Preview
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* *
* Official GRAOUMF TRACKER module file format .GT2 v1 - v4 *
* and old GT modules .GTK *
* *
* By L. de Soras - 11/11/96 *
* *
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===============================================================================
Format of GT2 modules
===============================================================================
This format is composed of various chunks. They must follow them (but not
necessarily in order), in this way you can read them easily. Put in your module
just the chunks you need. Intel coders, be careful : all words and double words
are in Motorola format, LSByte stored AFTER MSByte.
You may NOT expect that the first pattern chunk is 12 bytes after the
pattern set chunk, for example. Although it usually is, this may change in
future releases. In addition, it's possible that a chunk even doesn't exist in
the file. Therefore, you MUST check the chunk ID before accessing the chunk.
Finally, when writing GT2's you set undefined/reserved fields to zeros.
Note : chunk length can be odd.
General info chunk
~~~~~~~~~~~~~~~~~~
This is always the first chunk.
+--------+-------+------------------------------------------------------------+
| 0 | 3 | 'GT2' File magic |
| 3 | 1 | Version of the format (not in ascii!) : |
| | | $01 : G.T. v0.7 |
| | | $02 : G.T. v0.726 |
| | | $03 : G.T. v0.731 |
| 4 | 4 | Chunk size. It's the total length of the chunk, included |
| | | id and this dword. |
+--------+-------+------------------------------------------------------------+
| 8 | 32 | Name of the module. |
+--------+-------+------------------------------------------------------------+
| 40 | 160 | Small comments, name of the author |
+--------+-------+------------------------------------------------------------+
| 200 | 4 | Date |
| | | Day : 1 byte |
| | | Month : 1 byte |
| | | Year : 1 word |
+--------+-------+------------------------------------------------------------+
| 204 | 24 | Name of the tracker of creation |
+--------+-------+------------------------------------------------------------+
| 228 | 2 | Initial speed (Beat length * 6) |
| 230 | 2 | Initial tempo (BPM) |
+--------+-------+------------------------------------------------------------+
| 232 | 2 | Initial master volume (000..FFF) |
| | | Shouldn't excess $600. You can calculate it: |
| | | MasterVol = $3000 / (NbrTrack + 3) |
+--------+-------+------------------------------------------------------------+
| 234 | 2 | Number of voices (just for this panning section) |
| 236 | n*2 | Panning for each voice (000..800..FFF) |
+--------+-------+------------------------------------------------------------+
Track volume chunk (v4)
~~~~~~~~~~~~~~~~~~~~~~~
+--------+-------+------------------------------------------------------------+
| 0 | 4 | 'TVOL' |
| 4 | 4 | Chunk size |
+--------+-------+------------------------------------------------------------+
| 8 | 2 | Number of track volumes defined in this section |
| 10 | n*2 | Volume for each track (0000..1000..FFFF) |
+--------+-------+------------------------------------------------------------+
Extra-comment chunk (v2)
~~~~~~~~~~~~~~~~~~~~~~~~
+--------+-------+------------------------------------------------------------+
| 0 | 4 | 'XCOM' |
| 4 | 4 | Chunk size |
+--------+-------+------------------------------------------------------------+
| 8 | 4 | Extra-comment length |
| 12 | ECL | Extra-comment |
+--------+-------+------------------------------------------------------------+
Tracker configuration chunk
~~~~~~~~~~~~~~~~~~~~~~~~~~~
This chunk is specific to the Graoumf Tracker.
