From 15e0b9155a4e7a27a6c67437234d196da3509cb7 Mon Sep 17 00:00:00 2001 From: Cristhian Date: Tue, 15 Sep 2026 06:26:10 -0300 Subject: [PATCH] add a worked example wiring dora-webcam into this node The only dataflow here drove the viewer from a test fixture, so nothing showed how to consume a real producer. dataflow_webcam.yml wires dora-webcam v0.1.0 into it: the camera publishes std/media/v1/Image and this node draws it, with depth, camera_info, text and bbox simply unwired, which is what every input being optional buys. The dependency points one way only. A consumer naming its producer is an arrow; dora-webcam names no consumer, so there is no cycle. Two things are deliberate. The camera's output type is repeated in the dataflow because a `git:` node's manifest is not read at validate time, only at build, so without it the two contracts are never compared -- a deliberate mismatch is caught with the annotation and passes silently without it. And the file carries no strict_types: a camera publishes an image and nothing else, and strict validation warns about every typed input a dataflow leaves unwired. Interoperability was verified directly, feeding dora-webcam's packed payload into this node's decoder across bgr8, rgb8, jpeg, png and yuv420: the struct types are identical and the lossless encodings round-trip exactly. The dataflow validates but was not run: with dora-cli 1.0.1 a `git:` node pointing at a private repository does not build over either transport, which the file and the README record. --- README.md | 25 +++++++++++++++++++++++++ dataflow_webcam.yml | 40 ++++++++++++++++++++++++++++++++++++++++ 2 files changed, 65 insertions(+) create mode 100644 dataflow_webcam.yml diff --git a/README.md b/README.md index d7f4ee3..9c63c1d 100644 --- a/README.md +++ b/README.md @@ -66,6 +66,31 @@ CI=true SOURCE_FRAMES=30 dora run dataflow.yml --uv `SOURCE_WIDTH` and `SOURCE_HEIGHT` (default 640x480) set the frame size. +### With a real camera + +[`dataflow_webcam.yml`](dataflow_webcam.yml) wires +[dora-webcam](https://gitea.liria.cl/liria/dora-webcam) into this node, and is the +worked example of consuming something that is not a test fixture: + +```bash +dora run dataflow_webcam.yml --uv +``` + +The camera publishes `std/media/v1/Image` and this node draws it. `depth`, +`camera_info`, `text` and `bbox` are simply unwired — every input is optional, so a +plain viewer is the result. + +It carries no `strict_types`, deliberately. A camera publishes an image and nothing +else, and `dora validate --strict` warns about every *typed* input this node declares +that a dataflow leaves unwired. The strictness belongs to `dataflow.yml`, which drives +all of them. + +**Known limitation (dora-cli 1.0.1).** A `git:` node pointing at a private repository +does not build: over `ssh://` on a non-standard port the connection fails, and over +`https://` libgit2 reports `remote authentication required but no callback set`. The +dataflow validates and the wiring is the form a consumer should use, but running it +needs that fixed or the repository made public. + ### Node manifest [`dora-node.yml`](dora-node.yml) declares the node's inputs with type URNs. No source diff --git a/dataflow_webcam.yml b/dataflow_webcam.yml new file mode 100644 index 0000000..4c6604c --- /dev/null +++ b/dataflow_webcam.yml @@ -0,0 +1,40 @@ +# A real camera into the viewer, and the worked example of wiring this node to +# something that is not a test fixture. +# +# Not run by CI: it needs a camera and it fetches dora-webcam over the network. +# dataflow.yml is the gate, and needs neither. +# +# Known limitation, dora-cli 1.0.1: a `git:` node pointing at a *private* +# repository does not build. Over ssh:// on a non-standard port the connection +# fails outright, and over https:// libgit2 reports "remote authentication +# required but no callback set" -- dora has no credential callback, so neither +# transport authenticates. This file validates, and the wiring below is the form +# a consumer should use; running it needs that fixed, or the repository public. +# +# `strict_types` is deliberately absent. A camera publishes an image and nothing +# else, and `dora validate --strict` warns about every *typed* input this node +# declares that a dataflow leaves unwired -- depth, camera_info and text here. +# The wiring is correct; the strictness is aimed at the self-contained dataflow, +# which drives all of them. + +nodes: + - id: camera + git: ssh://git@gitea.liria.cl:5001/liria/dora-webcam.git + tag: v0.1.0 + build: uv pip install . + path: dora-webcam + inputs: + tick: dora/timer/millis/33 + outputs: + - image + # dora-webcam's own manifest says this, but a `git:` node's manifest is not + # read at validate time -- only at build. Repeating it here is what makes + # the two contracts checked against each other now rather than at runtime. + output_types: + image: std/media/v1/Image + + - id: view + path: dora-image-view + build: uv pip install . + inputs: + image: camera/image