From 0445a6d0aa46c103be6a229b168d49bc3b4a0ea3 Mon Sep 17 00:00:00 2001 From: Duncan Tourolle Date: Sat, 22 Aug 2026 11:18:50 +0200 Subject: [PATCH] docs(requirements): DR-234 is in progress, not proposed The renderer-derived codec source was built while chasing four Android bugs that all turned out to be the same defect, so it landed ahead of the spec that allocates it. Five call sites now read one source instead of re-deriving or hardcoding the webview's answer. Not Done: on Linux it still resolves per platform, because there is still only one renderer there. It becomes the runtime question the spec describes when mpv draws the picture. --- docs/requirements.md | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/docs/requirements.md b/docs/requirements.md index 31a93a5c..28f646c5 100644 --- a/docs/requirements.md +++ b/docs/requirements.md @@ -428,7 +428,7 @@ Internal architecture, components, and application logic. | DR-231 | An mpv video backend that composites beneath the transparent webview, the desktop counterpart of the Android TextureView arrangement. mpv renders through its **render API** into an FBO the toolkit binds (`vo=libmpv` + `mpv_render_context_create` with `MPV_RENDER_PARAM_OPENGL_FBO`), rather than by embedding a foreign window — which is what the 2024 "not possible on Wayland at all" conclusion was about and why it does not apply. On Linux that is a `GtkOverlay` with a `GtkGLArea` as main child and Tauri's own webview reparented as the overlay child; the mpv half is shared and only the surface differs per platform. Webview transparency alone suffices — no window-level transparency is used or needed | Playback | UR-080 | Proposed | | DR-232 | The mpv render context's lifetime is bound to the GL context it draws into: created on `realize`, freed on `unrealize`, on the same thread, with the update callback unregistered *before* the free so a callback cannot land on a freed context. This is DR-184 on Android restated — a surface outliving its player — and it is a requirement in its own right rather than a fix for a specific crash. The spike observed one SIGSEGV in a decoder thread that three targeted soaks failed to reproduce; what is not in doubt is that the spike never called `mpv_render_context_free` and never tore down on `unrealize`, so nothing defended against the GL context being recreated underneath. Removing the likeliest cause is worth doing whether or not it was the cause | Playback | UR-080 | Proposed | | DR-233 | Frame pacing goes through mpv's update callback, with `mpv_render_context_report_swap` after each render. Recorded as a requirement because the failure mode misleads: driving the widget's frame clock every tick without reporting the swap leaves mpv with nothing to time against, which looks fine in a window and **judders at fullscreen** — reading as a compositing or GPU limit and being neither | Playback | UR-080 | Proposed | -| DR-234 | The device profile is derived from the **renderer that will decode the stream**, not from a compile-time platform constant. `video_codecs` was `#[cfg(target_os)]`, which is correct only while a build has one video renderer; once mpv and the webview element coexist it must be runtime state. This is the change that converts the measured 7% desktop direct-play rate toward the 85% the Android profile achieves on the same library, because the two differ by nothing except which component decodes. It looks like configuration and is not — it is the input that decides whether the server re-encodes, and getting it wrong fails silently, a claimed codec the renderer cannot decode being a black picture or silence (DR-148, and DR-227's audio override). The webview's narrower *audio* set stops applying to the video path once mpv decodes it, while the multichannel bound still does, since a 5.1 track direct-played into a two-channel sink is silence or inaudible dialogue | Repository | UR-080, UR-070 | Proposed | +| DR-234 | The device profile is derived from the **renderer that will decode the stream**, not from a compile-time platform constant. `video_codecs` was `#[cfg(target_os)]`, which is correct only while a build has one video renderer; once mpv and the webview element coexist it must be runtime state. This is the change that converts the measured 7% desktop direct-play rate toward the 85% the Android profile achieves on the same library, because the two differ by nothing except which component decodes. It looks like configuration and is not — it is the input that decides whether the server re-encodes, and getting it wrong fails silently, a claimed codec the renderer cannot decode being a black picture or silence (DR-148, and DR-227's audio override). The webview's narrower *audio* set stops applying to the video path once mpv decodes it, while the multichannel bound still does, since a 5.1 track direct-played into a two-channel sink is silence or inaudible dialogue | Repository | UR-080, UR-070 | In Progress | | DR-235 | The webview video path is deleted, not merely bypassed. Staged, because a path cannot be removed while a shipped platform still needs it: Linux moves to mpv first, Windows follows, and only then do `hls.js`, `html5Adapter.ts`, `videoLoaderFor` and the `