[{"id":38038,"web_url":"https://patchwork.libcamera.org/comment/38038/","msgid":"<85cy2rtbyy.fsf@mzamazal-thinkpadp1gen7.tpbc.csb>","date":"2026-01-30T14:24:37","subject":"Re: [PATCH] libcamera: layer_manager: Add support for global\n\tconfiguration","submitter":{"id":177,"url":"https://patchwork.libcamera.org/api/people/177/","name":"Milan Zamazal","email":"mzamazal@redhat.com"},"content":"Hi Paul,\n\nthe idea looks generally fine to me. A few comments below, others may\nhave more comments.\n\nPaul Elder writes:\n\n> Enable configuring the layer system with the global configuration file,\n> while retaining the ability to overwrite the global configuration via\n> environment variables. This allows users to more easily retain layer\n> setups without having to always set environment variables.\n>\n> To achieve this, the CameraManager needs to manually construct the\n> LayerManager to feed it the global configuration.\n>\n> While at it, add documentation for the layer configuration options\n>\n> Signed-off-by: Paul Elder \n> ---\n> This patch is on top of v6 of \"Add Layers support\" [0]\n>\n> [0] https://patchwork.libcamera.org/project/libcamera/list/?series=5753\n>\n> Documentation/runtime_configuration.rst | 13 +++++\n> include/libcamera/internal/camera_manager.h | 4 +-\n> include/libcamera/internal/layer_manager.h | 10 +++-\n> src/libcamera/camera_manager.cpp | 1 +\n> src/libcamera/layer_manager.cpp | 61 ++++++++++-----------\n> 5 files changed, 53 insertions(+), 36 deletions(-)\n>\n> diff --git a/Documentation/runtime_configuration.rst b/Documentation/runtime_configuration.rst\n> index e99ef2fb9561..a74a738803d6 100644\n> --- a/Documentation/runtime_configuration.rst\n> +++ b/Documentation/runtime_configuration.rst\n> @@ -139,6 +139,19 @@ LIBCAMERA__TUNING_FILE\n> \n> Example value: ``/usr/local/share/libcamera/ipa/rpi/vc4/custom_sensor.json``\n> \n> +LIBCAMERA_LAYER_PATH, layer.path\n> + Define custom search locations for Layer implementations.\n> +\n> + Example value: ``${HOME}/.libcamera/share/layer:/opt/libcamera/vendor/share/layer``\n> +\n> +LIBCAMERA_LAYERS_ENABLE, layer.layers\n> + Define an ordered list of Layers to load. The layer names are declared in the\n> + 'name' field of their repsective LayerInfo structs. The layers declared first\n\ns/repsective/respective/\n\n> + are closer to the application, and the layers declared later are closer to\n> + libcamera.\n> +\n> + Example value: ``inject_controls,sync``\n> +\n> pipelines.simple.supported_devices.driver, pipelines.simple.supported_devices.software_isp\n> Override whether software ISP is enabled for the given driver.\n> \n> diff --git a/include/libcamera/internal/camera_manager.h b/include/libcamera/internal/camera_manager.h\n> index cc3ede02507f..00afcd2177e7 100644\n> --- a/include/libcamera/internal/camera_manager.h\n> +++ b/include/libcamera/internal/camera_manager.h\n> @@ -46,7 +46,7 @@ public:\n> \t}\n> \n> \tIPAManager *ipaManager() const { return ipaManager_.get(); }\n> -\tconst LayerManager *layerManager() const { return &layerManager_; }\n> +\tconst LayerManager *layerManager() const { return layerManager_.get(); }\n\nIt doesn't look like a real problem but still, it feels like an abuse of\nunique_ptr. Should shared_ptr be used?