README.md

---
license: cc-by-4.0
task_categories:
- text-generation
- text-to-speech
- automatic-speech-recognition
tags:
- Urdu
language:
- ur
pretty_name: 'Munch Hashed Index'
---
# Munch Hashed Index - Lightweight Audio Reference Dataset

[![Original Dataset](https://img.shields.io/badge/🤗%20Original-Munch-blue)](https://huggingface.co/datasets/humair025/Munch)
[![Hashed Index](https://img.shields.io/badge/🤗%20Index-hashed__data-green)](https://huggingface.co/datasets/humair025/hashed_data)
[![Size](https://img.shields.io/badge/Size-~1GB-brightgreen)]()
[![Original Size](https://img.shields.io/badge/Original-1.27TB-orange)]()
[![Space Saved](https://img.shields.io/badge/Space%20Saved-99.92%25-success)]()

## 📖 Overview

**Munch Hashed Index** is a lightweight reference dataset that provides SHA-256 hashes for all audio files in the [Munch Urdu TTS Dataset](https://huggingface.co/datasets/humair025/Munch). Instead of storing 1.27 TB of raw audio, this index stores only metadata and cryptographic hashes, enabling:

- ✅ **Fast duplicate detection** across 4.17 million audio samples
- ✅ **Efficient dataset exploration** without downloading terabytes
- ✅ **Quick metadata queries** (voice distribution, text stats, etc.)
- ✅ **Selective audio retrieval** - download only what you need
- ✅ **Storage efficiency** - 99.92% space reduction (1.27 TB → ~1 GB)

### 🔗 Related Datasets

- **Original Dataset**: [humair025/Munch](https://huggingface.co/datasets/humair025/Munch) - Full audio dataset (1.27 TB)
- **This Index**: [humair025/hashed_data](https://huggingface.co/datasets/humair025/hashed_data) - Hashed reference (~1 GB)
- **Munch-1 (v2)**: [humair025/munch-1](https://huggingface.co/datasets/humair025/munch-1) - Newer version (3.28 TB, 3.86M samples)
- **Munch-1 Index**: [humair025/hashed_data_munch_1](https://huggingface.co/datasets/humair025/hashed_data_munch_1) - Index for v2

---

## 🎯 What Problem Does This Solve?

### The Challenge
The original [Munch dataset](https://huggingface.co/datasets/humair025/Munch) contains:
- 📊 **4,167,500 audio-text pairs**
- 💾 **1.27 TB total size**
- 📦 **~8,300 separate parquet files**

This makes it difficult to:
- ❌ Quickly check if specific audio exists
- ❌ Find duplicate audio samples
- ❌ Explore metadata without downloading everything
- ❌ Work on limited bandwidth/storage

### The Solution
This hashed index provides:
- ✅ **All metadata** (text, voice, timestamps) without audio bytes
- ✅ **SHA-256 hashes** for every audio file (unique fingerprint)
- ✅ **File references** (which parquet contains each audio)
- ✅ **Fast queries** - search 4.17M records in seconds
- ✅ **Retrieve on demand** - download only specific audio when needed

---

## 🚀 Quick Start

### Installation

```bash
pip install datasets pandas
```

### Basic Usage

```python
from datasets import load_dataset
import pandas as pd

# Load the entire hashed index (fast - only ~1 GB!)
ds = load_dataset("humair025/hashed_data", split="train")
df = pd.DataFrame(ds)

print(f"Total records: {len(df)}")
print(f"Unique audio hashes: {df['audio_bytes_hash'].nunique()}")
print(f"Voices: {df['voice'].unique()}")
```

### Find Duplicates

```python
# Check for duplicate audio
duplicates = df[df.duplicated(subset=['audio_bytes_hash'], keep=False)]

if len(duplicates) > 0:
    print(f"⚠️  Found {len(duplicates)} duplicate rows")
    print(f"   Unique audio files: {df['audio_bytes_hash'].nunique()}")
    print(f"   Redundancy: {(1 - df['audio_bytes_hash'].nunique()/len(df))*100:.2f}%")
else:
    print("✅ No duplicates found!")
```

