unitracker-player

The generic player of canonical unitracker documents, and their builder into standalone PSID .sid files. It reads a document with the grammar of unitracker-grammar and plays it to the state of the 25 SID registers ($D400-$D418) at the end of each tick. It knows only the document: its instruments, programs, expressions, phrases and timeline, and the note table F(k) at its clock.

Install

pip install "unitracker-player @ git+https://github.com/anarkiwi/unitracker-player"

Use

from unitracker_player import load, play, Player

frames = play(text)               # np.uint8 array (ticks, 25), to the end of an ending song
frames = play(text, ticks=3000)   # a looping song needs ticks
song = load(text)                 # parse and compile once; play(song, ...) reuses it
player = Player(song)
regs = player.step()              # the 25 registers after one tick; None once the song ends
player.regs                       # the register file the last tick wrote, one store per register

It plays formats 2.3 and 2.4, the grammar's formats: their sugar (prelude templates, chord names, instrument and phrase templates, groups, sections, first-use definitions) as the grammar's core expansion (unitracker_grammar.expand.core), and once bindings (pw:800!), lag:k, global:[cut], and 2.4's program layers (layers:{ctrl:[a,b]}, b.ctrl:c7, b.run:c7) and per-voice orderlists ( - voice:[p1,p2+2|loop:1]) itself; 2.4's prelude hard restart (restart:hr(2,15,0)) plays as the restart rows it stands for. Code templates run as 6502 routines on a jennings MPU, with per-voice state from the document's state line; templates, in the top-level mod section keyed by signatures (vib(c,s):|), are bound by calls (wob.freq:vib(3,40)), and code reads the note table as F.lo / F.hi. A program record may be a template keyed by its signature (arp(a,b):[{ctrl:65,note:+a},{wait:a,note:-b},{loop:0}]), which a call binds wherever a program's name stands (ctrl:arp(7,4), restart:hr(2,9,220), run:arp(7,4)). Any definition may also stand inline at its one use (C4.{ad:9}, run:pw[{pw:5},end], play:[[C4,-*3]+2], C4 pw:asm{lda phi; sta v; rts}, C4 pw:'v + 40') and plays as its named form. A cell's repeated keys and commands apply in the order written, reset restarts a binding's phi (C4 pw:ptab(3) pw:reset), and a regs line gives the 25 registers before tick 0.

read(text) returns the document as plain dataclasses. A text outside the grammar raises unitracker_grammar.CanonicalError; a document the player refuses raises PlayError.

unitracker-play song.yaml --ticks 3000 --out frames.npz   # array "frames"
unitracker-play song.yaml --out frames.csv                # one row per tick, d400..d418
unitracker-play song.yaml                                 # CSV to stdout

unitracker-sid song.yaml                         # song.sid
unitracker-sid song.yaml --out x.sid --ticks 3000 --load 0x2000

unitracker-sid renders the song here, proves where a looping song repeats, and assembles a 6502 playroutine (llvm-mos, locally or in the docker-mos-llvm-sdk image) whose raster IRQ plays the same registers tick for tick.

Docs

docs/semantics.md: the meaning of every construct of the grammar as played. docs/sid.md: how a document becomes a .sid, and the tests that check it. tools/corpus.py: records the documents a test suite parses, plays a directory of them and compares two such runs, to check that a change keeps what documents play.