test0r
b47938e0bc
build and publish packages / distcc-avahi-aarch64 (push) Successful in 1m3s
build and publish packages / lmcp-any (push) Successful in 9s
build and publish packages / lmcp-debian (push) Successful in 4s
build and publish packages / claude-his-any (push) Failing after 4s
build and publish packages / ffmpeg-v4l2-request-aarch64 (push) Has been skipped
build and publish packages / claude-his-debian (push) Has been skipped
Mirrors phase6/step1/ from the ohm_gl_fix campaign. Contract-correct
hantro multi-planar / chromium-149-era stateless H.264 port of
bootlin's libva-v4l2-request, patches 0001..0018 + fourier-local.
Honest characterisation in README:
- Builds cleanly on chromium-builder LXC (boltzmann)
- vainfo enumerates H.264 profiles cleanly with LIBVA_DRIVER_NAME=v4l2_request
- NOT on Brave's decode path on ohm_gl_fix stack — Brave uses
Chromium's own V4L2VideoDecoder in media/gpu/v4l2/.
- Most likely useful for a future Firefox-via-libavcodec-vaapi
campaign, modulo a separate Mesa-panfrost WSI pitch issue.
- DEBUG patches (0010, 0011, 0014) intentionally kept in series
for development; remove for cleaner production runs.
Audit trail in the source repo at ohm_gl_fix:
phase6/step1/audit_0008_decode_params_2026-05-01.md
phase6/step1/api_contract_findings_2026-05-01.md
phase3_remeasure_2026-05-02/B3_decoder_discovery.md (why this
isn't on Brave's path)
146 lines
4.3 KiB
Diff
146 lines
4.3 KiB
Diff
From: Markus Fritsche <fritsche.markus@gmail.com>
|
|
Date: 2026-05-01
|
|
Subject: [PATCH] v4l2: add QUERYCTRL/QUERYMENU capability-probe helpers
|
|
|
|
Pure utility additions, no behaviour change. Three helpers in
|
|
src/v4l2.{c,h}:
|
|
|
|
- v4l2_query_ext_ctrl(): wraps VIDIOC_QUERY_EXT_CTRL by CID.
|
|
Returns 0 if the control exists, -1 if not. Caller passes NULL
|
|
qec to test existence only.
|
|
|
|
- v4l2_query_menu(): wraps VIDIOC_QUERYMENU at a given index.
|
|
Returns 0 if a menu item exists at that index, -1 otherwise.
|
|
|
|
- v4l2_ctrl_menu_has_value(): convenience layered on the above.
|
|
For a menu/intmenu-type control, walks all menu items between
|
|
minimum and maximum and returns true iff `value` is a valid
|
|
entry. Used by callers that ask "does this driver accept menu
|
|
value X for this CID?" without caring about iteration details.
|
|
|
|
These unblock commit 3 (request_pool — needs ext-ctrl probing for
|
|
codec-ops dispatch) and commit 4 (probe-then-set DECODE_MODE/
|
|
START_CODE — replaces 0002's unconditional set with a real probe)
|
|
of the upstreamable design's six-commit series.
|
|
|
|
Forward-declarations in v4l2.h keep the header lean: existing
|
|
prototypes already use opaque struct v4l2_ext_control * pointers
|
|
without including <linux/videodev2.h>; we follow the same
|
|
convention for struct v4l2_query_ext_ctrl and struct v4l2_querymenu.
|
|
|
|
No call sites added in this commit. Compile-only verification:
|
|
the .so links cleanly with three new exports.
|
|
|
|
Signed-off-by: Markus Fritsche <fritsche.markus@gmail.com>
|
|
---
|
|
src/v4l2.c | 60 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
|
|
src/v4l2.h | 33 +++++++++++++++++++++++++++++
|
|
2 files changed, 93 insertions(+)
|
|
|
|
--- a/src/v4l2.h
|
|
+++ b/src/v4l2.h
|
|
@@ -64,4 +64,37 @@ int v4l2_set_control(int video_fd, int request_fd, unsigned int id, void *data,
|
|
unsigned int size);
|
|
int v4l2_set_stream(int video_fd, unsigned int type, bool enable);
|
|
|
|
+/*
|
|
+ * Capability-probe helpers. These let calling code discover what the
|
|
+ * backing kernel driver supports rather than hardcoding assumptions
|
|
+ * about specific decoder hardware.
