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Implement ESPCM_4 recording

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This commit is contained in:
Kagamiin~
2024-03-13 19:28:12 -03:00
parent 416edcf1a5
commit 6fc43a8082
2 changed files with 90 additions and 4 deletions
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7
src/include/86box/snd_sb_dsp.h
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@@ -152,9 +152,10 @@ typedef struct sb_dsp_t {
uint8_t espcm_sample_idx;
uint8_t espcm_range;
uint8_t espcm_byte_buffer[4];
uint8_t espcm_code_buffer[10]; /* used for ESPCM_3 */
uint8_t espcm_table_index; /* used for ESPCM_3 */
uint8_t espcm_last_value; /* used for ESPCM_3 */
uint8_t espcm_code_buffer[19]; /* used for ESPCM_3 and for ESPCM_4 recording */
int8_t espcm_sample_buffer[19]; /* used for ESPCM_4 recording */
uint8_t espcm_table_index; /* used for ESPCM_3 */
uint8_t espcm_last_value; /* used for ESPCM_3 */
mpu_t *mpu;
} sb_dsp_t;

87
src/sound/snd_sb_dsp.c
View File

@@ -124,7 +124,7 @@ uint8_t adjustMap2[24] = {
* This current table is part software reverse engineering, part guesswork/extrapolation.
* It's close enough to what's in the chip to produce acceptable results, but not exact.
**/
uint8_t espcm_range_map[512] = {
int8_t espcm_range_map[512] = {
-8, -7, -6, -5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5, 6, 7,
-10, -8, -7, -5, -4, -3, -2, -1, 0, 2, 3, 4, 5, 6, 8, 9,
-12, -11, -9, -8, -6, -5, -3, -2, 0, 2, 3, 5, 6, 8, 10, 11,
@@ -2331,6 +2331,7 @@ pollsb(void *priv)
}
dsp->espcm_table_index = dsp->espcm_byte_buffer[0] & 0x03;
dsp->espcm_code_buffer[0] = (dsp->espcm_byte_buffer[0] >> 2) & 0x07;
dsp->espcm_code_buffer[1] = (dsp->espcm_byte_buffer[0] >> 5) & 0x07;
dsp->espcm_code_buffer[2] = (dsp->espcm_byte_buffer[1]) & 0x07;
@@ -2613,6 +2614,90 @@ sb_poll_i(void *priv)
dsp->record_pos_read += 2;
dsp->record_pos_read &= 0xFFFF;
break;
case ESPCM_4:
// I assume the real hardware double-buffers the blocks or something like that.
// We're not gonna do that here.
dsp->espcm_sample_buffer[dsp->espcm_sample_idx] = dsp->record_buffer[dsp->record_pos_read] >> 8;
dsp->espcm_sample_idx++;
dsp->record_pos_read += 2;
dsp->record_pos_read &= 0xFFFF;
if (dsp->espcm_sample_idx >= 19)
{
int i, bit, table_addr, sigma, last_sigma;
int8_t min_sample = 127, max_sample = -128, s;
uint8_t b;
for (i = 0; i < 19; i++)
{
s = dsp->espcm_sample_buffer[i];
if (s < min_sample)
{
min_sample = s;
}
if (s > max_sample)
{
max_sample = s;
}
}
if (min_sample < 0)
{
min_sample = -min_sample;
}
if (max_sample < 0)
{
max_sample = -max_sample;
}
if (min_sample > max_sample)
{
max_sample = min_sample;
}
for (table_addr = 15; table_addr < 256; table_addr += 16)
{
if (max_sample <= espcm_range_map[table_addr])
{
break;
}
}
dsp->espcm_range = table_addr >> 4;
for (i = 0; i < 19; i++)
{
table_addr = dsp->espcm_range << 4;
last_sigma = 9999;
s = dsp->espcm_sample_buffer[i];
for (; (table_addr >> 4) == dsp->espcm_range; table_addr++)
{
sigma = espcm_range_map[table_addr] - s;
if (sigma < 0)
{
sigma = -sigma;
}
if (sigma > last_sigma)
{
break;
}
last_sigma = sigma;
}
table_addr--;
dsp->espcm_code_buffer[i] = table_addr & 0x0F;
}
b = dsp->espcm_range | (dsp->espcm_code_buffer[0] << 4);
dsp->dma_writeb(dsp->dma_priv, b);
dsp->sb_8_length--;
dsp->ess_dma_counter++;
for (i = 1; i < 10; i++)
{
b = dsp->espcm_code_buffer[i * 2 - 1] | (dsp->espcm_code_buffer[i * 2] << 4);
dsp->dma_writeb(dsp->dma_priv, b);
dsp->sb_8_length--;
dsp->ess_dma_counter++;
}
dsp->espcm_sample_idx = 0;
}
default:
break;