gramps
87509bcf99
TASKS.md is now the index (status table, open items, research pointer). 33 files: 32 task files + 1 research facts file. The full take-saga narrative and all design decisions are preserved verbatim; the catalog makes the queue readable without opening every task body. Schema and AGENTS.md updated to reflect the new layout.
32 lines
2.0 KiB
Markdown
32 lines
2.0 KiB
Markdown
# TASK 12 — Master limiter on the live mix (2026-08-15)
|
||
|
||
> Catalog: [`TASKS.md`](../TASKS.md) — status and requirements live here.
|
||
|
||
|
||
**Queued by the creator during the TRAX discussion:** "should the soundtrack be limited to avoid
|
||
squandering resources / should it cap at 20% / how do the three sound events balance?" Review
|
||
conclusions (all three instincts checked out, only ONE real gap):
|
||
|
||
- **File size — no guard needed.** `MusicPlayer` uses `MediaFoundationReader`, which **streams from
|
||
disk** (progressive source): memory is flat (~a few MB) regardless of file size; CPU negligible.
|
||
- **20% cap — already enforced by construction.** `MusicPlayer.MusicVolume = 0.20f` + music rides the
|
||
SAME WASAPI loopback (and therefore the same gain) as game audio, so music:game is always exactly
|
||
**0.20:1 at any slider position** — it literally cannot rise above 20% of the current desktop volume.
|
||
- **The gap:** `AudioMixer.FillAndMix` summed mic + loopback with **no output ceiling** — mic 100% +
|
||
loud game/music could pass 0 dBFS and clip the AAC encode.
|
||
|
||
**Shipped:**
|
||
1. ✅ **`Services/Audio/MasterLimiter.cs`** (pure, unit-tested) — a **−1 dBFS ceiling** (`Ceiling =
|
||
0.891`), **instant attack per frame** (a hot frame is scaled exactly to the ceiling — no overshoot),
|
||
**smoothed release** toward unity so loud passages don't pump; gain never exceeds 1 (no boosting).
|
||
Applied at the end of `AudioMixer.FillAndMix`, right before the pipe write.
|
||
2. ✅ **Unit tests** — over-ceiling frames trimmed to ≤ ceiling; sub-ceiling frames never boosted; gain
|
||
recovers to unity after the loud frame ends.
|
||
3. ✅ **ONE integration test** (`MasterLimiter_CapsTheLiveMix_OnThePipe`) — real mixer + pipe harness:
|
||
a 0.95 loopback bed (hotter than the ceiling) is capped to exactly 0.891 on the wire while staying
|
||
audible.
|
||
4. ✅ **Docs in the same commit** — `ai.md` (go-live audio section), `Services/index.md` (new row).
|
||
|
||
No changes to `MusicPlayer`, the 0.20 cap, the ducker, or the meter zones. Build 0 warnings.
|
||
|