/*
* Copyright (C) 2016 The Android Open Source Project
*
* 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.
*/
#define LOG_NDEBUG 0
#define LOG_TAG "EmulatedCamera_Exif"
#include <cutils/log.h>
#include <inttypes.h>
#include <math.h>
#include <stdint.h>
#include "guest/libs/platform_support/api_level_fixes.h"
#if VSOC_PLATFORM_SDK_BEFORE(O_MR1)
#include <camera/CameraParameters.h>
#else
#include <CameraParameters.h>
using ::android::hardware::camera::common::V1_0::helper::CameraParameters;
using ::android::hardware::camera::common::V1_0::helper::Size;
#endif
#include "Exif.h"
#include <libexif/exif-data.h>
#include <libexif/exif-entry.h>
#include <libexif/exif-ifd.h>
#include <libexif/exif-tag.h>
#include <string>
#include <vector>
// For GPS timestamping we want to ensure we use a 64-bit time_t, 32-bit
// platforms have time64_t but 64-bit platforms do not.
#if defined(__LP64__)
#include <time.h>
using Timestamp = time_t;
#define TIMESTAMP_TO_TM(timestamp, tm) gmtime_r(timestamp, tm)
#else
#include <time64.h>
using Timestamp = time64_t;
#define TIMESTAMP_TO_TM(timestamp, tm) gmtime64_r(timestamp, tm)
#endif
namespace android {
// A prefix that is used for tags with the "undefined" format to indicate that
// the contents are ASCII encoded. See the user comment section of the EXIF spec
// for more details http://www.exif.org/Exif2-2.PDF
static const unsigned char kAsciiPrefix[] = {
0x41, 0x53, 0x43, 0x49, 0x49, 0x00, 0x00, 0x00 // "ASCII\0\0\0"
};
// Remove an existing EXIF entry from |exifData| if it exists. This is useful
// when replacing existing data, it's easier to just remove the data and
// re-allocate it than to adjust the amount of allocated data.
static void removeExistingEntry(ExifData* exifData, ExifIfd ifd, int tag) {
ExifEntry* entry = exif_content_get_entry(exifData->ifd[ifd],
static_cast<ExifTag>(tag));
if (entry) {
exif_content_remove_entry(exifData->ifd[ifd], entry);
}
}
static ExifEntry* allocateEntry(int tag,
ExifFormat format,
unsigned int numComponents) {
ExifMem* mem = exif_mem_new_default();
ExifEntry* entry = exif_entry_new_mem(mem);
unsigned int size = numComponents * exif_format_get_size(format);
entry->data = reinterpret_cast<unsigned char*>(exif_mem_alloc(mem, size));
entry->size = size;
entry->tag = static_cast<ExifTag>(tag);
entry->components = numComponents;
entry->format = format;
exif_mem_unref(mem);
return entry;
}
// Create an entry and place it in |exifData|, the entry is initialized with an
// array of floats from |values|
template<size_t N>
static bool createEntry(ExifData* exifData,
ExifIfd ifd,
int tag,
const float (&values)[N],
float denominator = 1000.0) {
removeExistingEntry(exifData, ifd, tag);
ExifByteOrder byteOrder = exif_data_get_byte_order(exifData);
ExifEntry* entry = allocateEntry(tag, EXIF_FORMAT_RATIONAL, N);
exif_content_add_entry(exifData->ifd[ifd], entry);
unsigned int rationalSize = exif_format_get_size(EXIF_FORMAT_RATIONAL);
for (size_t i = 0; i < N; ++i) {
ExifRational rational = {
static_cast<uint32_t>(values[i] * denominator),
static_cast<uint32_t>(denominator)
};
exif_set_rational(&entry->data[i * rationalSize], byteOrder, rational);
}
// Unref entry after changing owner to the ExifData struct
exif_entry_unref(entry);
return true;
}
// Create an entry with a single float |value| in it and place it in |exifData|
static bool createEntry(ExifData* exifData,
ExifIfd ifd,
int tag,
const float value,
float denominator = 1000.0) {
float values[1] = { value };
// Recycling functions is good for the environment
return createEntry(exifData, ifd, tag, values, denominator);
}
// Create an entry and place it in |exifData|, the entry contains the raw data
// pointed to by |data| of length |size|.