+--------+-------+------------------------------------------------------------+
| 0 | 4 | 'TCN1' |
| 4 | 4 | Chunk size |
+--------+-------+------------------------------------------------------------+
| 8 | 2 | Version number |
+--------+-------+------------------------------------------------------------+
| Version 0 : |
| 10 | 2 | Song position |
| 12 | 2 | line position |
| 14 | 2 | Preset number |
| 16 | 2 | Pattern display type |
| | | 0 : Note and instrument |
| | | 1 : Note, instrument and effect |
| | | 2 : Note, instrument, effect and volume |
| 18 | 2 | Curseur position #1 (column number, on screen) |
| 20 | 2 | Curseur position #2 |
| | | 0 : Note |
| | | 1-2 : Instrument |
| | | 3-6 : Effect |
| | | 7-8 : Volume column |
| 22 | 2 | Flags : |
| | | Bit 0-1 : Play mode |
| | | 00 = stop |
| | | 01 = play song |
| | | 10 = play pattern |
| | | Bit 2 : Edit |
| 24 | 2 | Lower octave on keyboard (0-6) |
| 26 | 2 | Line step |
| 28 | 2 | Instrument number |
| 30 | 2 | Sample number |
+--------+-------+------------------------------------------------------------+
| 32 | 32*2 | Number of tracks displayed for each preset |
| 96 | 32*16 | Name of each preset (16 char strings) |
| 608 |32*32*2| 32 track numbers for 32 presets |
+--------+-------+------------------------------------------------------------+
| 2654 | 4 | Bits 0-31 : 0 = muted track, 1 = track ok |
+--------+-------+------------------------------------------------------------+
Song chunk
~~~~~~~~~~
+--------+-------+------------------------------------------------------------+
| 0 | 4 | 'SONG' |
| 4 | 4 | Chunk size |
+--------+-------+------------------------------------------------------------+
| 8 | 2 | Song length |
| 10 | 2 | Song repeat point |
+--------+-------+------------------------------------------------------------+
| 12 | SL | Song data : pattern numbers, in words |
+--------+-------+------------------------------------------------------------+
Pattern set chunk
~~~~~~~~~~~~~~~~~
+--------+-------+------------------------------------------------------------+
| 0 | 4 | 'PATS' |
| 4 | 4 | Chunk size |
+--------+-------+------------------------------------------------------------+
| 8 | 2 | Number of tracks for all the song. |
| | | Perhaps in a future version, patterns will have different |
| | | numbers of tracks, and this value will be the max. |
+--------+-------+------------------------------------------------------------+
| 10 | 2 | Number of patterns saved |
+--------+-------+------------------------------------------------------------+
Pattern chunk
~~~~~~~~~~~~~
+--------+-------+------------------------------------------------------------+
| 0 | 4 | 'PATD' |
| 4 | 4 | Chunk size |
+--------+-------+------------------------------------------------------------+
| 8 | 2 | Pattern number |
| 10 | 16 | Pattern name |
+--------+-------+------------------------------------------------------------+
| 26 | 2 | Codage version : 0 |
+--------+-------+------------------------------------------------------------+
| Version 0 (full pattern) : |
| 28 | 2 | Number of lines |
| 30 | 2 | Number of tracks saved. This word is used only out of a |
| | | module (single chunk) for the moment. Set the same value |
| | | in all patterns |
| 32 | 5*L*T | Pattern, raw data, 5 bytes/note : NN II EEEE VV |
| | | NN : Note (24-127), 48 is middle C-2. 0 for no note |
| | | II : Instrument (1-255). 0 for no instrument |
| | | EEEE : Effect, see doc for more details. 0 for no FX |
| | | VV : Volume (1-255). 0 for no volume |
+--------+-------+------------------------------------------------------------+
Instrument set chunk
~~~~~~~~~~~~~~~~~~~~
+--------+-------+------------------------------------------------------------+
| 0 | 4 | 'ORCH' |
| 4 | 4 | Chunk size |
+--------+-------+------------------------------------------------------------+
| 8 | 2 | Number of instruments saved |
+--------+-------+------------------------------------------------------------+
Instrument chunk
~~~~~~~~~~~~~~~~
+--------+-------+------------------------------------------------------------+
| 0 | 4 | 'INST' |
| 4 | 4 | Chunk size (316) |
+--------+-------+------------------------------------------------------------+
| 8 | 2 | Instrument number (1-255) |
