[{"id":37507,"web_url":"https://patchwork.libcamera.org/comment/37507/","msgid":"","date":"2026-01-07T10:19:01","subject":"Re: [PATCH] libcamera: rpi: Make the controller min frame duration\n\tconfigurable","submitter":{"id":34,"url":"https://patchwork.libcamera.org/api/people/34/","name":"Naushir Patuck","email":"naush@raspberrypi.com"},"content":"Hi David,\n\nThank you for this change. Few minor comments below:\n\nOn Wed, 7 Jan 2026 at 09:38, David Plowman\n wrote:\n>\n> The controller min frame duration is used to rate limit how often we\n> run IPAs. Historically this has been set to 33333us, meaning that the\n> algorithms effectively skip frames when the camera is running faster\n> than 30fps.\n>\n> This patch adds a small amount of plumbing that allows this value to\n> be set in the Raspberry Pi configuration file. Some applications or\n> platforms (such as Pi 5) are easily capable of running these more\n> often, should there be a need to do so.\n>\n> Signed-off-by: David Plowman \n> ---\n> include/libcamera/ipa/raspberrypi.mojom | 1 +\n> src/ipa/rpi/common/ipa_base.cpp | 11 ++++++++-\n> src/ipa/rpi/common/ipa_base.h | 2 ++\n> .../pipeline/rpi/common/pipeline_base.cpp | 24 ++++++++++++++-----\n> .../pipeline/rpi/common/pipeline_base.h | 5 ++++\n> .../pipeline/rpi/pisp/data/example.yaml | 6 +++++\n> .../pipeline/rpi/vc4/data/example.yaml | 6 +++++\n> 7 files changed, 48 insertions(+), 7 deletions(-)\n>\n> diff --git a/include/libcamera/ipa/raspberrypi.mojom b/include/libcamera/ipa/raspberrypi.mojom\n> index 12b083e9..1b7e0358 100644\n> --- a/include/libcamera/ipa/raspberrypi.mojom\n> +++ b/include/libcamera/ipa/raspberrypi.mojom\n> @@ -18,6 +18,7 @@ struct SensorConfig {\n> struct InitParams {\n> bool lensPresent;\n> libcamera.IPACameraSensorInfo sensorInfo;\n> + float controllerMinFrameDurationUs;\n> /* PISP specific */\n> libcamera.SharedFD fe;\n> libcamera.SharedFD be;\n> diff --git a/src/ipa/rpi/common/ipa_base.cpp b/src/ipa/rpi/common/ipa_base.cpp\n> index 14aba450..2fd101da 100644\n> --- a/src/ipa/rpi/common/ipa_base.cpp\n> +++ b/src/ipa/rpi/common/ipa_base.cpp\n> @@ -184,6 +184,15 @@ int32_t IpaBase::init(const IPASettings &settings, const InitParams ¶ms, Ini\n>\n> result->controlInfo = ControlInfoMap(std::move(ctrlMap), controls::controls);\n>\n> + /*\n> + * This determines the minimum allowable inter-frame duration to run the\n> + * controller algorithms. If the pipeline handler provider frames at a\n> + * rate higher than this, we rate-limit the controller Prepare() and\n> + * Process() calls to lower than or equal to this rate.\n> + */\n> + double dur_us = params.controllerMinFrameDurationUs;\n> + controllerMinFrameDuration_ = std::chrono::duration(dur_us);\n\nProbably should use utils::Duration in place of std::chrono.