Sega Saturn Development > General Jo Engine Help
Request for real hardware tests
ponut64:
Hey guys,
I just want to know if you run this ISO if the sound eventually annihilates your sanity (with static, of course).
It would only ever do this on real hardware. You can test emulators if you want, but about all you will get are some skips and the end of the file not terminating the sound.
http://www.mediafire.com/file/gvvevvruvr4cwnb/sl_coff.iso
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"But!" you may ask, "what is this?!"
This is streamed PCM playback of 30720 Hz (30.72KHz) audio using SGL, with the sound effect itself being copied straight to the PCM playback buffer.
Is this useful? Hell man, I don't know! But this actually plays sound, so it's what I have to work with because I cannot for the life of me get SBL to play any sound at all.
"What is the problem?"
I'm not sure. It could be a limitation of SGL. It could be a hardware limitation that SBL circumvents. It could just be my Saturn. But after so long of playing back the file, static gets thrown into the mix and I do not know how to suppress it.
Theories:
- SGL PCM playback pointer moves to a region of memory that has bad data
- SGL PCM playback pointer eventually starts playing back the incomplete data in LWRAM as its being copied
- SGL PCM playback pointer eventually leaves the Saturn's entire possible memory map range, returning NULL data
- A-bus and B-bus DMA processes eventually cross-corrupt
- SGL PCM playback library eventually attempts to mux PCM sound outputs, resulting in garbage added
Things I have tried:
- Attempt to move SGL playback start pointer (You cannot, slPCMOn will not change its parameters once started)
- Using NULL for PCM data region (I don't want it to point to any region, since I am copying the PCM data directly to the PCM buffer) (Result: Garbage)
- Using end-of-memory for PCM data region (Result: Crash)
- Different DMA modes
- Not much else (only one song and bitrate on real hardware)
MAJOR ISSUE:
No emulators replicate this problem.
Relevant code:
--- Code: ---
#ifndef __AUDIO_H__
#define __AUDIO_H__
#define SECTOR_SIZE (2048)
#define RING_BUF_SIZE (2048*10)
#define PCM_ADDR ((void*)0x25a20000)
#define PCM_SIZE (4096*2)
#define SMP_1TASK_SAMPLE (1024)
#define SMP_TR_MODE_CD (PCM_TRMODE_CPU)
#define SMP_LOAD_NUM (10)
#define PCMRAM (631734272)
#define LWRAM (2097152)
#define HIMEM (100679680)
//(31122)
#define S4410KHZ (0)
#define S3780KHZ (31451)
//THIS IS TESTED
#define M3072KHZ (31118)
//
#define S2205KHZ (30720)
#define S1920KHZ (29431)
#define S18900HZ (29404)
#define S1600KHZ (29134)
#define S1536KHZ (29074)
#define S1100KHZ (27643)
#define S0800KHZ (27086)
extern jo_sound main_pcmfx;
extern jo_sound music_pcmfx;
//Functions go here
void pcm_music_play(void(*sysframe)(void));
void* load_pcm(Sint8* filename, const jo_sound_mode mode, jo_sound *sound, void * workAddress);
void sound_on_channel(jo_sound * const sound, const unsigned char channel);
#endif
//Modified Jo Engine functions
jo_sound music_pcmfx;
jo_sound main_pcmfx;
static PCM _pcm[JO_SOUND_MAX_CHANNEL] =
{
{(_Stereo | _PCM16Bit), 0, 127, 0, 0x0, 0, 0, 0, 0},
{(_Stereo | _PCM16Bit), 2, 127, 0, 0x0, 0, 0, 0, 0},
{(_Stereo | _PCM16Bit), 4, 127, 0, 0x0, 0, 0, 0, 0},
{(_Stereo | _PCM16Bit), 6, 127, 0, 0x0, 0, 0, 0, 0},
{(_Stereo | _PCM16Bit), 8, 127, 0, 0x0, 0, 0, 0, 0},
{(_Stereo | _PCM16Bit), 10, 127, 0, 0x0, 0, 0, 0, 0},
};
static Sint16 music_frames = 0;
static Sint16 music_sectors = 0;
void pcm_music_play(void(*sysframe)(void))
{
//DEBUG INFORMATION
Sint8* filename = "B.PCM";
music_pcmfx.mode = JoSoundMono16Bit;
//This function is supposed to play a mono PCM sound effect constantly.
//Some LWRAM is consumed in the process (10 sectors / 20KB).
void* pcm = LWRAM;
void* write_buffer = LWRAM;
Sint32 fid = GFS_NameToId(filename);
GfsHn gfsm = GFS_Open(fid);
Sint8 fetch_timer = 0;
Sint32 fsize;
Sint32 nsct;
Sint32 stat;
Sint32 rdsize;
//Rate of data reading
Sint16 rt_step = (2 * 2048);
Sint16 rt_sector = 2;
//Get sectors
//HEY! SBL DOCUMENTATION IS WRONG! THIRD ITEM nzect IS GFS SECTOR COUNT. SECOND ITEM IS CD SECTOR SIZE.
