Slice 10 from today-slices (d1126dd): UVC cameras default MediaFrameReader to their
FIRST media type (YUY2 at crippled fps — C920 720p = 5fps). A 60fps container
then shows a 5-20fps face cam as "every few frames cut out". Fix:
VideoDeviceController.SetMediaStreamPropertiesAsync negotiated to best MJPEG
>=640x360 @>=30fps (<=1280 wide) BEFORE creating the frame reader, with
device-default fallback. Plus a startup.log truth line of the actual agreed media
type so the next diagnosis starts from facts (no more re-deriving the fps).
Build 0 warnings, 289 tests.
Roll-forward of today-slices 6fd1d9c onto the slice-8 base, two-loop hunk dropped.
Release counter (per-build GUID read as noise; +1 per commit from git rev-list,
baseline 241 -> #13, generated by GenerateBuildStamp; GUID demotes to startup.log).
Tests pinned to Label/#N >= 13; wordmark display test asserts the Label.
Flash fix (take 14 finding): consumer holds must never outlive depth x source
period — 4 slots at high refresh lap ~27ms vs a <=50ms compositor read, so a
recycled slot flashed its new frame over the lagged old one. All shared rings 4->8
(OBS/overlay precedent for ring discipline).
Camera producer now rotates an 8-deep ring + Epoch instead of a fresh ~3.7MB
array per device frame (110-220MB/s LOH churn); WebView2 capture reuses a canvas
scratch + 8-deep output ring + a reused WriteableBitmap instead of two fresh
arrays + a fresh bitmap per 10Hz tick. Paste cache stays identity-keyed (Epoch).
gramps