docs: README clip-bar label and J/K vs U/I navigation accuracy

Bring the clip-playback section in line with the current UI:
- label example now shows the dB prominence and notes the visible label
  and screen-reader announcement are one identical string
- tooltip holds only the filename + in-file offset (score moved into
  the label)
- explain that the position count is the chronological index under J/K
  and the loudness rank under U/I, with the denominator always the full
  set (U/I has no top-N cutoff; only the chip display is capped)
- document that J/K and U/I share one queue and cursor, so U/I to find a
  spot then J/K to review the time-adjacent clips works as expected

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

CLAUDE.md

@@ -38,8 +38,8 @@ Dependencies: `requests` (streams), `numpy` + `soundfile` (FLAC output and FLAC
 - Serving: `_stream()` (Range support), `_copy_to_response()`, `_safe_path()` (path traversal guard).
 
 `webui.html` (one `<script>` block):
-- Clip review: `clipQueue`/`clipCursor` globals, `playClip()`, `playFileSection()`, `hideClipBar()`; markup is the `#clip-bar` div. The clip label shows the wall-clock occurrence time + queue position (`03:46:20 to 03:46:22 (73 / 187)`): queue entries carry `absStart` (epoch s), derived from `fileStartEpoch(f.date)` — the filename clock — with in-file offsets as fallback for non-standard names; filename/score live in the label tooltip.
-- Day review: `dayHighlights()` builds `dayActiveSections` (chronological); `jumpToDaySection()` arms the queue. Section `absStart` comes from `fileStartEpoch(f.date)` (filename clock), mtime−duration only as fallback. **The user is blind and uses a screen reader — there is deliberately no day-timeline SVG** (one existed and was removed on request as useless); the highlights panel is linear text/buttons: summary line → key-hint note → chips toggle → chips. Do not add decorative visualizations; any future graphic must be aria-hidden and must not be the only carrier of information. Chip lists longer than 12 are collapsed behind an `aria-expanded` toggle button (the `.chips[hidden]{display:none}` rule is required — the author-level `display:flex` on `.chips` would otherwise override the UA `[hidden]` rule). Group `aria-label`s stay short ("Day loud sections") — the J/K/U/I key explanation lives only in the visible note, per user feedback against repeating info text in labels. The Highlights button is a collapse/expand toggle (`setHlExpanded()` keeps arrow + `aria-expanded` in sync, also from the day-collapse path): a built panel is kept and re-armed from `dayHlSections` instead of recomputing, keyed by `hlRow.dataset.loaded = hlParams()` (margin|gap|minDur string) so changed params force a re-run. The `#dayhls-<dayId>` "· analysed" suffix appears when every file's `cached_analysis` passes `cachedParamsMatch()`; `fetchAnalysis()` updates `f.cached_analysis` client-side so the marker survives re-renders without refetching `/api/files`.
+- Clip review: `clipQueue`/`clipCursor` globals, `playClip()`, `playFileSection()`, `hideClipBar()`; markup is the `#clip-bar` div. The clip label shows wall-clock occurrence time + dB prominence + position (`17:09:56 to 17:09:57 · +30 dB (30 / 426)`): queue entries carry `absStart` (epoch s), derived from `fileStartEpoch(f.date)` — the filename clock — with in-file offsets as fallback for non-standard names; only the filename/in-file offset lives in the tooltip now. **`playClip()` builds one `text` string used for both `label.textContent` and the `announce()` aria-live message** — they must never diverge (a past bug had the announcement read `Clip N of M: …` while the label read the wall-clock form). `playClip(i, byScore)`: when `byScore` (a U/I or "highlights only" loudness walk), the position shown is the rank in `scoreOrder()` ("3rd loudest of 426"), not the time-order index `i`; `stepClip`'s by-score branch passes `true`, every other caller (chip click, J/K, Prev/Next) leaves it false for the time-order index.
