investigate roadroller for compression

[KilledByAPixel]

Investigate using a variant of roadroller to improve compression...

const options = {
    inBits: 7,
    outBits: -81,
    sparseSelectors: [0, 1, 2, 3, 6, 7, 13, 21, 25, 42, 50, 57],
    contextBits: 12,
    precision: 16,
    modelMaxCount: 127,
    recipLearningRate: 128,
    //preset: [...preset].map(c => c.charCodeAt(0)),
    modelQuotes: true,
};
let model;
                                                                                                     
model = new DefaultModel(options);
const compressed = compressWithModel(input, model, options);
                                                                                                     
model = new DefaultModel(options);
const decompressed = decompressWithModel(compressed, model, options);
t.deepEqual(decompressed, input);
                                                                                                     
// .#..#.######################.#.############################....#.##########################...#.
const SYMBOLS = "!$&'()*+,-./0123456789:;=?@ABCDEFGHIJKLMNOPQRSTUVWXYZ_abcdefghijklmnopqrstuvwxyz~";
let out = '';
let state = compressed.state; // 21 bits
for (let i = 0; i < 4; ++i) {
    out = SYMBOLS[state % SYMBOLS.length] + out;
    state = state / SYMBOLS.length | 0;
}
out += compressed.buf.map(i => SYMBOLS[i]).join('');
console.warn(out, out.length);

Result from ZzFX example (857 bytes)...

K?.BaP7Np*wg;4XAq&-pkT6lDY@!/wI0O~M/rNM,0nX?v;B4EvWwQ*v6Bqc8IY@uCTz+B6C.d;DGRFuQDAPJ:&fJRXplr7RX/S7Ch'FC3$3q@7VD?A+EIWXhRCcV~0'xOfOTs=dS,di2j$)2)EKp:cn(dSS7eeal~znz/.ycA')XAH2XEUuM1i@U5JgYTe-:4N+A!Nkjs2hoyyB?r(H+I,!mp7xlA1Uzq8m1cHK)Nz,-JD/k7Oeekvy)@sXx/YZsQZTVhD@kIXrCglwnak63U=**CC-SdMDSrb~@V8jv&J6UEfC$$?7UZam!=voPB&9M-5I?IamvSfuqHiKKABX=uYo~Bw~4c',IN&.F_VH=1KTx/8=.vlP;7(b)a@,jT&1c0Mbr$rMHyR*~fi~qVu*-c6k$-p':yoq*zyr/BXIKP@gBu5od6+z@s?9o+UzGkt-SHiplp=_pEP5SorwPLe6=_')-:o.Yfl9Vuk;sPOhuG4TK_6T3FgtBPbH(WmU(rZ4;i9UYFKegWRev:42J$aiWkjl:3eZTVy1&-M5.sjf($lg*5qRs.yT=ZS~WVEp;BZH@SZQDlNH8R5J8)FC0e&3B9hp/.@KRTXo~xV?YyN~:=$CIUp,idD~,OwMiRvpFfNKMG'NmV1qYG,unLHWM+Y!~JqoNgzYHAD+bxfhZxDs+P_VgekJ(UF2p)C--sI~0@1:QIiY.'g5'y_,(UyJA/A=27an;2-5MPm1AzCY6jOQTVo-8+'zy(+:LSapNrSw/)OH2lySYDF;YD0nEH(3HGjM/NC**OGQ@i?qFxJ6.f;C'/stP9++yyUWblOgpGvKS@meIesC7Kj,=;u.!WVVb4v5kc!8:N