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// license:BSD-3-Clause
// copyright-holders:Andrew Gardner,Aaron Giles
/***************************************************************************
okiadpcm.h
OKI ADCPM emulation.
***************************************************************************/
#ifndef MAME_SOUND_OKIADPCM_H
#define MAME_SOUND_OKIADPCM_H
#pragma once
// ======================> oki_adpcm_state
// Internal ADPCM state, used by external ADPCM generators with compatible specs to the OKIM 6295.
class oki_adpcm_state
{
public:
oki_adpcm_state() { compute_tables(); reset(); }
void reset();
int16_t clock(uint8_t nibble);
int16_t output() { return m_signal; }
void save();
void restore();
int32_t m_signal;
int32_t m_step;
int32_t m_loop_signal;
int32_t m_loop_step;
bool m_saved;
private:
static const int8_t s_index_shift[8];
static int s_diff_lookup[49*16];
static void compute_tables();
static bool s_tables_computed;
};
// ======================> oki_adpcm2_state
// Internal ADPCM2 state, used by external ADPCM generators with compatible specs to the OKI MSM9810.
// TODO: not thoroughly tested: is the output 15 bit?
class oki_adpcm2_state
{
public:
oki_adpcm2_state() { compute_tables(); reset(); }
void reset();
int16_t clock(uint8_t nibble);
int16_t output() { return m_signal; }
void save();
void restore();
int32_t m_signal;
int32_t m_step;
int32_t m_loop_signal;
int32_t m_loop_step;
bool m_saved;
private:
static const int8_t s_index_shift[8];
static int s_diff_lookup[49*16];
static void compute_tables();
static bool s_tables_computed;
};
#endif // MAME_SOUND_OKIADPCM_H
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