main
3 Commits
| Author | SHA1 | Message | Date | |
|---|---|---|---|---|
 marfrit
|
5965805d86 |
Phase 8.7: media controller + multi-frame streaming verification
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>
|
||
|
marfrit
|
6f4b580f7c |
Phase 8.5: full V4L2 m2m driver, VP9 decode via QBUF/DQBUF
Replaces the Phase 8.4 debugfs-triggered chardev path with a
real V4L2 m2m driver. Userspace clients now drive decoding the
standard way — S_FMT / REQBUFS / QBUF on the OUTPUT (bitstream)
queue, DQBUF on the CAPTURE (NV12M) queue. Kernel device_run
packs the bitstream into REQ_DECODE; daemon decodes via FFmpeg;
RESP_FRAME's inline NV12 pixel payload lands in the CAPTURE
buffer. Phase 8.6 swaps the inline payload for dmabuf so big
frames stop being capped at 64 KiB.
Kernel (daedalus_v4l2_main.c, rewritten + main.h added):
- Per-open struct daedalus_ctx: v4l2_fh, m2m_ctx, ctrl_handler,
per-queue v4l2_pix_format_mplane.
- Two vb2_queues (vb2_vmalloc_memops for both — no DMA needed
yet; 8.6 switches CAPTURE to dma_contig for dmabuf-export):
OUTPUT = V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE, VP9_FRAME
CAPTURE = V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE, NV12M
- Full v4l2_ioctl_ops table: querycap, enum_fmt, g/s/try_fmt
for both queues, reqbufs/querybuf/qbuf/dqbuf/create_bufs/
prepare_buf/expbuf/streamon/streamoff via v4l2_m2m_ioctl_*
helpers.
- v4l2_m2m_ops.device_run: peeks next OUTPUT buf, builds
REQ_DECODE inline with the bitstream bytes, enqueues with an
auto-incrementing cookie, stores {ctx, src_buf, dst_buf} in
a per-device inflight list. Job stays open until RESP_FRAME.
- daedalus_complete_resp_frame(): pops the inflight entry,
memcpys inline NV12 pixels into the CAPTURE buffer (Y plane
+ interleaved CbCr), finishes via
v4l2_m2m_buf_done_and_job_finish — NOT plain buf_done +
job_finish, which leaves the src buf on the m2m queue and
causes device_run to immediately re-run on the same input
(caught on first run; second REQ_DECODE for same bitstream +
eventual oops in stop_streaming on teardown).
Kernel (daedalus_v4l2_chardev.c):
- RESP_FRAME handler now hands inline pixel payload to
daedalus_complete_resp_frame so it lands in the CAPTURE
vb2 buffer. Existing PONG and debugfs test_decode paths still
work; the latter produces a harmless ratelimited "unknown
cookie" since it bypasses V4L2 m2m.
Daemon (decoder.c, decoder.h):
- daedalus_decoder_run_request signature extended with
(nv12_out, nv12_cap, nv12_used). After the FNV-1a digest the
decoder packs YUV420P into NV12 in the caller's buffer: Y
plane line-by-line stripped of stride padding; Cb/Cr
interleaved into a single chroma plane. Truncation silent —
kernel only memcpys what fits in the CAPTURE plane.
Daemon (chardev_client.c):
- handle_req_decode allocates a response buffer sized for the
full chardev payload, lets decoder fill the pixel area
after the resp_frame struct, sends the full payload via the
existing send_response.
Test client (tools/test_m2m_decode.c, new):
- Minimal V4L2 m2m client: S_FMT both queues, REQBUFS 1 each,
mmap+fill OUTPUT, QBUF both, STREAMON, poll, DQBUF, dump
CAPTURE planes to a raw NV12 file. ~250 LOC; verifies the
whole flow without needing v4l2-ctl framing.
Roadmap update (docs/roadmap.md):
- Phase 8.4 retitled "daemon ↔ kernel decode round-trip"
to reflect what actually shipped (vs. the original V4L2-
ioctl-driven plan which moved here).
- Phase 8.5 retitled "full V4L2 m2m driver" with closure
status.
- Phase 8.6 reshaped to two tracks: dmabuf + AV1/H.264/
stateless controls + media controller. Adds the punch list
of v4l2-compliance failures (DECODER_CMD, S_FMT colorspace)
that 8.6 will fix.
Verification on hertz (Pi 5, 6.12.75+rpt-rpi-2712):
Kernel + daemon build clean (-Wall -Wextra clean both sides).
