scripts/zero_out_speech.py

"""
Zero out the speech channel (channel 0) from all WAV files in audio_mixtures_old_both
and strip speech from all JSON command variant targets.

Usage:
    python scripts/zero_out_speech.py \
        --src  data/audio_mixtures_old_both \
        --dst  data/audio_mixtures_no_speech \
        --splits train test test_700
"""

import argparse
import json
import os
import glob
from pathlib import Path

import torch
import torchaudio


def process_json(metadata):
    """Strip speech from all command variant targets. Returns count of empty-target variants."""
    empty_count = 0

    # List format (train/test)
    if "command_variants" in metadata:
        for variant in metadata["command_variants"]:
            variant["target_sources"] = [s for s in variant["target_sources"] if s != "speech"]
            variant["target_channels"] = [c for c in variant["target_channels"] if c != 0]
            if len(variant["target_sources"]) == 0:
                empty_count += 1

    # Singular dict format (test_700 pre-computed)
    if "command_variant" in metadata and isinstance(metadata["command_variant"], dict):
        cv = metadata["command_variant"]
        cv["target_sources"] = [s for s in cv["target_sources"] if s != "speech"]
        cv["target_channels"] = [c for c in cv["target_channels"] if c != 0]
        if len(cv["target_sources"]) == 0:
            empty_count += 1

    return empty_count


def process_split(src_dir, dst_dir):
    """Process all WAV/JSON pairs in a split directory."""
    os.makedirs(dst_dir, exist_ok=True)

    wav_files = sorted(glob.glob(os.path.join(src_dir, "*.wav")))
    total_files = 0
    total_empty_variants = 0

    for wav_path in wav_files:
        basename = os.path.splitext(os.path.basename(wav_path))[0]
        json_path = os.path.join(src_dir, basename + ".json")
        dst_wav = os.path.join(dst_dir, basename + ".wav")
        dst_json = os.path.join(dst_dir, basename + ".json")

        # --- WAV: zero out channel 0 (speech) ---
        audio, sr = torchaudio.load(wav_path)  # (5, T)
        audio[0, :] = 0.0
        torchaudio.save(dst_wav, audio, sr)

        # --- JSON: strip speech from targets ---
        if os.path.exists(json_path):
            with open(json_path, "r") as f:
                metadata = json.load(f)

            empty_count = process_json(metadata)
            total_empty_variants += empty_count

            with open(dst_json, "w") as f:
                json.dump(metadata, f, indent=2)

        total_files += 1
        if total_files % 500 == 0:
            print(f"  Processed {total_files}/{len(wav_files)} files...")

    return total_files, total_empty_variants


def main():
    parser = argparse.ArgumentParser(description="Zero out speech channel from audio_mixtures dataset")
    parser.add_argument("--src", required=True, help="Source audio_mixtures directory")
    parser.add_argument("--dst", required=True, help="Destination directory")
    parser.add_argument("--splits", nargs="+", default=["train", "test", "test_700"],
                        help="Split directories to process")
    args = parser.parse_args()

    print(f"Source: {args.src}")
    print(f"Destination: {args.dst}")
    print(f"Splits: {args.splits}")
    print()

    os.makedirs(args.dst, exist_ok=True)

    grand_total_files = 0
    grand_total_empty = 0

    for split in args.splits:
        src_split = os.path.join(args.src, split)
        dst_split = os.path.join(args.dst, split)

        if not os.path.isdir(src_split):
            print(f"Skipping {split}/ (not found)")
            continue

        print(f"Processing {split}/...")
        n_files, n_empty = process_split(src_split, dst_split)
        grand_total_files += n_files
        grand_total_empty += n_empty
        print(f"  Done: {n_files} files, {n_empty} empty-target variants (noise-cancelling)")
        print()

    print("=" * 50)
    print(f"Total files processed: {grand_total_files}")
    print(f"Total empty-target variants: {grand_total_empty}")
    print(f"Output at: {args.dst}")


if __name__ == "__main__":
    main()