Your First Copy
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1
Select Source
Click "Select Source", or drag & drop a folder directly from Finder. Choose the files or folders you want to copy.
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2
Select Destination
Choose an external drive or another folder under "Select Destination". You can add multiple destinations.
⚠ Note: If the destination is ExFAT-formatted, a warning appears. See "ExFAT Warning" below for the reason and what to do.
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3
Choose a Verify Mode and Start
Pick a verification level and click "Start Copy". After the copy finishes, MasterCopy automatically re-reads the written data and checks it.
Mode Speed Use For Eject Fast Verify Same as Finder Daily use, on-set work Immediately after completion Deep Verify About 2x time Master delivery, archive After verification complete Note: Verification runs after the copy. Fast Verify re-reads only the destination; Deep Verify re-reads both source and destination to compare.
After Completion
When the copy finishes, verification runs automatically and an MHL (manifest) file is generated. You are done when the checkmark appears.
MHL file: An ASC MHL 2.0 manifest is saved in the _MasterCopy_Reports/ folder on the destination. Use it as proof of data integrity for delivery.
※ If you chose Deep Verify, wait for "Verification Complete" before ejecting.
Features
Fast Verify
Validates destination files after copy by re-reading them. Same speed as Finder with guaranteed safety.
| Technology | XXH3-128 ハッシュ検証 |
|---|---|
| Speed | Destination only (lightweight) |
| Safety | 99.99% (collision: 1/2^128) |
| Use For | Ideal for daily backups and on-set work |
Point: Verification completes quickly as only destination is verified. Can eject immediately after verification.
Deep Verify
Re-reads both source and destination after copy. Industry-standard double-check.
| Technology | ソース+コピー先の両方を検証 |
|---|---|
| Speed | Approximately 2x Fast Verify time |
| Safety | 99.9999% (industry standard) |
| Use For | Master delivery, long-term archiving |
Warning: Wait for "Verification Complete" before ejecting.
Verify Mode Comparison
| Fast Verify | Deep Verify | |
|---|---|---|
| Method | コピー先のみ検証 コピー後に再読み |
ソース+コピー先検証 両方を再読み |
| Speed | ★★★★★ | ★★★☆☆ |
| Safety | ★★★★☆ | ★★★★★ |
| Recommended For | 現場作業、日常バックアップ | マスター納品、アーカイブ |
Incremental Copy (when a same-named folder exists)
If a folder with the same name exists at the destination, MasterCopy asks "How do you want to place these?" You can choose:
- Merge into this folder: Adds only the missing files. Files with the same name but different contents are kept separately in _versions/, so both are preserved (nothing is overwritten).
- Fast diff copy: Files matching size and modified date are skipped without reading their contents; only the missing files are copied. Fastest, but no content hash check.
- Verify: Hash-checks every same-named file and shows the confirmed result (same / different / new). You then choose whether to merge. Reads everything, so it takes time.
- Use a separate folder: Copies to a separate folder so it does not mix with the existing one.
- Re-copy everything: Ignores existing files and copies everything again.
Safe: None of these modify the source. No half-written, broken files are left if interrupted, and restarting with the same settings copies only the rest (resume).
ExFAT Warning
⚠ Important
ExFAT-formatted drives are prone to corruption if disconnected mid-write.
ExFAT is convenient because it works on both Windows and Mac, but it keeps no change journal. MasterCopy detects when the destination is ExFAT and shows a warning.
Why is it dangerous?
- With no change journal, an unplugged cable or power loss mid-copy can corrupt the whole drive directory, not just a single file
- Pulling the drive without ejecting can leave a write unfinished and corrupted
- Timestamps are recorded only in 2-second steps, making differential-copy checks coarser than APFS/HFS+
Solution: Never pull the drive mid-copy or mid-verify—always eject first. For long-term storage and master delivery, prefer APFS (macOS standard) or HFS+. If you must use ExFAT, double-check with Deep Verify.
MHL Output
Automatically generates manifest files in ASC MHL 2.0 format. Can be used as industry-standard delivery documentation.
Main Uses
- Delivery: Prove data integrity by delivering with MHL file
- Later verification: Can verify with other MHL-compatible tools (yocto, Silverstack, etc.)
- Archive: Long-term data integrity guarantee
- DIT workflow: Maintain chain from on-set to editing room
出力先: コピー先/_MasterCopy_Reports/*.mhl
ASC MHL ヒストリー（履歴チェーン）
.mhl マニフェストに加えて、コピーの履歴チェーン（ASC MHL History）も既定で自動生成します。「いつ・どのハッシュで」コピー／検証したかを世代をまたいで追跡でき、撮影〜編集〜アーカイブのチェーン・オブ・カストディ（受け渡しの証跡）になります。
出力先: コピー先/ascmhl/（ascmhl_chain.xml ほか）