marfrit
5965805d86
Two pieces — both shipped:
1. Media controller binding closes the last v4l2-compliance
failure from 8.6 (DECODER_CMD, which requires has_media on
stateless decoders) and unlocks the V4L2 request API for
libva-v4l2-request.
2. Multi-frame streaming test exercises the daemon's
AVCodecContext state preservation across many REQ_DECODE
calls — Phase 8.6's tests pushed exactly one keyframe per
invocation; real content has P-frame references.
Compliance now reaches **49/49 passing.**
Kernel (kernel/daedalus_v4l2_main.{c,h}):
- Added `struct media_device mdev` to daedalus_dev.
- media_device_init(&mdev) BEFORE v4l2_device_register so
v4l2-core sees v4l2_dev.mdev = &mdev and binds the m2m
entities into the graph during register.
- After video_register_device:
v4l2_m2m_register_media_controller(..., MEDIA_ENT_F_PROC_VIDEO_DECODER)
then media_device_register so userspace sees the complete
graph in /dev/mediaN with the decoder entity tagged.
- daedalus_remove unwinds in reverse: unregister media,
unregister mc, unregister video, release m2m, unregister
v4l2, cleanup mdev.
- Error paths added for both new failure points.
Test harness (tools/test_m2m_stream.c, new):
- Multi-frame V4L2 m2m client: parses IVF → 4-deep buffer
rings on both queues → per-frame QBUF/DQBUF loop →
concatenates decoded NV12 to output file. Returns 0 only
if every input frame decoded without error.
- Same codec vocabulary as test_m2m_decode (vp9 | av1 |
h264 via 5th arg).
Verification on hertz (Pi 5, 6.12.75+rpt-rpi-2712):
v4l2-compliance: 49 tests, 49 passed, 0 failed, 0 warnings.
$ v4l2-ctl --list-devices
daedalus-fourier V3D7+NEON (platform:daedalus_v4l2):
/dev/video0
/dev/media3
VP9 320×240 30 frames (1 keyframe + 29 P-frames, 3.46 MB
NV12): byte-for-byte match vs `ffmpeg -i in.ivf -pix_fmt
nv12 -f rawvideo`.
VP9 1920×1080 10 frames (31 MB NV12 through the dmabuf
path): byte-for-byte match vs same reference command.
Daemon log shows cookies 1..30 all completing cleanly in
order; lazily-opened AVCodecContext maintains reference
frames across the chardev round-trips.
Clean SIGTERM + rmmod, no oops/WARN.
Roadmap update (docs/roadmap.md):
- 8.7 marked closed with closure-doc reference.
- 8.8 reshaped: perf profiling, QPU dispatch substitution
via daedalus-fourier, multi-frame AV1/H.264, HDR (P010M).
Per correctness-before-speed:
- Order-correct media controller lifecycle (init → bind
v4l2_dev → register video → register mc → register
media; reverse for teardown).
- 4-deep buffer rings on both queues — the scheduler
actually pipelines multiple in-flight cookies through
the chardev (not just one-at-a-time as in 8.5/8.6 tests).
- Bit-exact comparison against ffmpeg, not "looks right."
- All resource paths cleaned on every error branch.
Phase 8.8 next: profile daemon hot loops, dlopen
daedalus-fourier from the daemon, swap FFmpeg per-block
calls for daedalus_dispatch_* where the kernel matches,
target 30fps@1080p from 30fps-floor-is-fine memory.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
daedalus-v4l2
V4L2 stateless decoder for the Raspberry Pi 5 / CM5, backed by the
daedalus-fourier kernel library (VP9 + AV1 CDEF + H.264 video
decode kernels on VideoCore VII compute + ARM NEON).
Status: scaffold (2026-05-18). Architecture locked per daedalus-fourier session memory; implementation not yet begun.
What this is
Sibling repo to daedalus-fourier (the kernel library; cycles 1-9 closed).
A two-piece userspace + kernel-module stack that exposes a V4L2
stateless decoder interface (/dev/videoNN) so that
libva-v4l2-request-fourier → firefox-fourier /
chromium-fourier can drive it the same way they drive existing
hardware-decode pipelines on Pi 5 / RK3588.
+-----------------------------------------------------------+
| firefox-fourier / chromium-fourier (existing) |
+-----------------------------------------------------------+
| VA-API |
+-----------------------------------------------------------+
| libva-v4l2-request-fourier (existing, sibling project) |
+-----------------------------------------------------------+
| V4L2 stateless ioctl uAPI |
+-----------------------------------------------------------+
| daedalus-v4l2 kernel module (`kernel/`) |
| - registers /dev/videoNN |
| - parses V4L2 stateless ioctls (VP9/AV1/H.264 controls) |
| - forwards bitstream + controls to userspace daemon |
| via chardev or netlink |
+-----------------------------------------------------------+
| daedalus-v4l2 userspace daemon (`daemon/`) |
| - takes bitstream blobs + per-slice controls |
| - drives FFmpeg parsers via dlopen (Option γ) |
| - dispatches per-block ops via daedalus-fourier |
| public API (daedalus_dispatch_*) |
| - posts decoded frames back to kernel module |
+-----------------------------------------------------------+
| daedalus-fourier kernel library (sibling project) |
| - exports include/daedalus.h public API |
| - per-kernel CPU NEON + opportunistic V3D QPU dispatch |
| - 9 closed cycles across VP9, AV1 CDEF, H.264 |
+-----------------------------------------------------------+
| V3D 7.1 (Mesa userspace v3dv) + ARM NEON (BCM2712) |
+-----------------------------------------------------------+
Why this architecture (Option B + γ + sibling)
Locked by user 2026-05-18 from 3 options in
daedalus-fourier/docs/phase8_scoping.md:
- Option B over A (userspace v4l2loopback): real
/dev/videoNN, proper DRM PRIME / dmabuf for browser zero-copy. - Option γ: dlopen FFmpeg as parser at runtime. No vendoring, fastest to v1.
- Sibling repo: per
project_consumer_targetconvention, V4L2-side work lives outside daedalus-fourier so the kernel-library has a clean API boundary.
Status
Initial scaffold only. See docs/architecture.md for the
deeper design and docs/roadmap.md for the
sub-phase breakdown.
Repo layout
kernel/— Linux kernel module (V4L2 device registration + ioctl handling + userspace chardev bridge). Out-of-tree.daemon/— userspace decoder daemon (linkslibdaedalus_core.afrom sibling daedalus-fourier; uses dlopen for FFmpeg parser).include/— shared headers between kernel and daemon.docs/— architecture + roadmap.
License
Kernel module: GPLv2 (required for kernel-tree compatibility). Userspace daemon: BSD-2-Clause (matches daedalus-fourier).