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window_window_manager/edidparse/edidparse.cpp
T
wangdi 4092a51582 parse edid1.3 bpc
Signed-off-by: wangdi <wangdi154@huawei.com>
2026-05-17 16:01:34 +08:00

326 lines
13 KiB
C++

/*
* Copyright (c) 2025 Huawei Device Co., Ltd.
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "edidparse.h"
#include "window_manager_hilog.h"
constexpr OHOS::HiviewDFX::HiLogLabel LABEL = {LOG_CORE, OHOS::Rosen::HILOG_DOMAIN_DISPLAY, "EdidParse"};
constexpr uint32_t EDID_BLOCK_SIZE = 128;
constexpr uint32_t EDID_MAX_BLOCK = 4;
constexpr uint32_t EDID_MAX_SIZE = EDID_BLOCK_SIZE * EDID_MAX_BLOCK;
constexpr uint32_t ONE_NUMBER_OF_BYTES = 8;
constexpr uint32_t TWO_NUMBER_OF_BYTES = 16;
constexpr uint32_t THREE_NUMBER_OF_BYTES = 24;
constexpr uint8_t EDID_VENDOR_START = 0x8;
constexpr uint8_t EDID_VENDOR_END = 0x11;
constexpr size_t BASE_YEAR = 1990;
constexpr size_t SN_SECOND_NUM = 2;
constexpr size_t SN_THIRD_NUM = 3;
constexpr uint8_t BASE_MINOR = 4;
constexpr size_t EDID_MINOR_OFFSET = 0x13;
constexpr size_t MANUFACTURE_WEEK_OFFSET = 0x10;
constexpr size_t MANUFACTURE_YEAR_OFFSET = 0x11;
constexpr size_t EDID_VIDEO_INPUT_DEFINITION_OFFSET = 0x14;
static constexpr uint8_t COLOR_DEPTH_BPC_CALC_SHIFT = 3;
static constexpr uint8_t COLOR_DEPTH_BPC_BASE_OFFSET = 4;
static constexpr uint8_t VIDEO_INPUT_DIGITAL_FLAG_MASK = 0x80;
static constexpr uint8_t COLOR_BIT_DEPTH_FIELD_MASK = 0x70;
static constexpr uint8_t COLOR_DEPTH_ENCODING_UNDEFINED = 0x00;
static constexpr uint8_t COLOR_DEPTH_ENCODING_RESERVED = 0x70;
// CEA-861 Extension Block Structure Constants
constexpr uint8_t EDID_VERSION_1_3 = 3;
static constexpr uint8_t EDID_NUM_EXT_OFFSET = 126; // Offset to the extension block count field
static constexpr uint8_t CEA_TAG = 0x02;
static constexpr uint8_t CEA_BLOCK_TAG_OFFSET = 0; // Block tag identifier offset
static constexpr uint8_t CEA_DTD_START_OFFSET = 2; // DTD (Detailed Timing Descriptor) start offset
static constexpr uint8_t CEA_DATA_BLOCK_START_OFFSET = 4; // Data block collection start offset
// Data Block Header Parsing Constants (Byte 0: TTTT TLLL)
static constexpr uint8_t DATA_BLOCK_TAG_SHIFT = 5;
static constexpr uint8_t DATA_BLOCK_TAG_MASK = 0x07; // Upper 3 bits: Tag code
static constexpr uint8_t DATA_BLOCK_LEN_MASK = 0x1F; // Lower 5 bits: Payload length
// Data Block Tag Types
static constexpr uint8_t VENDOR_SPECIFIC_TAG = 0x03;
// HDMI VSDB (Vendor Specific Data Block) Structure Constants
static constexpr uint32_t HDMI_OUI = 0x000C03;
static constexpr uint8_t HDMI_VSDB_MIN_LEN = 6; // Minimum valid length: OUI(3) + Physical Address(2) + Flags(1)
static constexpr uint8_t HDMI_VSDB_OUI_OFFSET = 1; // OUI start offset relative to the data block header
static constexpr uint8_t HDMI_VSDB_FLAGS_OFFSET = 6; // Deep Color flags byte offset relative to the data block header
