Next Generation Emulation banner

1 - 6 of 6 Posts

·
Registered
Joined
·
21 Posts
Discussion Starter #1
Why don't SPUs play the MIDI sequences as a MIDI rather than trying to emulate the MIDI synth on the PSX?
It would have less CPU overhead, no music skipping/pausing, and eliminate complicated coding to emulate the instruments properly.
People can then use soundfonts or DLS that work best, or use the Yamaha XG-MIDI softsyn which has almost exact tone generation compared to the PSX's Yamaha sound chip.
 

·
Registered
Joined
·
55 Posts
I've heard this mentioned before and from what I can tell there's no specified format for Midi on the PSX. Each programming team comes up with their own particular routine for coding a music player. This routine is emulated by the emulator. Like the SNES where you basically had to dump the entire contents of the music ram to save the tune. Which leads me to ask why we haven't something similar for Epsxe savestates? On the other hand even if the SPU author were able to use MIDI there would be far more of a delay before the sound than there is now. You could try program to sound card hardware directly but that's damn difficult and wouldn't be very compatible. (I dream of 8 splin interpolation in hardware)
 

·
Registered
Joined
·
48 Posts
If memory serves, PSX uses XG for its midi syth, only Yamaha cards support this in hardware, and the software syths are SLOW!!!!. Personaly im very impressed with what the current sound plugins can do.
 

·
Registered
Joined
·
1,857 Posts
this might be irrelevent, but...
VGS sounds perfect. Heck, even bleem! sounds pretty close to perfect. Neither does that MIDI thing you're talking about. HMMMmmm...
 

·
Registered
Joined
·
538 Posts
The PSX does not have a hardware midi engine. So, you can't just load up a MIDI file, send it to a hardware chip, and say "play that".
What it does have is a 24-voice mixing system, with 512kb of dedicated sample (and working-set) memory. In a lot of ways, this is similar to the Gravis Ultrasound cards, and the Creative AWE32. But the PSX uses ADPCM compressed samples, has ADSR envelope filtering per voice, reverb mixing per voice, and the ability to pass the output of one voice as the frequency modulator on the next voice.
So, when a PSX plays music in the SPU, it is very similar to a PC/Amiga playing back a .MOD/.S3M/.XM/.IT file, where the sample data must be downloaded for playback, plus the program is responsible for all voice management (i.e. playback).
The reproduction of this sound in the emulator is therefore highly dependent on the accuracy of the emulation of the SPU, and it's interactions with the rest of the system (i.e. interrupt generation to the CPU, etc.)
 
1 - 6 of 6 Posts
Top