Adds a build-time switch so platforms that will never see a
daedalus_v4l2 kernel module (Allwinner cedrus, RK without the
shim, etc.) can opt out of the probe entry + dispatch branch.
meson setup build # daedalus support on
meson setup build-off -Ddaedalus_v4l2=false # off
Implementation:
- meson_options.txt: new boolean `daedalus_v4l2`, default true.
- src/meson.build: when option is true, autoconfig.h gets
`#define HAVE_DAEDALUS_V4L2 1`.
- src/request.c: known_decoder_drivers[] entry, primary-driver
detection branch, and post-probe log line all gated by
#ifdef HAVE_DAEDALUS_V4L2.
- src/request.h: struct daedalus fields kept UNCONDITIONAL.
Two extra int per session and the struct layout stays stable
across translation units regardless of option — avoids the
ODR risk of every consumer of request.h needing to include
autoconfig.h before request.h.
Verified on hertz: both builds compile clean.
build/src/autoconfig.h has HAVE_DAEDALUS_V4L2; .so contains
"daedalus_v4l2" string + log message.
build-off/src/autoconfig.h doesn't; .so contains no daedalus
strings at all.
Default-on build still passes vainfo end-to-end:
vainfo: Driver version: v4l2-request
vainfo: Supported profile and entrypoints
VAProfileH264Main / High / ConstrainedBaseline / MultiviewHigh
/ StereoHigh : VAEntrypointVLD
VAProfileVP9Profile0 : VAEntrypointVLD
VAProfileAV1Profile0 : VAEntrypointVLD
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
The system normally has kernel headers shipped with the distribution.
These typically lag behind actual kernel releases. Thus they would not
have the latest API additions, such as the V4L2 request API this driver
uses.
However, it is also bad practice to just install new kernel headers into
the system wide default location, as there may be some differences
between it and what the C library was built against.
Add an option to specify a path to a set of up-to-date kernel headers.
This would allow the user to build this project in a safe but working
environment.
Signed-off-by: Chen-Yu Tsai <wens@csie.org>
marfrit
Chen-Yu Tsai