Files

T

marfrit 873a04c622 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>

2026-05-18 15:10:22 +00:00

src

Phase 8.3: userspace daemon scaffold + FFmpeg dlopen + parse path

2026-05-18 15:10:22 +00:00

CMakeLists.txt

Phase 8.3: userspace daemon scaffold + FFmpeg dlopen + parse path

2026-05-18 15:10:22 +00:00

README.md

Initial scaffold: daedalus-v4l2 sibling repo

2026-05-18 14:54:56 +00:00

README.md

daemon/ — daedalus-v4l2 userspace decoder daemon

Userspace daemon that:

Connects to the kernel module's chardev
Receives bitstream + V4L2 control blobs
Parses bitstream via dlopen'd FFmpeg
Dispatches per-block work via daedalus_dispatch_* from sibling daedalus-fourier
Returns decoded frames to kernel

Status

Scaffold only. Phase 8.3 not yet started.

Build dependencies (planned)

libdaedalus_core.a from sibling daedalus-fourier (static link)
FFmpeg dev headers (for AVPacket/AVCodec interface types) + runtime FFmpeg .so (loaded via dlopen)
libv4l2 (for V4L2 control struct definitions)
pthread

Build (when implemented)

mkdir build && cd build
cmake .. -DDAEDALUS_FOURIER_DIR=/path/to/daedalus-fourier
make

Layout (planned)

CMakeLists.txt
src/main.c — event loop, chardev connection
src/parser.c — FFmpeg dlopen wrapper + per-codec dispatch
src/decode_vp9.c, src/decode_av1.c, src/decode_h264.c — per-codec block walkers
src/frame_io.c — frame allocation, return to kernel

License

BSD-2-Clause (matches daedalus-fourier sibling).

Phase 8.3 starting point

A standalone program that:

Opens a .ivf or .mp4
Pulls codec packets via dlopen'd avformat
Calls dlopen'd avcodec to parse (without decoding)
Walks the block-level metadata
Validates output structure

No kernel involvement yet — just confirm the parse path works.