claude-noether
514da29a73
Switch the daemon's runtime dlopen targets from Debian-stock soname 61/61/59 (FFmpeg 7.1.3) to the Kwiboo fourier fork's soname 62/62/60 (FFmpeg 8.1) installed at the /opt/fourier prefix. Why --- The substitution arc tracked at daedalus-v4l2#11 needs daedalus- fourier kernel calls woven into libavcodec's H264DSPContext NEON init (replacing ff_h264_idct_add_neon etc. with thunks calling daedalus_recipe_dispatch_h264_*). We do that via patches in the ffmpeg-v4l2-request-fourier package source — which we own, in marfrit-packages, alongside the existing libudev-bypass and nv15-to-p010 patches. But that package builds the Kwiboo fork at soname 62 / /opt/fourier. The daemon currently dlopens soname 61 (Debian-stock + a separately-built +fourier2 patch that isn't in marfrit-packages' source tree), so substitution patches there wouldn't reach the daemon. Switching to soname 62 routes the daemon through the package we control — first step toward landing daedalus-fourier kernel substitution into the production decode path. Compat ------ - /opt/fourier libs are already on every host running the daemon (hard build-dep of ffmpeg-v4l2-request-fourier). Firefox-fourier and mpv-fourier already dlopen them via the same path. - /etc/ld.so.conf.d/fourier.conf entry resolves the new sonames from /opt/fourier/lib via the ld cache; dlopen-by-soname works without LD_LIBRARY_PATH wrappers. - Build-side: daemon's pkg_check_modules picks up libav*.pc from /opt/fourier/lib/pkgconfig when PKG_CONFIG_PATH includes that directory (build-deb.sh follow-up will set it). - API surface unchanged: avcodec_send_packet / receive_frame / AVCodecContext flags / AVFrame fields are all stable between FFmpeg 7.1 and 8.1. Verified clean cross-compile on hertz. Wire protocol unchanged. No kmod bump. Next step (follow-up PRs) ------------------------- 1. ffmpeg-v4l2-request-fourier patch: add 0003-daedalus-fourier- substitute-h264-idct4.patch that replaces ff_h264_idct_add_neon in libavcodec/aarch64/h264dsp_init_aarch64.c with a thunk calling daedalus_recipe_dispatch_h264_idct4. 2. Repeat for IDCT 8×8, deblock luma-v, qpel mc20 (one kernel per PR for reviewability; bench delta + decode_us delta documented per substitution). 3. marfrit-packages bump to pick up the new daemon + the substituted fourier package.
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 siblingdaedalus-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.txtsrc/main.c— event loop, chardev connectionsrc/parser.c— FFmpeg dlopen wrapper + per-codec dispatchsrc/decode_vp9.c,src/decode_av1.c,src/decode_h264.c— per-codec block walkerssrc/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.