// Deep Color Flag Bits (HDMI VSDB Byte 6)
static constexpr uint8_t DC_30bit = 0x10; // bit 4: 10 bpc
static constexpr uint8_t DC_36bit = 0x20; // bit 5: 12 bpc
static constexpr uint8_t DC_48bit = 0x40; // bit 6: 16 bpc
static constexpr uint8_t BPC_8bit = 8;
static constexpr uint8_t BPC_10bit = 10;
static constexpr uint8_t BPC_12bit = 12;
static constexpr uint8_t BPC_16bit = 16;
template <size_t I>
char GetLetter(uint16_t id)
{
static_assert(I < 3);
const char letter = 'A' + (static_cast<uint8_t>(id >> ((2 - I) * 5)) & 0b00011111) - 1;
return letter < 'A' || letter > 'Z' ? '\0' : letter;
}
static std::string GetManufacturerNameFromNum(uint16_t manufacturerId)
{
std::string manufacturerName;
constexpr uint32_t secondLetter = 2;
manufacturerName.push_back(GetLetter<0>(manufacturerId));
manufacturerName.push_back(GetLetter<1>(manufacturerId));
manufacturerName.push_back(GetLetter<secondLetter>(manufacturerId));
return manufacturerName;
}
static bool CheckEdidValid(const std::vector<uint8_t>& edid)
{
if (edid.empty() || edid.size() % EDID_BLOCK_SIZE != 0) {
WLOGFE("edid is invalid, size = %{public}u", static_cast<uint32_t>(edid.size()));
return false;
}
const uint8_t magicStr[] = {0, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0};
return std::equal(std::begin(magicStr), std::end(magicStr), edid.begin());
}
static std::string ParseEdidText(const std::vector<uint8_t>& edid)
{
std::string text(reinterpret_cast<const char*>(edid.data()), edid.size());
text = text.substr(0, text.find('\n'));
if (!std::all_of(text.begin(), text.end(), ::isprint)) {
WLOGFW("edid text is empty");
return {};
}
return text;
}
static void ParseDetailedTiming(const std::vector<uint8_t>& edid, struct baseEdid* outEdid)
{
constexpr size_t detailedTimingDescriptorStart = 0x36;
constexpr size_t detailedTimingDescriptorend = 0x6c;
constexpr size_t eachDetailedTimingDescriptorSize = 0x12;
constexpr size_t displayProductNameTag = 0xfc;
constexpr size_t alphanumericDataStringTag = 0xfe;
constexpr size_t displayProductSerialNumberTag = 0xff;
constexpr size_t displayDescriptorTagOffset = 3;
constexpr size_t displayDescriptorTagStart = 5;
constexpr size_t displayDescriptorTagEnd = 18;
for (size_t i = detailedTimingDescriptorStart; i <= detailedTimingDescriptorend;
i += eachDetailedTimingDescriptorSize) {
const size_t displayDescriptorTag = edid[i + displayDescriptorTagOffset];
std::vector<uint8_t> descriptorVec;
descriptorVec.assign(edid.begin() + i + displayDescriptorTagStart, edid.begin() + i + displayDescriptorTagEnd);
switch (displayDescriptorTag) {
case displayProductNameTag:
outEdid->displayProductName = ParseEdidText(descriptorVec);
break;
case alphanumericDataStringTag:
outEdid->asciiText = ParseEdidText(descriptorVec);
break;
case displayProductSerialNumberTag:
outEdid->displayProductSerialNumber = ParseEdidText(descriptorVec);
break;
default:
break;
}
}
outEdid->modelName = outEdid->displayProductName;
if (outEdid->modelName.empty()) {
WLOGFW("display product name is empty");
outEdid->modelName = outEdid->displayProductSerialNumber;
}
if (outEdid->modelName.empty()) {
WLOGFW("display product serial number is empty");
outEdid->modelName = outEdid->asciiText;
}
}
static bool CheckParamsValid(const uint8_t* edidData, const uint32_t edidSize, BaseEdid* outEdid)
{
if (!edidData || !outEdid) {
WLOGFE("edid is nullptr or outEdid i nullptr");
return false;
}
WLOGFW("edid size is %{public}u", edidSize);
if (edidSize == 0 || edidSize % EDID_BLOCK_SIZE != 0 || edidSize > EDID_MAX_SIZE) {
return false;
}
return true;
}
uint8_t ExtractBpcFromFlags(uint8_t flags)
{
if (flags & DC_48bit) {
return BPC_16bit;
}
if (flags & DC_36bit) {
return BPC_12bit;
}
if (flags & DC_30bit) {
return BPC_10bit;
}
return BPC_8bit;
}
bool TryParseHdmiVsdb(const std::vector<uint8_t>& edid, size_t pos, uint8_t len, uint8_t& bpc)
{
if (len < HDMI_VSDB_MIN_LEN) {
return false;
}
uint32_t oui = edid[pos + HDMI_VSDB_OUI_OFFSET] |
(static_cast<uint32_t>(edid[pos + HDMI_VSDB_OUI_OFFSET + 1]) << 8) |
(static_cast<uint32_t>(edid[pos + HDMI_VSDB_OUI_OFFSET + 2]) << 16);
if (oui == HDMI_OUI) {
uint8_t flags = edid[pos + HDMI_VSDB_FLAGS_OFFSET];
WLOGFI("Edid vsdb flag: 0x%{public}x, pos: 0x%{public}zx", flags, pos + HDMI_VSDB_FLAGS_OFFSET);
bpc = ExtractBpcFromFlags(flags);
return true;
}
return false;
}
bool ParseCeaDataBlocks(const std::vector<uint8_t>& edid, size_t base, uint8_t dtdStart, uint8_t& bpc)
{
size_t pos = base + CEA_DATA_BLOCK_START_OFFSET;
while (pos < base + dtdStart) {
uint8_t tag = (edid[pos] >> DATA_BLOCK_TAG_SHIFT) & DATA_BLOCK_TAG_MASK;
uint8_t len = edid[pos] & DATA_BLOCK_LEN_MASK;
if (tag == VENDOR_SPECIFIC_TAG &&
(pos + HDMI_VSDB_FLAGS_OFFSET) < edid.size() &&
TryParseHdmiVsdb(edid, pos, len, bpc)) {
return true;
}
pos += 1 + len;
}
return false;
}
bool ParseCeaExtensionBlock(const std::vector<uint8_t>& edid, size_t base, uint8_t& bpc)
{
if (edid[base + CEA_BLOCK_TAG_OFFSET] != CEA_TAG) {
return false;
}
uint8_t dtdStart = edid[base + CEA_DTD_START_OFFSET];
if (dtdStart < CEA_DATA_BLOCK_START_OFFSET || dtdStart >= EDID_BLOCK_SIZE) {
return false;
}
return ParseCeaDataBlocks(edid, base, dtdStart, bpc);
}
void ParseBpcFromCEABlock(const std::vector<uint8_t>& edid, const uint32_t edidSize, uint8_t& bpc)
{
bpc = BPC_8bit; // default
if (edid.size() < EDID_BLOCK_SIZE || edidSize < EDID_BLOCK_SIZE) {
return;
}
uint8_t numExt = edid[EDID_NUM_EXT_OFFSET];
size_t totalSize = EDID_BLOCK_SIZE + static_cast<size_t>(numExt) * EDID_BLOCK_SIZE;
if (numExt == 0 || edidSize < totalSize || edid.size() < totalSize) {
return;
}
for (uint8_t ext = 0; ext < numExt; ++ext) {
size_t base = EDID_BLOCK_SIZE + ext * EDID_BLOCK_SIZE;
if (ParseCeaExtensionBlock(edid, base, bpc)) {
return;
}
}
}
