mame/src/emu/sound/okim6295.c
2008-07-28 16:22:20 +00:00

673 lines
17 KiB
C

/**********************************************************************************************
*
* streaming ADPCM driver
* by Aaron Giles
*
* Library to transcode from an ADPCM source to raw PCM.
* Written by Buffoni Mirko in 08/06/97
* References: various sources and documents.
*
* HJB 08/31/98
* modified to use an automatically selected oversampling factor
* for the current sample rate
*
* Mish 21/7/99
* Updated to allow multiple OKI chips with different sample rates
*
* R. Belmont 31/10/2003
* Updated to allow a driver to use both MSM6295s and "raw" ADPCM voices (gcpinbal)
* Also added some error trapping for MAME_DEBUG builds
*
**********************************************************************************************/
#include <math.h>
#include "sndintrf.h"
#include "deprecat.h"
#include "streams.h"
#include "okim6295.h"
#define MAX_SAMPLE_CHUNK 10000
/* struct describing a single playing ADPCM voice */
struct ADPCMVoice
{
UINT8 playing; /* 1 if we are actively playing */
UINT32 base_offset; /* pointer to the base memory location */
UINT32 sample; /* current sample number */
UINT32 count; /* total samples to play */
struct adpcm_state adpcm;/* current ADPCM state */
UINT32 volume; /* output volume */
};
struct okim6295
{
#define OKIM6295_VOICES 4
struct ADPCMVoice voice[OKIM6295_VOICES];
INT32 command;
INT32 bank_offset;
UINT8 *region_base; /* pointer to the base of the region */
sound_stream *stream; /* which stream are we playing on? */
UINT32 master_clock; /* master clock frequency */
};
/* step size index shift table */
static const int index_shift[8] = { -1, -1, -1, -1, 2, 4, 6, 8 };
/* lookup table for the precomputed difference */
static int diff_lookup[49*16];
/* volume lookup table */
static UINT32 volume_table[16];
/* tables computed? */
static int tables_computed = 0;
/* useful interfaces */
const struct OKIM6295interface okim6295_interface_pin7high = { 1 };
const struct OKIM6295interface okim6295_interface_pin7low = { 0 };
/**********************************************************************************************
compute_tables -- compute the difference tables
***********************************************************************************************/
static void compute_tables(void)
{
/* nibble to bit map */
static const int nbl2bit[16][4] =
{
{ 1, 0, 0, 0}, { 1, 0, 0, 1}, { 1, 0, 1, 0}, { 1, 0, 1, 1},
{ 1, 1, 0, 0}, { 1, 1, 0, 1}, { 1, 1, 1, 0}, { 1, 1, 1, 1},
{-1, 0, 0, 0}, {-1, 0, 0, 1}, {-1, 0, 1, 0}, {-1, 0, 1, 1},
{-1, 1, 0, 0}, {-1, 1, 0, 1}, {-1, 1, 1, 0}, {-1, 1, 1, 1}
};
int step, nib;
/* loop over all possible steps */
for (step = 0; step <= 48; step++)
{
/* compute the step value */
int stepval = floor(16.0 * pow(11.0 / 10.0, (double)step));
/* loop over all nibbles and compute the difference */
for (nib = 0; nib < 16; nib++)
{
diff_lookup[step*16 + nib] = nbl2bit[nib][0] *
(stepval * nbl2bit[nib][1] +
stepval/2 * nbl2bit[nib][2] +
stepval/4 * nbl2bit[nib][3] +
stepval/8);
}
}
/* generate the OKI6295 volume table */
for (step = 0; step < 16; step++)
{
double out = 256.0;
int vol = step;
/* 3dB per step */
while (vol-- > 0)
out /= 1.412537545; /* = 10 ^ (3/20) = 3dB */
volume_table[step] = (UINT32)out;
}
tables_computed = 1;
}
/**********************************************************************************************
reset_adpcm -- reset the ADPCM stream
***********************************************************************************************/
void reset_adpcm(struct adpcm_state *state)
{
/* make sure we have our tables */
if (!tables_computed)
compute_tables();
/* reset the signal/step */
state->signal = -2;
state->step = 0;
}
/**********************************************************************************************
clock_adpcm -- clock the next ADPCM byte
***********************************************************************************************/
INT16 clock_adpcm(struct adpcm_state *state, UINT8 nibble)
{
state->signal += diff_lookup[state->step * 16 + (nibble & 15)];
/* clamp to the maximum */
if (state->signal > 2047)
state->signal = 2047;
