From patchwork Wed Jan 21 17:37:24 2026 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kieran Bingham X-Patchwork-Id: 25912 Return-Path: X-Original-To: parsemail@patchwork.libcamera.org Delivered-To: parsemail@patchwork.libcamera.org Received: from lancelot.ideasonboard.com (lancelot.ideasonboard.com [92.243.16.209]) by patchwork.libcamera.org (Postfix) with ESMTPS id 69803BDCBF for ; Wed, 21 Jan 2026 17:37:54 +0000 (UTC) Received: from lancelot.ideasonboard.com (localhost [IPv6:::1]) by lancelot.ideasonboard.com (Postfix) with ESMTP id 6990361FEC; Wed, 21 Jan 2026 18:37:51 +0100 (CET) Authentication-Results: lancelot.ideasonboard.com; dkim=pass (1024-bit key; unprotected) header.d=ideasonboard.com header.i=@ideasonboard.com header.b="ehk4YfEb"; dkim-atps=neutral Received: from perceval.ideasonboard.com (perceval.ideasonboard.com [IPv6:2001:4b98:dc2:55:216:3eff:fef7:d647]) by lancelot.ideasonboard.com (Postfix) with ESMTPS id 2E64461FCF for ; Wed, 21 Jan 2026 18:37:43 +0100 (CET) Received: from Monstersaurus.hippo-penny.ts.net (cpc89244-aztw30-2-0-cust6594.18-1.cable.virginm.net [86.31.185.195]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id 34DC11E31; Wed, 21 Jan 2026 18:37:11 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1769017031; bh=YPKAZ8pQo2lbCK5qntmjX92Vn+/WMTCEJzmlbRelYro=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ehk4YfEbY7EXfZ5GcnG0V2xG1vvvKcG4ItBZ8xAY566UUJjCngU5kZzjzqYivGrrh mCYs5PRrmSwK/eAyA1XpO+OYCID80aO/rjgmxesNNdpoWUjUyslUqAu7zW9NMjHyTH LPfSiWgXlChuKeYROXd3mmuB/sO8T2VclBtQaUoA= From: Kieran Bingham To: libcamera devel Cc: Kieran Bingham Subject: [PATCH v6 05/16] test: libipa: Provide FixedPoint Quantized tests Date: Wed, 21 Jan 2026 17:37:24 +0000 Message-ID: <20260121173737.376113-6-kieran.bingham@ideasonboard.com> X-Mailer: git-send-email 2.52.0 In-Reply-To: <20260121173737.376113-1-kieran.bingham@ideasonboard.com> References: <20260121173737.376113-1-kieran.bingham@ideasonboard.com> MIME-Version: 1.0 X-BeenThere: libcamera-devel@lists.libcamera.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: libcamera-devel-bounces@lists.libcamera.org Sender: "libcamera-devel" Provide tests to validate the conditions of FixedPoint types used within libcamera explicitly. Signed-off-by: Kieran Bingham --- v3: - Rename quantized_type to QuantizedType v5: - Use string_view for introduction of type - move min/max check to static assert - Squash down all tests into a single implementation and remove extra type proliferation. - Use Q/UQ types directly. - use std::cout consistently v6: - Add notes on test introduction - Expand Q12.4 to include clamp tests to validate int16_t range usage - Add storage selection assertion checks - Move clamp checks to their types to expand - Add {U,}Q<4,20> to check up to 24 bit precision Signed-off-by: Kieran Bingham --- test/ipa/libipa/fixedpoint.cpp | 162 ++++++++++++++++++++++++++++++++- 1 file changed, 158 insertions(+), 4 deletions(-) diff --git a/test/ipa/libipa/fixedpoint.cpp b/test/ipa/libipa/fixedpoint.cpp index 4b017e86a74f..500cd308be98 