+- Day review: `dayHighlights()` builds `dayActiveSections` (chronological); `jumpToDaySection()` arms the queue. Section `absStart` comes from `fileStartEpoch(f.date)` (filename clock), mtime−duration only as fallback. **The user is blind and uses a screen reader — there is deliberately no day-timeline SVG** (one existed and was removed on request as useless); the highlights panel is linear text/buttons: summary line → key-hint note → chips toggle → chips. Do not add decorative visualizations; any future graphic must be aria-hidden and must not be the only carrier of information. Chip lists longer than 12 are collapsed behind an `aria-expanded` toggle button (the `.chips[hidden]{display:none}` rule is required — the author-level `display:flex` on `.chips` would otherwise override the UA `[hidden]` rule). Group `aria-label`s stay short ("Day loud sections") — the J/K/U/I key explanation lives only in the visible note, per user feedback against repeating info text in labels. The Highlights button is a collapse/expand toggle (`setHlExpanded()` keeps arrow + `aria-expanded` in sync, also from the day-collapse path): a built panel is kept and re-armed from `dayHlSections` instead of recomputing, keyed by `hlRow.dataset.loaded = hlParams()` (margin|gap|minDur string) so changed params force a re-run. The `#dayhls-<dayId>` "· analysed" suffix appears when every file's `cached_analysis` passes `cachedParamsMatch()`; `fetchAnalysis()` updates `f.cached_analysis` client-side so the marker survives re-renders without refetching `/api/files`. **`aria-label` on a button replaces its visible content for screen readers** — any status text rendered inside a labelled button (like the analysed suffix) must be mirrored into the label (render path + the end of `dayHighlights()`), or the blind user never hears it. Likewise, the accessible text of a button built as `aria-hidden arrow span + text node` must not start the text node with a space (the hidden arrow drops out and the leading space reads as an indent) — keep separator spaces inside the aria-hidden span.
 - J/K/U/I/O: single document-level `keydown` listener — clip queue takes priority, in-player `currentTime` stepping is the fallback when no queue is armed; O calls `openClipInFile()` (shared with the "Open in file" button). J/K (and Prev/Next) always step in time order; U/I walk the loudest-first ranking from `scoreOrder()` — no top-N cutoff (the `#clip-top` input and `#clip-hl-only` checkbox were removed deliberately; J/K must never be affected by an auto-advance/highlights setting). Auto-advance is the `input[name="clip-adv"]` radio (off / next in time / next by loudness), read by `advanceMode()`; `stepClip(dir, byScore)` is the shared queue-stepping path. In-player U/I anchor the ranking on the section under the playhead, else start at the loudest.
 - Analysis: `fetchAnalysis()` (session `analysisCache`), `analyse()` (per-row render: meta line with section count + params, then chips — no waveform SVG, see day-review note on the blind user), `cachedParamsMatch()` (autoload guard).
 