else if (state->signal < -2048)
state->signal = -2048;
/* adjust the step size and clamp */
state->step += index_shift[nibble & 7];
if (state->step > 48)
state->step = 48;
else if (state->step < 0)
state->step = 0;
/* return the signal scaled up to 32767 */
return state->signal << 4;
}
/**********************************************************************************************
generate_adpcm -- general ADPCM decoding routine
***********************************************************************************************/
static void generate_adpcm(struct okim6295 *chip, struct ADPCMVoice *voice, INT16 *buffer, int samples)
{
/* if this voice is active */
if (voice->playing)
{
UINT8 *base = chip->region_base + chip->bank_offset + voice->base_offset;
int sample = voice->sample;
int count = voice->count;
/* loop while we still have samples to generate */
while (samples)
{
/* compute the new amplitude and update the current step */
int nibble = base[sample / 2] >> (((sample & 1) << 2) ^ 4);
/* output to the buffer, scaling by the volume */
*buffer++ = clock_adpcm(&voice->adpcm, nibble) * voice->volume / 256;
samples--;
/* next! */
if (++sample >= count)
{
voice->playing = 0;
break;
}
}
/* update the parameters */
voice->sample = sample;
}
/* fill the rest with silence */
while (samples--)
*buffer++ = 0;
}
/**********************************************************************************************
*
* OKIM 6295 ADPCM chip:
*
* Command bytes are sent:
*
* 1xxx xxxx = start of 2-byte command sequence, xxxxxxx is the sample number to trigger
* abcd vvvv = second half of command; one of the abcd bits is set to indicate which voice
* the v bits seem to be volumed
*
* 0abc d000 = stop playing; one or more of the abcd bits is set to indicate which voice(s)
*
* Status is read:
*
* ???? abcd = one bit per voice, set to 0 if nothing is playing, or 1 if it is active
*
***********************************************************************************************/
/**********************************************************************************************
okim6295_update -- update the sound chip so that it is in sync with CPU execution
***********************************************************************************************/
static void okim6295_update(void *param, stream_sample_t **inputs, stream_sample_t **outputs, int samples)
{
struct okim6295 *chip = param;
int i;
memset(outputs[0], 0, samples * sizeof(*outputs[0]));
for (i = 0; i < OKIM6295_VOICES; i++)
{
struct ADPCMVoice *voice = &chip->voice[i];
stream_sample_t *buffer = outputs[0];
INT16 sample_data[MAX_SAMPLE_CHUNK];
int remaining = samples;
/* loop while we have samples remaining */
while (remaining)
{
int samples = (remaining > MAX_SAMPLE_CHUNK) ? MAX_SAMPLE_CHUNK : remaining;
int samp;
generate_adpcm(chip, voice, sample_data, samples);
for (samp = 0; samp < samples; samp++)
*buffer++ += sample_data[samp];
remaining -= samples;
}
}
}
/**********************************************************************************************
state save support for MAME
***********************************************************************************************/
static void adpcm_state_save_register(struct ADPCMVoice *voice, int i)
{
char buf[20];
sprintf(buf,"ADPCM");
state_save_register_item(buf, i, voice->playing);
state_save_register_item(buf, i, voice->sample);
state_save_register_item(buf, i, voice->count);
state_save_register_item(buf, i, voice->adpcm.signal);
state_save_register_item(buf, i, voice->adpcm.step);
state_save_register_item(buf, i, voice->volume);
state_save_register_item(buf, i, voice->base_offset);
}
static void okim6295_state_save_register(struct okim6295 *info, int sndindex)
{
int j;
char buf[20];
sprintf(buf,"OKIM6295");
state_save_register_item(buf, sndindex, info->command);
state_save_register_item(buf, sndindex, info->bank_offset);
for (j = 0; j < OKIM6295_VOICES; j++)
adpcm_state_save_register(&info->voice[j], sndindex * 4 + j);
}
/**********************************************************************************************
OKIM6295_start -- start emulation of an OKIM6295-compatible chip
