marfrit
c7d8050cc9
V4L2 stateless decoder for Pi 5, backed by sibling
daedalus-fourier kernel library (VP9 + AV1 CDEF + H.264 video
decode kernels on VideoCore VII compute + ARM NEON).
Architecture locked 2026-05-18 by mfritsche per
daedalus-fourier/docs/phase8_scoping.md:
- Option B: Linux kernel V4L2 shim + userspace daemon (not
v4l2loopback). Real /dev/videoNN; proper DRM PRIME for
browser zero-copy.
- Option γ: dlopen FFmpeg at runtime as parser. No vendoring;
fastest to v1.
- Sibling repo (this repo): V4L2-side work outside of
daedalus-fourier so kernel-library API stays clean.
Components:
kernel/ - Linux out-of-tree kernel module (GPLv2; V4L2
device + chardev bridge to userspace daemon)
daemon/ - userspace decoder daemon (BSD-2-Clause; links
libdaedalus_core.a from sibling; dlopens FFmpeg)
docs/ - architecture + 7-phase roadmap (8.1..8.7)
include/ - shared headers between kernel and daemon
Roadmap (7 sub-phases, ~1 week each):
8.1 kernel skeleton (/dev/videoNN with no-op ioctls)
8.2 chardev bridge (kernel ↔ daemon ping-pong)
8.3 daemon FFmpeg dlopen + parse path
8.4 VP9 end-to-end via daedalus_dispatch_*
8.5 dmabuf / DRM PRIME for zero-copy
8.6 AV1 + H.264 codec support
8.7 performance: hit 30fps@1080p (project floor)
No code yet — only README + design docs + directory structure.
First implementation work starts in Phase 8.1 next session.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
35 lines
911 B
Markdown
35 lines
911 B
Markdown
# kernel/ — daedalus-v4l2 Linux kernel module
|
|
|
|
Out-of-tree kernel module providing a V4L2 stateless decoder
|
|
device that forwards work to a userspace daemon.
|
|
|
|
## Status
|
|
|
|
Scaffold only. Phase 8.1 not yet started.
|
|
|
|
## Build (when implemented)
|
|
|
|
```sh
|
|
make -C /lib/modules/$(uname -r)/build M=$(pwd)
|
|
sudo insmod daedalus_v4l2.ko
|
|
v4l2-ctl --list-devices # confirm /dev/videoNN appears
|
|
```
|
|
|
|
## Layout (planned)
|
|
|
|
- `Makefile` — kbuild stub
|
|
- `daedalus_v4l2_main.c` — module init + V4L2 device registration
|
|
- `daedalus_v4l2_chardev.c` — `/dev/daedalus-v4l2` chardev for
|
|
daemon communication
|
|
- `daedalus_v4l2_v4l2.c` — V4L2 ioctl dispatch (stateless controls)
|
|
|
|
## License
|
|
|
|
GPLv2. Required for kernel module symbol compatibility.
|
|
|
|
## Phase 8.1 starting point
|
|
|
|
Minimal example: register a /dev/videoNN that returns -ENOSYS on
|
|
every ioctl. Validates that the kernel build works and
|
|
v4l2-ctl can see the device.
|