README.md

@@ -154,12 +154,12 @@ The browser UI (HTML/CSS/JS) lives in `webui.html`, which `web.py` loads at star
 Shows recordings grouped by day with collapsible sections. Features:
 
 - **Day groups** — recordings are grouped under a collapsible day heading showing date, file count, total duration, and total size. The most recent day is expanded by default; older days start collapsed. Expanded state is preserved across filter changes.
-- **Day highlights** — click **Highlights** on any day heading to run loudness analysis across all WAV/FLAC files in that day. The button is a toggle: clicking again collapses the panel, and re-expanding it reuses the already-computed results (they are only recomputed when the analysis parameters change). A **· analysed** suffix on the button marks days where every file already has a cached analysis for the current parameters, i.e. highlights open instantly. The panel is plain text and buttons in linear reading order (screen-reader friendly): files-analysed/section totals, a key hint, then the section chips. When a day has more sections than fit as chips, the chips are the top 50 by score (loudest-above-background first) so the most promising events are reviewed first; long chip lists are collapsed behind a toggle button so the panel stays compact. J/K still steps through all sections in time order, and U/I steps through them by loudness.
+- **Day highlights** — click **Highlights** on any day heading to run loudness analysis across all WAV/FLAC files in that day. The button is a toggle: clicking again collapses the panel, and re-expanding it reuses the already-computed results (they are only recomputed when the analysis parameters change). A **· analysed** suffix on the button marks days where every file already has a cached analysis for the current parameters, i.e. highlights open instantly. The panel is plain text and buttons in linear reading order (screen-reader friendly): files-analysed/section totals, a key hint, then the section chips. When a day has more sections than fit as chips, the chips are the top 50 by score (loudest-above-background first) so the most promising events are reviewed first; long chip lists are collapsed behind a toggle button so the panel stays compact. J/K still steps through all sections in time order, and U/I steps through them by loudness. Holding **Shift** jumps straight to an extreme: **Shift+J**/**Shift+K** to the first/last section in time, **Shift+U**/**Shift+I** to the loudest/quietest.
 - **Inline playback** — collapsible `Play` button per row; audio loads lazily via a seekable `/stream/` endpoint with HTTP Range support. Metadata is fetched immediately so the duration is visible without pressing play.
 - **Loudness analysis** — on demand per file; computes RMS per 100 ms window and lists sections that stand out above the background as clickable chips (no visual waveform — the UI is built for screen-reader use). Detection is **adaptive**: a rolling noise floor (20th percentile per 30 s block) is estimated across the file, and a section is flagged when the level rises at least *margin* dB (default 12) above that floor. Slow ambience changes — rain setting in, day/night traffic hum — move the floor instead of producing false positives. Each section gets a **score** used to rank it: its peak dB above the floor, capped by the sharpest rise within 0.5 s. Abrupt events — voices, impacts, barks — rise fast, so their score is their full prominence; a gradual swell (a gust, a distant approaching car) that drifts up faster than the floor can track still gets flagged, but scores near zero and sinks to the bottom of the highlight ranking. Supported for WAV and FLAC (FLAC requires `numpy` + `soundfile`). Pure-Python fallback for WAV when numpy is absent. Results are cached in `recordings/analyses/<filename>.analysis.json`; subsequent requests at the same margin, min-gap, and min-duration settings return instantly without re-reading the audio. The cache file is deleted automatically when the audio file is deleted. Orphaned cache files (audio deleted outside the UI) are pruned on startup.
 - **Grace period** — configurable in the controls bar (default 2 s). Loud sections separated by less than this gap are merged into one. Raise this (e.g. to 15–30 s) when a single event generates many timestamps due to brief quiet gaps within it.
 - **Min duration** — configurable in the controls bar (default 0.5 s). Loud sections shorter than this (after grace-period merging) are discarded, so isolated sub-second pops — a click, a single raindrop — don't flood a day with thousands of near-zero-length sections. Set to 0 to disable.
