File size: 6,727 Bytes
6eed659
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
#!/usr/bin/env python3
"""SHONA v2 — pousser le levier qui a payé (+0.001127 au LB).
Constat v1 : seul un SPÉCIALISTE shona marche comme rescoreur (sna_r2 −0.0029 ; cont2 −0.0002 ;
cont +0.0011 = nuit). Or 4 autres modèles shona n'ont JAMAIS été testés.
Oracle 10-best = 0.0949 (marge −0.0332) : la marge est dans la SÉLECTION.
Ici : (1) tous les rescoreurs shona en solo, (2) N-best élargi 25, (3) combinaison des 2 meilleurs
(avec garde-fou : on ne retient la combinaison que si elle bat nettement le meilleur solo,
sinon sur-apprentissage sur 433 clips — leçon §4c).
"""
import json, os, pickle
import jiwer, numpy as np, soundfile as sf, torch
from multiprocessing import Pool
from pyctcdecode import build_ctcdecoder
from transformers import AutoModelForCTC, AutoProcessor

M1 = "/root/models/sna_ps_best"
R = "/scratch/restore"
NBEST = int(os.environ.get("NBEST", "25"))
AUD = "/root/devhard_audio"
CANDS_R = [("sna_r2", R + "/sna_r2_best"), ("sna_r", R + "/sna_r_best"),
           ("sna_s1", R + "/sna_s1_best"), ("sna_s2", R + "/sna_s2_best"),
           ("sna_ws", R + "/sna_ws_best")]


def comb(refs, hyps):
    pr = [(r, h) for r, h in zip(refs, hyps) if r.strip()]
    a = [x for x, _ in pr]; b = [y for _, y in pr]
    return 0.5 * jiwer.wer(a, b) + 0.5 * jiwer.cer(a, b)


def encode_for(tok, text):
    v = tok.get_vocab()
    delim = getattr(tok, "word_delimiter_token", "|")
    s = text.replace(" ", delim)
    keep = "".join(c for c in s if c in v)
    if not keep:
        keep = "".join(c for c in text.lower().replace(" ", delim) if c in v)
    return [v[c] for c in keep if v[c] != tok.pad_token_id]


def ctc_score(logp, ids, blank):
    T = logp.shape[0]
    if not ids or len(ids) > T:
        return -1e9
    lp = torch.from_numpy(logp).unsqueeze(1)
    return -float(torch.nn.functional.ctc_loss(
        lp, torch.tensor(ids).unsqueeze(0), torch.tensor([T]), torch.tensor([len(ids)]),
        blank=blank, reduction="sum", zero_infinity=True))


def compute_logits(model_dir, rows):
    proc = AutoProcessor.from_pretrained(model_dir)
    m = AutoModelForCTC.from_pretrained(model_dir, dtype=torch.float32).cuda().eval()
    out = []
    with torch.inference_mode():
        for i in range(0, len(rows), 4):
            b = rows[i:i + 4]
            au = [sf.read(r["audio"], dtype="float32")[0] for r in b]
            x = proc(au, sampling_rate=16000, return_tensors="pt", padding=True)
            x = {k: v.cuda() for k, v in x.items()}
            lg = m(**x).logits.log_softmax(-1).float().cpu().numpy()
            for j in range(len(b)):
                out.append(lg[j])
    del m; torch.cuda.empty_cache()
    return proc, out


def main():
    rows = [json.loads(l) for l in open("/root/devhard/devhard_linsna.jsonl", encoding="utf-8")]
    sub = [r for r in rows if r["lang"] == "sna"]
    for r in sub:
        r["audio"] = os.path.join(AUD, os.path.basename(r["audio"]))
    sub = [r for r in sub if os.path.exists(r["audio"])]
    refs = [r["text"] for r in sub]
    print("devhard-sna %d clips | NBEST=%d" % (len(sub), NBEST), flush=True)

