SEQ sample (Sega MIDI-style music playback) for SRL #108

Frogbull · 2026-01-18T11:45:22Z

Heavely inspired by the Jo Engine sample made by jfsantos (João Felipe Santos) https://github.com/jfsantos/mid2seq

ReyeMe

Looked through the sample, and the SEQ playback loks simple enough.

But, as is now I cannot let it pass, since it cannot be used properly with other parts of SRL, especially PCM playback.

SRL already includes the sound driver, so there is no need to duplicate that. I would also prefer the backround music functions to be wrapped nicely and available through the Sound class, simmilar to CDDA and PCM.

I guess there is no way to change SEQ without reinitializing sound?

ReyeMe · 2026-01-18T15:27:48Z

Samples/Sound - SEQ/src/main.cxx

+
+void Initialize_SoundSystem_SEQ_SaturnMIDI(void)
+{
+    slInitSound(sddrvstsk, sizeof(sddrvstsk), (uint8_t *)mechs_map, sizeof(mechs_map) );


since slInitSound is already called within SRL, woudn't it be better to implement this as a propper API instead of this hack?

Yeah, way better and it will avoid conflict with PCM/CDDA

ReyeMe · 2026-01-18T15:29:06Z

Samples/Sound - SEQ/src/main.cxx

+    uint8_t seqVolume = 127;
+
+    // Auto-Play the SEQ music track
+    slBGMOn((1 << 8) + 0, 0, seqVolume, 0);


I am fine with direct SGL calls, but again, woudn't it be better to implement this as proper API?

Also: Magic numbers

yeah, (1 << 8) + 0 for the track index looks weird. And totaly agreed to make proper API to handle all this properly.

slBGMOn(SongIndex, Priority, Volume, Rate);

SongIndex: Uint16 for SEQ Track Index
Priority: Uint8 for Priority (range only from 0 to 31. The larger the value, the higher the priority)
Volume: Uint8 for Track Volume (range only from 0 to 127)
Rate: Uint8 for Track Rate (range from 0 to 255)

https://www.jo-engine.org/upload/files/SEGA/ST-238-R1-051795.pdf

ReyeMe · 2026-01-18T15:31:03Z

Samples/Sound - SEQ/src/main.cxx

@@ -0,0 +1,138 @@
+#include "SDDRVS.DAT"


sound driver is already included with SRL, and is loaded when initialize is called

Great, I don't know well your code, if we can track when it's loaded we could set a proper SoundMem Address 👍

here is where the init will happen https://github.com/ReyeMe/SaturnRingLib/blob/main/saturnringlib/srl_sound.hpp#L50

ReyeMe · 2026-01-18T15:31:53Z

Samples/Sound - SEQ/src/main.cxx

+    tonFILE.LoadBytes(0, tonFILE.Size.Bytes, tonBuf);
+
+    // SEQ data
+    slDMACopy(seqBuf, (void *)((uint8_t*)SoundMem + 0x21fdc), seqFILE.Size.Bytes);


what does this magic number means?

The driver has probably an allocated buffer for SEQ data starting at +0x21fdc (but I'm not sure)

ReyeMe · 2026-01-18T15:32:03Z

Samples/Sound - SEQ/src/main.cxx

+    slDMACopy(seqBuf, (void *)((uint8_t*)SoundMem + 0x21fdc), seqFILE.Size.Bytes);
+
+    // TON data
+    slDMACopy(tonBuf, (void *)((uint8_t*)SoundMem + 0x2737c), tonFILE.Size.Bytes);


what does this magic number means?

The driver has probably an allocated buffer for TON data starting at +0x2737c (but I'm not sure)

ReyeMe · 2026-01-18T15:32:36Z

Samples/Sound - SEQ/src/main.cxx

+        SRL::Debug::Print(1,9, "Press Left/Right to change the Tempo");
+        if (pad.WasPressed(SRL::Input::Digital::Button::Left))
+        {
+            if (musicTempo > -32768+16)


magic number again?

slBGMTempo(Tempo)

Tempo: Sint16 (range from -32768 to 32767)

https://www.jo-engine.org/upload/files/SEGA/ST-238-R1-051795.pdf

Do you have -32768 or 32767 defined as max value for a Sint16?