Test harness drives one VP9 keyframe end-to-end:
OUTPUT REQBUFS -> 2
CAPTURE REQBUFS -> 2
QBUF OUTPUT[0] bytesused=1566
QBUF CAPTURE[0]; STREAMON both
poll revents=0x5
DQBUF OUTPUT[0] flags=0x4001 (DONE)
DQBUF CAPTURE[0] flags=0x4000 payloads=[12288, 6144]
wrote 12288 Y + 6144 UV bytes to /tmp/out_m2m.nv12
Pixel correctness vs reference:
ffmpeg -i vp9_small.ivf -pix_fmt nv12 -f rawvideo -y ref.nv12
cmp /tmp/out_m2m.nv12 /tmp/ref.nv12 → match ✓
Byte-for-byte identical to FFmpeg's stock CPU decode.
v4l2-compliance: detected as Stateless Decoder; most ioctls
pass; two expected fails documented in closure doc
(DECODER_CMD/media controller, S_FMT colorspace).
Clean teardown: SIGTERM the daemon, rmmod the module, no
oops/WARN in dmesg.
Per correctness-before-speed:
- Real V4L2 ioctl table (not stubs); uses v4l2-core helpers
where they exist instead of reinventing.
- v4l2_m2m_buf_done_and_job_finish (not the manual sequence)
to keep scheduler state consistent.
- Bit-exact reference comparison, not just "looks right."
- Documented every compliance failure with the planned fix.
- All resource paths (kmalloc/kfree, inflight list cleanup,
src/dst buf removal in stop_streaming) handled on every
error branch.
Phase 8.6 next: dmabuf-export for CAPTURE (removes 64 KiB
frame-size cap), add AV1+H.264 codecs, add V4L2 stateless
controls + media controller binding, fix the colorspace +
cookie-namespace compliance issues.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
|
||
|
marfrit
|
895f57c63a |
Phase 8.2: kernel ↔ daemon chardev bridge with round-trip test
Adds /dev/daedalus-v4l2 misc chardev to the kernel module. The
chardev is the IPC channel for the future userspace decoder
daemon: kernel enqueues REQ_* messages, daemon read()s them,
processes, write()s RESP_* back.
Wire protocol (pre-1.0, header in include/daedalus_v4l2_proto.h):
- struct daedalus_msg_hdr: magic (D04V) + version + type +
cookie + payload_len + reserved
- Request/response separated by high bit of type field
- Max 64 KiB payload per message
- Cookie correlates request with matching response
Kernel implementation (kernel/daedalus_v4l2_chardev.{c,h}):
- Single-instance chardev (-EBUSY on second open)
- In-kernel FIFO bounded at 64 messages
- Blocking + non-blocking read; poll() with EPOLLIN on queued
- write() parses + validates header, logs response at pr_debug
- Bad magic → -EBADMSG, bad version → -EPROTO, oversize → -EMSGSIZE
- All error paths free resources
Phase 8.2 test trigger via debugfs:
- /sys/kernel/debug/daedalus_v4l2/test_ping — any byte
enqueues a PING with a fixed 24-byte payload. Removed in
Phase 8.4 when real REQ_DECODE from V4L2 path takes over.
Userspace verification tool (tools/test_chardev_pingpong.c):
- Real C program, proper error reporting via strerror
- Validates the 6-step round-trip: open → empty-queue EAGAIN →
trigger ping → read PING → verify all fields → write PONG → close
- Builds with -Wall -Wextra clean
Verification on hertz (Pi 5, 6.12.75+rpt-rpi-2712):
$ sudo insmod daedalus_v4l2.ko
$ sudo tools/test_chardev_pingpong
opening /dev/daedalus-v4l2...
non-blocking read on empty queue: EAGAIN ✓
injected PING via debugfs ✓
read PING: magic ✓ version ✓ type=PING ✓ cookie=0x1234 ✓ payload=24 bytes
payload: "DAEDALUS-V4L2-PING-PL"
wrote PONG (cookie=0x1234) ✓
ALL TESTS PASSED.
$ sudo rmmod daedalus_v4l2 # clean
Per correctness-before-speed: full kerneldoc on structs, 8-tab
kernel style, SPDX headers, proper error paths, real test
program (not "I ran it once"), failure-mode coverage documented.
Phase 8.3 next: userspace daemon with dlopen'd FFmpeg parse path.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
|