    CACHE = "/scratch/lm/logits_sna.pkl"
    L1 = pickle.load(open(CACHE, "rb")) if os.path.exists(CACHE) else compute_logits(M1, sub)[1]
    tok = AutoProcessor.from_pretrained(M1).tokenizer
    v = tok.get_vocab()
    lab = [None] * len(v)
    for t, i in v.items():
        lab[i] = t
    lab[tok.word_delimiter_token_id] = " "
    lab[tok.unk_token_id] = "⁇"
    lab[tok.pad_token_id] = ""
    greedy = [" ".join(tok.decode(l.argmax(-1)).replace("|", " ").split()) for l in L1]
    REF = comb(refs, greedy)
    print("baseline greedy %.4f" % REF, flush=True)

    dec = build_ctcdecoder(lab)
    with Pool(8) as p:
        allbeams = dec.decode_beams_batch(p, L1, beam_width=128)
    with Pool(8) as p:
        db = [" ".join(x.split()) for x in dec.decode_batch(p, L1, beam_width=128)]

    cands, AC1, NW = [], [], []
    for i, bs in enumerate(allbeams):
        c = [" ".join(b[0].split()) for b in bs[:NBEST]]
        a = [(b[3] if len(b) > 3 else 0.0) for b in bs[:NBEST]]
        for extra in (db[i], greedy[i]):
            if extra and extra not in c:
                c.append(extra)
                a.append(ctc_score(L1[i], encode_for(tok, extra), tok.pad_token_id))
        cands.append(c); AC1.append(np.array(a))
        NW.append(np.array([float(len(x.split())) for x in c]))
    orc = [min(cands[i], key=lambda h: comb([refs[i]], [h]) if refs[i].strip() else 0)
           for i in range(len(cands))]
    print("ORACLE %d-best %.4f (marge %+.4f)" % (NBEST, comb(refs, orc), comb(refs, orc) - REF), flush=True)

    SC = {}
    for tag, mdl in CANDS_R:
        if not os.path.isdir(mdl):
            print("%-8s ABSENT" % tag, flush=True); continue
        proc, LG = compute_logits(mdl, sub)
        t2 = proc.tokenizer
        SC[tag] = [np.array([ctc_score(LG[i], encode_for(t2, x), t2.pad_token_id)
                             for x in cands[i]]) for i in range(len(cands))]
        print("%-8s OK" % tag, flush=True)

    def ev(W):
        hyps = []
        for i in range(len(cands)):
            tot = AC1[i].copy()
            for t, w in W.items():
                if w:
                    tot = tot + w * SC[t][i]
            hyps.append(cands[i][int(np.argmax(tot))])
        return comb(refs, hyps)

    print("\n--- solo (ref %.4f) ---" % REF, flush=True)
    solo = {}
    for t in SC:
        bb = (9.0, 0.0)
        for w in (0.3, 0.5, 1.0, 1.5, 2.5, 4.0):
            m = ev({t: w})
            if m < bb[0]:
                bb = (m, w)
        solo[t] = bb
        print("  %-8s %.4f (w=%.1f)  %+.4f" % (t, bb[0], bb[1], bb[0] - REF), flush=True)

    ranked = sorted(solo, key=lambda t: solo[t][0])
    best_solo = solo[ranked[0]]
    print("\n--- combinaison des 2 meilleurs (%s + %s) ---" % (ranked[0], ranked[1]), flush=True)
    bc = (9.0, None, None)
    for w1 in (0.5, 1.0, 1.5, 2.5):
        for w2 in (0.0, 0.3, 0.5, 1.0, 1.5):
            m = ev({ranked[0]: w1, ranked[1]: w2})
            if m < bc[0]:
                bc = (m, w1, w2)
    print("  best %.4f (%s=%.1f %s=%.1f)  %+.4f vs solo" % (bc[0], ranked[0], bc[1], ranked[1], bc[2], bc[0] - best_solo[0]), flush=True)
    keep_combo = bc[0] < best_solo[0] - 0.0015          # garde-fou anti sur-apprentissage
    print("\nRETENU : %s" % ("COMBINAISON" if keep_combo else "SOLO %s w=%.1f" % (ranked[0], best_solo[1])), flush=True)
    json.dump({"ref": REF, "solo": {k: list(v) for k, v in solo.items()},
               "combo": list(bc), "keep_combo": bool(keep_combo), "nbest": NBEST},
              open("/root/sna_v2.json", "w"))
    print("SNA_V2_DONE", flush=True)


if __name__ == "__main__":
    main()