Sonic and Sega Retro Message Board: ValleyBell - Viewing Profile - Sonic and Sega Retro Message Board

When working on SMPSPlay and DEPlay there was always one thing that bothered me: the DAC frequency
It's something I couldn't just get right, so I decided to do some research.

I startet with Oerg866's SMPS Player, which uses jman2050's DAC driver:
At first I made an SMPS file that plays a few DAC sounds and made each sound play the same sample, but with different DAC rates.
Then I used MESS to make a VGM of it. (MESS because MAME's timing system is extremely accurate.)
After that I wrote a small tool in VB that reads that VGM and calculated the frequency of each sound.
Finally I made another small VB tool that recalculated the formula FreqHz = BaseVal / (RateBase + DACRate) for the DAC rates I logged. With this tool I tested values for RateBase until I found a perfect one. (I made it recalculate BaseVal with the tested frequency of rate 01 and RateBase.)

Then I did the same with plain Sonic 1, Sonic 2, and Barver Battle Saga (because I already had its pointers) for the Data East driver.

And here are my results:
(The columns are DACRate, logged DAC samples, length of the DAC sound in VGM ticks (44100 Hz), DAC samples per VGM sample, DAC frequency.)

jman2050's DAC driver
---------------------
01	8,238	 11,940	  1.45	30,426.784
02	8,238	 13,275	  1.61	27,366.915
03	8,238	 14,600	  1.77	24,883.274
04	8,238	 15,937	  1.93	22,795.746
05	8,238	 17,268	  2.10	21,038.673
06	8,238	 18,602	  2.26	19,529.932
07	8,238	 19,938	  2.42	18,221.276
08	8,238	 21,265	  2.58	17,084.213
0C	8,238	 26,598	  3.23	13,658.764
10	8,238	 31,926	  3.88	11,379.308
20	8,238	 53,243	  6.46	 6,823.353
30	8,238	 74,561	  9.05	 4,872.464
40	8,082	 94,060	 11.64	 3,789.243
80	4,278	 94,054	 21.99	 2,005.867
C0	2,908	 94,020	 32.33	 1,363.995
FF	2,212	 94,038	 42.51	 1,037.338
00	8,238	352,309	 42.77	 1,031.185
-> FreqHz = 272624 / (7.96 + DACRate)
 Calculating with (8 + prim) is still a good approximation. (DACSmpl/VGMSmpl variance is <0.2 for rates <= 80)


Sonic 1 DAC driver
------------------
01	8,236	 15,517	  1.88	23,407.076
02	8,236	 16,846	  2.05	21,560.465
03	8,236	 18,190	  2.21	19,967.433
04	8,236	 19,530	  2.37	18,597.419
05	8,236	 20,866	  2.53	17,406.671
06	8,236	 22,209	  2.70	16,354.073
07	8,236	 23,550	  2.86	15,422.828
08	8,236	 24,882	  3.02	14,597.203
0C	8,236	 30,252	  3.67	12,006.069
10	8,236	 35,602	  4.32	10,201.888
20	8,236	 57,041	  6.93	 6,367.483
40	8,236	 99,906	 12.13	 3,635.493
80	8,236	185,658	 22.54	 1,956.326
C0	5,710	188,159	 32.95	 1,338.288
FF	4,354	188,077	 43.20	 1,020.919
00	8,236	357,141	 43.36	 1,016.987
-> FreqHz = 271053 / (10.58 + DACRate)


Sonic 2 DAC driver
------------------
[without gaps]
01	5,994	 10,634	  1.77	24,857.570
02	5,994	 11,593	  1.93	22,801.294
03	5,994	 12,550	  2.09	21,062.582
04	5,994	 13,505	  2.25	19,573.151
05	5,994	 14,464	  2.41	18,275.401
06	5,994	 15,442	  2.58	17,117.951
07	5,994	 16,400	  2.74	16,118.012
08	5,994	 17,349	  2.89	15,236.348
0C	5,994	 21,209	  3.54	12,463.360
10	5,994	 25,016	  4.17	10,566.653
20	5,994	 40,424	  6.74	 6,539.071
40	5,994	 71,112	 11.86	 3,717.170
80	4,384	 96,853	 22.09	 1,996.163
C0	3,014	 97,425	 32.32	 1,364.305
FF	2,312	 98,042	 42.41	 1,039.954
00	5,994	255,585	 42.64	 1,034.237
-> FreqHz = 275173 / (10.07 + DACRate)

