[{"id":37983,"web_url":"https://patchwork.libcamera.org/comment/37983/","msgid":"<176958876871.744885.7065770197755269300@neptunite.rasen.tech>","date":"2026-01-28T08:26:08","subject":"Re: [PATCH v5 7/8] layer: Add layer to inject AeEnable control","submitter":{"id":17,"url":"https://patchwork.libcamera.org/api/people/17/","name":"Paul Elder","email":"paul.elder@ideasonboard.com"},"content":"Hi me,\n\nQuoting Paul Elder (2026-01-28 16:49:55)\n> Add a layer to implement the AeEnable control, so that we can remove it\n> from all IPAs and the Camera class, so that it is transparent to all\n> parties and it is available for applications to use.\n> \n> Signed-off-by: Paul Elder \n> \n> ---\n> For layers like this that we forsee to be \"always built-in\" we might\n> want a way to build it into libcamera instead of into separate shared\n> object files. In any case, this also serves as a demo of how I envision\n> a layer implementation to work.\n> \n> No change in v4\n> \n> No change in v3\n> \n> Changes in v2:\n> - add init() and terminate()\n> - use closures\n> - remove layer namespacing\n> - add gnu_symbol_visibility\n> ---\n> src/layer/inject_controls/inject_controls.cpp | 176 ++++++++++++++++++\n> src/layer/inject_controls/inject_controls.h | 24 +++\n> src/layer/inject_controls/meson.build | 16 ++\n> src/layer/meson.build | 2 +\n> 4 files changed, 218 insertions(+)\n> create mode 100644 src/layer/inject_controls/inject_controls.cpp\n> create mode 100644 src/layer/inject_controls/inject_controls.h\n> create mode 100644 src/layer/inject_controls/meson.build\n> \n> diff --git a/src/layer/inject_controls/inject_controls.cpp b/src/layer/inject_controls/inject_controls.cpp\n> new file mode 100644\n> index 000000000000..f12faff8318c\n> --- /dev/null\n> +++ b/src/layer/inject_controls/inject_controls.cpp\n> @@ -0,0 +1,176 @@\n> +/* SPDX-License-Identifier: LGPL-2.1-or-later */\n> +/*\n> + * Copyright (C) 2025, Ideas On Board Oy\n> + *\n> + * Layer implementation for injecting controls\n> + */\n> +\n> +#include \"inject_controls.h\"\n> +\n> +#include \n> +#include \n> +\n> +#include \n> +#include \n> +#include \n> +#include \n> +\n> +void *init([[maybe_unused]] const std::string &id)\n> +{\n> + InjectControls *closure = new InjectControls;\n> + *closure = {};\n> + return static_cast(closure);\n> +}\n> +\n> +void terminate(void *closure)\n> +{\n> + InjectControls *obj = static_cast(closure);\n> + delete obj;\n> +}\n> +\n> +libcamera::ControlInfoMap::Map updateControls(void *closure, libcamera::ControlInfoMap &ctrls)\n> +{\n> + InjectControls *obj = static_cast(closure);\n> +\n> + auto it = ctrls.find(&libcamera::controls::ExposureTimeMode);\n> + if (it != ctrls.end()) {\n> + for (auto entry : it->second.values()) {\n> + if (entry == libcamera::ControlValue(libcamera::controls::ExposureTimeModeAuto))\n> + obj->aeAvailable = true;\n> + if (entry == libcamera::ControlValue(libcamera::controls::ExposureTimeModeManual))\n> + obj->meAvailable = true;\n> + }\n> + }\n> +\n> + it = ctrls.find(&libcamera::controls::AnalogueGainMode);\n> + if (it != ctrls.end()) {\n> + for (auto entry : it->second.values()) {\n> + if (entry == libcamera::ControlValue(libcamera::controls::AnalogueGainModeAuto))\n> + obj->agAvailable = true;\n> + if (entry == libcamera::ControlValue(libcamera::controls::AnalogueGainModeManual))\n> + obj->mgAvailable = true;\n> + }\n> + }\n> +\n> + std::set values;\n> + if (obj->aeAvailable || obj->agAvailable)\n> + values.insert(true);\n> + if (obj->meAvailable || obj->mgAvailable)\n> + values.insert(false);\n> +\n> + if (values.empty())\n> + return {};\n> +\n> + if (values.size() == 1) {\n> + bool value = *values.begin();\n> + return { { &libcamera::controls::AeEnable,\n> + libcamera::ControlInfo(value, value, value) } };\n> + }\n> +\n> + return { { &libcamera::controls::AeEnable, libcamera::ControlInfo(false, true, true) } };\n> +}\n> +\n> +void queueRequest(void *closure, libcamera::Request *request)\n> +{\n> + InjectControls *obj = static_cast(closure);\n> +\n> + libcamera::ControlList &ctrls = request->controls();\n> + auto aeEnable = ctrls.get(libcamera::controls::AeEnable);\n> + if (!aeEnable)\n> + return;\n> +\n> + if (*aeEnable) {\n> + if (obj->aeAvailable) {\n> + ctrls.set(libcamera::controls::ExposureTimeMode,\n> + libcamera::controls::ExposureTimeModeAuto);\n> + }\n> +\n> + if (obj->agAvailable) {\n> + ctrls.set(libcamera::controls::AnalogueGainMode,\n> + libcamera::controls::AnalogueGainModeAuto);\n> + }\n> + } else {\n> + if (obj->meAvailable) {\n> + ctrls.set(libcamera::controls::ExposureTimeMode,\n> + libcamera::controls::ExposureTimeModeManual);\n> + }\n> +\n> + if (obj->mgAvailable) {\n> + ctrls.set(libcamera::controls::AnalogueGainMode,\n> + libcamera::controls::AnalogueGainModeManual);\n> + }\n> + }\n> +}\n> +\n> +void requestCompleted([[maybe_unused]] void *closure, libcamera::Request *request)\n> +{\n> + libcamera::ControlList &metadata = request->metadata();\n\nMetadata can no longer be written externally so we'll have to redesign this.\n\n*sigh*\n\n\nPaul\n\n> +\n> + auto eMode = metadata.get(libcamera::controls::ExposureTimeMode);\n> + auto aMode = metadata.get(libcamera::controls::AnalogueGainMode);\n> +\n> + if (!eMode && !aMode)\n> + return;\n> +\n> + bool ae = eMode && eMode == libcamera::controls::ExposureTimeModeAuto;\n> + bool me = eMode && eMode == libcamera::controls::ExposureTimeModeManual;\n> + bool ag = aMode && aMode == libcamera::controls::AnalogueGainModeAuto;\n> + bool mg = aMode && aMode == libcamera::controls::AnalogueGainModeManual;\n> +\n> + /* Exposure time not reported at all; use gain only */\n> + if (!ae && !me) {\n> + metadata.set(libcamera::controls::AeEnable, ag);\n> + return;\n> + }\n> +\n> + /* Analogue gain not reported at all; use exposure time only */\n> + if (!ag && !mg) {\n> + metadata.set(libcamera::controls::AeEnable, ae);\n> + return;\n> + }\n> +\n> + /*\n> + * Gain mode and exposure mode are not equal; therefore at least one is\n> + * manual, so set AeEnable to false\n> + */\n> + if (ag != ae) {\n> + metadata.set(libcamera::controls::AeEnable, false);\n> + return;\n> + }\n> +\n> + /* ag and ae are equal, so just choose one */\n> + metadata.set(libcamera::controls::AeEnable, ag);\n> + return;\n> +}\n> +\n> +namespace libcamera {\n> +\n> +extern \"C\" {\n> +\n> +[[gnu::visibility(\"default\")]]\n> +struct LayerInfo layerInfo{\n> + .name = \"inject_controls\",\n> + .layerAPIVersion = 1,\n> +};\n> +\n> +[[gnu::visibility(\"default\")]]\n> +struct LayerInterface layerInterface{\n> + .init = init,\n> + .terminate = terminate,\n> + .bufferCompleted = nullptr,\n> + .requestCompleted = requestCompleted,\n> + .disconnected = nullptr,\n> + .acquire = nullptr,\n> + .release = nullptr,\n> + .controls = updateControls,\n> + .properties = nullptr,\n> + .configure = nullptr,\n> + .createRequest = nullptr,\n> + .queueRequest = queueRequest,\n> + .start = nullptr,\n> + .stop = nullptr,\n> +};\n> +\n> +}\n> +\n> +} /* namespace libcamera */\n> diff --git a/src/layer/inject_controls/inject_controls.h b/src/layer/inject_controls/inject_controls.h\n> new file mode 100644\n> index 000000000000..42c094d7f76a\n> --- /dev/null\n> +++ b/src/layer/inject_controls/inject_controls.h\n> @@ -0,0 +1,24 @@\n> +/* SPDX-License-Identifier: LGPL-2.1-or-later */\n> +/*\n> + * Copyright (C) 2025, Ideas On Board Oy\n> + *\n> + * Layer implementation for injecting controls\n> + */\n> +\n> +#pragma once\n> +\n> +#include \n> +#include \n> +\n> +struct InjectControls {\n> + bool aeAvailable;\n> + bool meAvailable;\n> + bool agAvailable;\n> + bool mgAvailable;\n> +};\n> +\n> +void *init(const std::string &id);\n> +void terminate(void *closure);\n> +libcamera::ControlInfoMap::Map updateControls(void *closure, libcamera::ControlInfoMap &ctrls);\n> +void queueRequest(void *closure, libcamera::Request *request);\n> +void requestCompleted([[maybe_unused]] void *closure, libcamera::Request *request);\n> diff --git a/src/layer/inject_controls/meson.build b/src/layer/inject_controls/meson.build\n> new file mode 100644\n> index 000000000000..d1e402746990\n> --- /dev/null\n> +++ b/src/layer/inject_controls/meson.build\n> @@ -0,0 +1,16 @@\n> +# SPDX-License-Identifier: CC0-1.0\n> +\n> +layer_name = 'layer_inject_controls'\n> +\n> +layer_inject_sources = files([\n> + 'inject_controls.h',\n> + 'inject_controls.cpp',\n> +])\n> +\n> +mod = shared_module(layer_name, layer_inject_sources,\n> + name_prefix : '',\n> + include_directories : [layer_includes],\n> + dependencies : libcamera_public,\n> + gnu_symbol_visibility: 'hidden',\n> + install : true,\n> + install_dir : layer_install_dir)\n> diff --git a/src/layer/meson.build b/src/layer/meson.build\n> index 45dded512a13..3d8b70ad2cd2 100644\n> --- a/src/layer/meson.build\n> +++ b/src/layer/meson.build\n> @@ -12,3 +12,5 @@ config_h.set('LAYER_DIR',\n> layers_env = environment()\n> layers_env.set('LIBCAMERA_LAYER_PATH', meson.current_build_dir())\n> meson.add_devenv(layers_env)\n> +\n> +subdir('inject_controls')\n> -- \n> 2.47.2\n>","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 4F716C3200\n\tfor ;\n\tWed, 28 Jan 2026 08:26:17 +0000 (UTC)","from lancelot.ideasonboard.com (localhost [IPv6:::1])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTP id 979F761FCF;\n\tWed, 28 Jan 2026 09:26:16 +0100 (CET)","from perceval.ideasonboard.com (perceval.ideasonboard.com\n\t[IPv6:2001:4b98:dc2:55:216:3eff:fef7:d647])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTPS id 9961361F84\n\tfor ;\n\tWed, 28 Jan 2026 09:26:15 +0100 (CET)","from neptunite.rasen.tech (unknown\n\t[IPv6:2404:7a81:160:2100:508d:7983:72a6:2eeb])\n\tby perceval.ideasonboard.com (Postfix) with UTF8SMTPSA id E12F5581\n\tfor ;\n\tWed, 28 Jan 2026 09:25:37 +0100 (CET)"],"Authentication-Results":"lancelot.ideasonboard.com; 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