\n\n> +\n> return platformInit(params, result);\n> }\n>\n> @@ -465,7 +474,7 @@ void IpaBase::prepareIsp(const PrepareParams ¶ms)\n> /* Allow a 10% margin on the comparison below. */\n> Duration delta = (frameTimestamp - lastRunTimestamp_) * 1.0ns;\n> if (lastRunTimestamp_ && frameCount_ > invalidCount_ &&\n> - delta < controllerMinFrameDuration * 0.9 && !hdrChange) {\n> + delta < controllerMinFrameDuration_ * 0.9 && !hdrChange) {\n> /*\n> * Ensure we merge the previous frame's metadata with the current\n> * frame. This will not overwrite exposure/gain values for the\n> diff --git a/src/ipa/rpi/common/ipa_base.h b/src/ipa/rpi/common/ipa_base.h\n> index 5348f2ea..90f018b2 100644\n> --- a/src/ipa/rpi/common/ipa_base.h\n> +++ b/src/ipa/rpi/common/ipa_base.h\n> @@ -142,6 +142,8 @@ private:\n> } flickerState_;\n>\n> bool awbEnabled_;\n> +\n> + utils::Duration controllerMinFrameDuration_;\n> };\n>\n> } /* namespace ipa::RPi */\n> diff --git a/src/libcamera/pipeline/rpi/common/pipeline_base.cpp b/src/libcamera/pipeline/rpi/common/pipeline_base.cpp\n> index fb8e466f..b7655d8d 100644\n> --- a/src/libcamera/pipeline/rpi/common/pipeline_base.cpp\n> +++ b/src/libcamera/pipeline/rpi/common/pipeline_base.cpp\n> @@ -33,6 +33,12 @@ LOG_DEFINE_CATEGORY(RPI)\n>\n> using StreamFlag = RPi::Stream::StreamFlag;\n>\n> +/*\n> + * The IPA's algorithms will not be called more often than this many\n> + * microseconds. The default corresponds to 30fps.\n> + */\n> +constexpr float defaultControllerMinimumFrameDurationUs = 1000000.0 / 30.0;\n> +\n> namespace {\n>\n> constexpr unsigned int defaultRawBitDepth = 12;\n> @@ -800,6 +806,12 @@ int PipelineHandlerBase::registerCamera(std::unique_ptr &camera\n> if (!data->sensor_)\n> return -EINVAL;\n>\n> + ret = data->loadPipelineConfiguration();\n> + if (ret) {\n> + LOG(RPI, Error) << \"Unable to load pipeline configuration\";\n> + return ret;\n> + }\n> +\n> /* Populate the map of sensor supported formats and sizes. */\n> for (auto const mbusCode : data->sensor_->mbusCodes())\n> data->sensorFormats_.emplace(mbusCode,\n> @@ -859,12 +871,6 @@ int PipelineHandlerBase::registerCamera(std::unique_ptr &camera\n> if (ret)\n> return ret;\n>\n> - ret = data->loadPipelineConfiguration();\n> - if (ret) {\n> - LOG(RPI, Error) << \"Unable to load pipeline configuration\";\n> - return ret;\n> - }\n> -\n> /* Setup the general IPA signal handlers. */\n> data->frontendDevice()->dequeueTimeout.connect(data, &RPi::CameraData::cameraTimeout);\n> data->frontendDevice()->frameStart.connect(data, &RPi::CameraData::frameStarted);\n> @@ -1096,6 +1102,7 @@ int CameraData::loadPipelineConfiguration()\n> {\n> config_ = {\n> .cameraTimeoutValue = 0,\n> + .controllerMinFrameDurationUs = defaultControllerMinimumFrameDurationUs,\n> };\n>\n> /* Initial configuration of the platform, in case no config file is present */\n> @@ -1145,6 +1152,9 @@ int CameraData::loadPipelineConfiguration()\n> frontendDevice()->setDequeueTimeout(config_.cameraTimeoutValue * 1ms);\n> }\n>\n> + config_.controllerMinFrameDurationUs =\n> + phConfig[\"controller_min_frame_duration_us\"].get(config_.controllerMinFrameDurationUs);\n> +\n> return platformPipelineConfigure(root);\n> }\n>\n> @@ -1173,6 +1183,8 @@ int CameraData::loadIPA(ipa::RPi::InitResult *result)\n> }\n>\n> params.lensPresent = !!sensor_->focusLens();\n> + params.controllerMinFrameDurationUs = config_.controllerMinFrameDurationUs;\n> +\n> ret = platformInitIpa(params);\n> if (ret)\n> return ret;\n> diff --git a/src/libcamera/pipeline/rpi/common/pipeline_base.h b/src/libcamera/pipeline/rpi/common/pipeline_base.h\n> index 6257a934..597eb587 100644\n> --- a/src/libcamera/pipeline/rpi/common/pipeline_base.h\n> +++ b/src/libcamera/pipeline/rpi/common/pipeline_base.h\n> @@ -169,6 +169,11 @@ public:\n> * on frame durations.