***********************************************************************************************/
static void *okim6295_start(const char *tag, int sndindex, int clock, const void *config)
{
const struct OKIM6295interface *intf = config;
struct okim6295 *info;
int voice;
int divisor = intf->pin7 ? 132 : 165;
info = auto_malloc(sizeof(*info));
memset(info, 0, sizeof(*info));
compute_tables();
info->command = -1;
info->bank_offset = 0;
info->region_base = memory_region(Machine, (intf->rgnoverride != NULL) ? intf->rgnoverride : tag);
info->master_clock = clock;
/* generate the name and create the stream */
info->stream = stream_create(0, 1, clock/divisor, info, okim6295_update);
/* initialize the voices */
for (voice = 0; voice < OKIM6295_VOICES; voice++)
{
/* initialize the rest of the structure */
info->voice[voice].volume = 255;
reset_adpcm(&info->voice[voice].adpcm);
}
okim6295_state_save_register(info, sndindex);
/* success */
return info;
}
/**********************************************************************************************
OKIM6295_stop -- stop emulation of an OKIM6295-compatible chip
***********************************************************************************************/
static void okim6295_reset(void *chip)
{
struct okim6295 *info = chip;
int i;
stream_update(info->stream);
for (i = 0; i < OKIM6295_VOICES; i++)
info->voice[i].playing = 0;
}
/**********************************************************************************************
OKIM6295_set_bank_base -- set the base of the bank for a given voice on a given chip
***********************************************************************************************/
void OKIM6295_set_bank_base(int which, int base)
{
struct okim6295 *info = sndti_token(SOUND_OKIM6295, which);
stream_update(info->stream);
info->bank_offset = base;
}
/**********************************************************************************************
OKIM6295_set_pin7 -- adjust pin 7, which controls the internal clock division
***********************************************************************************************/
void OKIM6295_set_pin7(int which, int pin7)
{
struct okim6295 *info = sndti_token(SOUND_OKIM6295, which);
int divisor = pin7 ? 132 : 165;
stream_set_sample_rate(info->stream, info->master_clock/divisor);
}
/**********************************************************************************************
OKIM6295_status_r -- read the status port of an OKIM6295-compatible chip
***********************************************************************************************/
static int OKIM6295_status_r(int num)
{
struct okim6295 *info = sndti_token(SOUND_OKIM6295, num);
int i, result;
result = 0xf0; /* naname expects bits 4-7 to be 1 */
/* set the bit to 1 if something is playing on a given channel */
stream_update(info->stream);
for (i = 0; i < OKIM6295_VOICES; i++)
{
struct ADPCMVoice *voice = &info->voice[i];
/* set the bit if it's playing */
if (voice->playing)
result |= 1 << i;
}
return result;
}
/**********************************************************************************************
OKIM6295_data_w -- write to the data port of an OKIM6295-compatible chip
***********************************************************************************************/
static void OKIM6295_data_w(int num, int data)
{
struct okim6295 *info = sndti_token(SOUND_OKIM6295, num);
/* if a command is pending, process the second half */
if (info->command != -1)
{
int temp = data >> 4, i, start, stop;
unsigned char *base;
/* update the stream */
stream_update(info->stream);
/* determine which voice(s) (voice is set by a 1 bit in the upper 4 bits of the second byte) */
for (i = 0; i < OKIM6295_VOICES; i++, temp >>= 1)
{
if (temp & 1)
{
struct ADPCMVoice *voice = &info->voice[i];
/* determine the start/stop positions */
base = &info->region_base[info->bank_offset + info->command * 8];
start = ((base[0] << 16) + (base[1] << 8) + base[2]) & 0x3ffff;
stop = ((base[3] << 16) + (base[4] << 8) + base[5]) & 0x3ffff;
/* set up the voice to play this sample */
if (start < stop)
{
if (!voice->playing) /* fixes Got-cha and Steel Force */
{
voice->playing = 1;
voice->base_offset = start;
