History and generations
A folder's history is its ascmhl folder. It holds one chain file and one manifest for each time a job recorded that folder. Each job adds one generation at the end. No job edits an earlier generation.
What the expander shows
The detail pane of a verify job or a seal job holds a History row. Click it to open it. Each row inside is one generation:
0002 · 2026-09-12 13:03
studio-01 — mediacopy3000 0.1.0.0 · xxh64 · transferA generation with failures ends its second line with · 2 failures.
| The row says | What it means |
|---|---|
0002 | The generation number. Generations are numbered from 1 and never reused. |
2026-09-12 13:03 | When the generation was written. |
studio-01 | The computer that wrote it. |
mediacopy3000 0.1.0.0 | The tool that wrote it, and its version. |
xxh64 | The hash format of that generation. |
transfer | What was done. |
· 2 failures | How many files did not agree. The row turns red. |
An offload has no such row. Its destination carries the media source's history and one new generation, and a verify of the destination shows them. A resumed offload carries the same history as a fresh one.
What a process word means
The specification allows three, and no others:
| Word | What it means |
|---|---|
in-place | The files were hashed where they already were. A seal and a verify both write this. |
transfer | The files were copied into this folder, and the copies were hashed here. |
flatten | The files were copied into one folder without their directory structure. |
Why the chain matters
The chain file is ascmhl/ascmhl_chain.xml. It names every generation in order, and it holds a c4 hash of each manifest file.
The chain, not the folder listing, says what the history holds. The c4 hash is there so that a reader can tell whether a manifest was changed after it was written.
MediaCopy 3000 writes that hash, and fills it in for an older entry that has none. It does not compare a manifest against it when it reads a history. Another ASC MHL tool can make that check.
MediaCopy 3000 refuses a history whose chain names a manifest that is not there, and one whose chain cannot be read. Both are blockers. The Findings page lists them.