\n> */\n> unsigned int cameraTimeoutValue;\n> + /*\n> + * The minimum frame duration between the IPA's calls to the\n> + * algorithms themselves (in microseconds).\n> + */\n> + float controllerMinFrameDurationUs;\n\nI wonder if it would be better to use unsigned int instead of float\nhere to match cameraTimeoutValue? Not too bothered either way.\n\nRegards,\nNaush\n\n> };\n>\n> Config config_;\n> diff --git a/src/libcamera/pipeline/rpi/pisp/data/example.yaml b/src/libcamera/pipeline/rpi/pisp/data/example.yaml\n> index baf03be7..c5edbba0 100644\n> --- a/src/libcamera/pipeline/rpi/pisp/data/example.yaml\n> +++ b/src/libcamera/pipeline/rpi/pisp/data/example.yaml\n> @@ -36,5 +36,11 @@\n> # framebuffers required for its operation.\n> #\n> # \"disable_hdr\": false,\n> +\n> + # Limits the rate at which IPAs are called. The algorithms will\n> + # be skipped until this many microseconds have elapsed since\n> + # the last call. The default value represents a 30fps limit.\n> + #\n> + # \"controller_min_frame_duration_us\": 33333.333,\n> }\n> }\n> diff --git a/src/libcamera/pipeline/rpi/vc4/data/example.yaml b/src/libcamera/pipeline/rpi/vc4/data/example.yaml\n> index 27e54348..2ee2b864 100644\n> --- a/src/libcamera/pipeline/rpi/vc4/data/example.yaml\n> +++ b/src/libcamera/pipeline/rpi/vc4/data/example.yaml\n> @@ -37,5 +37,11 @@\n> # timeout value.\n> #\n> # \"camera_timeout_value_ms\": 0,\n> +\n> + # Limits the rate at which IPAs are called. The algorithms will\n> + # be skipped until this many microseconds have elapsed since\n> + # the last call. The default value represents a 30fps limit.\n> + #\n> + # \"controller_min_frame_duration_us\": 33333.333,\n> }\n> }\n> --\n> 2.47.3\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 50E0ABE08B\n\tfor ;\n\tWed, 7 Jan 2026 10:19:41 +0000 (UTC)","from lancelot.ideasonboard.com (localhost [IPv6:::1])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTP id 4962061FA0;\n\tWed, 7 Jan 2026 11:19:40 +0100 (CET)","from mail-vk1-xa36.google.com (mail-vk1-xa36.google.com\n\t[IPv6:2607:f8b0:4864:20::a36])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTPS id 510FC61F61\n\tfor ;\n\tWed, 7 Jan 2026 11:19:38 +0100 (CET)","by mail-vk1-xa36.google.com with SMTP id\n\t71dfb90a1353d-55a4ea09d34so55144e0c.3\n\tfor ;\n\tWed, 07 Jan 2026 02:19:38 -0800 (PST)"],"Authentication-Results":"lancelot.ideasonboard.com; dkim=pass (2048-bit key;\n\tunprotected) header.d=raspberrypi.com header.i=@raspberrypi.com\n\theader.b=\"GCLuJdhE\"; dkim-atps=neutral","DKIM-Signature":"v=1; a=rsa-sha256; c=relaxed/relaxed;\n\td=raspberrypi.com; s=google; t=1767781177; x=1768385977;\n\tdarn=lists.libcamera.org; \n\th=cc:to:subject:message-id:date:from:in-reply-to:references\n\t:mime-version:from:to:cc:subject:date:message-id:reply-to;\n\tbh=jDC2pJXVcgmmL+RZlACdlEAz2rFW7tw8Q6/7pisDmls=;\n\tb=GCLuJdhEH02721bhMnC8oj2PJY997YiMG6cu6X7N6UeeCu5QqM4HoP7vidDNNJz3Wj\n\tyrca4osMbkmXsTf811GR1bmpWzHhLM5qq9hdA95XjKC7ay1YnWXdh6oezsfF8daf9lgq\n\t25Bekdegft/yBtZy9pmiNDCvuBkBR+NK6RUQieYjzLGfjxL+JV/sjl2AobjdvvmRYxlv\n\tEx34nyZ8DJln1P5vPlPxRhkzRU5S9oZeT6+DqpLbrkbjIjzysncmv8Nd2SHibcSuoKVI\n\tWM6/RLS0wsz9lnm2LSyprZPJs7MuMOc1xAQtFbCaeLoeaj2jQ4nrrRa1jVQB7piOiHdw\n\t6v5g==","X-Google-DKIM-Signature":"v=1; a=rsa-sha256; c=relaxed/relaxed;\n\td=1e100.net; s=20230601; t=1767781177; x=1768385977;\n\th=cc:to:subject:message-id:date:from:in-reply-to:references\n\t:mime-version:x-gm-gg:x-gm-message-state:from:to:cc:subject:date\n\t:message-id:reply-to;\n\tbh=jDC2pJXVcgmmL+RZlACdlEAz2rFW7tw8Q6/7pisDmls=;\n\tb=NwZMDPj0pHDu6hvMNZABRz9+rXlQsSEMrncTNvSyAtOr9+09pfXT3p93lbiY4FgIew\n\tz/zPjK3R9HCoVadoY20ZlKFQCoEoRVidOx/ziAJCmkzYdzjtxll7lbZsdMReDgUeK6D4\n\tZ+SLQWvTKSk+2i5XgGkLFCDGajt8RPoZh+OiQvwjQnKbUpoiyzieqjOn+qPiHM90qCis\n\tdCuWzcotURQRCbqGWy1jMUuAuyMU4wfkARdn+NRAwvBAdKqlppIWo8BhgtXAGW3OFOt2\n\twNVLP3UA4Pl8UKPMNSXorViFMiHexlai+WvUwufWdNmEXG4kI6CA1WpO6T4t0ffv9Sqr\n\tHpxA==","X-Gm-Message-State":"AOJu0YwBmi4aAIQaC+yZ9b0u4H80iHxsaUMfkIwarVtY+t+hwJusTtW6\n\tp4mCmknJzxmIaW31vmRKB/pWeGMSGuOzVn0dSuxbkELGG0PD+bMwepl2h2VEWdmK4rZ49WgXPGL\n\taWylKDTlHoMVlDiut3pvoF3/AipRePYPlLz3esG+wzQ==","X-Gm-Gg":"AY/fxX7qLEnPtHyjaFK013FyuBPmYiQnSVDkultc673sgBown5ThUAk5ukvsM/Jhcqb\n\tvL3XfYgQ4xxi0V8C2UNv8n56Sq+pOOS7kC8iiitmEcOi9ScfIU++67qccRTJIMotP0RbifoAMGO\n\tCUIcSKQlyfAFdoeJG35+AScaRPyS5Odr6Xr2cXTsf9oYScameA2JG80Q/OXCx93Qk49JHnMnqU4\n\tuLsFx0i9M++mx55Fdnjy6tJ83Uv9N7UryybEIfucG3m+7a7SF5ybbQYg6RI8tTfksLYzN5o2rh/\n\thWb1U5W3LuxYrwx3TycZf7kvjuk=","X-Google-Smtp-Source":"AGHT+IE87dYuCcvspM8Px8qqLUiD5MVjiPmBFaPrcE5Pih58QSTVGnA8ztB8F3pHmmZJsJGDXpBBnZVe7L4YtunRksI=","X-Received":"by 2002:a05:6102:190a:b0:5e4:9555:8984 with SMTP id\n\tada2fe7eead31-5ecb6957bd8mr293989137.6.1767781176975; Wed, 07 Jan 2026\n\t02:19:36 -0800 (PST)","MIME-Version":"1.0","References":"<20260107093821.14600-1-david.plowman@raspberrypi.com>","In-Reply-To":"<20260107093821.14600-1-david.plowman@raspberrypi.com>","From":"Naushir Patuck ","Date":"Wed, 7 Jan 2026 10:19:01 +0000","X-Gm-Features":"AQt7F2qDONw44WiHIwvY7wqd56d77nFvGrOgAVX8eHX48LzjTVDORoOlCCPkg0Q","Message-ID":"","Subject":"Re: [PATCH] libcamera: rpi: Make the controller min frame duration\n\tconfigurable","To":"David Plowman ","Cc":"libcamera-devel@lists.libcamera.org","Content-Type":"text/plain; charset=\"UTF-8\"","X-BeenThere":"libcamera-devel@lists.libcamera.org","X-Mailman-Version":"2.1.29","Precedence":"list","List-Id":"","List-Unsubscribe":",\n\t","List-Archive":"","List-Post":"","List-Help":"","List-Subscribe":",\n\t","Errors-To":"libcamera-devel-bounces@lists.libcamera.org","Sender":"\"libcamera-devel\" "}},{"id":37509,"web_url":"https://patchwork.libcamera.org/comment/37509/","msgid":"","date":"2026-01-07T11:03:56","subject":"Re: [PATCH] libcamera: rpi: Make the controller min frame duration\n\tconfigurable","submitter":{"id":42,"url":"https://patchwork.libcamera.org/api/people/42/","name":"David Plowman","email":"david.plowman@raspberrypi.com"},"content":"Hi Naush\n\nThanks for the review!