M7 DONE via delegation — pv.youtube plays HD with audio

After hitting the segment-timing wall on our hand-rolled DASH MPD
(audio drifted -25s -> -44s behind video on long content), pivoted to
delegating playback to plugin.video.youtube v7.4.3 which already has
years of sidx-parsed SegmentTimeline + multi-client fallback work.

torttube._play() now:
  1. Tries _delegate_to_pv_youtube(yt_id) — sets a resolved URL of
     'plugin://plugin.video.youtube/play/?video_id=<id>'. Kodi
     chain-resolves to pv.youtube which builds the proper MPD and
     hands inputstream.adaptive a correctly-aligned manifest. Default.
  2. Falls back to our DASH builder (still in code, gated by
     'dash_enabled' setting + dash.on marker) if pv.youtube is absent.
  3. Falls through to yt-dlp progressive 360p as the final safety net.

When delegating, we skip our SponsorBlock monitor — pv.youtube has its
own and would double-skip otherwise.

Cobb-verified live on Livingroom Pi: LTT 'Trump Phone' (which crashed
our DASH with audio sync errors growing to -44s) now plays HD with
audio synced. 'Please sign in' message in log is from the tv_unplugged
Innertube client; pv.youtube falls back to a working client
automatically — no user account required.

Settings: prefer_pv_youtube boolean (default true). Addon v0.0.11.
Reference: https://kodi.wiki/view/Add-on:YouTube

MILESTONES.md

@@ -86,7 +86,30 @@
       progressive) is deprecated by YouTube; higher quality needs DASH
       manifest generation. Code path exists, gated behind `TORTTUBE_DASH=1`.
 
-## M7 — DASH / HD playback [WIP — close on segment timing]
+## M7 — HD playback [DONE via delegation]
+
+**Strategy pivoted 2026-05-23.** After hitting a wall on segment-timing
+alignment in our hand-rolled DASH MPD (audio drifted -25s → -44s behind
+video on long-form content), pivoted to delegating playback to the
+already-installed `plugin.video.youtube` v7.4.3. They already have
+years of sidx-parsed-SegmentTimeline + multi-client fallback work.
+Our delegation:
+
+- `_play()` first calls `_delegate_to_pv_youtube(yt_id)` which sets
+  `plugin://plugin.video.youtube/play/?video_id=<id>` via setResolvedUrl
+- Kodi chain-resolves to pv.youtube, which builds the proper MPD
+- inputstream.adaptive plays 1080p H.264 cleanly, audio in sync
+- Multi-client Innertube fallback handles "Please sign in" rejection
+  on the `tv_unplugged` client — succeeds on the next client without
+  needing the user to link an account
+
+Verified live on Livingroom Pi 2026-05-23 — LTT 'Trump Phone' video
+played at 1080p with audio, fullscreen.
+
+Settings: `prefer_pv_youtube` (default true). Disable to fall through
+to our native DASH/progressive paths.
+
+## M7-rejected — native DASH builder [PARKED]
 
 - [x] sidecar `resolve_dash` op returns rustypipe's full
       `video_only_streams` + `audio_streams` arrays (16+ representations)

addon/plugin.video.torttube/addon.xml

@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="UTF-8" standalone="yes"?>
 <addon id="plugin.video.torttube"
        name="torttube"
-       version="0.0.10"
+       version="0.0.11"
        provider-name="Sulkta-Coop">
   <requires>
     <import addon="xbmc.python" version="3.0.0"/>

addon/plugin.video.torttube/main.py

@@ -152,6 +152,16 @@ class _MpdHandler(http.server.BaseHTTPRequestHandler):
         return
 
 
+def _has_setting(setting_id: str) -> bool:
+    """Best-effort check that a setting exists in resources/settings.xml.
+    Returns False if the lookup throws (older builds, missing schema)."""
+    try:
+        ADDON.getSetting(setting_id)
+        return True
+    except Exception:
+        return False
+
+
 def _lan_ip() -> str:
     """Detect this host's LAN IP by opening a UDP socket toward an external
     address (no packets actually sent — just lets the kernel pick the source IP).
@@ -295,9 +305,14 @@ def _build_dash_mpd(
     parts.append(
         f'    <AdaptationSet mimeType="{a_mime}" startWithSAP="1" segmentAlignment="true">'
     )
+    # NOTE: NOT setting audioSamplingRate here on purpose. rustypipe doesn't
+    # expose the sample rate, and hard-coding 44100 caused a ~9% playback-rate
+    # mismatch (= growing audio-vs-video desync) for content at 48000 Hz.
+    # inputstream.adaptive reads the actual rate from the audio init segment's
+    # mdhd box when this attribute is omitted, which is correct for any source.
     parts.append(
         f'      <Representation id="{a["itag"]}" mimeType="{a_mime}" codecs="{a_codec}"'
-        f' bandwidth="{a.get("bitrate", 0)}" audioSamplingRate="44100" startWithSAP="1">'
+        f' bandwidth="{a.get("bitrate", 0)}" startWithSAP="1">'
     )
     parts.append(
         '        <AudioChannelConfiguration'
@@ -344,18 +359,55 @@ def _try_dash(yt_id: str) -> tuple[bytes | None, dict[str, Any]]:
     return mpd.encode("utf-8"), resp
 
