latency: cache profile writes; docs: data2 resolved, latency and fade measurements

README.md

@@ -110,8 +110,10 @@ wrapper, so the WebUI does not need to implement them. See `docs/TTS-DESIGN.md`.
   windows.
 - Flextalk numeric speaker settings must be `REG_DWORD` (the installer script handles
   this); `REG_SZ` values cause a monotone buzz. Pitch and speed work on all voices.
-- The Flextalk archive lacks `data2.cab`; `unshield -O` extracts `data1.cab`
-  but one tail file (`WatsonUNInstall.dll`) is incomplete.
+- Flextalk extraction needs `unshield -O` (old compression). The installer is
+  single-volume: the new decompressor reports a phantom `data2.cab`, but `-O` extracts
+  all 450 entries with exact sizes and valid PE files (the original 1997 upload log lists
+  `data1.cab` only).
 
 ## Reference material
 

docs/NOTES.md

@@ -47,8 +47,25 @@ From `msttsl/mstts.inf` (`[TTSReg]`):
   `.COD` codebook, plus shared `DICT_CI.*`, `phondef`, `AMPRULES`, `ENDINGS`.
 
 Extraction: `unshield -O -d extracted x installer/flextalk/data1.cab`
-(`-O` = old compression; the archive.org package has no `data2.cab`, so the
-final file `WatsonUNInstall.dll` is incomplete).
+(`-O` = old compression). The package is single-volume: the original 1997 upload log
+(`WS_FTP.LOG`) lists `data1.cab` only, and `-O` extracts all 450 entries with exact
+sizes. Without `-O`, unshield's new decompressor reports a phantom "volume 2" and fails
+on `MSVCRT.DLL` / `WatsonUNInstall.dll`; with `-O` both are complete, valid PE files.
+
+The `.ENV` files the engine probes (`ae1m11lc.ENV`) were never shipped; synthesis works
+without them.
+
+## Latency and output shape (measured 2026-09-16)
+
+- Warm wrapper time: ~410-425 ms per short line (engine call 190-220 ms, ffmpeg measure
+  ~110 ms, apply ~90 ms, profile write ~57 ms when it runs). First (cold) call ~730 ms.
+- The Flextalk profile write is cached per voice in the Wine prefix
+  (`~/.wine-microslopsam/.microslopsam-profile<GUID>.reg`): unchanged profiles skip
+  `wine reg import`. Recreating the prefix invalidates the cache.
+- Fades: the 8 ms fade-in/out is applied to the trimmed file whose 25-30 ms padding
+  silence is retained, so it shapes silence, not speech. Measured head: first sample
+  >30 at 22.6 ms, speech (>500) at 29.6 ms, natural ~15 ms attack; tail decays over
+  ~18 ms. No click, no attenuation of the first word.
 
 ## SAPI4 runtime engine discovery (`speech.dll`)
 

docs/TTS-DESIGN.md

@@ -229,6 +229,11 @@ record what the engine needs to interpret, add, or hide._
 - Verified: Keith Bell -18.4 LUFS, Kerry Watson -17.9 LUFS, Sam -20.6 LUFS; every file is
   48 kHz mono s16le at -3.0 dBFS true peak. The WAV handed to Veskslop is compliant; the
   "Veskslop does not normalize" rule holds.
+- Fades: the 8 ms fade-in/out is applied to the trimmed file, and the retained 25-30 ms
+  padding silence sits at the edges, so the fade shapes silence, not the first phoneme.
+  Measured on a Keith Bell line: first sample >30 at 22.6 ms, speech (>500) at 29.6 ms,
+  attack rising naturally over about 15 ms, tail decaying over about 18 ms. No click and
+  no attenuation of the first word; Veskslop's 150 ms playback lead-in sits on top.
 