static bool createEntry(ExifData* exifData,
ExifIfd ifd,
int tag,
const unsigned char* data,
size_t size,
ExifFormat format = EXIF_FORMAT_UNDEFINED) {
removeExistingEntry(exifData, ifd, tag);
ExifEntry* entry = allocateEntry(tag, format, size);
memcpy(entry->data, data, size);
exif_content_add_entry(exifData->ifd[ifd], entry);
// Unref entry after changing owner to the ExifData struct
exif_entry_unref(entry);
return true;
}
// Create an entry and place it in |exifData|, the entry is initialized with
// the string provided in |value|
static bool createEntry(ExifData* exifData,
ExifIfd ifd,
int tag,
const char* value) {
unsigned int length = strlen(value) + 1;
const unsigned char* data = reinterpret_cast<const unsigned char*>(value);
return createEntry(exifData, ifd, tag, data, length, EXIF_FORMAT_ASCII);
}
// Create an entry and place it in |exifData|, the entry is initialized with a
// single byte in |value|
static bool createEntry(ExifData* exifData,
ExifIfd ifd,
int tag,
uint8_t value) {
return createEntry(exifData, ifd, tag, &value, 1, EXIF_FORMAT_BYTE);
}
// Create an entry and place it in |exifData|, the entry is default initialized
// by the exif library based on |tag|
static bool createEntry(ExifData* exifData,
ExifIfd ifd,
int tag) {
removeExistingEntry(exifData, ifd, tag);
ExifEntry* entry = exif_entry_new();
exif_content_add_entry(exifData->ifd[ifd], entry);
exif_entry_initialize(entry, static_cast<ExifTag>(tag));
// Unref entry after changing owner to the ExifData struct
exif_entry_unref(entry);
return true;
}
// Create an entry with a single EXIF LONG (32-bit value) and place it in
// |exifData|.
static bool createEntry(ExifData* exifData,
ExifIfd ifd,
int tag,
int value) {
removeExistingEntry(exifData, ifd, tag);
ExifByteOrder byteOrder = exif_data_get_byte_order(exifData);
ExifEntry* entry = allocateEntry(tag, EXIF_FORMAT_LONG, 1);
exif_content_add_entry(exifData->ifd[ifd], entry);
exif_set_long(entry->data, byteOrder, value);
// Unref entry after changing owner to the ExifData struct
exif_entry_unref(entry);
return true;
}
static bool getCameraParam(const CameraParameters& parameters,
const char* parameterKey,
const char** outValue) {
const char* value = parameters.get(parameterKey);
if (value) {
*outValue = value;
return true;
}
return false;
}
static bool getCameraParam(const CameraParameters& parameters,
const char* parameterKey,
float* outValue) {
const char* value = parameters.get(parameterKey);
if (value) {
*outValue = parameters.getFloat(parameterKey);
return true;
}
return false;
}
static bool getCameraParam(const CameraParameters& parameters,
const char* parameterKey,
int64_t* outValue) {
const char* value = parameters.get(parameterKey);
if (value) {
char dummy = 0;
// Attempt to scan an extra character and then make sure it was not
// scanned by checking that the return value indicates only one item.
// This way we fail on any trailing characters
if (sscanf(value, "%" SCNd64 "%c", outValue, &dummy) == 1) {
return true;
}
}
return false;
}
// Convert a GPS coordinate represented as a decimal degree value to sexagesimal
// GPS coordinates comprised of <degrees> <minutes>' <seconds>"
static void convertGpsCoordinate(float degrees, float (*result)[3]) {
float absDegrees = fabs(degrees);
// First value is degrees without any decimal digits
(*result)[0] = floor(absDegrees);
// Subtract degrees so we only have the fraction left, then multiply by
// 60 to get the minutes
float minutes = (absDegrees - (*result)[0]) * 60.0f;
(*result)[1] = floor(minutes);
// Same thing for seconds but here we store seconds with the fraction
float seconds = (minutes - (*result)[1]) * 60.0f;
(*result)[2] = seconds;
}
// Convert a UNIX epoch timestamp to a timestamp comprised of three floats for
// hour, minute and second, and a date part that is represented as a string.
static bool convertTimestampToTimeAndDate(int64_t timestamp,
float (*timeValues)[3],
std::string* date) {
Timestamp time = timestamp;
struct tm utcTime;
if (TIMESTAMP_TO_TM(&time, &utcTime) == nullptr) {
ALOGE("Could not decompose timestamp into components");
return false;
}
(*timeValues)[0] = utcTime.tm_hour;
(*timeValues)[1] = utcTime.tm_min;
(*timeValues)[2] = utcTime.tm_sec;
char buffer[64] = {};
if (strftime(buffer, sizeof(buffer), "%Y:%m:%d", &utcTime) == 0) {
ALOGE("Could not construct date string from timestamp");
return false;
}
*date = buffer;
return true;
}
ExifData* createExifData(const CameraParameters& params) {
ExifData* exifData = exif_data_new();
exif_data_set_option(exifData, EXIF_DATA_OPTION_FOLLOW_SPECIFICATION);
exif_data_set_data_type(exifData, EXIF_DATA_TYPE_COMPRESSED);
exif_data_set_byte_order(exifData, EXIF_BYTE_ORDER_INTEL);
// Create mandatory exif fields and set their default values
exif_data_fix(exifData);
float triplet[3];
float floatValue = 0.0f;
const char* stringValue;
int64_t degrees;
// Datetime, creating and initializing a datetime tag will automatically
// set the current date and time in the tag so just do that.
