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| Shin'en GHX Sound Engine documentation | |
| Additional binary context from BinarySerializer | |
| History context and research made possible by www.vgmpf.com | |
| // | |
| AHX/GHX sound engines programmed by Martin Wodok (Dexter) | |
| == | |
| Special thanks to Manfred Linzner (Pink) for their mind-blowing and awesome tunez! | |
| -------------------------------------------------------------------- | |
| GHX Sound Engine (November 23rd, 1999/December 31st, 2001) | |
| - First used in Crazy Zone/JetPak DX | |
| - Saw last use in Planet of the Apes | |
| - Coded in Z80* ASM | |
| - The software used to create and edit AHX tracks is a specially-modified variant of AHX v2.3d-sp3(1) for the Commodore Amiga. | |
| - The software can convert ProTracker(4), as well as FastTracker II and Commodore 64 .sid music formats(5) into the GHX format. | |
| // | |
| ////////////////////////////////////////////////////////////// | |
| GHX Audio Engine (shinen.com GHX demos) | |
| [TBC] | |
| == | |
| GHX Sound Engine - Ver. 00530 | |
| (used in Barbie: Magic Genie Adventure, Blue's Clues: Blue's Alphabet Book, NASCAR Heat) | |
| // | |
| GHX Sound Engine - Ver. 01206t (WIP) | |
| (used in SpongeBob SquarePants: Legend of the Lost Spatula, Tomb Raider: Curse of the Sword) | |
| == | |
| [GHX file format] | |
| > Tip: The pointers are relative to the bank the | |
| GHX version info (and likely the replayer) is in | |
| ========================================== | |
| uint16 - Unknown pointer | |
| [File header] | |
| [ASCII] - "GHX" | |
| uint8 - Number of subsongs | |
| uint8 - Number of rows (Shared across all subsongs) | |
| uint8 - Reserved | |
| uint16 - Pointer to pattern data | |
| uint16 - Pointer to instrument data | |
| // | |
| uint16 - Pointer to song playback settings | |
| // | |
| [Song playback settings] | |
| For each song: | |
| uint8 - Song length | |
| uint16 - Pointer to start of pattern playlist | |
| uint8 - Length of loop (after the song loops) | |
| uint16 - Restart position (pointer to a pattern playlist) | |
| [Pattern list format] | |
| For each pattern in the song: | |
| >>Pattern number corresponds to an ID into the pattern pointers struct. | |
| uint8 - Pulse #1 pattern number | |
| int8 - Pulse #1 transpose | |
| == | |
| uint8 - Pulse #2 pattern number | |
| int8 - Pulse #2 transpose | |
| == | |
| uint8 - Wave pattern number | |
| int8 - Wave #1 transpose | |
| == | |
| uint8 - Noise pattern number | |
| [Pattern pointers] | |
| For each pattern in the data file: | |
| uint16 - Pattern start offset | |
| [Instrument data (WIP)](2) | |
| uint8 - Number of steps | |
| uint8 - Step speed | |
| ** Bit 7 - Use wavetable | |
| // - Allows the use of realtime generated wave patterns(3) (i.e Wacky Racers, Rinkapink (unreleased), and Asterix: Search for Dogmatix) | |
| uint8 - Volume control bitfield | |
| ** | |
| ** Lower nybble - Volume | |
| ** Upper nybble: | |
| ** Bit 3 - Fade type | |
| ** Bit 2:0 - Fade length (0 - No fade) | |
| [For each instrument step] | |
| int8 - Note transpose | |
| uint8[2] - Effect type and param bitfield | |
| ** | |
| ** Lower nybble: | |
| ** Bit 7-6 | |
| ** 0 - None | |
| ** 1 - Set volume | |
| ** 2 - Jump to step | |
| ** 3 - Set waveform | |
| ** Lower-upper nybble: | |
| ** Bit 5:0 - Effect param | |
| [If the instrument is a wavetable] | |
| uint8 - Number of steps | |
| uint8 - Step speed | |
| ** Bit 7 - Use wavetable = Set to 1 here | |
| uint8 - Wavetable volume? | |
| uint8 - Reserved? | |
| uint8 - Vibrato controls | |
| ** Lower nybble - Vibrato speed | |
| ** Upper nybble - Vibrato depth | |
| uint8 - Wavetable sweep strength | |
| uint8 - Wavetable settings | |
| ** Bit 7-6 - ?? | |