\n\nOn Wed, 7 Jan 2026 at 10:19, Naushir Patuck wrote:\n>\n> Hi David,\n>\n> Thank you for this change. Few minor comments below:\n>\n> On Wed, 7 Jan 2026 at 09:38, David Plowman\n> wrote:\n> >\n> > The controller min frame duration is used to rate limit how often we\n> > run IPAs. Historically this has been set to 33333us, meaning that the\n> > algorithms effectively skip frames when the camera is running faster\n> > than 30fps.\n> >\n> > This patch adds a small amount of plumbing that allows this value to\n> > be set in the Raspberry Pi configuration file. Some applications or\n> > platforms (such as Pi 5) are easily capable of running these more\n> > often, should there be a need to do so.\n> >\n> > Signed-off-by: David Plowman \n> > ---\n> > include/libcamera/ipa/raspberrypi.mojom | 1 +\n> > src/ipa/rpi/common/ipa_base.cpp | 11 ++++++++-\n> > src/ipa/rpi/common/ipa_base.h | 2 ++\n> > .../pipeline/rpi/common/pipeline_base.cpp | 24 ++++++++++++++-----\n> > .../pipeline/rpi/common/pipeline_base.h | 5 ++++\n> > .../pipeline/rpi/pisp/data/example.yaml | 6 +++++\n> > .../pipeline/rpi/vc4/data/example.yaml | 6 +++++\n> > 7 files changed, 48 insertions(+), 7 deletions(-)\n> >\n> > diff --git a/include/libcamera/ipa/raspberrypi.mojom b/include/libcamera/ipa/raspberrypi.mojom\n> > index 12b083e9..1b7e0358 100644\n> > --- a/include/libcamera/ipa/raspberrypi.mojom\n> > +++ b/include/libcamera/ipa/raspberrypi.mojom\n> > @@ -18,6 +18,7 @@ struct SensorConfig {\n> > struct InitParams {\n> > bool lensPresent;\n> > libcamera.IPACameraSensorInfo sensorInfo;\n> > + float controllerMinFrameDurationUs;\n> > /* PISP specific */\n> > libcamera.SharedFD fe;\n> > libcamera.SharedFD be;\n> > diff --git a/src/ipa/rpi/common/ipa_base.cpp b/src/ipa/rpi/common/ipa_base.cpp\n> > index 14aba450..2fd101da 100644\n> > --- a/src/ipa/rpi/common/ipa_base.cpp\n> > +++ b/src/ipa/rpi/common/ipa_base.cpp\n> > @@ -184,6 +184,15 @@ int32_t IpaBase::init(const IPASettings &settings, const InitParams ¶ms, Ini\n> >\n> > result->controlInfo = ControlInfoMap(std::move(ctrlMap), controls::controls);\n> >\n> > + /*\n> > + * This determines the minimum allowable inter-frame duration to run the\n> > + * controller algorithms. If the pipeline handler provider frames at a\n> > + * rate higher than this, we rate-limit the controller Prepare() and\n> > + * Process() calls to lower than or equal to this rate.\n> > + */\n> > + double dur_us = params.controllerMinFrameDurationUs;\n> > + controllerMinFrameDuration_ = std::chrono::duration(dur_us);\n>\n> Probably should use utils::Duration in place of std::chrono.\n\nYes, I will find something tidier, those duration/chrono casts always\ndo my head in a bit! I guess\n\ncontrollerMinFrameDuration_ = params.controllerMinFrameDurationUs * 1us;\n\nwould be fine and looks better.