you can use INT16_MAX, and INT16_MIN

ReyeMe · 2026-01-18T15:32:47Z

Samples/Sound - SEQ/src/main.cxx

+        }
+        else if (pad.WasPressed(SRL::Input::Digital::Button::Right))
+        {
+            if (musicTempo < 32767-16)


magic number

Same as -32768 (Sint16 max positive value)

Integrated SEQ Support (optional)

With better integration in SRL

SRL_USE_SGL_SOUND_DRIVER = 1

Frogbull · 2026-01-18T19:38:16Z

Updated:

Way better Integration with SRL
Less magic numbers
No more ugly audio driver init
PCM integrated in the sample to show PCM played over SEQ music

ReyeMe · 2026-01-18T22:38:10Z

saturnringlib/srl_sound.hpp

 }

+#if SRL_ENABLE_AUDIO_SEQ_SUPPORT == 1
+    uint8_t audio_map_seq[] = {


why does this need to be defined here?

constant defined outside of namespace

constant naming does not follow style quideline

ReyeMe · 2026-01-18T22:39:26Z

saturnringlib/srl_sound.hpp

    #include <sega_pcm.h>
 }

+#if SRL_ENABLE_AUDIO_SEQ_SUPPORT == 1


special define should not be needed, the way you have done it now is a hack that will work with that sample, its not generic

ReyeMe · 2026-01-18T22:39:54Z

saturnringlib/srl_sound.hpp

 	            SND_ChgMap(0);

-                slInitSound(programBuffer, program.Size.Bytes, areaMapBuffer, areaMap.Size.Bytes);
+                #if SRL_ENABLE_AUDIO_SEQ_SUPPORT == 1


not a generic solution, and will not allow to load different map during runtime

I've a new solution that allow CUSTOM.MAP (no more MAP array in the C)

ReyeMe · 2026-01-18T22:41:14Z

Samples/Sound - SEQ/src/main.cxx

@@ -0,0 +1,144 @@
+#define SRL_ENABLE_AUDIO_SEQ_SUPPORT 1
+#define SoundMem 0x25a0b000 // The playback data is stored starting from address 0xB000 in the MC68000 memory area (0x25A0B000 in the program) https://antime.kapsi.fi/sega/files/ST-237-R1-051795.pdf


this should be handled within a wrapper, not used by sample directly

ReyeMe · 2026-01-18T22:41:58Z

Samples/Sound - SEQ/src/main.cxx

+    SRL::Core::Initialize(SRL::Types::HighColor::Colors::Black);
+
+    // Load and initialize a Saturn SEQ music track (Sega MIDI-style music playback)
+    Load_SEQ_SaturnMIDI();


function name does not follow style quidelines

SEQ sample (Sega MIDI-style music playback) for SRL

1f81b32

Heavely inspired by the Jo Engine sample made by jfsantos (João Felipe Santos) https://github.com/jfsantos/mid2seq

ReyeMe requested changes Jan 18, 2026

View reviewed changes

Frogbull added 5 commits January 18, 2026 20:29

A Test PCM file

5a61e5b

Update srl_sound.hpp

fc2fccb

Integrated SEQ Support (optional)

SRL SEQ Sample Updated

52e27ee

With better integration in SRL

Delete Samples/Sound - SEQ/src/SDDRVS.DAT

3cc1ec7

Updated Makefile

9a6458b

SRL_USE_SGL_SOUND_DRIVER = 1

ReyeMe requested changes Jan 18, 2026

View reviewed changes

Frogbull added 3 commits January 19, 2026 21:59

Add files via upload

83843b4

Update srl_sound.hpp

10e065f

Update main.cxx

1d217e4

		@@ -0,0 +1,144 @@
		#define SRL_ENABLE_AUDIO_SEQ_SUPPORT 1
		#define SoundMem 0x25a0b000 // The playback data is stored starting from address 0xB000 in the MC68000 memory area (0x25A0B000 in the program) https://antime.kapsi.fi/sega/files/ST-237-R1-051795.pdf

SEQ sample (Sega MIDI-style music playback) for SRL #108

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SEQ sample (Sega MIDI-style music playback) for SRL #108

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Frogbull commented Jan 18, 2026

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Frogbull Jan 18, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

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Frogbull commented Jan 18, 2026

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Frogbull Jan 18, 2026 •

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