diff options
Diffstat (limited to 'src/android/jpeg')
| -rw-r--r-- | src/android/jpeg/exif.cpp | 188 | ||||
| -rw-r--r-- | src/android/jpeg/exif.h | 46 |
2 files changed, 234 insertions, 0 deletions
diff --git a/src/android/jpeg/exif.cpp b/src/android/jpeg/exif.cpp new file mode 100644 index 00000000..0e2d364d --- /dev/null +++ b/src/android/jpeg/exif.cpp @@ -0,0 +1,188 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* + * Copyright (C) 2020, Google Inc. + * + * exif.cpp - EXIF tag creation using libexif + */ + +#include "exif.h" + +#include "libcamera/internal/log.h" + +using namespace libcamera; + +LOG_DEFINE_CATEGORY(EXIF) + +/* + * 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() method. + */ +Exif::Exif() + : valid_(false), data_(nullptr), 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_, EXIF_BYTE_ORDER_INTEL); + + /* Create the mandatory EXIF fields with default data. */ + exif_data_fix(data_); +} + +Exif::~Exif() +{ + if (exifData_) + free(exifData_); + + if (data_) + 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::setShort(ExifIfd ifd, ExifTag tag, uint16_t item) +{ + ExifEntry *entry = createEntry(ifd, tag); + if (!entry) + return; + + exif_set_short(entry->data, EXIF_BYTE_ORDER_INTEL, 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, EXIF_BYTE_ORDER_INTEL, item); + exif_entry_unref(entry); +} + +void Exif::setRational(ExifIfd ifd, ExifTag tag, ExifRational item) +{ + ExifEntry *entry = createEntry(ifd, tag); + if (!entry) + return; + + exif_set_rational(entry->data, EXIF_BYTE_ORDER_INTEL, item); + exif_entry_unref(entry); +} + +void Exif::setString(ExifIfd ifd, ExifTag tag, ExifFormat format, const std::string &item) +{ + /* Pad 1 extra byte for null-terminated string. */ + size_t length = item.length() + 1; + + ExifEntry *entry = createEntry(ifd, tag, format, length, length); + if (!entry) + return; + + memcpy(entry->data, item.c_str(), length); + exif_entry_unref(entry); +} + +[[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; +} diff --git a/src/android/jpeg/exif.h b/src/android/jpeg/exif.h new file mode 100644 index 00000000..8dfc3245 --- /dev/null +++ b/src/android/jpeg/exif.h @@ -0,0 +1,46 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* + * Copyright (C) 2020, Google Inc. + * + * exif.h - EXIF tag creator using libexif + */ +#ifndef __ANDROID_JPEG_EXIF_H__ +#define __ANDROID_JPEG_EXIF_H__ + +#include <ctime> +#include <string> + +#include <libexif/exif-data.h> + +#include <libcamera/span.h> + +class Exif +{ +public: + Exif(); + ~Exif(); + + libcamera::Span<const uint8_t> data() const { return { exifData_, size_ }; } + [[nodiscard]] int generate(); + +private: + ExifEntry *createEntry(ExifIfd ifd, ExifTag tag); + ExifEntry *createEntry(ExifIfd ifd, ExifTag tag, ExifFormat format, + unsigned long components, unsigned int size); + + void setShort(ExifIfd ifd, ExifTag tag, uint16_t item); + void setLong(ExifIfd ifd, ExifTag tag, uint32_t item); + void setString(ExifIfd ifd, ExifTag tag, ExifFormat format, + const std::string &item); + void setRational(ExifIfd ifd, ExifTag tag, ExifRational item); + + bool valid_; + + ExifData *data_; + ExifMem *mem_; + + unsigned char *exifData_; + unsigned int size_; +}; + +#endif /* __ANDROID_JPEG_EXIF_H__ */ |