voice->sample = 0;
voice->count = 2 * (stop - start + 1);
/* also reset the ADPCM parameters */
reset_adpcm(&voice->adpcm);
voice->volume = volume_table[data & 0x0f];
}
else
{
logerror("OKIM6295:%d requested to play sample %02x on non-stopped voice\n",num,info->command);
}
}
/* invalid samples go here */
else
{
logerror("OKIM6295:%d requested to play invalid sample %02x\n",num,info->command);
voice->playing = 0;
}
}
}
/* reset the command */
info->command = -1;
}
/* if this is the start of a command, remember the sample number for next time */
else if (data & 0x80)
{
info->command = data & 0x7f;
}
/* otherwise, see if this is a silence command */
else
{
int temp = data >> 3, i;
/* update the stream, then turn it off */
stream_update(info->stream);
/* determine which voice(s) (voice is set by a 1 bit in bits 3-6 of the command */
for (i = 0; i < 4; i++, temp >>= 1)
{
if (temp & 1)
{
struct ADPCMVoice *voice = &info->voice[i];
voice->playing = 0;
}
}
}
}
/**********************************************************************************************
OKIM6295_status_0_r -- generic status read functions
OKIM6295_status_1_r
***********************************************************************************************/
READ8_HANDLER( OKIM6295_status_0_r )
{
return OKIM6295_status_r(0);
}
READ8_HANDLER( OKIM6295_status_1_r )
{
return OKIM6295_status_r(1);
}
READ8_HANDLER( OKIM6295_status_2_r )
{
return OKIM6295_status_r(2);
}
READ16_HANDLER( OKIM6295_status_0_lsb_r )
{
return OKIM6295_status_r(0);
}
READ16_HANDLER( OKIM6295_status_1_lsb_r )
{
return OKIM6295_status_r(1);
}
READ16_HANDLER( OKIM6295_status_2_lsb_r )
{
return OKIM6295_status_r(2);
}
READ16_HANDLER( OKIM6295_status_0_msb_r )
{
return OKIM6295_status_r(0) << 8;
}
READ16_HANDLER( OKIM6295_status_1_msb_r )
{
return OKIM6295_status_r(1) << 8;
}
READ16_HANDLER( OKIM6295_status_2_msb_r )
{
return OKIM6295_status_r(2) << 8;
}
/**********************************************************************************************
OKIM6295_data_0_w -- generic data write functions
OKIM6295_data_1_w
***********************************************************************************************/
WRITE8_HANDLER( OKIM6295_data_0_w )
{
OKIM6295_data_w(0, data);
}
WRITE8_HANDLER( OKIM6295_data_1_w )
{
OKIM6295_data_w(1, data);
}
WRITE8_HANDLER( OKIM6295_data_2_w )
{
OKIM6295_data_w(2, data);
}
WRITE16_HANDLER( OKIM6295_data_0_lsb_w )
{
if (ACCESSING_BITS_0_7)
OKIM6295_data_w(0, data & 0xff);
}
WRITE16_HANDLER( OKIM6295_data_1_lsb_w )
{
if (ACCESSING_BITS_0_7)
OKIM6295_data_w(1, data & 0xff);
}
WRITE16_HANDLER( OKIM6295_data_2_lsb_w )
{
if (ACCESSING_BITS_0_7)
OKIM6295_data_w(2, data & 0xff);
}
WRITE16_HANDLER( OKIM6295_data_0_msb_w )
{
if (ACCESSING_BITS_8_15)
OKIM6295_data_w(0, data >> 8);
}
WRITE16_HANDLER( OKIM6295_data_1_msb_w )
{
if (ACCESSING_BITS_8_15)
OKIM6295_data_w(1, data >> 8);
}
WRITE16_HANDLER( OKIM6295_data_2_msb_w )
{
if (ACCESSING_BITS_8_15)
OKIM6295_data_w(2, data >> 8);
}
/**************************************************************************
* Generic get_info
**************************************************************************/
static void okim6295_set_info(void *token, UINT32 state, sndinfo *info)
{
switch (state)
{
/* no parameters to set */
}
}
void okim6295_get_info(void *token, UINT32 state, sndinfo *info)
{
switch (state)
{
/* --- the following bits of info are returned as 64-bit signed integers --- */
/* --- the following bits of info are returned as pointers to data or functions --- */
case SNDINFO_PTR_SET_INFO: info->set_info = okim6295_set_info; break;
case SNDINFO_PTR_START: info->start = okim6295_start; break;
case SNDINFO_PTR_STOP: /* nothing */ break;
case SNDINFO_PTR_RESET: info->reset = okim6295_reset; break;
/* --- the following bits of info are returned as NULL-terminated strings --- */
case SNDINFO_STR_NAME: info->s = "OKI6295"; break;
case SNDINFO_STR_CORE_FAMILY: info->s = "OKI ADPCM"; break;
case SNDINFO_STR_CORE_VERSION: info->s = "1.0"; break;
case SNDINFO_STR_CORE_FILE: info->s = __FILE__; break;
case SNDINFO_STR_CORE_CREDITS: info->s = "Copyright Nicola Salmoria and the MAME Team"; break;
}
}