NSZ file converter

NSZ file converter analyzes the input NSZ archive, detects the header, and performs data transformation without altering the original payload semantics. It can decompress NSZ to a raw binary or to a standard archive, or re-pack the data into NSZ or ZIP containers depending on the selected target. The implementation abstracts compression details behind a stable interface, enabling reliable conversions across platforms. By operating at the byte level, the tool avoids drift in data interpretation and maintains compatibility with downstream tools that expect uncompressed saves or standard archives. The process emphasizes correctness, auditability, and repeatable results, with deterministic outputs even for large or multi‑part saves. It records provenance metadata when requested to support traceability in archival workflows.\n\nIt benefits game preservationists, QA engineers, and platform engineers who manage Nintendo save data, backups, and cross‑device migrations. The tool’s value lies in deterministic output, clear naming conventions, and optional validation checks that confirm the integrity of converted data. Unique differentiators include configurable compression_level, output basename rules to prevent overwrites, and an integrated integrity check that compares checksums before and after transformation. It supports both single-file and batch processing, enabling scripted workflows for large libraries. The results are designed to be portable across environments, with transparent extension handling and predictable file sizes.\n\nCore features include input validation, format negotiation between NSZ, raw, and ZIP, lossless transformation, and batch processing. Users can specify target_format, compression_level, and output basename; the system returns an output file with a predictable extension, a status, and a concise log. The tool provides optional pre-flight checks to catch corrupted data and a post‑conversion verification to ensure parity with the source. Typical use cases include backing up saves prior to firmware updates, sharing data between devices, cross‑platform data preservation, and long‑term archiving. The design prioritizes reliability, reproducibility, and auditability across diverse workflows.