46006406a4
Cross-checked the instrument built last iteration against an independent grabber while both watched the same screen, and it fails. A single long-lived ffmpeg x11grab stream degrades and then freezes: 862 frames in 540.1 s = 1.60 fps (it starts at 3.98) t=450/480/510/540 s: surface mean 5.21, identical every time At that same moment `import` read surface mean 125.65, and a freshly started ffmpeg stream read 122.43 -- agreeing with import to 3%. So the acquisition was broken, not the analysis: the stream replayed a stale frame while the screen was 24x brighter. That withdraws last iteration's headline. "2391 frames over 600 s from t=0, max glyph 0" cannot distinguish "the title never appeared" from "the stream froze early and repeated one frame 2391 times". Its 3.98 fps was measured over the first 20 s, before the degradation. Sample count is not coverage unless the samples are known independent. Fixed: the stream is now torn down and restarted every 30 s. Startup is ~0.3 s, cheap against the title's window, and it guarantees live frames. Separately, the cache hypothesis was tested and is SUPPORTED. cache, cache0, cache1, cache_host moved aside (to /tmp/xenia-cache-aside, not deleted) and the surface renders again: import reads mean 54.8 and 68.6 with 100% non-black warm content, against 0.07 and 0.08% non-black in the black run; 773 of 862 probe frames had >2% non-black. One run each side and many kill -9s before the black one, so it is supported, not proven -- the old caches are kept for reproduction. Still no title, but that number now comes from a stalling probe and establishes nothing either way. METHOD: validating a probe on static images tests its analysis, not its acquisition -- cross-check against an independent grabber during a run.