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GET /api/1.1/patches/23090/?format=api
{ "id": 23090, "url": "https://patchwork.libcamera.org/api/1.1/patches/23090/?format=api", "web_url": "https://patchwork.libcamera.org/patch/23090/", "project": { "id": 1, "url": "https://patchwork.libcamera.org/api/1.1/projects/1/?format=api", "name": "libcamera", "link_name": "libcamera", "list_id": "libcamera_core", "list_email": "libcamera-devel@lists.libcamera.org", "web_url": "", "scm_url": "", "webscm_url": "" }, "msgid": "<20250401123633.58887-4-stefan.klug@ideasonboard.com>", "date": "2025-04-01T12:36:11", "name": "[v2,3/5] libipa: histogram: Fix quantile() calculation for fractional results", "commit_ref": null, "pull_url": null, "state": "accepted", "archived": false, "hash": "a4551f17865540283513930979b1347514e123f7", "submitter": { "id": 184, "url": "https://patchwork.libcamera.org/api/1.1/people/184/?format=api", "name": "Stefan Klug", "email": "stefan.klug@ideasonboard.com" }, "delegate": null, "mbox": "https://patchwork.libcamera.org/patch/23090/mbox/", "series": [ { "id": 5099, "url": "https://patchwork.libcamera.org/api/1.1/series/5099/?format=api", "web_url": "https://patchwork.libcamera.org/project/libcamera/list/?series=5099", "date": "2025-04-01T12:36:08", "name": "Fix histogram for some (corner) cases", "version": 2, "mbox": "https://patchwork.libcamera.org/series/5099/mbox/" } ], "comments": "https://patchwork.libcamera.org/api/patches/23090/comments/", "check": "pending", "checks": "https://patchwork.libcamera.org/api/patches/23090/checks/", "tags": {}, "headers": { "Return-Path": "<libcamera-devel-bounces@lists.libcamera.org>", "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 846DCC3213\n\tfor <parsemail@patchwork.libcamera.org>;\n\tTue, 1 Apr 2025 12:36:49 +0000 (UTC)", "from lancelot.ideasonboard.com (localhost [IPv6:::1])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTP id 456686898A;\n\tTue, 1 Apr 2025 14:36:49 +0200 (CEST)", "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 81CE568987\n\tfor <libcamera-devel@lists.libcamera.org>;\n\tTue, 1 Apr 2025 14:36:47 +0200 (CEST)", "from ideasonboard.com (unknown\n\t[IPv6:2a00:6020:448c:6c00:14c7:4fcc:495b:719f])\n\tby perceval.ideasonboard.com (Postfix) with ESMTPSA id 57E128DB;\n\tTue, 1 Apr 2025 14:34:55 +0200 (CEST)" ], "Authentication-Results": "lancelot.ideasonboard.com; dkim=pass (1024-bit key;\n\tunprotected) header.d=ideasonboard.com header.i=@ideasonboard.com\n\theader.b=\"ApnMNn2I\"; dkim-atps=neutral", "DKIM-Signature": "v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com;\n\ts=mail; t=1743510895;\n\tbh=l3JdK+kvaObWpCAA5lqKijrnmQNvjPFPucRyBvKUfMI=;\n\th=From:To:Cc:Subject:Date:In-Reply-To:References:From;\n\tb=ApnMNn2IabMUGMW2FhdyR56T9SG+GgjsmcIqMszJ527Y+5YZlyB5Bz/W8lal+zrwn\n\t5JcpdLpp8kpn3fuUYCOUleJcQXlmGAKCtgvlSj/fr6OQ9jqNqjXRbKPsN9au6Jqe6i\n\tUXeSnzk2S1wScCKuZuQhOYoSRIp0Z8doS+GPFqSk=", "From": "Stefan Klug <stefan.klug@ideasonboard.com>", "To": "libcamera-devel@lists.libcamera.org", "Cc": "Stefan Klug <stefan.klug@ideasonboard.com>,\n\tKieran Bingham <kieran.bingham@ideasonboard.com>,\n\tLaurent Pinchart <laurent.pinchart@ideasonboard.com>", "Subject": "[PATCH v2 3/5] libipa: histogram: Fix quantile() calculation for\n\tfractional results", "Date": "Tue, 1 Apr 2025 14:36:11 +0200", "Message-ID": "<20250401123633.58887-4-stefan.klug@ideasonboard.com>", "X-Mailer": "git-send-email 2.43.0", "In-Reply-To": "<20250401123633.58887-1-stefan.klug@ideasonboard.com>", "References": "<20250401123633.58887-1-stefan.klug@ideasonboard.com>", "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": "<libcamera-devel.lists.libcamera.org>", "List-Unsubscribe": "<https://lists.libcamera.org/options/libcamera-devel>,\n\t<mailto:libcamera-devel-request@lists.libcamera.org?subject=unsubscribe>", "List-Archive": "<https://lists.libcamera.org/pipermail/libcamera-devel/>", "List-Post": "<mailto:libcamera-devel@lists.libcamera.org>", "List-Help": "<mailto:libcamera-devel-request@lists.libcamera.org?subject=help>", "List-Subscribe": "<https://lists.libcamera.org/listinfo/libcamera-devel>,\n\t<mailto:libcamera-devel-request@lists.libcamera.org?subject=subscribe>", "Errors-To": "libcamera-devel-bounces@lists.libcamera.org", "Sender": "\"libcamera-devel\" <libcamera-devel-bounces@lists.libcamera.org>" }, "content": "The calculation of the frac variable is based solely on integers and\ntherefore results in the fractional part being either 0 or 1.\n\nIn the original code from RaspberryPi this is mitigated by casting the\nnominator to a double. This works for most cases, but fails when q is\nvery small because of the quantization introduced by item being an\ninteger.\n\nFix both issues by doing the full calculation in double and remove the\nshould_fail tag.\n\nSigned-off-by: Stefan Klug <stefan.klug@ideasonboard.com>\nReviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>\nReviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>\n\n---\n\nChanges in v2:\n- Order fix patch after test\n- Remove should_fail tag\n- Break line before operator instead of after\n---\n src/ipa/libipa/histogram.cpp | 3 ++-\n test/ipa/libipa/meson.build | 2 +-\n 2 files changed, 3 insertions(+), 2 deletions(-)", "diff": "diff --git a/src/ipa/libipa/histogram.cpp b/src/ipa/libipa/histogram.cpp\nindex 10e44b54a0cf..ea042f0a17b9 100644\n--- a/src/ipa/libipa/histogram.cpp\n+++ b/src/ipa/libipa/histogram.cpp\n@@ -130,7 +130,8 @@ double Histogram::quantile(double q, uint32_t first, uint32_t last) const\n \tif (cumulative_[first + 1] == cumulative_[first])\n \t\tfrac = 0;\n \telse\n-\t\tfrac = (item - cumulative_[first]) / (cumulative_[first + 1] - cumulative_[first]);\n+\t\tfrac = (q * total() - cumulative_[first])\n+\t\t / (cumulative_[first + 1] - cumulative_[first]);\n \treturn first + frac;\n }\n \ndiff --git a/test/ipa/libipa/meson.build b/test/ipa/libipa/meson.build\nindex 83c84bd8c227..8c63ebd8e2f7 100644\n--- a/test/ipa/libipa/meson.build\n+++ b/test/ipa/libipa/meson.build\n@@ -2,7 +2,7 @@\n \n libipa_test = [\n {'name': 'fixedpoint', 'sources': ['fixedpoint.cpp']},\n- {'name': 'histogram', 'sources': ['histogram.cpp'], 'should_fail': true},\n+ {'name': 'histogram', 'sources': ['histogram.cpp']},\n {'name': 'interpolator', 'sources': ['interpolator.cpp']},\n ]\n \n", "prefixes": [ "v2", "3/5" ] }