Added manifest and download/prepare script

scripts/download.py

@@ -0,0 +1,159 @@
+#!/usr/bin/env python
+"""
+Downloads and extracts additional data from the Cityscapes dataset, moving the
+required files to (existing) data directory.
+"""
+
+import tempfile
+from tqdm import tqdm
+import os
+import re
+from pathlib import Path
+import shutil
+import zipfile
+import argparse
+import pandas as pd
+
+from cityscapesscripts.download import downloader
+
+PACKAGE_TO_VARIABLE = {
+    "vehicle_sequence": "vehicle",
+    "timestamp_sequence": "timestamp",
+    "leftImg8bit_sequence_trainvaltest": "image",
+    "camera_trainvaltest": "camera",
+}
+
+
+def parse_args() -> argparse.Namespace:
+    parser = argparse.ArgumentParser(
+        description="Download and extract the Cityscapes dataset."
+    )
+
+    parser.add_argument(
+        "downloads_dir",
+        type=Path,
+        help="Path to the directory where ZIP files are/will be stored (e.g., 'downloads').",
+    )
+    parser.add_argument(
+        "data_dir",
+        type=Path,
+        help="Path to the directory where extracted files should be moved (e.g., 'data').",
+    )
+    parser.add_argument(
+        "manifest_file",
+        type=Path,
+        help="Path to the manifest file (e.g., 'manifest.csv').",
+    )
+    return parser.parse_args()
+
+
+def read_manifest(manifest_file: str) -> pd.DataFrame:
+    """
+    Read the manifest file and return a DataFrame.
+    """
+    df = pd.read_csv(manifest_file, index_col="primary_key")
+    assert "split" in df.columns, "Missing 'split' column in manifest."
+    assert "sequence" in df.columns, "Missing 'sequence' column in manifest."
+    assert "frame" in df.columns, "Missing 'frame' column in manifest."
+    return df
+
+
+def download_files(downloads_dir: str, zip_files: list[str]):
+    if not zip_files:
+        print("No files to download.")
+        return
+
+    session = downloader.login()
+
+    downloader.download_packages(
+        session=session,
+        package_names=zip_files,
+        destination_path=downloads_dir,
+        resume=True,
+    )
+
+
+def unzip_and_move(
+    pkg: str,
+    downloads_dir: Path,
+    data_dir: Path,
+    manifest: pd.DataFrame,
+    source_split: str,
+):
+    """
+    Unzip, rename, and move the requested split files for a single package.
+    """
+    zip_path = downloads_dir / f"{pkg}.zip"
+    pkg_type = PACKAGE_TO_VARIABLE[pkg]
+
+    re_name = re.compile(r"([^_]*_[^_]*_[^_]*)_.*")
+
+    if not zip_path.is_file():
+        print(f"Warning: ZIP file not found => {zip_path}. Skipping...")
+        return
+
+    print(f"Processing: {zip_path}")
+
+    with tempfile.TemporaryDirectory() as td, zipfile.ZipFile(zip_path, "r") as zf:
+        names = zf.namelist()
+        for member in tqdm(names):
+            if f"/{source_split}/" not in member:
+                continue
+
+            # Extract the file and get its new path in the temporary directory
+            res_path = Path(zf.extract(member, td))
+
+            if res_path.is_dir():
+                continue
+
+            # Read the manifest to find the specification of this sample
+            primary_key = re_name.sub(r"\1", res_path.stem)
+            sample = manifest.loc[primary_key]
+
+            # New name is: split/<sequence>/<frame>.<type>.<ext>
+            new_path = (
+                data_dir
+                / sample["split"]
+                / "{:06d}".format(sample["sequence"])
+                / "{:06d}.{:s}{:s}".format(sample["frame"], pkg_type, res_path.suffix)
+            )
+            new_path.parent.mkdir(parents=True, exist_ok=True)
+
+            shutil.move(res_path, new_path)
+
+
+def main():
+    args = parse_args()
+
+    # Create directories if not exists
+    for dir in (args.downloads_dir, args.data_dir):
+        os.makedirs(dir, exist_ok=True)
+
+    # Read the manifest file
+    manifest = read_manifest(args.manifest_file)
+
+    # Prepare list of package zip files
+    packages = list(PACKAGE_TO_VARIABLE.keys())
+    zip_files = [f"{pkg}.zip" for pkg in packages]
+
+    # Filter out existing ZIPs
+    download_list = []
+    for zf in zip_files:
+        zf_path = os.path.join(args.downloads_dir, zf)
+        if os.path.isfile(zf_path):
+            print(f"Already downloaded: {zf_path}")
+        else:
+            download_list.append(zf)
+
+    # Download missing ZIP files using csDownload directly
+    download_files(args.downloads_dir, download_list)
+
+    # Unzip, rename, and move each package
+    for pkg in packages:
+        unzip_and_move(pkg, args.downloads_dir, args.data_dir, manifest, "val")
+
+    print(f"Successfully processed: {packages}")
+
+
+if __name__ == "__main__":
+    main()