| ** Bit 5-4 - ?? | |
| ** Upper nybble - Wavetable init | |
| uint24 - Null | |
| uint16 - Loop bitfield | |
| ** Upper nybble - | |
| ** 0 | No loop | |
| ** 1 | Loop | |
| ** Lower nybble + uint8 - Number of wave ticks to wait until playing waveform again (0-65295) | |
| uint8 - Wavetable step | |
| uint16 - Wavetable parameters | |
| [For each instrument step] | |
| int8 - Note transpose | |
| uint8[2] - Effect type and param bitfield | |
| ** | |
| ** Lower nybble: | |
| ** Bit 7-6 | |
| ** 0 - None | |
| ** 1 - Set volume | |
| ** 2 - Jump to step | |
| ** 3 - Init square | |
| ** Lower-upper nybble: | |
| ** Bit 5:0 - Effect param | |
| [Sequence data (WIP)] | |
| uint8 - Note | |
| ** Bit 7 - | |
| 1 | Note + effect(s) <if note is not 0> | |
| 1 | Effect only <if note is 0 + effect bitfield is blank> | |
| 0 | Note only | |
| Effect bitfield > | |
| ** Bit 6 - | |
| Effect type = Set volume | |
| ** Bit 5 only in lower nybble- | |
| Slide to defined pitch | |
| Upper nybble is now pitch value (-6 : +8) | |
| The resulting command is 1 byte. | |
| ** Only bit 6 set - | |
| Effect only, set volume. The next is the effect param and the resulting command is 2 bytes | |
| uint8 - Instrument | |
| ** Bit 7:6 - If a set volume command is present, it is set to the volume param. | |
| ** Bit 5:0 - Instrument number (0-63) | |
| [If effect bit is set] | |
| uint8 - Effect type and param bitfield | |
| ** Lower nybble - Effect param | |
| ** Upper nybble - Effect type | |
| uint8 - Command byte | |
| An empty row is represented with 0x00. | |
| Available effects: | |
| 00 | None | |
| ?? | |
| 0C | Set volume | |
| 0F | Set speed | |
| FF | Stop song | |
| AHX effects: | |
| 00 | None (Filter position if given param) | |
| 01 | Portamento up | |
| 02 | Portamento down | |
| 03 | Init square modulation | |
| 04 | Start/stop modulation | |
| 05 | Jump to step | |
| 0C | Set volume | |
| 0F | Set speed | |
| [Song "metadata"] | |
| [ASCII] - 'SONG' | |
| ****************** | |
| Song ID and name list formatted as: | |
| 00: MAIN MENU.......01: CUTSCENES.......02: SUBSCREENS...... | |
| ************************************************************** | |
| The list can be viewed properly if one sets the bytes per row in a hex editor to 20 bytes. | |
| [ASCII] The song's ID (00-99) followed by a colon and a space. | |
| (Sometimes the space is absent and the rest of the string is padded with 0x2e.) | |
| [ASCII] The song's internal name (max. 16 characters, padded by 0x2e/period) | |
| > The name is uppercase for most of the time, but this doesn't mean the titles can't be uppercase. | |
| Example from Blue's Clues: Blue's Alphabet Book (USA): | |
| 00: EMPTy........... | |
| 07:Thinking Chair... | |
| // | |
| Tyrannosaurus Tex and the GHX demos don't have this metadata saved. | |
| [Sample data] | |
| (uint4) - 4-bit PCM data | |
| ==Citations== | |
| /// | |
| * - Sharp LR35902 | |
| == | |
| 1 - https://web.archive.org/web/20071027020933/http://www.shinen.com/music/images/ahx-1.gif | |
| 2 - https://web.archive.org/web/20231119210018/https://shinen.com/music/images/ahx-2.gif, http://www.abyss-online.de/static/www.amigascne.org/abyss/ahx/ | |
| 3 - https://gbstudiocentral.com/interviews/making-game-boy-music-during-its-heyday/#:~:text=use%20of%20custom%20voices%20in%20the%20wave%20channel | |
| 4 - https://gbstudiocentral.com/interviews/making-game-boy-music-during-its-heyday/#:~:text=We%20could%20import%20different%20music%20formats%20(like%20ProTracker%20etc.) | |
| 5 - https://www.shinen.com/music/music.php3?ghx#:~:text=We%20already%20have%20some%20music%20composed%20as%20MID/WAV/MOD/XM/SID | |
| /// | |
| ==End of citations== |
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