[v1,0/2] rpi: Expose Unicam frontend sequence as SensorSequence metadata
mbox series

Message ID 20260626003712.26624-1-ballen4705@googlemail.com
Headers show
Series
  • rpi: Expose Unicam frontend sequence as SensorSequence metadata
Related show

Message

Bruce Allen June 26, 2026, 12:37 a.m. UTC 
Hi,

This tiny patch series adds a Raspberry Pi vendor metadata control
SensorSequence that exposes the Unicam frontend
FrameBuffer::metadata().sequence on completed requests (VC4 pipeline).

Motivation: applications diagnosing frame loss need a counter tied to
frontend capture, not just delivered-frame or control-list
timing. Gaps in this sequence indicate frames that did not reach the
frontend stream before the previous request completed.

The control is defined in control_ids_rpi.yaml, set in vc4.cpp at
Unicam dequeue, and propagated in pipeline_base.cpp like
SensorTimestamp and FrameWallClock. Python bindings follow from
existing pycamera codegen.

Tested: builds on master @ 29eb112 with -Dpipelines=rpi/vc4
-Dipas=rpi/vc4 -Dpycamera=enabled; verified
libcamera.controls.rpi.SensorSequence imports from the staged
tree. Tested on Raspberry Pi CM4, correctly detects dropped frames.

Cheers,
Bruce Allen