### Search by Voice

```python
# Find all "ash" voice samples
ash_samples = df[df['voice'] == 'ash']
print(f"Ash voice samples: {len(ash_samples)}")

# Get file containing first ash sample
first_ash = ash_samples.iloc[0]
print(f"File: {first_ash['parquet_file_name']}")
print(f"Text: {first_ash['text']}")
```

### Search by Text

```python
# Find audio for specific text
query = "یہ ایک نمونہ"
matches = df[df['text'].str.contains(query, na=False)]
print(f"Found {len(matches)} matches")
```

### Retrieve Original Audio

```python
from datasets import load_dataset as load_original
import numpy as np
from scipy.io import wavfile
import io

def get_audio_by_hash(audio_hash, index_df):
    """Retrieve original audio bytes using the hash"""
    # Find the row with this hash
    row = index_df[index_df['audio_bytes_hash'] == audio_hash].iloc[0]
    
    # Download only the specific parquet file containing this audio
    ds = load_original(
        "humair025/Munch",
        data_files=[row['parquet_file_name']],
        split="train"
    )
    
    # Find matching row by ID
    for audio_row in ds:
        if audio_row['id'] == row['id']:
            return audio_row['audio_bytes']
    
    return None

# Example: Get audio for first row
row = df.iloc[0]
audio_bytes = get_audio_by_hash(row['audio_bytes_hash'], df)

# Convert to WAV and play
def pcm16_to_wav(pcm_bytes, sample_rate=22050):
    audio_array = np.frombuffer(pcm_bytes, dtype=np.int16)
    wav_io = io.BytesIO()
    wavfile.write(wav_io, sample_rate, audio_array)
    wav_io.seek(0)
    return wav_io

wav_io = pcm16_to_wav(audio_bytes)
# In Jupyter: IPython.display.Audio(wav_io, rate=22050)
```

---

## 📊 Dataset Structure

### Data Fields

| Field | Type | Description |
|-------|------|-------------|
| `id` | int | Original paragraph ID from source dataset |
| `parquet_file_name` | string | Source file in [Munch](https://huggingface.co/datasets/humair025/Munch) dataset |
| `text` | string | Original Urdu text |
| `transcript` | string | TTS transcript (may differ from input) |
| `voice` | string | Voice used (alloy, echo, fable, onyx, nova, shimmer, coral, verse, ballad, ash, sage, amuch, dan) |
| `audio_bytes_hash` | string | SHA-256 hash of audio_bytes (64 hex chars) |
| `audio_size_bytes` | int | Size of original audio in bytes |
| `timestamp` | string | ISO timestamp of generation (nullable) |
| `error` | string | Error message if generation failed (nullable) |

### Example Row

```python
{
    'id': 42,
    'parquet_file_name': 'tts_data_20251203_130314_83ab0706.parquet',
    'text': 'یہ ایک نمونہ متن ہے۔',
    'transcript': 'یہ ایک نمونہ متن ہے۔',
    'voice': 'ash',
    'audio_bytes_hash': 'a3f7b2c8e9d1f4a5b6c7d8e9f0a1b2c3d4e5f6a7b8c9d0e1f2a3b4c5d6e7f8a9',
    'audio_size_bytes': 52340,
    'timestamp': '2025-12-03T13:03:14.123456',
    'error': None
}
```

---

## 🎯 Use Cases

### 1. **Dataset Quality Analysis**
```python
# Check for duplicates
unique_ratio = df['audio_bytes_hash'].nunique() / len(df)
print(f"Unique audio ratio: {unique_ratio*100:.2f}%")

# Analyze voice distribution
voice_dist = df['voice'].value_counts()
print(voice_dist)

# Find failed generations
failed = df[df['error'].notna()]
print(f"Failed generations: {len(failed)}")
```

### 2. **Efficient Data Exploration**
```python
# Browse dataset without downloading audio
print(df[['id', 'text', 'voice', 'audio_size_bytes']].head(20))

# Filter by criteria
short_audio = df[df['audio_size_bytes'] < 30000]
long_text = df[df['text'].str.len() > 200]
```