\n\n> protected:\n> \tvoid run() override;\n> @@ -73,7 +73,7 @@ private:\n> \tstd::unique_ptr enumerator_;\n> \n> \tstd::unique_ptr ipaManager_;\n> -\tLayerManager layerManager_;\n> +\tstd::unique_ptr layerManager_;\n> \n> \tconst GlobalConfiguration configuration_;\n> };\n> diff --git a/include/libcamera/internal/layer_manager.h b/include/libcamera/internal/layer_manager.h\n> index 8427ec3eb5d9..82a6a1d82461 100644\n> --- a/include/libcamera/internal/layer_manager.h\n> +++ b/include/libcamera/internal/layer_manager.h\n> @@ -26,6 +26,8 @@\n> #include \n> #include \n> \n> +#include \"libcamera/internal/global_configuration.h\"\n> +\n> namespace libcamera {\n> \n> LOG_DECLARE_CATEGORY(LayerLoaded)\n> @@ -150,7 +152,9 @@ struct LayerInstance {\n> class LayerController\n> {\n> public:\n> -\tLayerController(const Camera *camera, const ControlList &properties,\n> +\tLayerController(const Camera *camera,\n> +\t\t\tconst GlobalConfiguration &configuration,\n\nThere are plans to generally pass CameraManager instead. This is a part\nof the huge Laurent's patch series, which may hang around for a while\nbefore it gets merged. I'd suggest keeping eye on it and change the\nargument if/when needed.\n\n> +\t\t\tconst ControlList &properties,\n> \t\t\tconst ControlInfoMap &controlInfoMap,\n> \t\t\tconst std::map> &layers);\n> \t~LayerController();\n> @@ -190,7 +194,7 @@ private:\n> class LayerManager\n> {\n> public:\n> -\tLayerManager();\n> +\tLayerManager(const GlobalConfiguration &configuration);\n> \t~LayerManager() = default;\n> \n> \tstd::unique_ptr\n> @@ -200,6 +204,8 @@ public:\n> \n> private:\n> \tstd::map> layers_;\n> +\n> +\tconst GlobalConfiguration &configuration_;\n> };\n> \n> } /* namespace libcamera */\n> diff --git a/src/libcamera/camera_manager.cpp b/src/libcamera/camera_manager.cpp\n> index 554cd935339a..a8e7cfe9daff 100644\n> --- a/src/libcamera/camera_manager.cpp\n> +++ b/src/libcamera/camera_manager.cpp\n> @@ -43,6 +43,7 @@ CameraManager::Private::Private()\n> \t: Thread(\"CameraManager\"), initialized_(false)\n> {\n> \tipaManager_ = std::make_unique(this->configuration());\n> +\tlayerManager_ = std::make_unique(this->configuration());\n> }\n> \n> int CameraManager::Private::start()\n> diff --git a/src/libcamera/layer_manager.cpp b/src/libcamera/layer_manager.cpp\n> index bef69f6bd04b..445e26234b23 100644\n> --- a/src/libcamera/layer_manager.cpp\n> +++ b/src/libcamera/layer_manager.cpp\n> @@ -25,6 +25,7 @@\n> #include \n> #include \n> \n> +#include \"libcamera/internal/global_configuration.h\"\n> #include \"libcamera/internal/utils.h\"\n> \n> /**\n> @@ -276,6 +277,7 @@ LayerLoaded::LayerLoaded(const std::string &filename)\n> /**\n> * \\brief Initialize the Layers\n> * \\param[in] camera The Camera for whom to initialize layers\n> + * \\param[in] configuration The global configuration\n> * \\param[in] properties The Camera properties\n> * \\param[in] controlInfoMap The Camera controls\n> * \\param[in] layers Map of available layers\n> @@ -290,29 +292,26 @@ LayerLoaded::LayerLoaded(const std::string &filename)\n> * efficiently returned at properties() and controls(), respectively.\n> */\n> LayerController::LayerController(const Camera *camera,\n> +\t\t\t\t const GlobalConfiguration &configuration,\n> \t\t\t\t const ControlList &properties,\n> \t\t\t\t const ControlInfoMap &controlInfoMap,\n> \t\t\t\t const std::map> &layers)\n> {\n> \t/* Order the layers */\n> -\t/* \\todo Document this. First is closer to application, last is closer to libcamera */\n> -\t/* \\todo Get this from configuration file */\n> -\tconst char *layerList = utils::secure_getenv(\"LIBCAMERA_LAYERS_ENABLE\");\n> -\tif (layerList) {\n> -\t\tfor (const auto &layerName : utils::split(layerList, \",\")) {\n> -\t\t\tif (layerName.empty())\n> -\t\t\t\tcontinue;\n> -\n> -\t\t\tconst auto &it = layers.find(layerName);\n> -\t\t\tif (it == layers.end()) {\n> -\t\t\t\tLOG(LayerController, Warning)\n> -\t\t\t\t\t<< \"Requested layer '\" << layerName\n> -\t\t\t\t\t<< \"' not found\";\n> -\t\t\t\tcontinue;\n> -\t\t\t}\n> -\n> -\t\t\texecutionQueue_.emplace_back(std::make_unique(it->second));\n> +\tstd::vector