/* SPDX-License-Identifier: LGPL-2.1-or-later */ /* * Copyright (C) 2020, Google Inc. * * exif.cpp - EXIF tag creation using libexif */ #include "exif.h" #include <cmath> #include <iomanip> #include <map> #include <sstream> #include <tuple> #include <uchar.h> #include <libcamera/base/log.h> #include <libcamera/base/utils.h> using namespace libcamera; LOG_DEFINE_CATEGORY(EXIF) /* * List of EXIF tags that we set directly because they are not supported * by libexif version 0.6.21. */ enum class _ExifTag { OFFSET_TIME = 0x9010, OFFSET_TIME_ORIGINAL = 0x9011, OFFSET_TIME_DIGITIZED = 0x9012, }; /* * The Exif class should be instantiated and specific properties set * through the exposed public API. * * Once all desired properties have been set, the user shall call * generate() to process the entries and generate the Exif data. * * Calls to generate() must check the return code to determine if any error * occurred during the construction of the Exif data, and if successful the * data can be obtained using the data() function. */ Exif::Exif() : valid_(false), data_(nullptr), order_(EXIF_BYTE_ORDER_INTEL), exifData_(0), size_(0) { /* Create an ExifMem allocator to construct entries. */ mem_ = exif_mem_new_default(); if (!mem_) { LOG(EXIF, Error) << "Failed to allocate ExifMem Allocator"; return; } data_ = exif_data_new_mem(mem_); if (!data_) { LOG(EXIF, Error) << "Failed to allocate an ExifData structure"; return; } valid_ = true; exif_data_set_option(data_, EXIF_DATA_OPTION_FOLLOW_SPECIFICATION); exif_data_set_data_type(data_, EXIF_DATA_TYPE_COMPRESSED); /* * Big-Endian: EXIF_BYTE_ORDER_MOTOROLA * Little Endian: EXIF_BYTE_ORDER_INTEL */ exif_data_set_byte_order(data_, order_); setString(EXIF_IFD_EXIF, EXIF_TAG_EXIF_VERSION, EXIF_FORMAT_UNDEFINED, "0231"); /* Create the mandatory EXIF fields with default data. */ exif_data_fix(data_); } Exif::~Exif() { if (exifData_) free(exifData_); if (data_) { /* * Reset thumbnail data to avoid getting double-freed by * libexif. It is owned by the caller (i.e. PostProcessorJpeg). */ data_->data = nullptr; data_->size = 0; exif_data_unref(data_); } if (mem_) exif_mem_unref(mem_); } ExifEntry *Exif::createEntry(ExifIfd ifd, ExifTag tag) { ExifContent *content = data_->ifd[ifd]; ExifEntry *entry = exif_content_get_entry(content, tag); if (entry) { exif_entry_ref(entry); return entry; } entry = exif_entry_new_mem(mem_); if (!entry) { LOG(EXIF, Error) << "Failed to allocated new entry"; valid_ = false; return nullptr; } exif_content_add_entry(content, entry); exif_entry_initialize(entry, tag); return entry; } ExifEntry *Exif::createEntry(ExifIfd ifd, ExifTag tag, ExifFormat format, unsigned long components, unsigned int size) { ExifContent *content = data_->ifd[ifd]; /* Replace any existing entry with the same tag. */ ExifEntry *existing = exif_content_get_entry(content, tag); exif_content_remove_entry(content, existing); ExifEntry *entry = exif_entry_new_mem(mem_); if (!entry) { LOG(EXIF, Error) << "Failed to allocated new entry"; valid_ = false; return nullptr; } void *buffer = exif_mem_alloc(mem_, size); if (!buffer) { LOG(EXIF, Error) << "Failed to allocate buffer for variable entry"; exif_mem_unref(mem_); valid_ = false; return nullptr; } entry->data = static_cast<unsigned char *>(buffer); entry->components = components; entry->format = format; entry->size = size; entry->tag = tag; exif_content_add_entry(content, entry); return entry; } void Exif::setByte(ExifIfd ifd, ExifTag tag, uint8_t item) { ExifEntry *entry = createEntry(ifd, tag, EXIF_FORMAT_BYTE, 1, 1); if (!entry) return; entry->data[0] = item; exif_entry_unref(entry); } void Exif::setShort(ExifIfd ifd, ExifTag tag, uint16_t item) { ExifEntry *entry = createEntry(ifd, tag); if (!entry) return; exif_set_short(entry->data, order_, item); exif_entry_unref(entry); } void Exif::setLong(ExifIfd ifd, ExifTag tag, uint32_t item) { ExifEntry *entry = createEntry(ifd, tag); if (!entry) return; exif_set_long(entry->data, order_, item); exif_entry_unref(entry); } void Exif::setRational(ExifIfd ifd, ExifTag tag, ExifRational item) { setRational(ifd, tag, { &item, 1 }); } void Exif::setRational(ExifIfd ifd, ExifTag tag, Span<const ExifRational> items) { ExifEntry *entry = createEntry(ifd, tag, EXIF_FORMAT_RATIONAL, items.size(), items.size() * sizeof(ExifRational)); if (!entry) return; for (size_t i = 0; i < items.size(); i++) exif_set_rational(entry->data + i * sizeof(ExifRational), order_, items[i]); exif_entry_unref(entry); } static const std::map<Exif::StringEncoding, std::array<uint8_t, 8>> stringEncodingCodes = { { Exif::ASCII, { 0x41, 0x53, 0x43, 0x49, 0x49, 0x00, 0x00, 0x00 } }, { Exif::Unicode, { 0x55, 0x4e, 0x49, 0x43, 0x4f, 0x44, 0x45, 0x00 } }, }; void Exif::setString(ExifIfd ifd, ExifTag tag, ExifFormat format, const std::string &item, StringEncoding encoding) { std::string ascii; size_t length; const char *str; std::vector<uint8_t> buf; if (format == EXIF_FORMAT_ASCII) { ascii = utils::toAscii(item); str = ascii.c_str(); /* Pad 1 extra byte to null-terminate the ASCII string. */ length = ascii.length() + 1; } else { std::u16string u16str; auto encodingString = stringEncodingCodes.find(encoding); if (encodingString != stringEncodingCodes.end()) { buf = { encodingString->second.begin(), encodingString->second.end() }; } switch (encoding) { case Unicode: u16str = utf8ToUtf16(item); buf.resize(8 + u16str.size() * 2); for (size_t i = 0; i < u16str.size(); i++) { if (order_ == EXIF_BYTE_ORDER_INTEL) { buf[8 + 2 * i] = u16str[i] & 0xff; buf[8 + 2 * i + 1] = (u16str[i] >> 8) & 0xff; } else { buf[8 + 2 * i] = (u16str[i] >> 8) & 0xff; buf[8 + 2 * i + 1] = u16str[i] & 0xff; } } break; case ASCII: case NoEncoding: buf.insert(buf.end(), item.begin(), item.end()); break; } str = reinterpret_cast<const char *>(buf.data()); /* * Strings stored in different formats (EXIF_FORMAT_UNDEFINED) * are not null-terminated. */ length = buf.size(); } ExifEntry *entry = createEntry(ifd, tag, format, length, length); if (!entry) return; memcpy(entry->data, str, length); exif_entry_unref(entry); } void Exif::setMake(const std::string &make) { setString(EXIF_IFD_0, EXIF_TAG_MAKE, EXIF_FORMAT_ASCII, make); } void