//TIP: MEMORY MUST BE MANAGED IN SECTORS (2KB)
GFS_GetFileSize(gfsm, NULL, &nsct, NULL);
GFS_GetFileInfo(gfsm, NULL, NULL, &fsize, NULL);
//This determines playback time?
music_pcmfx.data_length = (fsize);
_pcm[(int)0].mode = (Uint8)music_pcmfx.mode;
_pcm[(int)0].pitch = M3072KHZ;
//How many frames are we reading?
if(rt_step < fsize){
music_sectors = (fsize + (rt_step - 1))/(rt_step);
}
jo_printf(0, 18, "(%i)", fsize);
GFS_SetReadPara(gfsm, rt_step);
GFS_SetTransPara(gfsm, rt_sector);
GFS_SetTmode(gfsm, GFS_TMODE_CPU);
//Loading follows
GFS_NwCdRead(gfsm, (10 * 2048));
for( ; music_frames <= music_sectors ; ){
//Copy memory from work area buffer directly into the PCM stream buffer
slDMACopy(write_buffer, PCMRAM, (8 * 2048));
slDMAWait();
//Very tightly timed! Not even timed right! Saturn appears to playback sounds faster than advertised; check pitch?
fetch_timer++;
if(music_frames < 4){
GFS_NwFread(gfsm, rt_sector, write_buffer + (music_frames * rt_step), rt_step);
}
do{
sysframe();
slSynch();
if(music_frames < 4){
GFS_NwExecOne(gfsm);
GFS_NwGetStat(gfsm, &stat, &rdsize);
}
jo_printf(0, 7, "(%i)", music_frames);
jo_printf(7, 7, "(%i)", music_sectors);
jo_printf(0, 11, "(%i)", rdsize);
jo_printf(10, 11, "(fetched filesize)");
}while(stat != GFS_SVR_COMPLETED && rdsize < rt_step);
if(music_frames < 4){
music_frames++;
}
if(music_frames == 4 && fetch_timer == 8){
music_frames = 0; fetch_timer = 0;
}
slSndFlush();
music_pcmfx.data = pcm;
jo_printf(0, 0, "(%i)", pcm);
music_pcmfx.current_playing_channel = 0;
//HEY! slPCMOn does -NOT- accept changes to the data address during playback. IT WILL DO NOTHING.
slPCMOn(&_pcm[(int)0], music_pcmfx.data, music_pcmfx.data_length);
slPCMParmChange(&_pcm[(int)0]);
}
GFS_Close(gfsm);
}
--- End code ---
LackofTrack:
I tested the iso on my Japanese Model 2. On all the 3 test tries I did, at about 1 minute and 42 seconds in static began to appear in the song.
Also the song doesn't stop correctly and keeps repeating the last second of itself. A brief look at the code and it looks fine.
I wonder why the problem occurs only on real hardware.
ponut64:
Stopping the song is easy that's not a problem. More to my point since I have the static issue, I don't feel like fixing the song ending.
That static though, that's a problem!
Thanks for testing. Now I know it's not just my Saturn. My real concern is testing a fix for it... I only have so many CD-Rs...
By the way, in my experience, the most accurate emulator for SGL PCM testing is Bizhawk (Saturnus based).
The other emulators do not playback the stream at the correct pitch rate.
SaturnTeam:
Which Saturn version are you testing it on? Can you give me the model number?
ponut64:
Saturn MK-80 000 A
SERIAL AE66078526
Manufactured September 1996 MALAYSIA
"US Model 2"
DO NOTE: My Saturn is a strange one.
Internally, the plastic shell has the hook for the Model 1-type CD open sensor, as well as what looks to be mounting points for the Model 1 CD activity light acrylic light tube.
The CD Drive is distinctly a later model Saturn. The CD OPEN sensor is the gear-switch type (no cable). The CD door has a different plastic finish than the rest of the console (it's a darker black).
Only one or two out of the five screwholes on the bottom actually screw in to the top half of the Saturn; I'm pretty sure the top half has 6 screw holes actually in it, and I'm afraid if I pick the console up wrong that I will rip the top off. There's also some other strange cavity in the bottom of the console that shines onto the back of a PCB on the right side of the console.
I bought my first Saturn (and had my first experience with it!) early in 2018, so my guess is my Saturn is cobbled together parts from broken units.
Personally, I am suspicious of it and think that internally it's probably a Model 1 more than a Model 2, but it does have BIOS Rev 1.01 / 1995. I say that because the eBay seller I bought it from clearly had pictures showing a Model 1 Saturn (and a Model 2 controller, which I got) and my guess is he broke it and hastily slapped a shell from a broken console on it. And I can tell some work and care was given to it, since when I received it, there was a cloth shim in the backup RAM battery preventing unnecessary battery usage/leakage. But you know, he jipped me a bit, because this thing is a mismatch!
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