| 10 | 28 | Instrument name |
+--------+-------+------------------------------------------------------------+
| 38 | 2 | Instrument type (0 = sample) |
+--------+-------+------------------------------------------------------------+
| 40 | 2 | Volume (0-255) |
+--------+-------+------------------------------------------------------------+
| 42 | 2 | Autopanning (000..800..FFF) |
| | | -1 : no autopannig |
+--------+-------+------------------------------------------------------------+
| 44 | 2 | Volume envelope number (0 = no env) |
| 46 | 2 | Tone envelope number (0 = no env) |
| 48 | 2 | Pan envelope number (0 = no env) |
+--------+-------+------------------------------------------------------------+
| 50 | 10 | Reserved, must be set to 0 |
+--------+-------+------------------------------------------------------------+
| For n=0 to 127 : |
| 60+n*2 | 1 | Sample number for MIDI note n |
| 61+n*2 | 1 | Transposition for note n, signed byte |
+--------+-------+------------------------------------------------------------+
Sample chunk
~~~~~~~~~~~~
+--------+-------+------------------------------------------------------------+
| 0 | 4 | 'SAMP' |
| 4 | 4 | Chunk size |
+--------+-------+------------------------------------------------------------+
| 8 | 2 | Sample number (1-255) |
| 10 | 28 | Sample name |
+--------+-------+------------------------------------------------------------+
| 38 | 2 | Bit 0 : 0 = mono, 1 = stereo |
| | | Bit 1 : 0 = normal loop, 1 = ping-pong loop (v3) |
+--------+-------+------------------------------------------------------------+
| 40 | 2 | Autopanning (000..800..FFF) |
+--------+-------+------------------------------------------------------------+
| 42 | 2 | Number of bits (8 or 16) |
| 44 | 2 | Sample frequency in Hz (2000-65000) |
+--------+-------+------------------------------------------------------------+
| 46 | 4 | Length (in bytes), even |
| 50 | 4 | Repeat start (in bytes), even |
| 54 | 4 | Repeat length (in bytes), even |
+--------+-------+------------------------------------------------------------+
| 58 | 2 | Volume (0-255) |
+--------+-------+------------------------------------------------------------+
| 60 | 2 | Finetune (-8..+7 -> -1..+7/8 halftone) |
+--------+-------+------------------------------------------------------------+
| 62 | 2 | Codage version : 0 |
+--------+-------+------------------------------------------------------------+
| Version 0 (raw data) : |
| 64 | L | Sample data, signed bytes or words |
+--------+-------+------------------------------------------------------------+
Envelope chunk
~~~~~~~~~~~~~~
+--------+-------+------------------------------------------------------------+
| 0 | 4 | 'VENV' (volume), |
| | | 'TENV' (tone) or |
| | | 'PENV' (panning) |
| 4 | 4 | Chunk size |
+--------+-------+------------------------------------------------------------+
| 8 | 2 | Envelope number |
| 10 | 20 | Envelope name |
+--------+-------+------------------------------------------------------------+
| 30 | 2 | 'Key Off' offset (from data start) |
+--------+-------+------------------------------------------------------------+
| 32 | CS-32 | Envelope data |
+--------+-------+------------------------------------------------------------+
Vol/Tone/Pan envelope codes:
00 : End
01 + word : Jump
02 + word : Wait
03 + byte : Set Counter
04 : Loop
05 : Key Off
Volume envelope codes :
80 + word : Set Volume (16384 = 100%, max = 32767)
81 + word : Set Volume step
82 + word : Set Volume speed
83 : Tremolo On
84 : Tremolo Off
85 + byte : Set Tremolo Width
86 + byte : Set Tremolo Speed
87 : Tremor On
88 : Tremor On
89 : Set Tremor Time 1
8A : Set Tremor Time 2
Tone envelope codes :
A0 + word : Set Tone (4096 = normal period)
A1 + word : Set Tone step
A2 + word : Set Tone speed
A3 : Vibrato On
A4 : Vibrato Off
A5 + byte : Set Vibrato Width
A6 + byte : Set Vibrato Speed
Panning envelope codes :
C0 + word : Set Panning (2048 = normal position)
C1 + word : Set Pan step
C2 + word : Set Pan speed
Volume = Volume * (EnvVol+Tremolo)/16384 * TremorFlag
Period = Period * (Tone+Vibrato)/4096
Panning = Panning + (PanEnv-2048)*(2048-abs(Panning-2048))/2048
End chunk (v3)
~~~~~~~~~~~~~~
This chunk should end the module and must always exist.
