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Diffstat (limited to 'src/gui/util/qedidparser.cpp')
| -rw-r--r-- | src/gui/util/qedidparser.cpp | 256 |
1 files changed, 256 insertions, 0 deletions
diff --git a/src/gui/util/qedidparser.cpp b/src/gui/util/qedidparser.cpp new file mode 100644 index 0000000000..4dae151e6a --- /dev/null +++ b/src/gui/util/qedidparser.cpp @@ -0,0 +1,256 @@ +// Copyright (C) 2017 Pier Luigi Fiorini <pierluigi.fiorini@gmail.com> +// Copyright (C) 2021 Klarälvdalens Datakonsult AB, a KDAB Group company, info@kdab.com, author Giuseppe D'Angelo <giuseppe.dangelo@kdab.com> +// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only + +#include <QtCore/QFile> +#include <QtCore/QByteArrayView> + +#include "qedidparser_p.h" +#include "qedidvendortable_p.h" + +#define EDID_DESCRIPTOR_ALPHANUMERIC_STRING 0xfe +#define EDID_DESCRIPTOR_PRODUCT_NAME 0xfc +#define EDID_DESCRIPTOR_SERIAL_NUMBER 0xff + +#define EDID_DATA_BLOCK_COUNT 4 +#define EDID_OFFSET_DATA_BLOCKS 0x36 +#define EDID_OFFSET_LAST_BLOCK 0x6c +#define EDID_OFFSET_PNP_ID 0x08 +#define EDID_OFFSET_SERIAL 0x0c +#define EDID_PHYSICAL_WIDTH 0x15 +#define EDID_OFFSET_PHYSICAL_HEIGHT 0x16 +#define EDID_TRANSFER_FUNCTION 0x17 +#define EDID_FEATURE_SUPPORT 0x18 +#define EDID_CHROMATICITIES_BLOCK 0x19 + +QT_BEGIN_NAMESPACE + +using namespace Qt::StringLiterals; + +static QString lookupVendorIdInSystemDatabase(QByteArrayView id) +{ + QString result; + + const QString fileName = "/usr/share/hwdata/pnp.ids"_L1; + QFile file(fileName); + if (!file.open(QFile::ReadOnly)) + return result; + + // On Ubuntu 20.04 the longest line in the file is 85 bytes, so this + // leaves plenty of room... + constexpr int MaxLineSize = 512; + char buf[MaxLineSize]; + + while (!file.atEnd()) { + auto read = file.readLine(buf, MaxLineSize); + if (read < 0 || read == MaxLineSize) // read error + break; + + QByteArrayView line(buf, read - 1); // -1 to remove the trailing newline + if (line.isEmpty()) + continue; + + if (line.startsWith('#')) + continue; + + auto tabPosition = line.indexOf('\t'); + if (tabPosition <= 0) // no vendor id + continue; + if (tabPosition + 1 == line.size()) // no vendor name + continue; + + if (line.first(tabPosition) == id) { + auto vendor = line.sliced(tabPosition + 1); + result = QString::fromUtf8(vendor.data(), vendor.size()); + break; + } + } + + return result; +} + +bool QEdidParser::parse(const QByteArray &blob) +{ + const quint8 *data = reinterpret_cast<const quint8 *>(blob.constData()); + const size_t length = blob.size(); + + // Verify header + if (length < 128) + return false; + if (data[0] != 0x00 || data[1] != 0xff) + return false; + + /* Decode the PNP ID from three 5 bit words packed into 2 bytes + * /--08--\/--09--\ + * 7654321076543210 + * |\---/\---/\---/ + * R C1 C2 C3 */ + char pnpId[3]; + pnpId[0] = 'A' + ((data[EDID_OFFSET_PNP_ID] & 0x7c) / 4) - 1; + pnpId[1] = 'A' + ((data[EDID_OFFSET_PNP_ID] & 0x3) * 8) + ((data[EDID_OFFSET_PNP_ID + 1] & 0xe0) / 32) - 1; + pnpId[2] = 'A' + (data[EDID_OFFSET_PNP_ID + 1] & 0x1f) - 1; + + // Clear manufacturer + manufacturer = QString(); + + // Serial number, will be overwritten by an ASCII descriptor + // when and if it will be found + quint32 serial = data[EDID_OFFSET_SERIAL] + + (data[EDID_OFFSET_SERIAL + 1] << 8) + + (data[EDID_OFFSET_SERIAL + 2] << 16) + + (data[EDID_OFFSET_SERIAL + 3] << 24); + if (serial > 0) + serialNumber = QString::number(serial); + else + serialNumber = QString(); + + // Parse EDID data + for (int i = 0; i < EDID_DATA_BLOCK_COUNT; ++i) { + const uint offset = EDID_OFFSET_DATA_BLOCKS + i * 18; + + if (data[offset] != 0 || data[offset + 1] != 0 || data[offset + 2] != 0) + continue; + + if (data[offset + 3] == EDID_DESCRIPTOR_PRODUCT_NAME) + model = parseEdidString(&data[offset + 5]); + else if (data[offset + 3] == EDID_DESCRIPTOR_ALPHANUMERIC_STRING) + identifier = parseEdidString(&data[offset + 5]); + else if (data[offset + 3] == EDID_DESCRIPTOR_SERIAL_NUMBER) + serialNumber = parseEdidString(&data[offset + 5]); + } + + // Try to use cache first because it is potentially more updated + manufacturer = lookupVendorIdInSystemDatabase(pnpId); + + if (manufacturer.isEmpty()) { + // Find the manufacturer from the vendor lookup table + const auto compareVendorId = [](const VendorTable &vendor, const char *str) + { + return strncmp(vendor.id, str, 3) < 0; + }; + + const auto b = std::begin(q_edidVendorTable); + const auto e = std::end(q_edidVendorTable); + auto it = std::lower_bound(b, + e, + pnpId, + compareVendorId); + + if (it != e && strncmp(it->id, pnpId, 3) == 0) + manufacturer = QString::fromUtf8(it->name); + } + + // If we don't know the manufacturer, fallback to PNP ID + if (manufacturer.isEmpty()) + manufacturer = QString::fromUtf8(pnpId, std::size(pnpId)); + + // Physical size + physicalSize = QSizeF(data[EDID_PHYSICAL_WIDTH], data[EDID_OFFSET_PHYSICAL_HEIGHT]) * 10; + + // Gamma and transfer function + const uint igamma = data[EDID_TRANSFER_FUNCTION]; + if (igamma != 0xff) { + gamma = 1.0 + (igamma / 100.0f); + useTables = false; + } else { + gamma = 0.0; // Defined in DI-EXT + useTables = true; + } + sRgb = data[EDID_FEATURE_SUPPORT] & 0x04; + + // Chromaticities + int rx = (data[EDID_CHROMATICITIES_BLOCK] >> 6) & 0x03; + int ry = (data[EDID_CHROMATICITIES_BLOCK] >> 4) & 0x03; + int gx = (data[EDID_CHROMATICITIES_BLOCK] >> 2) & 0x03; + int gy = (data[EDID_CHROMATICITIES_BLOCK] >> 0) & 0x03; + int bx = (data[EDID_CHROMATICITIES_BLOCK + 1] >> 6) & 0x03; + int by = (data[EDID_CHROMATICITIES_BLOCK + 1] >> 4) & 0x03; + int wx = (data[EDID_CHROMATICITIES_BLOCK + 1] >> 2) & 0x03; + int wy = (data[EDID_CHROMATICITIES_BLOCK + 1] >> 0) & 0x03; + rx |= data[EDID_CHROMATICITIES_BLOCK + 2] << 2; + ry |= data[EDID_CHROMATICITIES_BLOCK + 3] << 2; + gx |= data[EDID_CHROMATICITIES_BLOCK + 4] << 2; + gy |= data[EDID_CHROMATICITIES_BLOCK + 5] << 2; + bx |= data[EDID_CHROMATICITIES_BLOCK + 6] << 2; + by |= data[EDID_CHROMATICITIES_BLOCK + 7] << 2; + wx |= data[EDID_CHROMATICITIES_BLOCK + 8] << 2; + wy |= data[EDID_CHROMATICITIES_BLOCK + 9] << 2; + + redChromaticity.setX(rx * (1.0f / 1024.0f)); + redChromaticity.setY(ry * (1.0f / 1024.0f)); + greenChromaticity.setX(gx * (1.0f / 1024.0f)); + greenChromaticity.setY(gy * (1.0f / 1024.0f)); + blueChromaticity.setX(bx * (1.0f / 1024.0f)); + blueChromaticity.setY(by * (1.0f / 1024.0f)); + whiteChromaticity.setX(wx * (1.0f / 1024.0f)); + whiteChromaticity.setY(wy * (1.0f / 1024.0f)); + + // Find extensions + for (uint i = 1; i < length / 128; ++i) { + uint extensionId = data[i * 128]; + if (extensionId == 0x40) { // DI-EXT + // 0x0E (sub-pixel layout) + // 0x20->0x22 (bits per color) + // 0x51->0x7e Transfer characteristics + const uchar desc = data[i * 128 + 0x51]; + const uchar len = desc & 0x3f; + if ((desc & 0xc0) == 0x40) { + if (len > 45) + return false; + QList<uint16_t> whiteTRC; + whiteTRC.reserve(len + 1); + for (uint j = 0; j < len; ++j) + whiteTRC[j] = data[0x52 + j] * 0x101; + whiteTRC[len] = 0xffff; + tables.append(whiteTRC); + } else if ((desc & 0xc0) == 0x80) { + if (len > 15) + return false; + QList<uint16_t> redTRC; + QList<uint16_t> greenTRC; + QList<uint16_t> blueTRC; + blueTRC.reserve(len + 1); + greenTRC.reserve(len + 1); + redTRC.reserve(len + 1); + for (uint j = 0; j < len; ++j) + blueTRC[j] = data[0x52 + j] * 0x101; + blueTRC[len] = 0xffff; + for (uint j = 0; j < len; ++j) + greenTRC[j] = data[0x61 + j] * 0x101; + greenTRC[len] = 0xffff; + for (uint j = 0; j < len; ++j) + redTRC[j] = data[0x70 + j] * 0x101; + redTRC[len] = 0xffff; + tables.append(redTRC); + tables.append(greenTRC); + tables.append(blueTRC); + } + } + } + + return true; +} + +QString QEdidParser::parseEdidString(const quint8 *data) +{ + QByteArray buffer(reinterpret_cast<const char *>(data), 13); + + for (int i = 0; i < buffer.size(); ++i) { + // If there are less than 13 characters in the string, the string + // is terminated with the ASCII code ‘0Ah’ (line feed) and padded + // with ASCII code ‘20h’ (space). See EDID 1.4, sections 3.10.3.1, + // 3.10.3.2, and 3.10.3.4. + if (buffer[i] == '\n') { + buffer.truncate(i); + break; + } + + // Replace non-printable characters with dash + if (buffer[i] < '\040' || buffer[i] > '\176') + buffer[i] = '-'; + } + + return QString::fromLatin1(buffer); +} + +QT_END_NAMESPACE |