{"id":24503,"url":"https://patchwork.libcamera.org/api/patches/24503/?format=json","web_url":"https://patchwork.libcamera.org/patch/24503/","project":{"id":1,"url":"https://patchwork.libcamera.org/api/projects/1/?format=json","name":"libcamera","link_name":"libcamera","list_id":"libcamera_core","list_email":"libcamera-devel@lists.libcamera.org","web_url":"","scm_url":"","webscm_url":""},"msgid":"<20250930124208.14391-1-robert.mader@collabora.com>","date":"2025-09-30T12:42:07","name":"[v3,1/2] pipeline: simple: Allow buffer counts from 1 to 32","commit_ref":null,"pull_url":null,"state":"accepted","archived":false,"hash":"31340b2c2da44e1e17af0524f765d66b9eb1c85a","submitter":{"id":140,"url":"https://patchwork.libcamera.org/api/people/140/?format=json","name":"Robert Mader","email":"robert.mader@collabora.com"},"delegate":null,"mbox":"https://patchwork.libcamera.org/patch/24503/mbox/","series":[{"id":5469,"url":"https://patchwork.libcamera.org/api/series/5469/?format=json","web_url":"https://patchwork.libcamera.org/project/libcamera/list/?series=5469","date":"2025-09-30T12:42:07","name":"[v3,1/2] pipeline: simple: Allow buffer counts from 1 to 32","version":3,"mbox":"https://patchwork.libcamera.org/series/5469/mbox/"}],"comments":"https://patchwork.libcamera.org/api/patches/24503/comments/","check":"pending","checks":"https://patchwork.libcamera.org/api/patches/24503/checks/","tags":{},"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 59611C324C\n\tfor ;\n\tTue, 30 Sep 2025 12:42:38 +0000 (UTC)","from lancelot.ideasonboard.com (localhost [IPv6:::1])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTP id 0DFA06B5F3;\n\tTue, 30 Sep 2025 14:42:38 +0200 (CEST)","from sender4-pp-f112.zoho.com (sender4-pp-f112.zoho.com\n\t[136.143.188.112])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTPS id 15DFB62C35\n\tfor ;\n\tTue, 30 Sep 2025 14:42:35 +0200 (CEST)","by mx.zohomail.com with SMTPS id 1759236152115499.2979136776106;\n\tTue, 30 Sep 2025 05:42:32 -0700 (PDT)"],"Authentication-Results":"lancelot.ideasonboard.com; dkim=pass (1024-bit key;\n\tunprotected) header.d=collabora.com\n\theader.i=robert.mader@collabora.com header.b=\"k02O99b0\"; \n\tdkim-atps=neutral","ARC-Seal":"i=1; a=rsa-sha256; t=1759236153; cv=none; \n\td=zohomail.com; s=zohoarc; \n\tb=M26GriJbXPZBj1YWjQtTdcf8PsgbYM463ibI2oYLR5wct3kMHZ74vMFoORMBrtkX0qgGz0O97IVcNYi4erMTO0snKRya04dpmFbyrvEtmzWtArOyVs3KX9owrnbMwW5hbUD4TNPIAb20jcW4A6oGXgwPw8H6oDxEak3WfNc14sk=","ARC-Message-Signature":"i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; \n\ts=zohoarc; t=1759236153;\n\th=Content-Transfer-Encoding:Cc:Cc:Date:Date:From:From:MIME-Version:Message-ID:Subject:Subject:To:To:Message-Id:Reply-To;\n\tbh=ZN6XdIA4YAd11mwP9nr+iwhay6aTsY7vM4zXnujmZ7k=; \n\tb=dA0ufoPGM6hVW2v5BV/GC3QP9T1FIFbo8nqbuFFeHICLAIEA01xK6qpkTRkqHBEphgQC1uMzXINiC0xJBB4ZvFH/1m53N69mvEUqnB1ty0xRB0K/UjnuDsCHCst7RtALdifnh+D/fHKjmRaS1ZF+QaffpjHSaZNl+CfBbT7JEjQ=","ARC-Authentication-Results":"i=1; mx.zohomail.com;\n\tdkim=pass header.i=collabora.com;\n\tspf=pass smtp.mailfrom=robert.mader@collabora.com;\n\tdmarc=pass header.from=","DKIM-Signature":"v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; t=1759236152;\n\ts=zohomail; d=collabora.com; i=robert.mader@collabora.com;\n\th=From:From:To:To:Cc:Cc:Subject:Subject:Date:Date:Message-ID:MIME-Version:Content-Transfer-Encoding:Message-Id:Reply-To;\n\tbh=ZN6XdIA4YAd11mwP9nr+iwhay6aTsY7vM4zXnujmZ7k=;\n\tb=k02O99b0ZdRsBG2leik6wRXe12pa80+P6VqaSE3op0l6Z8YIwcgMMSBWGzo5kMLh\n\tR2Gut2WDRRY8hrPKMJJhZlT3ObApkGfo0x5zldDgvj0FqEJMYrb1ruDfM+3m6BgG+59\n\tFGC1FEsIjAk1HL5/92Rody00F+3CMrSm3At+ZzZU=","From":"Robert