fix buzzing sound in audio

This commit is contained in:
Michael Hahn
2021-01-16 19:45:24 -05:00
parent 3d38cd1c79
commit e8ae39f00c
+11 -272
View File
@@ -1,276 +1,15 @@
/*
* votraxsnd.c - Atari800 interface to votrax.c
*
* Copyright (C) 2007-2010 Atari800 development team (see DOC/CREDITS)
*
* This file is part of the Atari800 emulator project which emulates
* the Atari 400, 800, 800XL, 130XE, and 5200 8-bit computers.
*
* Atari800 is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* Atari800 is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with Atari800; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#ifndef VOTRAXSND_H_
#define VOTRAXSND_H_
#include <stdio.h>
#include <stdlib.h>
#include "atari.h"
#include "util.h"
#include "votraxsnd.h"
#ifdef PBI_XLD
#include "pbi_xld.h"
#endif
#ifdef VOICEBOX
#include "voicebox.h"
#endif
#include "pokey.h"
#include "log.h"
#include "votrax.h"
/* Votrax */
#define VTRX_RATE 24500
static double ratio;
static int bit16;
#define VTRX_BLOCK_SIZE 1024
SWORD *temp_votrax_buffer = NULL;
SWORD *votrax_buffer = NULL;
int VOTRAXSND_busy = FALSE;
static int votrax_sync_samples;
static int dsprate;
static int num_pokeys;
static int samples_per_frame;
/*if SYNCHRONIZED_SOUND is not used and the sound generation runs in a
* separate thread, then these variables are accessed in two different
* threads: */
static int votrax_written = FALSE;
static int votrax_written_byte = 0x3f;
void VOTRAXSND_PutByte(UBYTE byte)
{
/* put byte to voice box */
votrax_sync_samples = (int)((1.0/ratio)*(double)Votrax_Samples((votrax_written_byte&0x3f), (byte&0x3f), votrax_sync_samples));
votrax_written = TRUE;
votrax_written_byte = byte;
if (!VOTRAXSND_busy) {
VOTRAXSND_busy = TRUE;
#ifdef PBI_XLD
if (PBI_XLD_enabled) {
PBI_XLD_votrax_busy_callback(TRUE); /* idle -> busy */
}
#endif
}
}
static void VOTRAXSND_busy_callback_async(int busy_status)
{
return;
/* do nothing */
}
static int votraxsnd_enabled(void)
{
if (
#ifdef VOICEBOX
!VOICEBOX_enabled &&
#endif
#ifdef PBI_XLD
!PBI_XLD_v_enabled &&
#endif
1) return FALSE;
else return TRUE;
}
/* called from POKEYSND_Init */
void VOTRAXSND_Init(int playback_freq, int n_pokeys, int b16)
{
static struct Votrax_interface vi;
int temp_votrax_buffer_size;
bit16 = b16;
dsprate = playback_freq;
num_pokeys = n_pokeys;
if (!votraxsnd_enabled()) return;
if (num_pokeys != 1 && num_pokeys != 2) {
Log_print("VOTRAXSND_Init: cannot handle num_pokeys=%d", num_pokeys);
#ifdef PBI_XLD
PBI_XLD_v_enabled = FALSE;
#endif
#ifdef VOICEBOX
VOICEBOX_enabled = FALSE;
#endif
return;
}
vi.num = 1;
vi.BusyCallback = VOTRAXSND_busy_callback_async;
Votrax_Stop();
Votrax_Start((void *)&vi);
samples_per_frame = dsprate/(Atari800_tv_mode == Atari800_TV_PAL ? 50 : 60);
ratio = (double)VTRX_RATE/(double)dsprate;
#ifdef VOICEBOX
temp_votrax_buffer_size = (int)(VTRX_BLOCK_SIZE*ratio*(VOICEBOX_BASEAUDF+1) + 10); /* +10 .. little extra? */
#else
temp_votrax_buffer_size = (int)(VTRX_BLOCK_SIZE*ratio + 10); /* +10 .. little extra? */
#endif
free(temp_votrax_buffer);
temp_votrax_buffer = (SWORD *)Util_malloc(temp_votrax_buffer_size*sizeof(SWORD));
free(votrax_buffer);
votrax_buffer = (SWORD *)Util_malloc(VTRX_BLOCK_SIZE*sizeof(SWORD));
VOTRAXSND_busy = FALSE;
votrax_sync_samples = 0;
}
void VOTRAXSND_Reinit(void)
{
if (dsprate) VOTRAXSND_Init(dsprate, num_pokeys, bit16);
}
/* process votrax and interpolate samples */
static void votrax_process(SWORD *v_buffer, int len, SWORD *temp_v_buffer)
{
static SWORD last_sample;
static SWORD last_sample2;
static double startpos;
static int have;