configLayers =\n> +\t\tconfiguration.envListOption(\"LIBCAMERA_LAYERS_ENABLE\", { \"layer\", \"layers\" }, \",\")\n> +\t\t\t .value_or(std::vector());\n> +\n> +\tfor (const std::string &layerName : configLayers) {\n> +\t\tconst auto &it = layers.find(layerName);\n> +\t\tif (it == layers.end()) {\n> +\t\t\tLOG(LayerController, Warning)\n> +\t\t\t\t<< \"Requested layer '\" << layerName\n> +\t\t\t\t<< \"' not found\";\n> +\t\t\tcontinue;\n> \t\t}\n> +\n> +\t\texecutionQueue_.emplace_back(std::make_unique(it->second));\n> \t}\n> \n> \tfor (std::unique_ptr &layer : executionQueue_)\n> @@ -532,7 +531,8 @@ void LayerController::stop()\n> * LayerController is responsible for organizing them into queues to be\n> * executed, and for managing closures for each Camera that they belong to.\n> */\n> -LayerManager::LayerManager()\n> +LayerManager::LayerManager(const GlobalConfiguration &configuration)\n> +\t: configuration_(configuration)\n> {\n> \t/* This is so that we can capture it in the lambda below */\n> \tstd::map> &layers = layers_;\n> @@ -560,19 +560,15 @@ LayerManager::LayerManager()\n> \t};\n> \n> \t/* User-specified paths take precedence. */\n> -\t/* \\todo Document this */\n> -\tconst char *layerPaths = utils::secure_getenv(\"LIBCAMERA_LAYER_PATH\");\n> -\tif (layerPaths) {\n> -\t\tfor (const auto &dir : utils::split(layerPaths, \":\")) {\n> -\t\t\tif (dir.empty())\n> -\t\t\t\tcontinue;\n> -\n> -\t\t\t/*\n> -\t\t\t * \\todo Move the shared objects into one directory\n> -\t\t\t * instead of each in their own subdir\n> -\t\t\t */\n> -\t\t\tutils::findSharedObjects(dir.c_str(), 1, soHandler);\n> -\t\t}\n> +\tstd::vector layerPaths =\n> +\t\tconfiguration.envListOption(\"LIBCAMERA_LAYER_PATH\", { \"layer\", \"path\" })\n> +\t\t\t .value_or(std::vector());\n> +\tfor (const auto &dir : layerPaths) {\n> +\t\t/*\n> +\t\t * \\todo Move the shared objects into one directory\n> +\t\t * instead of each in their own subdir\n> +\t\t */\n> +\t\tutils::findSharedObjects(dir.c_str(), 1, soHandler);\n> \t}\n> \n> \t/*\n> @@ -606,7 +602,8 @@ LayerManager::createController(const Camera *camera,\n> \t\t\t const ControlList &properties,\n> \t\t\t const ControlInfoMap &controlInfoMap) const\n> {\n> -\treturn std::make_unique(camera, properties, controlInfoMap, layers_);\n> +\treturn std::make_unique(camera, configuration_,\n> +\t\t\t\t\t\t properties, controlInfoMap, layers_);\n> }\n> \n> } /* namespace libcamera */","headers":{"Return-Path":"","X-Original-To":"parsemail@patchwork.libcamera.org","Delivered-To":"parsemail@patchwork.libcamera.org","Received":["from lancelot.ideasonboard.com (lancelot.ideasonboard.com\n\t[92.243.16.209])\n\tby patchwork.libcamera.org (Postfix) with ESMTPS id 14832BD78E\n\tfor ;\n\tFri, 30 Jan 2026 14:24:48 +0000 (UTC)","from lancelot.ideasonboard.com (localhost [IPv6:::1])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTP id 4695E61FCC;\n\tFri, 30 Jan 2026 15:24:47 +0100 (CET)","from us-smtp-delivery-124.mimecast.com\n\t(us-smtp-delivery-124.mimecast.com [170.10.129.124])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTPS id A400361F84\n\tfor ;\n\tFri, 30 Jan 2026 15:24:45 +0100 (CET)","from mail-lj1-f197.google.com (mail-lj1-f197.google.com\n\t[209.85.208.197]) by relay.mimecast.com with ESMTP with STARTTLS\n\t(version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id\n\tus-mta-679-B0o5dBJ7PLOdU5SiXmxmlQ-1; Fri, 30 Jan 2026 09:24:41 -0500","by mail-lj1-f197.google.com with SMTP id\n\t38308e7fff4ca-385d4c511e4so12645161fa.1\n\tfor ;\n\tFri, 30 Jan 2026 06:24:41 -0800 (PST)","from mzamazal-thinkpadp1gen7.tpbc.csb\n\t(ip-77-48-47-2.net.vodafone.cz. 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