	if (0 == is_be)
	{
		un.u32 = *in;
	}
	else
	{
		un.u32 = endian_swap32(*in);
	}

	for (int i = 0; i < 4; ++i)
	{
		out[i] = un.u8[i];
	}
}

void htowav16(uint16_t* in, uint8_t* out, uint8_t is_be)
{
	wav_u un;
	if (0 == is_be)
	{
		un.u16[0] = *in;
	}
	else
	{
		un.u16[0] = endian_swap16(*in);
	}

	for (int i = 0; i < 2; ++i)
	{
		out[i] = un.u8[i];
	}
}