### 3. **Selective Download**
```python
# Download only specific voices
ash_files = df[df['voice'] == 'ash']['parquet_file_name'].unique()
ds = load_dataset("humair025/Munch", data_files=list(ash_files))

# Download only short audio samples
small_files = df[df['audio_size_bytes'] < 40000]['parquet_file_name'].unique()
ds = load_dataset("humair025/Munch", data_files=list(small_files[:10]))
```

### 4. **Deduplication Pipeline**
```python
# Create deduplicated subset
df_unique = df.drop_duplicates(subset=['audio_bytes_hash'], keep='first')
print(f"Original: {len(df)} rows")
print(f"Unique: {len(df_unique)} rows")
print(f"Duplicates removed: {len(df) - len(df_unique)}")

# Save unique references
df_unique.to_parquet('unique_audio_index.parquet')
```

### 5. **Audio Similarity Search**
```python
# Find audio with similar hash prefixes (for clustering)
target_hash = df.iloc[0]['audio_bytes_hash']
prefix = target_hash[:8]

similar = df[df['audio_bytes_hash'].str.startswith(prefix)]
print(f"Similar audio candidates: {len(similar)}")
```

---

## 📈 Dataset Statistics

### Size Comparison

| Metric | Original Dataset | Hashed Index | Reduction |
|--------|------------------|--------------|-----------|
| Total Size | 1.27 TB | ~1 GB | **99.92%** |
| Records | 4,167,500 | 4,167,500 | Same |
| Files | ~8,300 parquet | Consolidated | **~8,300× fewer** |
| Download Time (100 Mbps) | ~28 hours | ~90 seconds | **~1,100×** |
| Load Time | Minutes-Hours | Seconds | **~100×** |
| Memory Usage | Cannot fit in RAM | ~2-3 GB RAM | **Fits easily** |

### Content Statistics

```
📊 Dataset Overview:
   Total Records: 4,167,500
   Total Files: ~8,300 parquet files
   Voices: 13 (alloy, echo, fable, onyx, nova, shimmer, coral, verse, ballad, ash, sage, amuch, dan)
   Language: Urdu (primary)
   Avg Audio Size: ~50-60 KB per sample
   Avg Duration: ~3-5 seconds per sample
   Total Duration: ~3,500-5,800 hours of audio
```

---

## 🔧 Advanced Usage

### Batch Analysis

```python
# Analyze all hash files
from datasets import load_dataset

ds = load_dataset("humair025/hashed_data", split="train")
df = pd.DataFrame(ds)

# Group by voice
voice_stats = df.groupby('voice').agg({
    'id': 'count',
    'audio_size_bytes': 'mean',
    'audio_bytes_hash': 'nunique'
}).rename(columns={
    'id': 'total_samples',
    'audio_size_bytes': 'avg_size',
    'audio_bytes_hash': 'unique_audio'
})

print(voice_stats)
```

### Cross-Reference with Original

```python
# Check if a hash exists in original dataset
def verify_hash_exists(audio_hash, parquet_file):
    """Verify a hash actually exists in the original dataset"""
    from datasets import load_dataset
    import hashlib
    
    ds = load_dataset(
        "humair025/Munch",
        data_files=[parquet_file],
        split="train"
    )
    
    for row in ds:
        computed_hash = hashlib.sha256(row['audio_bytes']).hexdigest()
        if computed_hash == audio_hash:
            return True
    
    return False

# Verify first entry
first_row = df.iloc[0]
exists = verify_hash_exists(
    first_row['audio_bytes_hash'],
    first_row['parquet_file_name']
)
print(f"Hash verified: {exists}")
```

### Export Unique Dataset

```python
# Create a new dataset with only unique audio
df_unique = df.drop_duplicates(subset=['audio_bytes_hash'], keep='first')

# Get list of unique parquet files needed
unique_files = df_unique['parquet_file_name'].unique()

print(f"Unique audio samples: {len(df_unique)}")
print(f"Files needed: {len(unique_files)} out of {df['parquet_file_name'].nunique()}")

# Calculate space savings
original_size = len(df) * df['audio_size_bytes'].mean()
unique_size = len(df_unique) * df_unique['audio_size_bytes'].mean()
savings = (1 - unique_size/original_size) * 100

print(f"Space savings: {savings:.2f}%")
```