[with gaps]
01	5,994	 11,152	  1.86	23,702.959
02	5,994	 12,146	  2.03	21,763.165
03	5,994	 13,140	  2.19	20,116.849
04	5,994	 14,163	  2.36	18,663.800
05	5,994	 15,155	  2.53	17,442.125
06	5,994	 16,181	  2.70	16,336.160
07	5,994	 17,175	  2.87	15,390.707
08	5,994	 18,178	  3.03	14,541.501
0C	5,994	 22,193	  3.70	11,910.756
10	5,994	 26,203	  4.37	10,087.982
20	5,994	 42,327	  7.06	 6,245.078
40	5,994	 74,027	 12.35	 3,570.797
80	4,384	100,639	 22.96	 1,921.068
C0	3,014	100,638	 33.39	 1,320.748
FF	2,312	 99,898	 43.21	 1,020.633
00	5,994	259,097	 43.23	 1,020.218
-> FreqHz = 265473 / (10.20 + DACRate)


Data East DAC driver
--------------------
01	5,309	 14,714	  2.77	15,911.846
02	5,309	 15,768	  2.97	14,848.231
03	5,309	 16,817	  3.17	13,922.037
04	5,309	 17,866	  3.37	13,104.607
05	5,309	 18,906	  3.56	12,383.735
06	5,309	 19,951	  3.76	11,735.096
07	5,309	 21,006	  3.96	11,145.716
08	5,309	 22,077	  4.16	10,605.014
0C	5,309	 26,261	  4.95	 8,915.384
10	5,309	 30,457	  5.74	 7,687.129
20	5,309	 47,284	  8.91	 4,951.504
40	5,309	 80,941	 15.25	 2,892.562
80	5,309	148,154	 27.91	 1,580.294
C0	5,309	215,537	 40.60	 1,086.249
FF	5,309	281,543	 53.03	   831.585
00	5,309	282,774	 53.26	   827.965
-> FreqHz = 222766 / (13 + prim)

All formulas are accurate enough that the difference between tested and recauculated (DAC samples per VGM sample) is <= 0.2 for all rates. (except for Sonic 2 with gaps)

The Sonic 2 driver does all work on the Z80, so it needs to interrupt the DAC stream every frame to do update the music engine. [without gaps] means, that I removed the small delays that occur because of this, [with gaps] means that I just took the approximate frequency including these delays.


The next update of SMPSPlay and DEPlay with feature perfect DAC rates. (For SMPSPlay they're adjustable via ini-files.)

Do you rememer this SMPS player?

Well, I worked a little on it. And although I didn't improve the actual smps playback a lot (aside from a few small bugfixes), I made a lot of other changes.

At first, it can log v1.60 VGMs. (press V to enable/disable logging)
Also all DACs sounds and PSG envelopes are dynamically loaded and are easy to change. (I included a small editor for the PSG envelope files.)
And I removed Allegro (and made it a console app), so it continues playing if the program doesn't have the focus.
Finally, there is a 32-bit version (compiled with MSVC6 for compatibility) and a 64-bit versions (compiled with MSVC2010, so you need .NET 4.0).

Download

Enjoy!

EDIT: File updated, see this post

Crosspost from RetroHack and SSRG:

Valley Bell, on 06 December 2011 - 05:22 PM, said:

I was always a fan of this sound driver.
It doesn't just use the LFO to make a nice vibrato and has lots of great PCM drums, but it's the only driver used in chinese pirates which actually sounds good. (if not great sometimes)

Recently I startet ripping another pirate with this sound driver and got the idea of reverse engineering the sound format.

Now, here are my results:

Data East music format:

Header
------
Size	Description
4	Absolute ROM-Pointer to Track 1
4	Absolute ROM-Pointer to Track 2
4	Absolute ROM-Pointer to Track 3
4	Absolute ROM-Pointer to Track 4
4	Absolute ROM-Pointer to Track 5
4	Absolute ROM-Pointer to Track 6 (DAC)
6	Channel Assignment for tracks 1-6 (default: 00 01 02 04 05 06, later version only)
	-> these values specify the 4 lower bits of the Key On/Off command (028)
	   changing these shuffles doesn't change the track's channel (only the key on/off channel),
	   so you better don't change it
	-> a value of FF causes the driver to ignore the channel

Track Data
----------
The early sound driver used in Side Pocket has to additional bytes at the beginning of each track:
Size	Description
1	unknown
1	Channel Assignment of current track
...	Commands

In later versions the track starts directly with the commands.

