Reverts the no_qpu → qpu-capable ctx flip that landed via patch 0014
(marfrit-packages PR #104).
PR #104 was justified by daedalus-fourier PR #36's "QPU 4.30x faster
than CPU NEON" bench result. That number was a measurement artifact:
v3d_runner.read_spv() did a bare cwd-relative fopen() with no path
search, so when the bench was run from the source dir (as in PR #36),
the SPVs at $builddir/v3d_*.spv were not found, every QPU dispatch
returned -1 fast, and the bench loop timed the failure path.
daedalus-fourier PR #37 fixes the SPV search + bench preflight.
Corrected numbers on hertz (Pi 5 V3D 7.1):
kernel CPU ns/op QPU ns/op winner
IDCT 4x4 luma 10.75 217.63 CPU 20.24x
IDCT 8x8 luma 29.69 785.94 CPU 26.47x
Deblock luma_v 17.63 467.42 CPU 26.51x
Deblock luma_h 38.30 498.53 CPU 13.02x
qpel mc20 (8x8) 30.17 1300.44 CPU 43.10x
qpel mc02 (8x8) 17.69 1363.40 CPU 77.08x
qpel mc22 (8x8) 71.60 1948.37 CPU 27.21x
1080p sum: CPU 5.57 ms vs QPU 123.54 ms — QPU 22x SLOWER.
Until daedalus QPU dispatch overhead is actually competitive (separate
multi-task effort tracked on the daedalus-fourier side), libavcodec.so
substitution must stay on daedalus_ctx_create_no_qpu() so the host
processes (firefox-fourier RDD, mpv-fourier, daedalus_v4l2_daemon)
don't pessimize their H.264 decode path.
Adds 0015-h264-ctx-revert-to-no-qpu.patch (2-line revert of patch 0014)
to both arch PKGBUILD and debian build-deb.sh. Both pkgrel bumped
11 → 12. Refs reauktion/daedalus-fourier!37.
claude-noether
f4047f3145