---

## 🛠️ How This Index Was Created

This dataset was generated using an automated pipeline:

### Processing Pipeline
1. **Batch Download**: Download 40 parquet files at a time from source
2. **Hash Computation**: Compute SHA-256 for each audio_bytes field
3. **Metadata Extraction**: Extract text, voice, and other metadata
4. **Save & Upload**: Save hash file, upload to HuggingFace
5. **Clean Up**: Delete local cache to save disk space
6. **Resume**: Track processed files, skip already-processed

### Pipeline Features
- ✅ **Resumable**: Checkpoint system tracks progress
- ✅ **Memory Efficient**: Processes in batches, clears cache
- ✅ **Error Tolerant**: Skips corrupted files, continues processing
- ✅ **No Duplicates**: Checks target repo to avoid reprocessing
- ✅ **Automatic Upload**: Streams results to HuggingFace

### Technical Details
```python
# Hash computation
import hashlib
hash = hashlib.sha256(audio_bytes).hexdigest()

# Batch size: 40 files per batch
# Processing time: ~4-6 hours for full dataset
# Output: Multiple hashed_*.parquet files
```

---

## 📊 Performance Metrics

### Query Performance

```python
import time

# Load index
start = time.time()
ds = load_dataset("humair025/hashed_data", split="train")
df = pd.DataFrame(ds)
print(f"Load time: {time.time() - start:.2f}s")

# Query by hash
start = time.time()
result = df[df['audio_bytes_hash'] == 'target_hash']
print(f"Hash lookup: {(time.time() - start)*1000:.2f}ms")

# Query by voice
start = time.time()
result = df[df['voice'] == 'ash']
print(f"Voice filter: {(time.time() - start)*1000:.2f}ms")
```

**Expected Performance**:
- Load full dataset: 10-30 seconds
- Hash lookup: < 10 milliseconds  
- Voice filter: < 50 milliseconds
- Full dataset scan: < 5 seconds

---

## 🔗 Integration with Original Dataset

### Workflow Example

```python
# 1. Query the index (fast)
df = pd.DataFrame(load_dataset("humair025/hashed_data", split="train"))
target_rows = df[df['voice'] == 'ash'].head(100)

# 2. Get unique parquet files
files_needed = target_rows['parquet_file_name'].unique()

# 3. Download only needed files (selective)
from datasets import load_dataset
ds = load_dataset(
    "humair025/Munch",
    data_files=list(files_needed),
    split="train"
)

# 4. Match by ID to get audio
for idx, row in target_rows.iterrows():
    for audio_row in ds:
        if audio_row['id'] == row['id']:
            # Process audio_bytes
            audio = audio_row['audio_bytes']
            break
```

---

## 📜 Citation

If you use this dataset in your research, please cite both the original dataset and this index:

### BibTeX

```bibtex
@dataset{munch_hashed_index_2025,
  title={Munch Hashed Index: Lightweight Reference Dataset for Urdu TTS},
  author={Munir, Humair},
  year={2025},
  publisher={Hugging Face},
  howpublished={\url{https://huggingface.co/datasets/humair025/hashed_data}},
  note={Index of humair025/Munch dataset with SHA-256 audio hashes}
}

@dataset{munch_urdu_tts_2025,
  title={Munch: Large-Scale Urdu Text-to-Speech Dataset},
  author={Munir, Humair},
  year={2025},
  publisher={Hugging Face},
  howpublished={\url{https://huggingface.co/datasets/humair025/Munch}}
}
```

### APA Format

```
Munir, H. (2025). Munch Hashed Index: Lightweight Reference Dataset for Urdu TTS 
[Dataset]. Hugging Face. https://huggingface.co/datasets/humair025/hashed_data

Munir, H. (2025). Munch: Large-Scale Urdu Text-to-Speech Dataset [Dataset]. 
Hugging Face. https://huggingface.co/datasets/humair025/Munch
```

### MLA Format

```
Munir, Humair. "Munch Hashed Index: Lightweight Reference Dataset for Urdu TTS." 
Hugging Face, 2025, https://huggingface.co/datasets/humair025/hashed_data.

Munir, Humair. "Munch: Large-Scale Urdu Text-to-Speech Dataset." Hugging Face, 2025, 
https://huggingface.co/datasets/humair025/Munch.
```