|
|
+ */
|
|
+
|
|
+/*
|
|
+ * Query the metadata of an extended control by CID. Fills *qec on
|
|
+ * success. Returns 0 if the control exists, -1 (errno=EINVAL) if the
|
|
+ * driver does not expose this CID. Pass qec=NULL to test existence
|
|
+ * only.
|
|
+ */
|
|
+struct v4l2_query_ext_ctrl;
|
|
+int v4l2_query_ext_ctrl(int video_fd, unsigned int id,
|
|
+ struct v4l2_query_ext_ctrl *qec);
|
|
+
|
|
+/*
|
|
+ * Query a single menu item of a menu/intmenu control at the given
|
|
+ * index. Fills *qm on success. Returns 0 if the menu item exists at
|
|
+ * this index, -1 otherwise.
|
|
+ */
|
|
+struct v4l2_querymenu;
|
|
+int v4l2_query_menu(int video_fd, unsigned int id, unsigned int index,
|
|
+ struct v4l2_querymenu *qm);
|
|
+
|
|
+/*
|
|
+ * Convenience: for a menu-type control, return true iff `value` is a
|
|
+ * valid menu entry (i.e. the driver accepts it). Walks all menu items
|
|
+ * up to the control's maximum to check.
|
|
+ */
|
|
+bool v4l2_ctrl_menu_has_value(int video_fd, unsigned int id,
|
|
+ unsigned int value);
|
|
+
|
|
#endif
|
|
--- a/src/v4l2.c
|
|
+++ b/src/v4l2.c
|
|
@@ -508,3 +508,63 @@ int v4l2_set_stream(int video_fd, unsigned int type, bool enable)
|
|
|
|
return 0;
|
|
}
|
|
+
|
|
+int v4l2_query_ext_ctrl(int video_fd, unsigned int id,
|
|
+ struct v4l2_query_ext_ctrl *qec)
|
|
+{
|
|
+ struct v4l2_query_ext_ctrl local;
|
|
+ struct v4l2_query_ext_ctrl *target = qec ? qec : &local;
|
|
+ int rc;
|
|
+
|
|
+ memset(target, 0, sizeof(*target));
|
|
+ target->id = id;
|
|
+
|
|
+ rc = ioctl(video_fd, VIDIOC_QUERY_EXT_CTRL, target);
|
|
+ if (rc < 0)
|
|
+ return -1;
|
|
+
|
|
+ return 0;
|
|
+}
|
|
+
|
|
+int v4l2_query_menu(int video_fd, unsigned int id, unsigned int index,
|
|
+ struct v4l2_querymenu *qm)
|
|
+{
|
|
+ int rc;
|
|
+
|
|
+ if (qm == NULL)
|
|
+ return -1;
|
|
+
|
|
+ memset(qm, 0, sizeof(*qm));
|
|
+ qm->id = id;
|
|
+ qm->index = index;
|
|
+
|
|
+ rc = ioctl(video_fd, VIDIOC_QUERYMENU, qm);
|
|
+ if (rc < 0)
|
|
+ return -1;
|
|
+
|
|
+ return 0;
|
|
+}
|
|
+
|
|
+bool v4l2_ctrl_menu_has_value(int video_fd, unsigned int id,
|
|
+ unsigned int value)
|
|
+{
|
|
+ struct v4l2_query_ext_ctrl qec;
|
|
+ struct v4l2_querymenu qm;
|
|
+ long long i;
|
|
+
|
|
+ if (v4l2_query_ext_ctrl(video_fd, id, &qec) < 0)
|
|
+ return false;
|
|
+
|
|
+ if (qec.type != V4L2_CTRL_TYPE_MENU &&
|
|
+ qec.type != V4L2_CTRL_TYPE_INTEGER_MENU)
|
|
+ return false;
|
|
+
|
|
+ for (i = qec.minimum; i <= qec.maximum; i += qec.step ? qec.step : 1) {
|
|
+ if (v4l2_query_menu(video_fd, id, (unsigned int)i, &qm) < 0)
|
|
+ continue;
|
|
+ if ((unsigned int)i == value)
|
|
+ return true;
|
|
+ }
|
|
+
|
|
+ return false;
|
|
+}
|