\n\n>\n> > +\n> > return platformInit(params, result);\n> > }\n> >\n> > @@ -465,7 +474,7 @@ void IpaBase::prepareIsp(const PrepareParams ¶ms)\n> > /* Allow a 10% margin on the comparison below. */\n> > Duration delta = (frameTimestamp - lastRunTimestamp_) * 1.0ns;\n> > if (lastRunTimestamp_ && frameCount_ > invalidCount_ &&\n> > - delta < controllerMinFrameDuration * 0.9 && !hdrChange) {\n> > + delta < controllerMinFrameDuration_ * 0.9 && !hdrChange) {\n> > /*\n> > * Ensure we merge the previous frame's metadata with the current\n> > * frame. This will not overwrite exposure/gain values for the\n> > diff --git a/src/ipa/rpi/common/ipa_base.h b/src/ipa/rpi/common/ipa_base.h\n> > index 5348f2ea..90f018b2 100644\n> > --- a/src/ipa/rpi/common/ipa_base.h\n> > +++ b/src/ipa/rpi/common/ipa_base.h\n> > @@ -142,6 +142,8 @@ private:\n> > } flickerState_;\n> >\n> > bool awbEnabled_;\n> > +\n> > + utils::Duration controllerMinFrameDuration_;\n> > };\n> >\n> > } /* namespace ipa::RPi */\n> > diff --git a/src/libcamera/pipeline/rpi/common/pipeline_base.cpp b/src/libcamera/pipeline/rpi/common/pipeline_base.cpp\n> > index fb8e466f..b7655d8d 100644\n> > --- a/src/libcamera/pipeline/rpi/common/pipeline_base.cpp\n> > +++ b/src/libcamera/pipeline/rpi/common/pipeline_base.cpp\n> > @@ -33,6 +33,12 @@ LOG_DEFINE_CATEGORY(RPI)\n> >\n> > using StreamFlag = RPi::Stream::StreamFlag;\n> >\n> > +/*\n> > + * The IPA's algorithms will not be called more often than this many\n> > + * microseconds. The default corresponds to 30fps.\n> > + */\n> > +constexpr float defaultControllerMinimumFrameDurationUs = 1000000.0 / 30.0;\n> > +\n> > namespace {\n> >\n> > constexpr unsigned int defaultRawBitDepth = 12;\n> > @@ -800,6 +806,12 @@ int PipelineHandlerBase::registerCamera(std::unique_ptr &camera\n> > if (!data->sensor_)\n> > return -EINVAL;\n> >\n> > + ret = data->loadPipelineConfiguration();\n> > + if (ret) {\n> > + LOG(RPI, Error) << \"Unable to load pipeline configuration\";\n> > + return ret;\n> > + }\n> > +\n> > /* Populate the map of sensor supported formats and sizes. */\n> > for (auto const mbusCode : data->sensor_->mbusCodes())\n> > data->sensorFormats_.emplace(mbusCode,\n> > @@ -859,12 +871,6 @@ int PipelineHandlerBase::registerCamera(std::unique_ptr &camera\n> > if (ret)\n> > return ret;\n> >\n> > - ret = data->loadPipelineConfiguration();\n> > - if (ret) {\n> > - LOG(RPI, Error) << \"Unable to load pipeline configuration\";\n> > - return ret;\n> > - }\n> > -\n> > /* Setup the general IPA signal handlers. */\n> > data->frontendDevice()->dequeueTimeout.connect(data, &RPi::CameraData::cameraTimeout);\n> > data->frontendDevice()->frameStart.connect(data, &RPi::CameraData::frameStarted);\n> > @@ -1096,6 +1102,7 @@ int CameraData::loadPipelineConfiguration()\n> > {\n> > config_ = {\n> > .cameraTimeoutValue = 0,\n> > + .controllerMinFrameDurationUs = defaultControllerMinimumFrameDurationUs,\n> > };\n> >\n> > /* Initial configuration of the platform, in case no config file is present */\n> > @@ -1145,6 +1152,9 @@ int CameraData::loadPipelineConfiguration()\n> > frontendDevice()->setDequeueTimeout(config_.cameraTimeoutValue * 1ms);\n> > }\n> >\n> > + config_.controllerMinFrameDurationUs =\n> > + phConfig[\"controller_min_frame_duration_us\"].get(config_.controllerMinFrameDurationUs);\n> > +\n> > return platformPipelineConfigure(root);\n> > }\n> >\n> > @@ -1173,6 +1183,8 @@ int CameraData::loadIPA(ipa::RPi::InitResult *result)\n> > }\n> >\n> > params.lensPresent = !!sensor_->focusLens();\n> > + params.controllerMinFrameDurationUs = config_.controllerMinFrameDurationUs;\n> > +\n> > ret = platformInitIpa(params);\n> > if (ret)\n> > return ret;\n> > diff --git a/src/libcamera/pipeline/rpi/common/pipeline_base.h b/src/libcamera/pipeline/rpi/common/pipeline_base.h\n> > index 6257a934..597eb587 100644\n> > --- a/src/libcamera/pipeline/rpi/common/pipeline_base.h\n> > +++ b/src/libcamera/pipeline/rpi/common/pipeline_base.h\n> > @@ -169,6 +169,11 @@ public:\n> > * on frame durations.