100644 --- a/test/ipa/libipa/fixedpoint.cpp +++ b/test/ipa/libipa/fixedpoint.cpp @@ -5,12 +5,14 @@ * Fixed / Floating point utility tests */ +#include "../src/ipa/libipa/fixedpoint.h" + #include #include #include #include -#include "../src/ipa/libipa/fixedpoint.h" +#include #include "test.h" @@ -95,14 +97,166 @@ protected: return TestPass; } - int run() + template + int quantizedCheck(float input, typename Q::QuantizedType expected, float value) { - /* fixed point conversion test */ - if (testFixedPoint() != TestPass) + Q q(input); + using T = typename Q::QuantizedType; + + std::cout << " Checking " << input << " == " << q << std::endl; + + T quantized = q.quantized(); + if (quantized != expected) { + std::cout << " ** Q Expected " << input + << " to quantize to " << utils::hex(expected) + << ", got " << utils::hex(quantized) + << " - (" << q << ")" + << std::endl; + return 1; + } + + if ((std::abs(q.value() - value)) > 0.0001f) { + std::cout << " ** V Expected " << input + << " to quantize to " << value + << ", got " << q.value() + << " - (" << q << ")" + << std::endl; + return 1; + } + + return 0; + } + + template + void introduce(std::string_view type) + { + using T = typename Q::QuantizedType; + + std::cout << std::endl; + + std::cout << type + << "(" << Q::TraitsType::min << " .. " << Q::TraitsType::max << ") " + << " Min: " << Q(Q::TraitsType::min) + << " -- Max: " << Q(Q::TraitsType::max) + << " Step:" << Q(T(1)).value() + << std::endl; + } + + int testFixedPointQuantizers() + { + unsigned int fails = 0; + + /* + * These aim to specifically test all the corner cases of the + * quantization and de-quantization process. Including clamping + * to min/max, zero points and making sure that steps are + * correct. + * + * In particular test signed and unsigned types and a mix of the + * highest bit width of a storage type and smaller widths that + * require bit masking and sign extension. + * + * Note we must hard code these. Any calculation of expected + * values risks replicating bugs in the implementation. + * + * As the underlying types are integer and float the limit of + * precision is around 24 bits so we do not test wider types. + */ + + /* clang-format off */ + + /* Q1.7(-1 .. 0.992188) Min: [0x80:-1] -- Max: [0x7f:0.992188] Step:0.0078125*/ + introduce>("Q1.7"); + fails += quantizedCheck>(-2.000f, 0b1'0000000, -1.0f); /* Clamped to Min */ + fails += quantizedCheck>(-1.000f, 0b1'0000000, -1.0f); /* Min */ + fails += quantizedCheck>(-0.992f, 0b1'0000001, -0.992188f); /* Min + 1 step */ + fails += quantizedCheck>(-0.006f, 0b1'1111111, -0.0078125f); /* -1 step */ + fails += quantizedCheck>( 0.000f, 0b0'0000000, 0.0f); /* Zero */ + fails += quantizedCheck>( 0.008f, 0b0'0000001, 0.0078125f); /* +1 step */ + fails += quantizedCheck>( 0.992f, 0b0'1111111, 0.992188f); /* Max */ + fails += quantizedCheck>( 2.000f, 0b0'1111111, 0.992188f); /* Clamped to Max */ + + /* UQ1.7(0 .. 