-- **Clip playback** — clicking a loud-section chip plays a short server-rendered WAV clip (`/api/clip`, pre-roll included) in a player bar at the bottom of the page. Playback starts instantly even for sections deep inside multi-hundred-MB FLACs, because the browser never has to seek the full file. The player bar labels each clip with the wall-clock time it occurred (derived from the recording's filename) and its position in the queue, e.g. `03:46:20 to 03:46:22 (73 / 187)`; the filename and score are in the label's hover tooltip. **J** / **K** (or the **Prev** / **Next** buttons) always step through the queued sections in time order — one file's, or a whole day's after **Highlights**. **U** / **I** step through the same queue by loudness instead: **I** plays the next-loudest section, **U** goes back up the ranking, so a day with thousands of detections is reviewed loudest-first for as long as it stays interesting — there is no top-N cutoff, just stop when it gets boring. The auto-advance radio in the player bar picks what happens when a clip ends: **Don't auto-advance**, **Auto-advance** (next section in time), or **Auto-advance highlights only** (next section by loudness) — it never changes what J/K do. The same keys work during full-file playback, seeking the open recording to the next section in time (J/K) or by loudness (U/I). **Open in file** (or the **O** key) switches to the full recording at the same position for context; each chip click also pre-fills the cut panel.
+- **Clip playback** — clicking a loud-section chip plays a short server-rendered WAV clip (`/api/clip`, pre-roll included) in a player bar at the bottom of the page. Playback starts instantly even for sections deep inside multi-hundred-MB FLACs, because the browser never has to seek the full file. The player bar labels each clip with the wall-clock time it occurred (derived from the recording's filename), its loudness above the background, and its position in the queue, e.g. `17:09:56 to 17:09:57 · +30 dB (30 / 426)` — and the exact same text is announced to screen readers, so the spoken and visible labels never differ. The filename and in-file offset are in the label's hover tooltip. **J** / **K** (or the **Prev** / **Next** buttons) always step through the queued sections in time order — one file's, or a whole day's after **Highlights** — and the position count is then the chronological index (e.g. `30 / 426` is the 30th section in time). **U** / **I** step through the same queue by loudness instead: **I** plays the next-loudest section, **U** goes back up the ranking, and the count becomes the rank in that loudness order (`1 / 426` is the loudest of all reachable sections, `2 / 426` the next-loudest, and so on) — the denominator stays the full count because U/I reaches every section, with no top-N cutoff; the chip list shown on screen is capped only for display. So a day with thousands of detections is reviewed loudest-first for as long as it stays interesting — just stop when it gets boring. Both key pairs drive one shared queue and one cursor, so you can mix them: find a loud moment with **U** / **I**, then press **J** / **K** to review the clips immediately before and after it in time (the count switches from rank back to the chronological index as you do). The auto-advance radio in the player bar picks what happens when a clip ends: **Don't auto-advance**, **Auto-advance** (next section in time), or **Auto-advance highlights only** (next section by loudness) — it never changes what J/K do. Holding **Shift** with any of these jumps to the extreme in that direction — **Shift+J**/**Shift+K** to the first/last section in time, **Shift+U**/**Shift+I** to the loudest/quietest. The same keys work during full-file playback, seeking the open recording to the next section in time (J/K) or by loudness (U/I). **Open in file** (or the **O** key) switches to the full recording at the same position for context; each chip click also pre-fills the cut panel.
 - **Cut & download** — `Cut` button opens the player row and reveals a cut panel. Enter start and end times in `m:ss` or `h:mm:ss` format and click **Download cut** to receive an ffmpeg-trimmed copy without re-encoding. Requires ffmpeg (included in the Docker image). The cut is named with the real wall-clock span it covers — `<YYYYMMDD>_<HH-MM-SS>_<HH-MM-SS>.<ext>`, e.g. a 22:31:30→22:32:30 slice of a recording started at 22:00:00 becomes `20260523_22-31-30_22-32-30.flac`.
 - **Filters** — live filename search and from/to date pickers above the table; applied client-side with no additional requests. Shows `N of M shown` when a filter is active.
 - **Delete** — `Delete` button per row with confirmation prompt; disabled for files currently being recorded; sends `DELETE /api/files/<name>` and re-renders the table.