\n> > */\n> > unsigned int cameraTimeoutValue;\n> > + /*\n> > + * The minimum frame duration between the IPA's calls to the\n> > + * algorithms themselves (in microseconds).\n> > + */\n> > + float controllerMinFrameDurationUs;\n>\n> I wonder if it would be better to use unsigned int instead of float\n> here to match cameraTimeoutValue? Not too bothered either way.\n\nSlightly inclined to leave this, but again, I don't really mind. I've\nbeen developing a bit of a philosophical aversion to using ints for\nmicroseconds in general, though I agree it would make no difference\nhere.\n\nAnyway, version 2 incoming!\n\nDavid\n\n>\n> Regards,\n> Naush\n>\n> > };\n> >\n> > Config config_;\n> > diff --git a/src/libcamera/pipeline/rpi/pisp/data/example.yaml b/src/libcamera/pipeline/rpi/pisp/data/example.yaml\n> > index baf03be7..c5edbba0 100644\n> > --- a/src/libcamera/pipeline/rpi/pisp/data/example.yaml\n> > +++ b/src/libcamera/pipeline/rpi/pisp/data/example.yaml\n> > @@ -36,5 +36,11 @@\n> > # framebuffers required for its operation.\n> > #\n> > # \"disable_hdr\": false,\n> > +\n> > + # Limits the rate at which IPAs are called. The algorithms will\n> > + # be skipped until this many microseconds have elapsed since\n> > + # the last call. The default value represents a 30fps limit.\n> > + #\n> > + # \"controller_min_frame_duration_us\": 33333.333,\n> > }\n> > }\n> > diff --git a/src/libcamera/pipeline/rpi/vc4/data/example.yaml b/src/libcamera/pipeline/rpi/vc4/data/example.yaml\n> > index 27e54348..2ee2b864 100644\n> > --- a/src/libcamera/pipeline/rpi/vc4/data/example.yaml\n> > +++ b/src/libcamera/pipeline/rpi/vc4/data/example.yaml\n> > @@ -37,5 +37,11 @@\n> > # timeout value.\n> > #\n> > # \"camera_timeout_value_ms\": 0,\n> > +\n> > + # Limits the rate at which IPAs are called. The algorithms will\n> > + # be skipped until this many microseconds have elapsed since\n> > + # the last call. The default value represents a 30fps limit.\n> > + #\n> > + # \"controller_min_frame_duration_us\": 33333.333,\n> > }\n> > }\n> > --\n> > 2.47.3\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 A68CEBDCBF\n\tfor ;\n\tWed, 7 Jan 2026 11:04:11 +0000 (UTC)","from lancelot.ideasonboard.com (localhost [IPv6:::1])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTP id AB5E361FC1;\n\tWed, 7 Jan 2026 12:04:10 +0100 (CET)","from mail-qv1-xf36.google.com (mail-qv1-xf36.google.com\n\t[IPv6:2607:f8b0:4864:20::f36])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTPS id DF75061F84\n\tfor ;\n\tWed, 7 Jan 2026 12:04:08 +0100 (CET)","by mail-qv1-xf36.google.com with SMTP id\n\t6a1803df08f44-88a34450f19so19219056d6.1\n\tfor ;\n\tWed, 07 Jan 2026 03:04:08 -0800 (PST)"],"Authentication-Results":"lancelot.ideasonboard.com; dkim=pass (2048-bit key;\n\tunprotected) header.d=raspberrypi.com