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#include "common/edidHelper.h"
void ffEdidGetPhysicalResolution(const uint8_t edid[128], uint32_t* width, uint32_t* height) {
const int dtd = 54;
*width = (((uint32_t) edid[dtd + 4] >> 4) << 8) | edid[dtd + 2];
*height = (((uint32_t) edid[dtd + 7] >> 4) << 8) | edid[dtd + 5];
}
void ffEdidGetPreferredResolutionAndRefreshRate(const uint8_t edid[128], uint32_t* width, uint32_t* height, double* refreshRate) {
for (uint32_t i = 0x36; i < 0x7E; i += 0x12) { // read through descriptor blocks...
if (edid[i] != 0x00 && edid[i + 1] != 0x00) { // a dtd
uint32_t hactive = edid[i + 2] + (uint32_t) ((edid[i + 4] & 0xf0) << 4);
uint32_t hblank = edid[i + 3] + (uint32_t) ((edid[i + 4] & 0x0f) << 8);
uint32_t vactive = edid[i + 5] + (uint32_t) ((edid[i + 7] & 0xf0) << 4);
uint32_t vblank = edid[i + 6] + (uint32_t) ((edid[i + 7] & 0x0f) << 8);
uint32_t pixclk = ((uint32_t) edid[i + 1] << 8) | (edid[i]);
*width = hactive;
*height = vactive;
*refreshRate = (double) pixclk * 10000 / (double) (hactive + hblank) / (double) (vactive + vblank);
return;
}
}
}
void ffEdidGetVendorAndModel(const uint8_t edid[128], FFstrbuf* result) {
// https://github.com/jinksong/read_edid/blob/master/parse-edid/parse-edid.c
ffStrbufAppendF(result, "%c%c%c%04X", (char) (((uint32_t) edid[8] >> 2 & 0x1f) + 'A' - 1), (char) (((((uint32_t) edid[8] & 0x3) << 3) | (((uint32_t) edid[9] & 0xe0) >> 5)) + 'A' - 1), (char) (((uint32_t) edid[9] & 0x1f) + 'A' - 1), (uint32_t) (edid[10] + (uint32_t) (edid[11] << 8)));
}
bool ffEdidGetName(const uint8_t edid[128], FFstrbuf* name) {
// https://github.com/jinksong/read_edid/blob/master/parse-edid/parse-edid.c
for (uint32_t i = 0x36; i < 0x7E; i += 0x12) { // read through descriptor blocks...
if (edid[i] == 0x00) { // not a timing descriptor
if (edid[i + 3] == 0xfc) { // Model Name tag
for (uint32_t j = 0; j < 13; j++) {
if (edid[i + 5 + j] == 0x0a) {
ffStrbufAppendNS(name, j, (const char*) &edid[i + 5]);
return true;
}
}
}
}
}
// use manufacturer + model number as monitor name
ffEdidGetVendorAndModel(edid, name);
return false;
}
void ffEdidGetPhysicalSize(const uint8_t edid[128], uint32_t* width, uint32_t* height) {
// Detailed Timing Descriptors
uint32_t dw = (((uint32_t) edid[68] & 0xF0) << 4) + edid[66];
uint32_t dh = (((uint32_t) edid[68] & 0x0F) << 8) + edid[67];
// Basic Display Parameters
uint32_t bw = edid[21] * 10;
uint32_t bh = edid[22] * 10;
// Some monitors report invalid data in DTD. See #1406
if (abs((int) dw - (int) bw) < 10 && abs((int) dh - (int) bh) < 10) {
*width = dw;
*height = dh;
} else {
*width = bw;
*height = bh;
}
}
void ffEdidGetSerialAndManufactureDate(const uint8_t edid[128], uint32_t* serial, uint16_t* year, uint16_t* week) {
if (edid[17] > 0 && edid[17] < 0xFF) {
*year = (uint16_t) (edid[17] + 1990);
*week = (uint16_t) edid[16];
if (*week == 0xFF) {
*week = 0;
}
} else {
*year = *week = 0;
}
*serial = *(uint32_t*) &edid[12];
}
bool ffEdidGetHdrCompatible(const uint8_t* edid, uint32_t length) {
if (length <= 128) {
return false;
}
for (const uint8_t* cta = &edid[128]; cta < &edid[length]; cta += 128) {
// https://en.wikipedia.org/wiki/Extended_Display_Identification_Data#CTA_EDID_Timing_Extension_Block
if (cta[0] != 0x02 /* CTA EDID */) {
continue;
}
if (cta[1] < 0x03 /* Version 3 */) {
continue;
}
const uint8_t offset = cta[2];
if (offset <= 4) {
continue;
}
for (uint8_t i = 4; i < offset;) {
uint8_t blkLen = cta[i] & 0x1f;
if (blkLen > 0) {
uint8_t blkTag = (cta[i] & 0xe0) >> 5;
if (blkTag == 0x07 /* Extended Block Type Tag */) {
uint8_t extendedTag = cta[i + 1];
if (extendedTag == 6 /* HDR SMDB */ || extendedTag == 7 /* HDR DMDB */) {
return true;
}
}
}
i += (uint8_t) (blkLen + 1);
}
}
return false;
}
bool ffEdidIsValid(const uint8_t edid[128], uint32_t length) {
if (length < 128 || length % 128 != 0) {
return false;
}
static const uint8_t edidHeader[] = { 0x00, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x00 };
if (memcmp(edid, edidHeader, sizeof(edidHeader)) != 0) {
return false;
}
uint8_t sum = 0;
for (uint32_t i = 0; i < 128; i++) {
sum += edid[i];
}
return sum == 0;
}
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