MAN relocation Confirmed

At a glance

Magic

none - operates on a decompressed scene MAN (header, three partition record-offset tables, record region, then the section chain)

Where on disc

Every scene bundle's LZS-compressed MAN, described by the scene_asset_table descriptor word (type<<24)|size

Stride

u24LE record-offset entries from 0x2B; the data region starts at 0x2B + 3 × total_records

Parser / editor

legaia_asset::man_edit (apply_dest_edits, apply_text_edits, rebuild_man, validate)

Confidence

Confirmed - dispatch path pinned by a live PCSX-Redux trace; disc-wide corpus census; round-trip backstop re-walks every record (how we know)

Used by

Door randomizer, Translation packs

Why resize a record at all?

Two consumers force the problem:

• The door randomizer. Its door shuffle re-points a scene exit at a different destination. Because the destination is an inline name, swapping town01 for a longer scene name grows the record; without the fixups below, every record after it - and the tables that index them - would decode as garbage.
• Translation. A language pack's dialog line that runs longer than the English original grows its record the same way. Growth is budgeted by the MAN's on-disc footprint: the recompressed file must still fit its original slot.

A resize is safe because the doors are reached at runtime through an offset table the format already exposes, not through absolute addresses scattered in code. Fix the table and every door stays addressable.

Relocation surface

A mid-buffer insert or delete of delta bytes at a record needs four fixups. Everything before the edit stays put; everything after it shifts.

How a door is reached: the partition-2 table

The field VM is the interpreter that runs a scene's event bytecode. A MAN's records are grouped into three partitions; partition 2 holds the named event records, doors included. A 0x3F op carries its destination inline:

On a transition the field controller sets the VM bytecode base to man_base + data_region + partition2[slot] and runs that record by fall-through - flag sets, an effect, a yield, the 0x3F warp, its entry trailer, then a self-loop. Selection is by stable slot index, so the offset table is the door index and resizing a record is safe once the table is fixed.

Safety

• Absolute-reference ops (0x45 0xC0 camera-apply, 0x4E abs-jump) are record-local and cannot be relocated blindly. apply_dest_edits errors out if it finds one in an edited record - none exist in the retail corpus - and the caller leaves that scene unchanged.
• Validate. man_edit::validate re-parses and re-walks the rebuilt MAN and confirms each edited op still decodes as a 0x3F carrying the intended name.
• Footprint. The recompressed MAN must fit the original asset's on-disc footprint (the gap to the next descriptor). A scene that cannot grow in place - the big overworld hubs, whose next asset is flush after the MAN - is skipped and reported rather than relocating the whole bundle.

Generalized interior-text growth

The same machinery generalizes from a door's destination name to any interior byte run - the dialog text a localization grows or shrinks. man_edit::apply_text_edits takes a set of TextEdit { offset, old_len, new_bytes } and rebuilds the MAN through the identical rebuild_man path. A dialog segment is a field-VM 0x49 0x00 message op whose text is framed 0x1F <text> 0x00; the decoder recovers the op's width by walking to the <= 0x1E terminator, so a grown run keeps the fall-through decode in sync.

Two invariants keep this safe:

1. Record-region gate. Every edit must lie strictly before section 0, inside a partition record with no absolute-reference op. Dialog is field-VM script, never a data section, so an edit that would touch the section chain or an abs-jump / camera-apply target is refused.
2. Round-trip backstop. man_edit::text_edits_preserve_scripts(original, rebuilt) re-walks every record in both buffers and requires an identical instruction stream - same opcodes in order, every control-flow target resolving to the same instruction ordinal. A mis-relocated jump is caught; the caller drops the growth and falls back to same-size abbreviation for that scene.

Budget = the MAN's on-disc footprint. Across the retail USA disc the scene-bundle entries are sector-aligned with zero padding and each compressed MAN already fills its footprint, so in-place growth fits only when the rewritten MAN recompresses no larger than the original - a small fraction of scenes. The rest are sector-crossers whose deficit is under one 2048-byte sector; supplying it is a disc-level relayout, which is what the PAL discs did at mastering (disc relayout, translation tooling).

How we know

Full page: docs/formats/man-relocation.md.

See also