File size: 5,777 Bytes
e112632
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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
# scripts/finetune_whisper_small.py
import argparse, os, sys, pandas as pd, numpy as np, soundfile as sf, librosa, torch
from datasets import Dataset
from transformers import (
    WhisperProcessor, WhisperForConditionalGeneration,
    Seq2SeqTrainingArguments, Seq2SeqTrainer
)

SAMPLE_RATE = 16000
DUR_SEC = 2.0
N_SAMPLES = int(SAMPLE_RATE * DUR_SEC)

def load_2s(path: str) -> np.ndarray:
    try:
        audio, sr = sf.read(path, dtype="float32", always_2d=False)
        if audio.ndim > 1:
            audio = np.mean(audio, axis=1)
    except Exception:
        # fallback if soundfile cannot read
        audio, sr = librosa.load(path, sr=None, mono=True)
        audio = audio.astype(np.float32)

    if sr != SAMPLE_RATE:
        audio = librosa.resample(audio, orig_sr=sr, target_sr=SAMPLE_RATE).astype(np.float32)

    if len(audio) >= N_SAMPLES:
        audio = audio[:N_SAMPLES]
    else:
        pad = np.zeros(N_SAMPLES, dtype=np.float32)
        pad[: len(audio)] = audio
        audio = pad
    return np.ascontiguousarray(audio, dtype=np.float32)

def make_transform():
    # set_transform can be called on single example or batch; handle both
    def _tx(batch):
        paths = batch["path"] if isinstance(batch["path"], list) else [batch["path"]]
        texts = batch["text"] if isinstance(batch["text"], list) else [batch["text"]]
        # we only attach raw 2s audio; features are made in data_collator
        audios = [load_2s(p) for p in paths]
        out = {
            "audio_2s": audios if len(audios) > 1 else audios[0],
            "text": texts if len(texts) > 1 else texts[0],
            "path": paths if len(paths) > 1 else paths[0],
        }
        return out
    return _tx

class DataCollatorWhisper2s:
    def __init__(self, processor: WhisperProcessor):
        self.processor = processor
        self.tok = processor.tokenizer
        self.feat = processor.feature_extractor

    def __call__(self, features):
        # features contain: {"audio_2s": np.array, "text": str, "path": str}
        audios = [f["audio_2s"] for f in features]
        texts  = [f["text"] for f in features]

        # Whisper input features (80x3000), computed on-the-fly
        # processor.feature_extractor already pads to fixed shape
        inputs = self.feat(audios, sampling_rate=SAMPLE_RATE, return_tensors="pt")
        input_features = inputs.input_features  # [B, 80, 3000]

        # Tokenize targets; pad, then replace pad_token_id with -100
        labels = self.tok(texts, return_tensors="pt", padding=True).input_ids
        labels[labels == self.tok.pad_token_id] = -100

        return {"input_features": input_features, "labels": labels}

def main():
    ap = argparse.ArgumentParser()
    ap.add_argument("--csv", required=True, help="CSV with columns: path,transcription OR path,text")
    ap.add_argument("--out_dir", required=True)
    ap.add_argument("--base_model", default="openai/whisper-small")
    ap.add_argument("--lang", default="en")
    ap.add_argument("--epochs", type=int, default=3)
    ap.add_argument("--batch", type=int, default=8)
    ap.add_argument("--num_workers", type=int, default=4)
    args = ap.parse_args()

    out_dir_abs = os.path.abspath(args.out_dir)
    os.makedirs(out_dir_abs, exist_ok=True)
    print(f"[INFO] Will save to: {out_dir_abs}")

    head = pd.read_csv(args.csv, nrows=1)
    df = pd.read_csv(args.csv)
    if "transcription" in head.columns:
        df = df.rename(columns={"transcription": "text"})
    assert {"path","text"}.issubset(df.columns), "CSV must have columns path and transcription/text"
    df = df.dropna(subset=["path","text"])
    df = df[(df["path"].astype(str).str.len()>0) & (df["text"].astype(str).str.len()>0)]
    print(f"[INFO] Rows: {len(df)}")

    # Tiny, path-only dataset; we transform lazily
    ds = Dataset.from_pandas(df[["path","text"]], preserve_index=False)
    ds = ds.train_test_split(test_size=0.1, seed=42)
    train_ds, eval_ds = ds["train"], ds["test"]

    processor = WhisperProcessor.from_pretrained(args.base_model, language=args.lang, task="transcribe")
    model = WhisperForConditionalGeneration.from_pretrained(args.base_model)
    model.config.forced_decoder_ids = processor.get_decoder_prompt_ids(language=args.lang, task="transcribe")
    model.config.suppress_tokens = []  # better for short clips
    model.gradient_checkpointing_enable()  # less VRAM

    # lazy transforms (no big arrays stored)
    tx = make_transform()
    train_ds.set_transform(tx)
    eval_ds.set_transform(tx)

    collator = DataCollatorWhisper2s(processor)

    train_args = Seq2SeqTrainingArguments(
        output_dir=out_dir_abs,
        per_device_train_batch_size=args.batch,
        per_device_eval_batch_size=args.batch,
        dataloader_num_workers=args.num_workers,
        gradient_accumulation_steps=2,
        learning_rate=1e-5,
        num_train_epochs=args.epochs,
        evaluation_strategy="epoch",
        save_strategy="epoch",
        logging_strategy="steps",
        logging_steps=50,
        predict_with_generate=False,
        fp16=True,
        remove_unused_columns=False,   # keep our custom fields
        report_to=[]
    )

    trainer = Seq2SeqTrainer(
        model=model,
        args=train_args,
        train_dataset=train_ds,
        eval_dataset=eval_ds,
        tokenizer=processor.tokenizer,
        data_collator=collator,
    )

    try:
        trainer.train()
    finally:
        print("[INFO] Forcing save...")
        trainer.save_model(out_dir_abs)
        model.save_pretrained(out_dir_abs)
        processor.save_pretrained(out_dir_abs)
        open(os.path.join(out_dir_abs, "SAVE_OK"), "w").write("ok\n")
        print(f"[DONE] Saved to: {out_dir_abs}")

if __name__ == "__main__":
    main()