Command		Description
00-7F aa	Note (7F = rest)
		-> aa = length
80 aa		Tempo (track 1 only)
		-> aa = Tempo Value (00 = slow, FF = fast)
82 aa		Instrument Change
		-> aa = Instrument No. in Instrument Lib
83 aa		Volume Change
		-> aa = Volume (TL value)
86 aa		Note Stop value (default 08)
		-> when a note is started, a length-counter is set to the note's length and counts down
		   when this counter reaches a stop value that's adjusted by aa, the note is stopped
		   when the counter reaches 0, the next note is processed
		-> aa = 08 makes stop value = 01 (always)
		   aa > 08 can make the stop value negative or 00, resulting in bending notes
		   aa < 08 make the stop value higher
		stop_value = 1 + round(note_len * (08 - aa) / 8)
		
		table from driver:
		07 -> 07 of 30, 04 of 18, 03 of 0C, 06 of 24
		06 -> 0D of 30, 07 of 18, 04 of 0C, 0A of 24
		05 -> 13 of 30, 0A of 18, 06 of 0C, 0F of 24
		04 -> 19 of 30, 0D of 18, 07 of 0C, 13 of 24
		03 -> 1F of 30, 10 of 18, 09 of 0C, 18 of 24
87		??
88 aa		Loop Start (nested loops are possible)
		-> aa = loop count (00 = infinite)
89		Loop End
8D aa		??
8E aa		set LFO register (022) (track 1 only)
		-> aa = LFO value (ored with 08)
8F		??
90 aa bb	??
91		??
92 aa		Panorama
		-> aa = L/R mask
93 aa		??
94 aa		??
95		Track End
96 aa		DAC Volume (track 6 only)
		-> aa = Volume (00=loud, 03=low)

de2mid (with source, writing the tool took longer than reverse engineering the format, btw)

I didn't work on the unknown coordination flags yet, as I found them when testing de2mid.

Example call for de2mid:
de2mid BarverBattleSaga.bin l 0019868A 0x16
(extracts call songs from Barver Battle Saga, works only with the v1.00 translation patch)


Feedback and comments are welcome.

Update: updated tool to add full support for Side Pocket and added some more unknown flags
another example call: de2mid "Side Pocket (JU) [!].bin" le 30DDE

Today I present you the opposite tool of smps2mid: mid2smps.

You can download the tool with some example files here.
Demo songs are: FF4 Boss Theme, The Final Countdown, Tales Of Phantasia: Boss Theme

Features:
- full support for Pan, PitchBend and Tempo changes
- support for volume changes via note velocity and Main Volume controller (no Expression-Controller)
- support for ymx instrument files
- per-channel looping (with Controller 111, value 0 is loop start, 1-127 is loop end)
- force E7 flag between notes (Portatemento Controller 65, Off <=63, On >=64)
- export to binary smps-file or directly into a ROM

How to use:
1. [optional] load a ROM (recommended for quick testing) and select the song you want to overwrite from the list
2. load YMX Instrument file (must only be done once)
3. set Tick/Qrtr and TempoDiv values, if wanted
4. click MID2SMPS

Notes:
- The tool will NOT ask you if you want to save the ROM. It will just silently overwrite the data.
- Instruments are assinged in order they are used.
- You can convert files without loading any instruments. It just won't attach any instrument data to the smps file.
- Currently the channel mapping is hardcoded. See table below:
-Drum mapping:
DAC Drums: 2x Bass Drum, 2x Snare Drum, Clap, 2x Cymbal, all Toms
Noise Drums: all Hi-Hats, 2xRide Cymbal, Ride Bell

- PSG instrument selection is done with Bank Select LSB. An (ignored) patch change message must follow the Bank Select message to confirm it.
- Modulation isn't yet implemented
- only Sonic 1 support (will care about the others later)
- The conversions are quite unoptimized. I'll write an optimized sometime in the future.

Thanks to:
- all the people who contributed to the Music Hacking Guide
- nineko for the tempo calcuation algorithm
- Oerg866 for the SMPS Player and info about the PSG envelopes (that helped me to make the example files)
- Rob Jinnai for notes on SMPS flags
- Tamkis for making a terrible FF4 Boss conversion that convinced me that I had to make a better one (that's why I wrote mid2smps)

The Music Hacking Guide has quite some misinformation that caused me trouble.
I took some notes and will correct these things.

Now listen to the demo files, try the tool and comment! (tool and demo files)

EDIT: Added notes about demo songs, volume change support and thanks to Tamkis
EDIT2: Updated the tool with instrument editor.