webui.html

@@ -352,7 +352,10 @@ function seekToSection(idx, filename, startSec, endSec, sectionIdx) {
 let clipQueue = [];
 let clipCursor = -1;
 
-function playClip(i) {
+// byScore: this play is part of a loudness walk (U/I or "highlights only"
+// auto-advance), so the position shown is the rank in the loudest-first
+// ranking ("3rd loudest of 426"), not the time-order index.
+function playClip(i, byScore) {
   if (i < 0 || i >= clipQueue.length) return;
   clipCursor = i;
   const c  = clipQueue[i];
@@ -363,18 +366,22 @@ function playClip(i) {
         + '&start=' + cs.toFixed(1) + '&end=' + ce.toFixed(1);
   a.play().catch(() => {});
   // Label = wall-clock time of occurrence (absStart from the filename clock);
-  // falls back to in-file offsets for non-standard filenames.
+  // falls back to in-file offsets for non-standard filenames. The visible
+  // label and the screen-reader announcement use one identical string:
+  // "17:09:56 to 17:09:57 · +30 dB (30 / 426)".
   const when = c.absStart != null
     ? `${fmtClock(c.absStart)} to ${fmtClock(c.absStart + (c.end - c.start))}`
     : `${fmtDur(c.start)} to ${fmtDur(c.end)}`;
+  const score = c.score != null ? ` · +${Math.round(c.score)} dB` : '';
+  const pos   = byScore ? scoreOrder(clipQueue).indexOf(i) : i;
+  const text  = `${when}${score} (${pos + 1} / ${clipQueue.length})`;
   const label = document.getElementById('clip-label');
-  label.textContent = `${when} (${i + 1} / ${clipQueue.length})`;
-  label.title = `${c.filename} @ ${fmtDur(c.start)}–${fmtDur(c.end)}`
-    + (c.score != null ? ` · +${Math.round(c.score)} dB` : '');
+  label.textContent = text;
+  label.title = `${c.filename} @ ${fmtDur(c.start)}–${fmtDur(c.end)}`;
   document.getElementById('clip-bar').hidden = false;
   document.body.classList.add('clip-open');
   setCutFields(c.fileIdx, c.start, c.end);
-  announce(`Clip ${i + 1} of ${clipQueue.length}: ${when}`);
+  announce(text);
 }
 
 function hideClipBar() {
@@ -410,18 +417,20 @@ const advanceMode = () =>
   document.querySelector('input[name="clip-adv"]:checked')?.value || 'off';
 
 // Step the clip queue by dir (±1): in time order, or with byScore down/up
-// the loudest-first ranking (next = next quieter).
-function stepClip(dir, byScore) {
+// the loudest-first ranking (next = next quieter). With jump=true, go straight
+// to the extreme in that direction (first/last section, or loudest/quietest).
+function stepClip(dir, byScore, jump) {
   if (!clipQueue.length) return;
   if (byScore) {
     const order = scoreOrder(clipQueue);
     const pos   = order.indexOf(clipCursor);        // -1: nothing played yet
-    const next  = pos === -1 ? (dir > 0 ? 0 : -1) : pos + dir;
-    if (next >= 0 && next < order.length) playClip(order[next]);
+    const next  = jump ? (dir > 0 ? order.length - 1 : 0)
+                       : pos === -1 ? (dir > 0 ? 0 : -1) : pos + dir;
+    if (next >= 0 && next < order.length) playClip(order[next], true);
     else announce(dir < 0 ? 'Loudest highlight reached' : 'End of highlights');
     return;
   }
-  const i = clipCursor + dir;
+  const i = jump ? (dir > 0 ? clipQueue.length - 1 : 0) : clipCursor + dir;
   if (i >= 0 && i < clipQueue.length) playClip(i);
   else announce(dir < 0 ? 'Beginning of sections' : 'End of sections');
 }
@@ -534,8 +543,9 @@ async function analyse(idx, filename, cell, btn, force = false) {
 }
 
 // J/K = previous/next section in time order, U/I = up/down the loudest-first
-// ranking, O = open the current clip in the full file.
-// Only when focus is not in an input.
+// ranking, O = open the current clip in the full file. Holding Shift jumps to
+// the extreme in that direction: Shift+J/K = first/last section in time,
+// Shift+U/I = loudest/quietest. Only when focus is not in an input.
 document.addEventListener('keydown', e => {
   if (e.target.tagName === 'INPUT' || e.target.tagName === 'TEXTAREA') return;
   if (e.ctrlKey || e.metaKey || e.altKey) return;
@@ -545,10 +555,11 @@ document.addEventListener('keydown', e => {
   if (key === 'o') { openClipInFile(); return; }
   const dir     = (key === 'j' || key === 'u') ? -1 : 1;
   const byScore = key === 'u' || key === 'i';
+  const jump    = e.shiftKey;
 
   // Clip queue navigation (a chip was clicked or day highlights are loaded)
   if (clipQueue.length) {
-    stepClip(dir, byScore);
+    stepClip(dir, byScore, jump);
     return;
   }
 
