 marfrit
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873a04c622
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Phase 8.3: userspace daemon scaffold + FFmpeg dlopen + parse path
Builds the daemon executable per the locked Phase 8 architecture
(Option γ: dlopen FFmpeg at runtime). Phase 8.3 scope: parse
path validation only — no V4L2 wiring, no decode, no chardev
connection.
Components:
- daemon/CMakeLists.txt — CMake with -Wall -Wextra -Wpedantic
clean. pkg-config for FFmpeg headers; only -ldl + -lpthread
at link time.
- daemon/src/main.c — entry point, signal handlers
(SIGINT/SIGTERM), command dispatcher. Currently `parse <file>`.
- daemon/src/ffmpeg_loader.{c,h} — runtime FFmpeg loader.
dlopens libavformat.so.61, libavcodec.so.61, libavutil.so.59.
Resolves 22 function pointers using POSIX-recommended
*(void**)& dlsym idiom (per POSIX.1-2017 dlsym(3p) Rationale).
- daemon/src/parser.{c,h} — demux loop via avformat_open_input +
av_read_frame. Per-frame logging on -v.
- daemon/src/log.{c,h} — logging facade (stderr Phase 8.3;
syslog/journal planned for 8.5+).
Verification on hertz:
$ ffmpeg -f lavfi -i testsrc=duration=2:size=320x240:rate=30 \
-c:v libvpx-vp9 -y /tmp/testsrc.ivf
$ daedalus_v4l2_daemon parse /tmp/testsrc.ivf
[INFO] FFmpeg loaded: 7.1.3-0+deb13u1+rpt1 (libavformat 61.7.100)
[INFO] video stream #0: codec=vp9 (Google VP9) 320x240, 0/0 fps
[INFO] parse complete: 60 frames (1 key) total 17859 bytes
Error paths verified:
- Missing file → "avformat_open_input(...): code -2", exit 1
- No command → usage message, exit 2
- Bad command → usage message, exit 2
Per correctness-before-speed:
- Real CMake (no Makefile hacks)
- pkg-config for headers
- POSIX-conformant dlsym pattern (no -Wpedantic suppression)
- Real signal handling + proper exit codes
- Real logging with timestamp + level
- Headers included at compile-time for type safety; dlopen
decouples runtime
- All FFmpeg resources freed on every exit path
- Builds clean on -Wall -Wextra -Wpedantic
Phase 8.3 acceptance criteria met:
- ✓ daemon binary builds
- ✓ dlopen FFmpeg at runtime
- ✓ demux a VP9 IVF file end-to-end
- ✓ per-frame metadata logged correctly
- ✓ frame count + keyframe count + byte total accurate
Phase 8.4 next: wire daemon to /dev/daedalus-v4l2 chardev,
add REQ_DECODE / RESP_FRAME handling, drive VP9 decode
end-to-end via daedalus_dispatch_* from daedalus-fourier.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
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2026-05-18 15:10:22 +00:00 |
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marfrit
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c7d8050cc9
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Initial scaffold: daedalus-v4l2 sibling repo
V4L2 stateless decoder for Pi 5, backed by sibling
daedalus-fourier kernel library (VP9 + AV1 CDEF + H.264 video
decode kernels on VideoCore VII compute + ARM NEON).
Architecture locked 2026-05-18 by mfritsche per
daedalus-fourier/docs/phase8_scoping.md:
- Option B: Linux kernel V4L2 shim + userspace daemon (not
v4l2loopback). Real /dev/videoNN; proper DRM PRIME for
browser zero-copy.
- Option γ: dlopen FFmpeg at runtime as parser. No vendoring;
fastest to v1.
- Sibling repo (this repo): V4L2-side work outside of
daedalus-fourier so kernel-library API stays clean.
Components:
kernel/ - Linux out-of-tree kernel module (GPLv2; V4L2
device + chardev bridge to userspace daemon)
daemon/ - userspace decoder daemon (BSD-2-Clause; links
libdaedalus_core.a from sibling; dlopens FFmpeg)
docs/ - architecture + 7-phase roadmap (8.1..8.7)
include/ - shared headers between kernel and daemon
Roadmap (7 sub-phases, ~1 week each):
8.1 kernel skeleton (/dev/videoNN with no-op ioctls)
8.2 chardev bridge (kernel ↔ daemon ping-pong)
8.3 daemon FFmpeg dlopen + parse path
8.4 VP9 end-to-end via daedalus_dispatch_*
8.5 dmabuf / DRM PRIME for zero-copy
8.6 AV1 + H.264 codec support
8.7 performance: hit 30fps@1080p (project floor)
No code yet — only README + design docs + directory structure.
First implementation work starts in Phase 8.1 next session.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
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2026-05-18 14:54:56 +00:00 |
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