Exif::setModel(const std::string &model) { setString(EXIF_IFD_0, EXIF_TAG_MODEL, EXIF_FORMAT_ASCII, model); } void Exif::setSize(const Size &size) { setLong(EXIF_IFD_EXIF, EXIF_TAG_PIXEL_Y_DIMENSION, size.height); setLong(EXIF_IFD_EXIF, EXIF_TAG_PIXEL_X_DIMENSION, size.width); } void Exif::setTimestamp(time_t timestamp, std::chrono::milliseconds msec) { struct tm tm; localtime_r(×tamp, &tm); char str[20]; strftime(str, sizeof(str), "%Y:%m:%d %H:%M:%S", &tm); std::string ts(str); setString(EXIF_IFD_0, EXIF_TAG_DATE_TIME, EXIF_FORMAT_ASCII, ts); setString(EXIF_IFD_EXIF, EXIF_TAG_DATE_TIME_ORIGINAL, EXIF_FORMAT_ASCII, ts); setString(EXIF_IFD_EXIF, EXIF_TAG_DATE_TIME_DIGITIZED, EXIF_FORMAT_ASCII, ts); /* Query and set timezone information if available. */ int r = strftime(str, sizeof(str), "%z", &tm); if (r <= 0) return; std::string tz(str); tz.insert(3, 1, ':'); setString(EXIF_IFD_EXIF, static_cast<ExifTag>(_ExifTag::OFFSET_TIME), EXIF_FORMAT_ASCII, tz); setString(EXIF_IFD_EXIF, static_cast<ExifTag>(_ExifTag::OFFSET_TIME_ORIGINAL), EXIF_FORMAT_ASCII, tz); setString(EXIF_IFD_EXIF, static_cast<ExifTag>(_ExifTag::OFFSET_TIME_DIGITIZED), EXIF_FORMAT_ASCII, tz); std::stringstream sstr; sstr << std::setfill('0') << std::setw(3) << msec.count(); std::string subsec = sstr.str(); setString(EXIF_IFD_EXIF, EXIF_TAG_SUB_SEC_TIME, EXIF_FORMAT_ASCII, subsec); setString(EXIF_IFD_EXIF, EXIF_TAG_SUB_SEC_TIME_ORIGINAL, EXIF_FORMAT_ASCII, subsec); setString(EXIF_IFD_EXIF, EXIF_TAG_SUB_SEC_TIME_DIGITIZED, EXIF_FORMAT_ASCII, subsec); } void Exif::setGPSDateTimestamp(time_t timestamp) { struct tm tm; gmtime_r(×tamp, &tm); char str[11]; strftime(str, sizeof(str), "%Y:%m:%d", &tm); std::string tsStr(str); setString(EXIF_IFD_GPS, static_cast<ExifTag>(EXIF_TAG_GPS_DATE_STAMP), EXIF_FORMAT_ASCII, tsStr); /* Set GPS_TIME_STAMP */ ExifRational ts[] = { { static_cast<ExifLong>(tm.tm_hour), 1 }, { static_cast<ExifLong>(tm.tm_min), 1 }, { static_cast<ExifLong>(tm.tm_sec), 1 }, }; setRational(EXIF_IFD_GPS, static_cast<ExifTag>(EXIF_TAG_GPS_TIME_STAMP), ts); } std::tuple<int, int, int> Exif::degreesToDMS(double decimalDegrees) { int degrees = std::trunc(decimalDegrees); double minutes = std::abs((decimalDegrees - degrees) * 60); double seconds = (minutes - std::trunc(minutes)) * 60; return { degrees, std::trunc(minutes), std::round(seconds) }; } void Exif::setGPSDMS(ExifIfd ifd, ExifTag tag, int deg, int min, int sec) { ExifRational coords[] = { { static_cast<ExifLong>(deg), 1 }, { static_cast<ExifLong>(min), 1 }, { static_cast<ExifLong>(sec), 1 }, }; setRational(ifd, tag, coords); } /* * \brief Set GPS location (lat, long, alt) * \param[in] coords Pointer to coordinates latitude, longitude, and altitude, * first two in degrees, the third in meters */ void Exif::setGPSLocation(const double *coords) { int deg, min, sec; std::tie<int, int, int>(deg, min, sec) = degreesToDMS(coords[0]); setString(EXIF_IFD_GPS, static_cast<ExifTag>(EXIF_TAG_GPS_LATITUDE_REF), EXIF_FORMAT_ASCII, deg >= 0 ? "N" : "S"); setGPSDMS(EXIF_IFD_GPS, static_cast<ExifTag>(EXIF_TAG_GPS_LATITUDE), std::abs(deg), min, sec); std::tie<int, int, int>(deg, min, sec) = degreesToDMS(coords[1]); setString(EXIF_IFD_GPS, static_cast<ExifTag>(EXIF_TAG_GPS_LONGITUDE_REF), EXIF_FORMAT_ASCII, deg >= 0 ? "E" : "W"); setGPSDMS(EXIF_IFD_GPS, static_cast<ExifTag>(EXIF_TAG_GPS_LONGITUDE), std::abs(deg), min, sec); setByte(EXIF_IFD_GPS, static_cast<ExifTag>(EXIF_TAG_GPS_ALTITUDE_REF), coords[2] >= 0 ? 