 ### Voice IDs
 
@@ -451,11 +456,15 @@ This tree is written to survive a copy into the Veskslop repository next to its
   text file, transliterates UTF-8 to CP1252, starts or reuses an Xvfb when `DISPLAY` is
   unset, calls the engine, then post-processes (trim, fades, measured fixed gain, 48 kHz
   mono s16le). A stale private Xvfb is retried once.
-- Measured on the dev host: engine-only synthesis is about 290 ms wall for Sam and about
-  40 ms for Flextalk, including process start; the full wrapper adds the ffmpeg
-  measure/apply passes, about 630-880 ms per short line. That is above the 500 ms target;
-  the known optimization is a per-voice static gain (skip the measurement pass), expected
-  to land around 400-500 ms.
+- Measured on the dev host (warm): engine call about 190 ms (Flextalk) to 220 ms (Sam)
+  including Wine start, ffmpeg measure about 110 ms, ffmpeg apply about 90 ms, profile
+  registry write about 57 ms when it runs. Full wrapper: about 410-425 ms per short line
+  warm, about 730 ms for the first (cold) call. The 500 ms target is met warm; Veskslop's
+  "Start engine" warm-up covers the cold case.
+- Latency optimization implemented: the Flextalk profile write is cached per voice inside
+  the Wine prefix (`.microslopsam-profile<GUID>.reg`); an unchanged profile skips the
+  `wine reg import` round-trip (about 57 ms warm, 300 ms cold). Recreating the prefix
+  invalidates the cache automatically.
 - Manual checks: `setup/run.sh -l`, `setup/run.sh -v "Keith Bell" -t "Hello." -o out.wav`
   (raw engine WAV), and the wrapper above for normalized output.
 - HTTP provider (later): a persistent process returning `audio/wav` bytes and `/voices`,
@@ -465,6 +474,10 @@ This tree is written to survive a copy into the Veskslop repository next to its
 
 - Flextalk numeric speaker settings must be `REG_DWORD`; `REG_SZ` values make the engine
   synthesize a buzz. `setup/setup-flextalk.sh` writes them correctly.
+- Flextalk cabinet is single-volume: `unshield -O` extracts all 450 entries with exact
+  sizes. Without `-O`, the new decompressor reports a phantom "volume 2" and fails on
+  `MSVCRT.DLL` / `WatsonUNInstall.dll`; both are complete with `-O` (verified against the
+  original 1997 upload log, which lists `data1.cab` only).
 - The mode list includes TruVoice names with no installed voice data; filter those out of
   `/voices` (or mark them `unavailable`).
 - Wine needs a working X display; the project helper starts a persistent Xvfb.

setup/veskslop-tts.sh

@@ -233,13 +233,26 @@ if [ -n "$SPEAKER_GUID" ]; then
         exit 1
     fi
 
-    if ! command -v "$MICROSLOP_WINE" >/dev/null 2>&1; then
-        echo "wine is required to set the Flextalk profile" >&2
-        exit 1
+    # Skip the wine round-trip when this voice's profile was already applied.
+    # The cache lives inside the prefix, so recreating the prefix invalidates
+    # it automatically.
+    PROFILE_CACHE="$WINEPREFIX/.microslopsam-profile$SPEAKER_GUID.reg"
+    if [ -f "$PROFILE_CACHE" ] && cmp -s "$TMP/profile.reg" "$PROFILE_CACHE"; then
+        PROFILE_APPLIED=1
+    else
+        PROFILE_APPLIED=0
     fi
-    if ! "$MICROSLOP_WINE" reg import "$TMP/profile.reg" >/dev/null 2>&1; then
-        echo "could not write the Flextalk profile" >&2
-        exit 1
+
+    if [ "$PROFILE_APPLIED" != "1" ]; then
+        if ! command -v "$MICROSLOP_WINE" >/dev/null 2>&1; then
+            echo "wine is required to set the Flextalk profile" >&2
+            exit 1
+        fi
+        if ! "$MICROSLOP_WINE" reg import "$TMP/profile.reg" >/dev/null 2>&1; then
+            echo "could not write the Flextalk profile" >&2
+            exit 1
+        fi
+        cp -f "$TMP/profile.reg" "$PROFILE_CACHE" 2>/dev/null || true
     fi
 fi