A Windows client with HDR off (video_caps=0) negotiates bit_depth=8, but the
H.26x IDD-push capture composition FOLLOWED the virtual display's live "Use
HDR" state rather than the negotiated depth. On a display whose advanced color
was on — leftover from a prior 10-bit session on a reused monitor, the driver
default, or the host's global toggle — the capturer emitted P010 and NVENC
stamped HEVC Main10 + BT.2020 PQ from the pixel format alone (the in-band HDR
upgrade). That 10-bit PQ stream reached a client that advertised SDR-only; on a
client whose monitor is HDR-capable but has "Use HDR" off, the PQ landed on an
SDR desktop and blew out.
Make client_10bit authoritative for the composition depth on BOTH codecs,
mirroring the PyroWave branch that already did this:
* setup: force advanced color OFF for any !client_10bit session (was
pyrowave-only), settling before the ring is sized;
* display_hdr gates on client_10bit alone, so an SDR-negotiated session
composes SDR even if a physical display forces HDR;
* the descriptor poller re-asserts SDR against a mid-session "Use HDR" flip for
any SDR-negotiated session (an HDR-negotiated H.26x session still follows
flips both ways — its encoder re-inits on the depth change).
Only Punktfunk's virtual display is touched, never the host's real desktop.
Not yet on-glass; the client-side robustness fix (presenter should tone-map PQ
on an SDR-mode display instead of taking an HDR10 swapchain) is a follow-up.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
enricobuehler
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