0 : 1); setRational(EXIF_IFD_GPS, static_cast<ExifTag>(EXIF_TAG_GPS_ALTITUDE), ExifRational{ static_cast<ExifLong>(std::abs(coords[2])), 1 }); } void Exif::setGPSMethod(const std::string &method) { setString(EXIF_IFD_GPS, static_cast<ExifTag>(EXIF_TAG_GPS_PROCESSING_METHOD), EXIF_FORMAT_UNDEFINED, method, NoEncoding); } void Exif::setOrientation(int orientation) { int value; switch (orientation) { case 0: default: value = 1; break; case 90: value = 6; break; case 180: value = 3; break; case 270: value = 8; break; } setShort(EXIF_IFD_0, EXIF_TAG_ORIENTATION, value); } /* * The thumbnail data should remain valid until the Exif object is destroyed. * Failing to do so, might result in no thumbnail data being set even after a * call to Exif::setThumbnail(). */ void Exif::setThumbnail(Span<const unsigned char> thumbnail, Compression compression) { data_->data = const_cast<unsigned char *>(thumbnail.data()); data_->size = thumbnail.size(); setShort(EXIF_IFD_0, EXIF_TAG_COMPRESSION, compression); } void Exif::setFocalLength(float length) { ExifRational rational = { static_cast<ExifLong>(length * 1000), 1000 }; setRational(EXIF_IFD_EXIF, EXIF_TAG_FOCAL_LENGTH, rational); } void Exif::setExposureTime(uint64_t nsec) { ExifRational rational = { static_cast<ExifLong>(nsec), 1000000000 }; setRational(EXIF_IFD_EXIF, EXIF_TAG_EXPOSURE_TIME, rational); } void Exif::setAperture(float size) { ExifRational rational = { static_cast<ExifLong>(size * 10000), 10000 }; setRational(EXIF_IFD_EXIF, EXIF_TAG_FNUMBER, rational); } void Exif::setISO(uint16_t iso) { setShort(EXIF_IFD_EXIF, EXIF_TAG_ISO_SPEED_RATINGS, iso); } void Exif::setFlash(Flash flash) { setShort(EXIF_IFD_EXIF, EXIF_TAG_FLASH, static_cast<ExifShort>(flash)); } void Exif::setWhiteBalance(WhiteBalance wb) { setShort(EXIF_IFD_EXIF, EXIF_TAG_WHITE_BALANCE, static_cast<ExifShort>(wb)); } /** * \brief Convert UTF-8 string to UTF-16 string * \param[in] str String to convert * * \return \a str in UTF-16 */ std::u16string Exif::utf8ToUtf16(const std::string &str) { mbstate_t state{}; char16_t c16; const char *ptr = str.data(); const char *end = ptr + str.size(); std::u16string ret; while (size_t rc = mbrtoc16(&c16, ptr, end - ptr + 1, &state)) { if (rc == static_cast<size_t>(-2) || rc == static_cast<size_t>(-1)) break; ret.push_back(c16); if (rc > 0) ptr += rc; } return ret; } [[nodiscard]] int Exif::generate() { if (exifData_) { free(exifData_); exifData_ = nullptr; } if (!valid_) { LOG(EXIF, Error) << "Generated EXIF data is invalid"; return -1; } exif_data_save_data(data_, &exifData_, &size_); LOG(EXIF, Debug) << "Created EXIF instance (" << size_ << " bytes)"; return 0; }