Mader ","To":"libcamera-devel@lists.libcamera.org","Cc":"Robert Mader ,\n\tMilan Zamazal ","Subject":"[PATCH v3 1/2] pipeline: simple: Allow buffer counts from 1 to 32","Date":"Tue, 30 Sep 2025 14:42:07 +0200","Message-ID":"<20250930124208.14391-1-robert.mader@collabora.com>","X-Mailer":"git-send-email 2.51.0","MIME-Version":"1.0","Content-Transfer-Encoding":"8bit","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\" "},"content":"While a default value of 4 buffers appears to be a good default that is\nused by other pipelines as well, allowing both higher and lower values\ncan be desirable, notably for:\n1. Video encoding, e.g. encoding multiple buffers in parallel.\n2. Clients requesting a single buffer - e.g. in multi-stream scenarios.\n\nThus allow buffer counts between 1 and 32 buffers - following the default\nmaximum from vb2 core - while keeping the default to the previous 4.\n\nWhile on it mark the config as adjusted when appropriate.\n\nSigned-off-by: Robert Mader \nReviewed-by: Milan Zamazal \n\n---\n\nChanges in v3:\n1. Adopeted code cleanup suggestion - no change in behavior.\n2. Split out change of kNumInternalBuffers.\n3. Minor commit message changes.\n\nChanges since v1 with title \"pipeline: simple: Allow buffer counts from 1 to 16 for swISP\"\n1: Cover all cases, not just the swISP one.\n2: Increase maximum to 32 to match vb2 core.\n3: Change constant naming to better match similar ones.\n4: Bump kNumInternalBuffers to 4.\n---\n src/libcamera/pipeline/simple/simple.cpp | 18 ++++++++++++++++--\n 1 file changed, 16 insertions(+), 2 deletions(-)","diff":"diff --git a/src/libcamera/pipeline/simple/simple.cpp b/src/libcamera/pipeline/simple/simple.cpp\nindex c816cffc9..2dcba04ec 100644\n--- a/src/libcamera/pipeline/simple/simple.cpp\n+++ b/src/libcamera/pipeline/simple/simple.cpp\n@@ -378,6 +378,9 @@ public:\n \tconst Transform &combinedTransform() const { return combinedTransform_; }\n \n private:\n+\tstatic constexpr unsigned int kNumBuffersDefault = 4;\n+\tstatic constexpr unsigned int kNumBuffersMax = 32;\n+\n \t/*\n \t * The SimpleCameraData instance is guaranteed to be valid as long as\n \t * the corresponding Camera instance is valid. In order to borrow a\n@@ -1239,7 +1242,7 @@ CameraConfiguration::Status SimpleCameraConfiguration::validate()\n \t\t cfg.size != pipeConfig_->captureSize)\n \t\t\tneedConversion_ = true;\n \n-\t\t/* Set the stride, frameSize and bufferCount. */\n+\t\t/* Set the stride and frameSize. */\n \t\tif (needConversion_) {\n \t\t\tstd::tie(cfg.stride, cfg.frameSize) =\n \t\t\t\tdata_->converter_\n@@ -1262,7 +1265,18 @@ CameraConfiguration::Status SimpleCameraConfiguration::validate()\n \t\t\tcfg.frameSize = format.planes[0].size;\n \t\t}\n \n-\t\tcfg.bufferCount = 4;\n+\t\tconst auto bufferCount = cfg.bufferCount;\n+\t\tif (bufferCount <= 0)\n+\t\t\tcfg.bufferCount = kNumBuffersDefault;\n+\t\telse if (bufferCount > kNumBuffersMax)\n+\t\t\tcfg.bufferCount = kNumBuffersMax;\n+\n+\t\tif (cfg.bufferCount != bufferCount) {\n+\t\t\tLOG(SimplePipeline, Debug)\n+\t\t\t\t<< \"Adjusting bufferCount from \" << bufferCount\n+\t\t\t\t<< \" to \" << cfg.bufferCount;\n+\t\t\tstatus = Adjusted;\n+\t\t}\n \t}\n \n \treturn status;\n","prefixes":["v3","1/2"]}