app.py

import os
import tarfile
import torch
import torchaudio
import numpy as np
import streamlit as st
from datasets import load_dataset
from transformers import (
    AutoProcessor,
    AutoModelForSpeechSeq2Seq,
    TrainingArguments,
    Trainer,
    DataCollatorForSeq2Seq,
)

# ================================
# 1️⃣ Load Model & Processor
# ================================
MODEL_NAME = "AqeelShafy7/AudioSangraha-Audio_to_Text"

# Load ASR model and processor
processor = AutoProcessor.from_pretrained(MODEL_NAME)
model = AutoModelForSpeechSeq2Seq.from_pretrained(MODEL_NAME)

# Move model to GPU if available
device = "cuda" if torch.cuda.is_available() else "cpu"
model.to(device)
print(f"✅ Model loaded on {device}")

# ================================
# 2️⃣ Load Dataset (LibriSpeech) from Extracted Path
# ================================
DATASET_TAR_PATH = "dev-clean.tar.gz"  # Uploaded dataset in your Hugging Face Space
EXTRACT_PATH = "./librispeech_dev_clean"  # Extracted dataset folder

# Extract dataset only if not already extracted
if not os.path.exists(EXTRACT_PATH):
    print("🔄 Extracting dataset...")
    with tarfile.open(DATASET_TAR_PATH, "r:gz") as tar:
        tar.extractall(EXTRACT_PATH)
    print("✅ Extraction complete.")
else:
    print("✅ Dataset already extracted.")

# ✅ Load dataset from extracted folder
dataset = load_dataset("librispeech_asr", data_dir=EXTRACT_PATH, split="train", trust_remote_code=True)
print(f"✅ Dataset Loaded Successfully! Size: {len(dataset)}")

# ================================
# 3️⃣ Preprocess Dataset
# ================================
def preprocess_audio(batch):
    """Converts raw audio to a model-compatible format."""
    audio = batch["audio"]
    waveform, sample_rate = torchaudio.load(audio["path"])

    # Resample to 16kHz (ASR models usually require this)
    waveform = torchaudio.transforms.Resample(orig_freq=sample_rate, new_freq=16000)(waveform)

    # Convert to model input format
    batch["input_values"] = processor(waveform.squeeze().numpy(), sampling_rate=16000).input_values[0]
    batch["labels"] = processor.tokenizer(batch["text"]).input_ids
    return batch

# Apply preprocessing
dataset = dataset.map(preprocess_audio, remove_columns=["audio"])
print(f"✅ Dataset Preprocessed! Ready for Fine-Tuning.")

# ================================
# 4️⃣ Training Arguments & Trainer
# ================================
training_args = TrainingArguments(
    output_dir="./asr_model_finetuned",
    evaluation_strategy="epoch",
    save_strategy="epoch",
    learning_rate=5e-5,
    per_device_train_batch_size=8,
    per_device_eval_batch_size=8,
    num_train_epochs=3,
    weight_decay=0.01,
    logging_dir="./logs",
    logging_steps=500,
    save_total_limit=2,
    push_to_hub=True,
    metric_for_best_model="wer",
    greater_is_better=False,
    save_on_each_node=True,  # Improves stability during multi-GPU training
    load_best_model_at_end=True,  # Saves best model
)

# Data collator (for dynamic padding)
data_collator = DataCollatorForSeq2Seq(processor.tokenizer, model=model)

# Define Trainer
trainer = Trainer(
    model=model,
    args=training_args,
    train_dataset=dataset,
    eval_dataset=None,  # No validation dataset for now
    tokenizer=processor.feature_extractor,
    data_collator=data_collator,
)

# ================================
# 5️⃣ Fine-Tuning Execution
# ================================
if st.button("Start Fine-Tuning"):
    with st.spinner("Fine-tuning in progress... Please wait!"):
        trainer.train()
    st.success("✅ Fine-Tuning Completed! Model updated.")

# ================================
# 6️⃣ Streamlit ASR Web App
# ================================
st.title("🎙️ Speech-to-Text ASR with Fine-Tuning 🎶")

# Upload audio file
audio_file = st.file_uploader("Upload an audio file", type=["wav", "mp3", "flac"])

if audio_file:
    # Save uploaded file temporarily
    audio_path = "temp_audio.wav"
    with open(audio_path, "wb") as f:
        f.write(audio_file.read())

    # Load and process audio
    waveform, sample_rate = torchaudio.load(audio_path)
    waveform = torchaudio.transforms.Resample(orig_freq=sample_rate, new_freq=16000)(waveform)

    # Convert audio to model input
    input_values = processor(waveform.squeeze().numpy(), sampling_rate=16000).input_values[0]

    # Perform ASR inference
    with torch.no_grad():
        input_tensor = torch.tensor([input_values]).to(device)
        logits = model(input_tensor).logits
        predicted_ids = torch.argmax(logits, dim=-1)
        transcription = processor.batch_decode(predicted_ids)[0]

    # Display transcription
    st.success("📄 Transcription:")
    st.write(transcription)

    # ================================
    # 7️⃣ Fine-Tune Model with User Correction
    # ================================
    user_correction = st.text_area("🔧 Correct the transcription (if needed):", transcription)

    if st.button("Fine-Tune with Correction"):
        if user_correction:
            corrected_input = processor.tokenizer(user_correction).input_ids

            # Dynamically add new example to dataset
            dataset = dataset.add_item({"input_values": input_values, "labels": corrected_input})

            # Perform quick re-training (1 epoch)
            trainer.args.num_train_epochs = 1
            trainer.train()

            st.success("✅ Model fine-tuned with new correction! Try another audio file.")