Mock capture

Part of Project Standalone. Compare EuRoC player.

Source: branch mock-camera-input of uwrealitylabs/standalone-monado-driver, single commit 9363dbe (2026-10-29) on top of dev at 3400e2f. All code is under tests/standalone-camera-mock/; paths below are relative to that folder. Nothing under src/xrt/ changes and the builder (target_builder_standalone.c) is untouched.

Per its README, the run was validated on Apple Silicon macOS (2026-10-28). Independent reproduction by a teammate, Linux/RB5 runs, and confirmation of the receiving interface are still pending.

What it is

A synthetic camera source plus a test harness:

Source. An xrt_fs frame server (see Sinks) that generates images on a producer thread and pushes them into whatever sinks it is started with.
Harness. Feeds the source through a few unmodified Monado sink nodes into an observer, then runs OpenCV corner detection in Python on the received pixels.

It does not create a builder, device, tracker (t_slam, Basalt, Mercury), service, compositor or OpenXR app.

Components

Package	Contents	Built from
`capture_mock/`	The source (`native/mock_capture.cpp`, `.h`), an original single-camera harness, fixtures, Python bindings and runner	Own CMake project; compiles Monado's `u_sink_queue.c` directly
`pipeline_matrix/`	Test graph: optional format converter, optional force-genlock pairing, queue, observer	Compiles `u_sink_converter.c`, `u_sink_force_genlock.c`, `u_frame.c`, `u_format.c` directly
`capture_e2e/`	Joins the source to the graph through a per-camera "guard" sink (`native/session.cpp`) and orchestrates end-to-end scenarios	Links the two above

Entry point: run.py (full suite, or --scenario four-l8 / four-rgb). Python 3.13, OpenCV via capture_mock/requirements.lock. reviewed-sources.json records hashes of the upstream Monado files it compiles and refuses to run if any changed.

The source

API in capture_mock/native/mock_capture.h:

Function	Behaviour
`wrl_mock_capture_create(_format)(xfctx, &config [, format])`	One camera. Implements `stream_start` into one sink; `slam_stream_start` returns `NOT_IMPLEMENTED` (`mock_capture.cpp:111`)
`wrl_mock_capture_group_create(_format)(xfctx, configs, n [, format])`	1–4 cameras behind one `xrt_fs`. `slam_stream_start` routes `configs[i]` to `sinks.cams[i]` (`:257`, `:276`)
`wrl_mock_capture_group_schedule`, `_group_stats`	Set the shared start time; read per-camera counters

Frames (make_frame, :150):

A real xrt_frame with its own pixel buffer and refcount; destroy frees it (:44).
One byte per pixel, R8 by default or L8 via the _format variants. Stride is width plus configurable padding.
Content: a checkerboard plus a 12×12 square that moves sideways each frame, with a 16-byte identity header (camera, sequence, seed, session) in the first pixels and a CRC over the buffer.