header.i=@raspberrypi.com\n\theader.b=\"D2G8Zz/u\"; dkim-atps=neutral","DKIM-Signature":"v=1; a=rsa-sha256; c=relaxed/relaxed;\n\td=raspberrypi.com; s=google; t=1767783848; x=1768388648;\n\tdarn=lists.libcamera.org; \n\th=cc:to:subject:message-id:date:from:in-reply-to:references\n\t:mime-version:from:to:cc:subject:date:message-id:reply-to;\n\tbh=a+1+VUuSkAeQoKtlWM6NXVVapcc0QrG5t9L5OxY2WOQ=;\n\tb=D2G8Zz/u25K4ZBntWYS0JfOcCtVz51VZ0ez9+nXX6W7bWx1rz5YrYUpdEmhWxL/VrY\n\tJPc3C6VK+/komdOjHwBqk8dwFPJZRKBB50qnu6oIiFX+FWLazZOXicfEvLIFD9pAJOCx\n\tQWv+I0pTy8nUp02oLMtA6UkNTA1v1/kFhuzK9DpmPXaa22hWbVA6c1EWqQea36ylUni6\n\tEAq9T0e1GuXajtYxBtIoOOHRhh/Y0BlrQTQHQ1Y7/RC419o433Uv/1uU7XswrnFzMsR+\n\ttNjvlb9vnXEEtkkfkurfXRkxazWOYgHTFPh0jEoc7MfKuovwJxSGRo0HSi1ekGtI97Ed\n\tEgJg==","X-Google-DKIM-Signature":"v=1; a=rsa-sha256; c=relaxed/relaxed;\n\td=1e100.net; s=20230601; t=1767783848; x=1768388648;\n\th=cc:to:subject:message-id:date:from:in-reply-to:references\n\t:mime-version:x-gm-gg:x-gm-message-state:from:to:cc:subject:date\n\t:message-id:reply-to;\n\tbh=a+1+VUuSkAeQoKtlWM6NXVVapcc0QrG5t9L5OxY2WOQ=;\n\tb=FPB96gd+5KnF6JD5NoTbPDIDOADxIEMeBs+Ow6oeZ6J3/O4MF9jFxjMOpNNwpH7vJL\n\tnb2UOGXsfsXwu3zhSPhOsHafMfOldtju3Xww/l/JcNQwGx6YdzmIBEvW06kB9YimO70U\n\tBNFRORAEfWRkCSRKYeoD6Algx2km0t0pvsaRrFUD563C4D4+zAgvER78qLchC3XhCown\n\tnTpf3x5G8lYm0lj3N3tmaT+35BMaVi/Ka0pzFwo37fLLHF4oefxHEfM6bQfzalQOeyVP\n\tissOTAD6LvfTIFd50RpVVw5e3z3h971bZGJGJMxSep7LuOZguQuri2IbgitoGs9AcXHt\n\tTZrQ==","X-Gm-Message-State":"AOJu0YyZzUyfmVlrJlEOU46PX6elH2HtnY3S0tecLvZBYSBFrXBhj+5h\n\t8XsJd/UNMhjY1unQj5LiQY4Td5jA10fLOwlFaxfGsMh93NyuuQhd+BVzRcH3kxNco6OXrMm6Egu\n\tveFPxeS6Wiay7mr41u1qlIBQ32bRIyFBSFZ/rwD+U0viLmmsCAPReYl28+Q==","X-Gm-Gg":"AY/fxX7wpYAIKPyQlwiLJ55MJR+JmJS+oMQlrEq7ZFmbWWLts5OYwBy1+yBud/hm8ew\n\tMPXyLY55PsLW4VL8yUkvkjd4nbCfcvxjin5VM8fTl2a2K1Ux2QPHd0DeVbauNhvSGxhgH77RqYN\n\tG1rXStrYPDhJzDh6w6G48PL/BK05mQj77YSDP3sKPRIUD82Q757RQvVINggBBL5+d+Ykz3qrx4C\n\t/0DXg5Uy37u9tGij080Qw6bq3qPWFbPsa8yEzhrT6Jk5B1WbLCB/0nZ2IQi8EgUS/aXi9LiIXQe\n\tbQxi/ZEnXzs6FpuTB0GbNQ1eMdWri0AQcOxlRzywmIUeQdmw1ohrVHxcaQJCMJiW+ZdHBIK/LNl\n\twEPHMLywXQI7D","X-Google-Smtp-Source":"AGHT+IHDw25rWTlto3suxqJRI2Pf+KoxXFfFUQIHBYViAdxIhzHHLaZWoYECQGBwqrNvxSiPQfpH/0+g5ABqZSeW5Y8=","X-Received":"by 2002:ad4:5c87:0:b0:888:7c7e:fce1 with SMTP id\n\t6a1803df08f44-89084175250mr30949376d6.4.1767783847485;\n\tWed, 07 Jan 2026 03:04:07 -0800 (PST)","MIME-Version":"1.0","References":"<20260107093821.14600-1-david.plowman@raspberrypi.com>\n\t","In-Reply-To":"","From":"David Plowman ","Date":"Wed, 7 Jan 2026 11:03:56 +0000","X-Gm-Features":"AQt7F2pwDEUx7vdKDy3-UGBS9PolA8YiZo1h9nyLCXxtLgE_SOL6q8cAa7esU20","Message-ID":"","Subject":"Re: [PATCH] libcamera: rpi: Make the controller min frame duration\n\tconfigurable","To":"Naushir Patuck ","Cc":"libcamera-devel@lists.libcamera.org","Content-Type":"text/plain; charset=\"UTF-8\"","X-BeenThere":"libcamera-devel@lists.libcamera.org","X-Mailman-Version":"2.1.29","Precedence":"list","List-Id":"","List-Unsubscribe":",\n\t","List-Archive":"","List-Post":"","List-Help":"","List-Subscribe":",\n\t","Errors-To":"libcamera-devel-bounces@lists.libcamera.org","Sender":"\"libcamera-devel\" "}}]