1.99219) Min: [0x00:0] -- Max: [0xff:1.99219] Step:0.0078125 */ + introduce>("UQ1.7"); + fails += quantizedCheck>(-1.0f, 0b0'0000000, 0.0f); /* Clamped to Min */ + fails += quantizedCheck>( 0.0f, 0b0'0000000, 0.0f); /* Min / Zero */ + fails += quantizedCheck>( 1.0f, 0b1'0000000, 1.0f); /* Mid */ + fails += quantizedCheck>( 1.992f, 0b1'1111111, 1.99219f); /* Max */ + fails += quantizedCheck>( 2.000f, 0b1'1111111, 1.99219f); /* Clamped to Max */ + + /* UQ4.8(0 .. 15.9961) Min: [0x0000:0] -- Max: [0x0fff:15.9961] Step:0.00390625 */ + introduce>("UQ4.8"); + fails += quantizedCheck>( 0.0f, 0b0000'00000000, 0.00f); + fails += quantizedCheck>(16.0f, 0b1111'11111111, 15.9961f); + + /* Q5.4(-16 .. 15.9375) Min: [0x0100:-16] -- Max: [0x00ff:15.9375] Step:0.0625 */ + introduce>("Q5.4"); + fails += quantizedCheck>(-16.00f, 0b10000'0000, -16.00f); + fails += quantizedCheck>( 15.94f, 0b01111'1111, 15.9375f); + + /* UQ5.8(0 .. 31.9961) Min: [0x0000:0] -- Max: [0x1fff:31.9961] Step:0.00390625 */ + introduce>("UQ5.8"); + fails += quantizedCheck>( 0.00f, 0b00000'00000000, 0.00f); + fails += quantizedCheck>(32.00f, 0b11111'11111111, 31.9961f); + + /* Q12.4(-2048 .. 2047.94) Min: [0x8000:-2048] -- Max: [0x7fff:2047.94] Step:0.0625 */ + introduce>("Q12.4"); + fails += quantizedCheck>( 0.0f, 0b000000000000'0000, 0.0f); + fails += quantizedCheck>( 7.5f, 0b000000000111'1000, 7.5f); + + /* UQ12.4(0 .. 4095.94) Min: [0x0000:0] -- Max: [0xffff:4095.94] Step:0.0625 */ + introduce>("UQ12.4"); + fails += quantizedCheck>(0.0f, 0b000000000000'0000, 0.0f); + fails += quantizedCheck>(7.5f, 0b000000000111'1000, 7.5f); + + /* Q4.20 */ + introduce>("Q4.20"); + fails += quantizedCheck>( -9.0f, 0b1000'00000000000000000000, -8.0f); + fails += quantizedCheck>( -8.0f, 0b1000'00000000000000000000, -8.0f); + fails += quantizedCheck>( 8.0f, 0b0111'11111111111111111111, 8.0f); + fails += quantizedCheck>( 9.0f, 0b0111'11111111111111111111, 8.0f); + + /* UQ4.20 */ + introduce>("UQ4.20"); + fails += quantizedCheck>(-1.0f, 0b0000'00000000000000000000, 0.0f); + fails += quantizedCheck>( 0.0f, 0b0000'00000000000000000000, 0.0f); + fails += quantizedCheck>(16.0f, 0b1111'11111111111111111111, 16.0f); + fails += quantizedCheck>(20.0f, 0b1111'11111111111111111111, 16.0f); + + /* Storage selection tests */ + static_assert(std::is_same_v::TraitsType::QuantizedType, int8_t>); + static_assert(std::is_same_v::TraitsType::QuantizedType, uint8_t>); + static_assert(std::is_same_v::TraitsType::QuantizedType, int16_t>); + static_assert(std::is_same_v::TraitsType::QuantizedType, uint16_t>); + static_assert(std::is_same_v::TraitsType::QuantizedType, int32_t>); + static_assert(std::is_same_v::TraitsType::QuantizedType, uint32_t>); + + /* clang-format on */ + + std::cout << std::endl; + + if (fails > 0) { + cout << "Fixed point quantizer tests failed: " + << std::dec << fails << " failures." << std::endl; return TestFail; + } return TestPass; } + + int run() + { + unsigned int fails = 0; + + /* fixed point conversion test */ + if (testFixedPoint() != TestPass) + fails++; + + if (testFixedPointQuantizers() != TestPass) + fails++; + + return fails ? TestFail : TestPass; + } }; TEST_REGISTER(FixedPointUtilsTest)