+--------+-------+------------------------------------------------------------+
| 0 | 4 | 'ENDC' |
| 4 | 4 | Chunk size |
+--------+-------+------------------------------------------------------------+
| 8 | 4 | Total module size |
+--------+-------+------------------------------------------------------------+
===============================================================================
Format of old GTK modules
===============================================================================
Structure des infos samples :
¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹
rsreset
name_s: rs.b 28 ; Nom du sample
rs.w 7 ; Libre (enfin, rserv pour des amliorations futures)
; Doit tre mis
0 !
autobal_s: rs.w 1 ; Balance automatique, -1 = rien
nbits_s: rs.w 1 ; 1 = 8 bits, 2 = 16 bits
fech_s: rs.w 1 ; Frquence d'chantillonnage du sample (8363 Hz par dfaut)
length_s: rs.l 1 ; Longueur du sample, paire
repeat_s: rs.l 1 ; Point de bouclage, pair
replen_s: rs.l 1 ; Longueur de boucle, paire
vol_s: rs.w 1 ; Volume ($0
$100)
ftune_s: rs.w 1 ; Finetune (-8
+7)
size_s: rs 1 ; Total : 64 octets
*** Toutes les valeurs sont au format Motorola et non Intel : ***
*** l'octet de poids fort en premier, et l'octet de poids faible ***
*** faible en dernier (sens de la lecture). ***
A titre indicatif, les versions de format 1 et 2 ne diffrent que par cette
structure :
- 1 : Taille totale 48 octets, le nom fait 32 caractres et il n'y a ni
balance, ni nombre de bits, ni frquence d'chantillonnage.
- 2 : Toujours 48 octets, le nom passe
28 caractres, pas de balance.
Structure du module :
¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹¹
Nom Offset Taille Fonction
gtk_id: 0 3 Identificateur "GTK"
form_num: 3 1 Numro de format : le numro 3
name: 4 32 Nom ASCII (pas de zro)
comment: 36 160 Commentaire ASCII (pas de zro)
n_spl: 196 2 Nombre d'instruments (0
255)
n_lines: 198 2 Nombre de lignes/pattern (1
256)
n_trk: 200 2 Nombre de voies/pattern (1
32 ?? ou + ??)
songlen: 202 2 Longueur de la song (1
256)
songrep: 204 2 Point de bouclage dans la song (0
songlen-1)
infos_s: 206 n_spl*size_s Descriptif des instruments (
partir du numro 1)
...
song: n_spl*size_s 256*2 La song (1 mot = 1 pattern), de la position 0 jusqu'
255
+ 206
...
patterns: n_spl*size_s (npatmax+1)*n_l*n_t*? Les patterns, de 0
npatmax.
+ 718 ? peut tre 4 (v3) ou 5 (v4)
...
samples: n_spl*size_s Les samples, 8 ou 16 bits signs
+ (npatmax+1)*n_l*n_t*?
+ 718
le numro du dernier pattern sauv est le plus grand pattern de la song, de
0
songlen-1.
Chaque pattern est subdivis en lignes, et chaque ligne en colonnes. On
obtient ainsi chaque note, code sur 4 (ou 5) octets :
NN II EE EE (VV)
- NN indique le numro de la note, de 24 (C-0)
83 (B-4). 0 = pas de note,
- II indique le numro de l'instrument. 0 = pas d'instrument,
- EEEE reprsente l'effet et son paramtre. Pour plus de prcision dessus,
se reporter
la documentation du tracker.
- VV, pour la version 4, indique le volume de la piste (1-255). 0 = pas de
changement de volume.
Attention, ce format est un format de prversion! Je ne garantis pas que la
version finale sera telle qelle est dcrite ici, alors avant de charger un
module de ce type, contrlez bien le numro.
Vous pouvez obtenir la dernire version de Graoumf Tracker (pour Atari
Falcon 030) auprs de son auteur :
Laurent de Soras
92 avenue Albert 1er
92500 Rueil-Malmaison
FRANCE