createEntry(exifData, EXIF_IFD_0, EXIF_TAG_DATE_TIME);
// Make and model
createEntry(exifData, EXIF_IFD_0, EXIF_TAG_MAKE, "Emulator-Cuttlefish");
createEntry(exifData, EXIF_IFD_0, EXIF_TAG_MODEL, "Emulator-Cuttlefish");
// Picture size
int width = -1, height = -1;
params.getPictureSize(&width, &height);
if (width >= 0 && height >= 0) {
createEntry(exifData, EXIF_IFD_EXIF,
EXIF_TAG_PIXEL_X_DIMENSION, width);
createEntry(exifData, EXIF_IFD_EXIF,
EXIF_TAG_PIXEL_Y_DIMENSION, height);
}
// Orientation
if (getCameraParam(params,
CameraParameters::KEY_ROTATION,
°rees)) {
// Exif orientation values, please refer to
// http://www.exif.org/Exif2-2.PDF, Section 4.6.4-A-Orientation
// Or these websites:
// http://sylvana.net/jpegcrop/exif_orientation.html
// http://www.impulseadventure.com/photo/exif-orientation.html
enum {
EXIF_ROTATE_CAMERA_CW0 = 1,
EXIF_ROTATE_CAMERA_CW90 = 6,
EXIF_ROTATE_CAMERA_CW180 = 3,
EXIF_ROTATE_CAMERA_CW270 = 8,
};
uint16_t exifOrien = 1;
switch (degrees) {
case 0:
exifOrien = EXIF_ROTATE_CAMERA_CW0;
break;
case 90:
exifOrien = EXIF_ROTATE_CAMERA_CW90;
break;
case 180:
exifOrien = EXIF_ROTATE_CAMERA_CW180;
break;
case 270:
exifOrien = EXIF_ROTATE_CAMERA_CW270;
break;
}
createEntry(exifData, EXIF_IFD_0, EXIF_TAG_ORIENTATION, exifOrien);
}
// Focal length
if (getCameraParam(params,
CameraParameters::KEY_FOCAL_LENGTH,
&floatValue)) {
createEntry(exifData, EXIF_IFD_EXIF, EXIF_TAG_FOCAL_LENGTH, floatValue);
}
// GPS latitude and reference, reference indicates sign, store unsigned
if (getCameraParam(params,
CameraParameters::KEY_GPS_LATITUDE,
&floatValue)) {
convertGpsCoordinate(floatValue, &triplet);
createEntry(exifData, EXIF_IFD_GPS, EXIF_TAG_GPS_LATITUDE, triplet);
const char* ref = floatValue < 0.0f ? "S" : "N";
createEntry(exifData, EXIF_IFD_GPS, EXIF_TAG_GPS_LATITUDE_REF, ref);
}
// GPS longitude and reference, reference indicates sign, store unsigned
if (getCameraParam(params,
CameraParameters::KEY_GPS_LONGITUDE,
&floatValue)) {
convertGpsCoordinate(floatValue, &triplet);
createEntry(exifData, EXIF_IFD_GPS, EXIF_TAG_GPS_LONGITUDE, triplet);
const char* ref = floatValue < 0.0f ? "W" : "E";
createEntry(exifData, EXIF_IFD_GPS, EXIF_TAG_GPS_LONGITUDE_REF, ref);
}
// GPS altitude and reference, reference indicates sign, store unsigned
if (getCameraParam(params,
CameraParameters::KEY_GPS_ALTITUDE,
&floatValue)) {
createEntry(exifData, EXIF_IFD_GPS, EXIF_TAG_GPS_ALTITUDE,
static_cast<float>(fabs(floatValue)));
// 1 indicated below sea level, 0 indicates above sea level
uint8_t ref = floatValue < 0.0f ? 1 : 0;
createEntry(exifData, EXIF_IFD_GPS, EXIF_TAG_GPS_ALTITUDE_REF, ref);
}
// GPS timestamp and datestamp
int64_t timestamp = 0;
if (getCameraParam(params,
CameraParameters::KEY_GPS_TIMESTAMP,
×tamp)) {
std::string date;
if (convertTimestampToTimeAndDate(timestamp, &triplet, &date)) {
createEntry(exifData, EXIF_IFD_GPS, EXIF_TAG_GPS_TIME_STAMP,
triplet, 1.0f);
createEntry(exifData, EXIF_IFD_GPS, EXIF_TAG_GPS_DATE_STAMP,
date.c_str());
}
}
// GPS processing method
if (getCameraParam(params,
CameraParameters::KEY_GPS_PROCESSING_METHOD,
&stringValue)) {
std::vector<unsigned char> data;
// Because this is a tag with an undefined format it has to be prefixed
// with the encoding type. Insert an ASCII prefix first, then the
// actual string. Undefined tags do not have to be null terminated.
data.insert(data.end(),
std::begin(kAsciiPrefix),
std::end(kAsciiPrefix));
data.insert(data.end(), stringValue, stringValue + strlen(stringValue));
createEntry(exifData, EXIF_IFD_GPS, EXIF_TAG_GPS_PROCESSING_METHOD,
&data[0], data.size());
}
return exifData;
}
void freeExifData(ExifData* exifData) {
exif_data_free(exifData);
}
} // namespace android