 
-def _play(yt_id: str) -> None:
+def _delegate_to_pv_youtube(yt_id: str) -> bool:
-    """Resolve via DASH (rustypipe, up to 1080p H.264) with progressive
+    """Hand playback off to plugin.video.youtube via its play URL. They have
-    yt-dlp fallback (360p).
+    the proper SegmentTimeline-aware MPD construction (sidx-parsed) that
+    unlocks HD without the audio-sync drift our naive MPD has. Returns True
+    if delegation succeeded (Kodi will chain-resolve)."""
+    if not _pv_youtube_installed():
+        return False
+    target = f"plugin://plugin.video.youtube/play/?video_id={yt_id}"
+    _log(f"delegating playback to plugin.video.youtube: {target}")
+    li = xbmcgui.ListItem(label=yt_id)
+    li.setPath(target)
+    li.setProperty("IsPlayable", "true")
+    xbmcplugin.setResolvedUrl(_HANDLE, True, li)
+    return True
 
-    DASH path is gated behind TORTTUBE_DASH=1 while the manifest-serving
+
-    HTTP server + inputstream.adaptive integration is being stabilized
+def _pv_youtube_installed() -> bool:
-    (file:// URLs don't work, and rapid retries via a port-0 HTTP server
+    """Check whether plugin.video.youtube is installed + enabled. We don't
-    can trigger Kodi's 'two concurrent busydialogs' fatal). Default OFF
+    enable it ourselves — if the user removed it, we fall back to our own
-    until that's solid — progressive yt-dlp path is reliable.
+    paths."""
+    try:
+        return bool(xbmc.getCondVisibility("System.HasAddon(plugin.video.youtube)"))
+    except Exception:
+        return False
+
+
+def _play(yt_id: str) -> None:
+    """Resolve playback in order of preference:
+    1. plugin.video.youtube delegation — HD via their proven DASH MPD with
+       sidx-parsed SegmentTimeline. Default, when available.
+    2. Our DASH path — only if `dash_enabled` setting / dash.on marker / env
+       are set (WIP, partial — see M7 milestone).
+    3. yt-dlp progressive — last-resort 360p, always works.
+    SponsorBlock attaches regardless of which path we took.
     """
     _log(f"play id={yt_id}")
 
+    # Tier 0: delegate to plugin.video.youtube if installed. Don't run our
+    # SponsorBlock monitor in this path — pv.youtube has its own and would
+    # double-skip if both fire.
+    use_pv_youtube = True
+    try:
+        use_pv_youtube = ADDON.getSettingBool("prefer_pv_youtube")
+    except Exception:
+        # Setting not yet in Kodi's cache (settings.xml just changed) — default on.
+        pass
+    if use_pv_youtube and _delegate_to_pv_youtube(yt_id):
+        return
+
     mpd_bytes: bytes | None = None
     dash_resp: dict[str, Any] = {}
     # DASH path: read setting first; fall back to env-var; OR honor a magic file

addon/plugin.video.torttube/resources/settings.xml

@@ -3,7 +3,10 @@
   <section id="torttube">
     <category id="general" label="General">
       <group id="quality" label="Quality">
-        <setting id="dash_enabled" type="boolean" label="Enable DASH (up to 1080p H.264) — WIP, may not work">
+        <setting id="prefer_pv_youtube" type="boolean" label="Use plugin.video.youtube for playback (HD)">
+          <default>true</default>
+        </setting>
+        <setting id="dash_enabled" type="boolean" label="Native DASH (WIP — fallback if pv.youtube absent)">
           <default>false</default>
         </setting>
       </group>

docs/upstream.md

@@ -25,6 +25,18 @@ _(none yet — opens with M1 development)_
   to setResolvedUrl. plugin.video.youtube uses this pattern via a long-lived
   service addon. Worth filing an enhancement to either accept `file://` or
   document the LAN-IP HTTP-server pattern in the inputstream.adaptive docs.
+- **Architecture resolution: torttube delegates playback to plugin.video.youtube**
+  2026-05-23. After spending an iteration on a native DASH MPD builder + HTTP
+  manifest server, conceded that solving segment-timing alignment correctly
+  (sidx-parse, SegmentTimeline emission, audio-rate detection, init-segment
+  presentationTimeOffset) is multiple-week work. plugin.video.youtube has
+  years of that work already. torttube now does what it's faster at (Rust
+  rustypipe search/browse, SponsorBlock skip with fewer false positives)
+  and hands the video_id to pv.youtube for actual playback. This is the
+  "stand on giants' shoulders" call rather than reinvent. Native DASH code
+  path stays in the addon as a fallback when pv.youtube is absent (or as a
+  testbed for someday revisiting). Reference: https://kodi.wiki/view/Add-on:YouTube
+
 - **DASH segment timing for googlevideo SegmentBase URLs** — Hit 2026-05-23.
   My MPD with one Representation per video/audio (using SegmentBase with
   indexRange to the sidx box of the static MP4) parses cleanly and segments