---

## 🤝 Contributing

### Report Issues
Found a problem? Please open an issue:
- Missing hash files
- Incorrect metadata
- Hash mismatches
- Documentation improvements

### Suggest Improvements
We welcome suggestions for:
- Additional metadata fields
- Better indexing strategies
- Integration examples
- Use case documentation

---

## 📄 License

This index dataset inherits the license from the original [Munch dataset](https://huggingface.co/datasets/humair025/Munch):

**Creative Commons Attribution 4.0 International (CC-BY-4.0)**

You are free to:
- ✅ **Share** — copy and redistribute
- ✅ **Adapt** — remix, transform, build upon
- ✅ **Commercial use** — use commercially

Under the terms:
- 📝 **Attribution** — Give appropriate credit to original dataset

---

## 🔗 Important Links

- 🎧 [**Original Audio Dataset**](https://huggingface.co/datasets/humair025/Munch) - Full 1.27 TB audio
- 📊 [**This Hashed Index**](https://huggingface.co/datasets/humair025/hashed_data) - Lightweight reference
- 🔄 [**Munch-1 (v2)**](https://huggingface.co/datasets/humair025/munch-1) - Newer version (3.28 TB)
- 📇 [**Munch-1 Index**](https://huggingface.co/datasets/humair025/hashed_data_munch_1) - Index for v2
- 💬 [**Discussions**](https://huggingface.co/datasets/humair025/hashed_data/discussions) - Ask questions
- 🐛 [**Report Issues**](https://huggingface.co/datasets/humair025/hashed_data/discussions) - Bug reports

---

## ❓ FAQ

### Q: Why use hashes instead of audio?
**A:** Hashes provide unique fingerprints for audio files while taking only 64 bytes vs ~50KB per audio. This enables duplicate detection and fast queries without storing massive audio files.

### Q: Can I reconstruct audio from hashes?
**A:** No. SHA-256 is a one-way cryptographic hash. You must download the original audio from the [Munch dataset](https://huggingface.co/datasets/humair025/Munch) using the file reference provided.

### Q: How accurate are the hashes?
**A:** SHA-256 has virtually zero collision probability. If two hashes match, the audio is identical (byte-for-byte).

### Q: How do I get the actual audio?
**A:** Use the `parquet_file_name` and `id` fields to locate and download the specific audio from the [original dataset](https://huggingface.co/datasets/humair025/Munch). See examples above.

### Q: Is this dataset complete?
**A:** Yes, this index covers all 4,167,500 rows across all ~8,300 parquet files from the original Munch dataset.

### Q: What's the difference between this and Munch-1 Index?
**A:** This indexes the original Munch dataset (1.27 TB, 4.17M samples). The [Munch-1 Index](https://huggingface.co/datasets/humair025/hashed_data_munch_1) indexes the newer Munch-1 dataset (3.28 TB, 3.86M samples).

### Q: Can I contribute?
**A:** Yes! Help verify hashes, report inconsistencies, or suggest improvements via discussions.

---

## 🙏 Acknowledgments

- **Original Dataset**: [humair025/Munch](https://huggingface.co/datasets/humair025/Munch)
- **TTS Generation**: OpenAI-compatible models
- **Voices**: 13 high-quality voices (alloy, echo, fable, onyx, nova, shimmer, coral, verse, ballad, ash, sage, amuch, dan)
- **Infrastructure**: HuggingFace Datasets platform
- **Hashing**: SHA-256 cryptographic hash function

---

## 📝 Version History

- **v1.0.0** (December 2025): Initial release
  - Processed all ~8,300 parquet files
  - 4,167,500 audio samples indexed
  - SHA-256 hashes computed for all audio
  - ~99.92% space reduction achieved

---

**Last Updated**: December 2025

**Status**: ✅ Complete

---

💡 **Pro Tip**: Start with this lightweight index to explore the dataset, then selectively download only the audio you need from the [original Munch dataset](https://huggingface.co/datasets/humair025/Munch)!