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improved audio accuracy (input samplerate is now adjusted according to emulated framerate)

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This commit is contained in:
ekeeke31 2009-12-30 15:24:12 +00:00
parent 1489a94be3
commit 46758ce339
7 changed files with 25 additions and 19 deletions
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15
HISTORY.txt
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@ -9,29 +9,32 @@ Genesis Plus GX 1.4.0 (??/??/????) (Eke-Eke)
* added an option to boost SN76489 Noise Channel
* removed outdated Gens YM2612 core
* improved YM2612 core general accuracy (SSG-EG, CSM mode,...) (based upon Nemesis recent tests on real MD)
* improved YM2612 LFO emulation (fixes "Spider-Man & Venom : Separation Anxiety" intro music)
* improved YM2612 LFO emulation accuracy (fixes "Spider-Man & Venom : Separation Anxiety" intro music)
* fixed YM2612 context saving/loading.
* added 3-Band EQ for fully configurable sound filtering (credits to Neil C / Etanza Systems)
* removed libsamplerate support, implemented faster/better FIR resampler (thanks to Blargg and AamirM)
* added 3-Band EQ for fully configurable sound filtering (thanks to Neil C)
* implemented faster FIR resampler, dropped libsamplerate support (thanks to Blargg & AamirM)
* improved VDP sprite masking emulation: fixes 3D level in Mickey Mania (thanks to Nemesis for his sprite test program)
* fixed 2-Cell vertical scrolling when column 0 is shifted.
* added support for 2-Cell vertical scrolling in Interlaced 2 mode.
* fixed lightgun autodetection: fixes cursor position in Lethal Enforcers II
* fixed lightgun auto detection: fixes cursor position in Lethal Enforcers II
* improved DIVU/DVIS (thanks to Jorge Cwik) & MULU/MULS 68000 instructions timing accuracy
* updated Z80 core to last version (fixes interrupt Mode 0 timing and some BIT instructions)
* fixed Backup Memory support in some games using serial EEPROM
* added Game Genie hardware emulation (Game Genie ROM is now fully supported, see README for more details)
* added Action Replay hardware emulation (Action replay ROM is now fully supported, see README for more details)
* added S&K "Lock-On" hardware emulation ("lock" any games to Sonic & Knuckles)
* added Cartridge "hot swap" feature (swap games without reseting the virtual console)
* various code cleanup & core optimizations
[Gamecube/Wii]
* improved audio/video synchronization: fixes video skipping issues in 60Hz modes
* fixed stability issues and some (potential) memory leaks
* fixed stability issues and some potential memory leaks
* added internal screenshot feature
* improved lightgun cursors
* implemented new FONT & GUI engines: use internal IPL FONT, GX hardware & multithreading for fast rendering.
* implemented new interface: incl. IR pointing, ROM snapshots, menu effects, sound effects, BGM... (check the README for more details)
* implemented new interface: incl. IR pointing, game snapshots, menu effects, sound effects, BGM...
(check the README for more details)

2
source/gx/main.c
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@ -126,7 +126,7 @@ void reloadrom (int size, char *name)
else
{
system_init (); /* Initialize System */
audio_init(48000); /* Audio System initialization */
audio_init(48000,vdp_pal?50.0:(1000000.0/16715.0));
ClearGGCodes (); /* Clear Game Genie patches */
system_reset (); /* System Power ON */
}

2
source/sound/Fir_Resampler.c
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@ -281,7 +281,7 @@ int Fir_Resampler_input_needed( unsigned long output_count )
output_count -= 2;
}
long input_extra = input_count - (write_pos - &buffer [(WIDTH - 1) * STEREO]);
long input_extra = input_count - (write_pos - &buffer [WRITE_OFFSET]);
if ( input_extra < 0 )
input_extra = 0;
return input_extra;

14
source/sound/sound.c
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@ -61,24 +61,26 @@ static inline void psg_update(int cnt)
}
/* initialize sound chips emulation */
void sound_init(int rate)
void sound_init(int rate, double fps)
{
double vclk = (vdp_pal ? (double)CLOCK_PAL : (double)CLOCK_NTSC) / 7.0; /* 68000 and YM2612 clock */
double zclk = (vdp_pal ? (double)CLOCK_PAL : (double)CLOCK_NTSC) / 15.0; /* Z80 and SN76489 clock */
/* cycle-accurate FM & PSG samples */
m68cycles_per_sample[0] = (int)(((double)m68cycles_per_line * (double)lines_per_frame * (double)vdp_rate / (double)rate) + 0.5);
m68cycles_per_sample[0] = (int)(((double)m68cycles_per_line * (double)lines_per_frame * fps/ (double)rate) + 0.5);
m68cycles_per_sample[1] = m68cycles_per_sample[0];
/* YM2612 is emulated at its original frequency (VLCK/144) */
if (config.hq_fm)
{
/* "real" ratio is (vclk/144.0)/(rate) but since we need perfect synchronization between video & audio
on the target system, we are not exactly running at the real genesis framerate but the target
framerate (which is calculated so that no video or audio frameskip occur)
*/
Fir_Resampler_time_ratio((double)m68cycles_per_line * (double)lines_per_frame * fps / 144.0 / (double)rate);
m68cycles_per_sample[0] = 144;
/* "real" ratio is (vclk/144.0)/(rate) but this causes scratchy sound in Wii/GCN 50Hz video mode */
/* since "real" framerate is lower than 50 fps whereas PAL Wii/GCN framerate is higher than 50 fps */
/* it's better to directly use the ratio between generated & expected numbers of samples per frame */
Fir_Resampler_time_ratio((double)m68cycles_per_line * (double)lines_per_frame * (double)vdp_rate / 144.0 / (double)rate);
}
/* initialize sound chips */

2
source/sound/sound.h
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@ -25,7 +25,7 @@
#define _SOUND_H_
/* Function prototypes */
extern void sound_init(int rate);
extern void sound_init(int rate, double fps);
extern void sound_update(int fm_len, int psg_len);
extern void fm_reset(void);
extern void fm_write(unsigned int cpu, unsigned int address, unsigned int data);

7
source/system.c
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@ -138,7 +138,7 @@ void audio_update (int size)
/****************************************************************
* AUDIO System initialization
****************************************************************/
int audio_init (int rate)
int audio_init (int rate, double fps)
{
/* Shutdown first */
audio_shutdown();
@ -151,7 +151,7 @@ int audio_init (int rate)
snd.sample_rate = rate;
/* Calculate the sound buffer size (for one frame) */
snd.buffer_size = (rate / vdp_rate) + 32;
snd.buffer_size = (rate / vdp_rate) + 8;
#ifndef NGC
/* Output buffers */
@ -182,7 +182,7 @@ int audio_init (int rate)
snd.enabled = 1;
/* Initialize Sound Chips emulation */
sound_init(rate);
sound_init(rate,fps);
return (0);
}
@ -238,6 +238,7 @@ void system_reset (void)
if (snd.fm.buffer[0]) memset (snd.fm.buffer[0], 0, SND_SIZE);
if (snd.fm.buffer[1]) memset (snd.fm.buffer[1], 0, SND_SIZE);
Fir_Resampler_clear();
llp = rrp = 0;
}
/****************************************************************

2
source/system.h
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@ -87,7 +87,7 @@ extern int32 current_z80;
extern uint8 system_hw;
/* Function prototypes */
extern int audio_init (int rate);
extern int audio_init (int rate,double fps);
extern void audio_shutdown (void);
extern void audio_update (int len);
extern void audio_set_equalizer(void);