@@ -570,10 +581,12 @@ document.addEventListener('keydown', e => {
   if (byScore) {
     // U/I walk the ranking; the anchor is the section the playhead sits in
     // (incl. its preroll lead-in). Anywhere else, I starts at the loudest.
+    // Shift jumps straight to the loudest (Shift+U) or quietest (Shift+I).
     const order  = scoreOrder(all);
     const curIdx = all.findIndex(s => cur >= s.start - preroll - 0.5 && cur <= s.end + 0.5);
     const pos    = curIdx === -1 ? -1 : order.indexOf(curIdx);
-    const next   = pos === -1 ? (dir > 0 ? 0 : -1) : pos + dir;
+    const next   = jump ? (dir > 0 ? order.length - 1 : 0)
+                        : pos === -1 ? (dir > 0 ? 0 : -1) : pos + dir;
     if (next >= 0 && next < order.length)
       jumpTo(all[order[next]], next, order.length, 'Highlight');
     else
@@ -581,6 +594,13 @@ document.addEventListener('keydown', e => {
     return;
   }
 
+  // Shift+J/K jump to the first/last section regardless of the playhead.
+  if (jump) {
+    const i = dir < 0 ? 0 : all.length - 1;
+    jumpTo(all[i], i, all.length, 'Section');
+    return;
+  }
+
   if (dir < 0) {
     for (let i = all.length - 1; i >= 0; i--) {
       if (all[i].start < cur - 1) { jumpTo(all[i], i, all.length, 'Section'); return; }
@@ -765,7 +785,7 @@ function renderFiles(files) {
       </h2>
       ${canHl ? `<button class="day-hl" id="dayhln-${dayId}"
         aria-expanded="false" aria-controls="dayhl-${dayId}"
-        aria-label="Day highlights for ${esc(day)}">
+        aria-label="Day highlights for ${esc(day)}${analysed ? ', analysed' : ''}">
         <span class="day-arrow" aria-hidden="true">▸</span> Highlights<span
           class="day-hl-status" id="dayhls-${dayId}"${analysed ? '' : ' hidden'}> · analysed</span></button>` : ''}`;
     section.appendChild(headBar);
@@ -1012,7 +1032,7 @@ async function dayHighlights(dayId, analyzableFiles) {
     const note = document.createElement('p');
     note.className = 'quiet';
     note.style.marginTop = '6px';
-    note.textContent = 'J / K plays through all sections in time order, U / I by loudness (loudest first)';
+    note.textContent = 'J / K plays through all sections in time order, U / I by loudness (loudest first). Hold Shift to jump to the first / last section (Shift + J / K) or the loudest / quietest (Shift + U / I)';
     box.appendChild(note);
 
     const MAX_DAY_CHIPS = 50;
@@ -1046,6 +1066,8 @@ async function dayHighlights(dayId, analyzableFiles) {
       const arrow = document.createElement('span');
       arrow.className = 'day-arrow';
       arrow.setAttribute('aria-hidden', 'true');
+      // the separator space lives inside the aria-hidden arrow: a leading
+      // space in the text node shows up as an indent in screen readers
       arrow.textContent = '▸ ';
       tog.appendChild(arrow);
       tog.appendChild(document.createTextNode(truncated
@@ -1067,8 +1089,13 @@ async function dayHighlights(dayId, analyzableFiles) {
   hlRow.dataset.loaded = hlParams();
   dayHlSections.set(dayId, dayActiveSections);
   // Every file is now cached with the current params
-  if (results.length === n)
+  if (results.length === n) {
     document.getElementById('dayhls-' + dayId)?.removeAttribute('hidden');
+    // aria-label overrides the button content, so the analysed marker has to
+    // be mirrored into it or screen readers never hear it
+    if (btn && !/, analysed$/.test(btn.getAttribute('aria-label') || ''))
+      btn.setAttribute('aria-label', btn.getAttribute('aria-label') + ', analysed');
+  }
   if (btn) btn.disabled = false;
 }