void ParseBpc(const std::vector<uint8_t>& edid, const uint32_t edidSize, uint8_t& bpc)
{
constexpr size_t videoInputDefinitionOffset = EDID_VIDEO_INPUT_DEFINITION_OFFSET;
if ((edid[videoInputDefinitionOffset] & VIDEO_INPUT_DIGITAL_FLAG_MASK) &&
(edid[EDID_MINOR_OFFSET] >= BASE_MINOR)) {
uint8_t colorBitDepth = edid[videoInputDefinitionOffset] & COLOR_BIT_DEPTH_FIELD_MASK;
if (!(colorBitDepth == COLOR_DEPTH_ENCODING_UNDEFINED || colorBitDepth == COLOR_DEPTH_ENCODING_RESERVED)) {
bpc = ((colorBitDepth >> COLOR_DEPTH_BPC_CALC_SHIFT) + COLOR_DEPTH_BPC_BASE_OFFSET);
}
} else if (edid[EDID_MINOR_OFFSET] == EDID_VERSION_1_3) {
ParseBpcFromCEABlock(edid, edidSize, bpc);
}
}
extern "C" {
int ParseBaseEdid(const uint8_t* edidData, const uint32_t edidSize, struct baseEdid* outEdid)
{
if (!CheckParamsValid(edidData, edidSize, outEdid)) {
return -1;
}
std::vector<uint8_t> edid(edidData, edidData + edidSize);
if (!CheckEdidValid(edid)) {
return -1;
}
uint32_t vendorDataSum = 0;
for (uint32_t i = EDID_VENDOR_START; i <= EDID_VENDOR_END; i++) {
vendorDataSum += edid[i];
}
WLOGFW("parseBaseEdid vendorDataSum is %{public}u", vendorDataSum);
// get the edid version
outEdid->edid_minor = edid[EDID_MINOR_OFFSET];
// get the manufacturer name
constexpr size_t manufacturerNameOffset = 0x8;
outEdid->manufacturerName =
GetManufacturerNameFromNum(static_cast<uint16_t>((edid[manufacturerNameOffset] << ONE_NUMBER_OF_BYTES) |
edid[manufacturerNameOffset + 1]));
// get the product code
constexpr size_t productIdOffset = 0xa;
outEdid->productCode = static_cast<uint16_t>(edid[productIdOffset] |
(edid[productIdOffset + 1] << ONE_NUMBER_OF_BYTES));
//get the serial number
constexpr size_t serialNumberOffset = 0xc;
outEdid->serialNumber = static_cast<uint32_t>(edid[serialNumberOffset] |
(edid[serialNumberOffset + 1] << ONE_NUMBER_OF_BYTES) |
(edid[serialNumberOffset + SN_SECOND_NUM] << TWO_NUMBER_OF_BYTES) |
(edid[serialNumberOffset + SN_THIRD_NUM] << THREE_NUMBER_OF_BYTES));
// get the manufacture week and year
outEdid->weekOfManufactureOrModelYearFlag = edid[MANUFACTURE_WEEK_OFFSET];
outEdid->yearOfManufactureOrModelYear = edid[MANUFACTURE_YEAR_OFFSET] + BASE_YEAR;
// get the bpc
uint8_t bpc = 0;
ParseBpc(edid, edidSize, bpc);
outEdid->bitsPerPrimaryColor = bpc;
// get the screen size
constexpr size_t HorizontalSceenSizeOffset = 0x15;
constexpr size_t VerticalSceenSizeOffset = 0x16;
if (edid[HorizontalSceenSizeOffset] != 0 && edid[VerticalSceenSizeOffset] != 0) {
outEdid->hScreenSize = edid[HorizontalSceenSizeOffset];
outEdid->vScreenSize = edid[VerticalSceenSizeOffset];
}
// get the detailed timing
ParseDetailedTiming(edid, outEdid);
WLOGFW("parseBaseEdid edid_minor is %{public}u, ScreenSize is %{public}u cm * %{public}u cm, bpc is %{public}u",
outEdid->edid_minor, outEdid->hScreenSize, outEdid->vScreenSize, outEdid->bitsPerPrimaryColor);
return 0;
}
}