claude-noether
9797a0daa6
Extends the AV1 OBU encoder pack (PR #22 landed the Sequence Header half) with the two remaining pieces of the per-frame OBU assembly: - av1_synth_temporal_delimiter_obu() — trivial 2-byte OBU (0x12, 0x00) that AV1 temporal units must start with so libavcodec's parser can detect access-unit boundaries. - av1_synth_frame_header_obu() — encodes a Frame Header OBU (AV1 §5.9) from V4L2_CID_STATELESS_AV1_SEQUENCE + V4L2_CID_STATELESS_ AV1_FRAME controls. ## Frame Header scope The encoder covers the libva-v4l2-request common-case path: - frame_type: KEY / INTER / INTRA_ONLY supported. SWITCH returns 0. - tile_info: single-tile uniform-spacing only (forced tile_cols_log2 = tile_rows_log2 = 0). - quantization_params: full coverage (base_q_idx, delta_q_*, qmatrix). - loop_filter_params: full coverage (levels, sharpness, ref/mode deltas). - cdef_params: full coverage. - segmentation: only enabled=0 path supported (returns 0 if enabled). - loop_restoration: only RESTORE_NONE supported (returns 0 if any plane uses Wiener / SGRPROJ / SWITCHABLE). - global_motion: only IDENTITY warp model emitted (returns 0 if any ref uses ROTZOOM / AFFINE / TRANSLATION). - film_grain_params: only "not present" path — returns 0 if the sequence header has FILM_GRAIN_PARAMS_PRESENT set. Out-of-scope branches return 0 so a future decoder.c integration can surface a coverage warning and fall back to direct libavcodec parsing of the original bitstream where the consumer happens to ship a fully-OBU'd access unit. ## Integration status The new primitives are NOT yet wired into decoder.c. The AV1 decode hot path still passes the OUTPUT buffer straight to libavcodec, which works only when the V4L2 consumer is sending a fully-OBU'd access unit (not strictly the V4L2 stateless contract). A real wiring needs a separate kernel-side change: - daedalus_v4l2_proto.h: add struct daedalus_av1_meta mirroring v4l2_ctrl_av1_sequence + v4l2_ctrl_av1_frame - kernel/daedalus_v4l2_main.c: capture V4L2_CID_STATELESS_AV1_{SEQUENCE, FRAME} at device_run, ship over the chardev - daemon/src/chardev_client.c: receive meta - daemon/src/decoder.c: assemble TD + SH + FH + OBU_TILE_GROUP-wrapped OUTPUT bytes, send to libavcodec Tracked as a follow-on. ## Tests test_av1_obu_synth.c grows 5 new cases (9 total, all green on hertz): === av1_synth_temporal_delimiter_obu === temporal delimiter: OK === av1_synth_frame_header_obu === KEY frame 1080p: OK (13 bytes) INTER frame: OK (18 bytes) SWITCH frame rejected: OK segmentation enabled rejected: OK AV1 OBU synth tests PASSED Bit-walk of the KEY-frame happy path confirms the OBU envelope (obu_type=3 = FRAME_HEADER, has_size_field=1, leb128 size byte), then steps through show_existing_frame, frame_type, show_frame, disable_cdf_update, allow_screen_content_tools. Fuller bit-walks would tie the test to encoder details that are spec-driven and already linear in the source; structural smoke + spec-driven linearity is the right gate. Build clean on hertz (Pi 5, Debian trixie, 6.18.29+rpt-rpi-2712, gcc -Wall -Wextra -Wpedantic). No new warnings. Closes daedalus backlog task #159 (AV1 Frame Header OBU synthesiser; decoder.c integration deferred per task notes above).
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.