int max_left_sample_index = (int)(startpos + (double)(len - 1)*ratio);
int pos = 0;
double fraction = 0;
int i;
int floor_next_pos;
if (have == 2) {
temp_v_buffer[0] = last_sample;
temp_v_buffer[1] = last_sample2;
Votrax_Update(0, temp_v_buffer + 2, (max_left_sample_index + 1 + 1) - 2);
}
else if (have == 1) {
temp_v_buffer[0] = last_sample;
Votrax_Update(0, temp_v_buffer + 1, (max_left_sample_index + 1 + 1) - 1);
}
else if (have == 0) {
Votrax_Update(0, temp_v_buffer, max_left_sample_index + 1 + 1);
}
else if (have < 0) {
Votrax_Update(0, temp_v_buffer, -have);
Votrax_Update(0, temp_v_buffer, max_left_sample_index + 1 + 1);
}
for (i = 0; i < len; i++) {
SWORD left_sample;
SWORD right_sample;
SWORD interp_sample;
pos = (int)(startpos + (double)i*ratio);
fraction = startpos + (double)i*ratio - (double)pos;
left_sample = temp_v_buffer[pos];
right_sample = temp_v_buffer[pos+1];
interp_sample = (int)(left_sample + fraction*(double)(right_sample-left_sample));
v_buffer[i] = interp_sample;
}
floor_next_pos = (int)(startpos + (double)len*ratio);
startpos = (startpos + (double)len*ratio) - (double)floor_next_pos;
if (floor_next_pos == max_left_sample_index)
{
have = 2;
last_sample = temp_v_buffer[floor_next_pos];
last_sample2 = temp_v_buffer[floor_next_pos+1];
}
else if (floor_next_pos == max_left_sample_index + 1) {
have = 1;
last_sample = temp_v_buffer[floor_next_pos];
}
else {
have = (floor_next_pos - (max_left_sample_index + 2));
}
}
/* 16 bit mixing */
static void mix(SWORD *dst, SWORD *src, int sndn, int volume)
{
SWORD s1, s2;
int val;
while (sndn--) {
s1 = *src;
s1 = s1*volume/128;
s2 = *dst;
src++;
val = s1 + s2;
if (val > 32767) val = 32767;
if (val < -32768) val = -32768;
*dst++ = val;
if (num_pokeys == 2) {
dst++;
}
}
}
/* 8 bit mixing */
static void mix8(UBYTE *dst, SWORD *src, int sndn, int volume)
{
SWORD s1, s2;
int val;
while (sndn--) {
s1 = *src;
s1 = s1*volume/128;
s2 = ((int)(*dst) - 0x80)*256;
src++;
val = s1 + s2;
if (val > 32767) val = 32767;
if (val < -32768) val = -32768;
*dst++ = (UBYTE)((val/256) + 0x80);
if (num_pokeys == 2) {
dst++;
}
}
}
void VOTRAXSND_Frame(void)
{
if (!votraxsnd_enabled()) return;
#ifdef VOICEBOX
if (VOICEBOX_enabled && VOICEBOX_ii) {
double factor = (VOICEBOX_BASEAUDF+1.0)/(POKEY_AUDF[3]+1.0);
ratio = (double)VTRX_RATE/(double)dsprate * factor;
samples_per_frame = ((double)dsprate/(double)(Atari800_tv_mode == Atari800_TV_PAL ? 50 : 60)) / factor;
}
#endif
votrax_sync_samples -= samples_per_frame;
if (votrax_sync_samples <= 0 ) {
votrax_sync_samples = 0;
VOTRAXSND_busy = FALSE;
#ifdef PBI_XLD
PBI_XLD_votrax_busy_callback(FALSE); /* busy -> idle */
#endif
}
}
void VOTRAXSND_Process(void *sndbuffer, int sndn)
{
if (!votraxsnd_enabled()) return;
if(votrax_written) {
votrax_written = FALSE;
Votrax_PutByte(votrax_written_byte);
}
sndn /= num_pokeys;
while (sndn > 0) {
int amount = ((sndn > VTRX_BLOCK_SIZE) ? VTRX_BLOCK_SIZE : sndn);
votrax_process(votrax_buffer, amount, temp_votrax_buffer);
if (bit16) mix((SWORD *)sndbuffer, votrax_buffer, amount, POKEYSND_volume >> 3);
else mix8((UBYTE *)sndbuffer, votrax_buffer, amount, POKEYSND_volume >> 3);
sndbuffer = (char *) sndbuffer + VTRX_BLOCK_SIZE*(bit16 ? 2 : 1)*((num_pokeys == 2) ? 2: 1);
sndn -= VTRX_BLOCK_SIZE;
}
}
void VOTRAXSND_PutByte(UBYTE byte);
void VOTRAXSND_Init(int playback_freq, int n_pokeys, int b16);
void VOTRAXSND_Frame(void);
void VOTRAXSND_Process(void *sndbuffer, int sndn);
extern int VOTRAXSND_busy;
void VOTRAXSND_Reinit(void);
void VOTRAXSND_ModifyRatio(double factor);
#endif /* VOTRAXSND_H_ */