[libcamera-devel] [PATCH v2 4/9] android: jpeg: exif: Add functions for setting various values
Paul Elder
paul.elder at ideasonboard.com
Thu Jan 21 11:15:44 CET 2021
Add functions for setting the following EXIF fields:
- GPSDatestamp
- GPSTimestamp
- GPSLocation
- GPSLatitudeRef
- GPSLatitude
- GPSLongitudeRef
- GPSLongitude
- GPSAltitudeRef
- GPSAltitude
- GPSProcessingMethod
- FocalLength
- ExposureTime
- FNumber
- ISO
- Flash
- WhiteBalance
- SubsecTime
- SubsecTimeOriginal
- SubsecTimeDigitized
These are in preparation for fixing the following CTS tests:
- android.hardware.camera2.cts.StillCaptureTest#testFocalLengths
- android.hardware.camera2.cts.StillCaptureTest#testJpegExif
Signed-off-by: Paul Elder <paul.elder at ideasonboard.com>
---
Changes in v2:
- some cosmetic and precision changes
- use the new setString
---
src/android/jpeg/exif.cpp | 159 ++++++++++++++++++++++++++++++++++++++
src/android/jpeg/exif.h | 40 ++++++++++
2 files changed, 199 insertions(+)
diff --git a/src/android/jpeg/exif.cpp b/src/android/jpeg/exif.cpp
index 8a185130..d3d0026a 100644
--- a/src/android/jpeg/exif.cpp
+++ b/src/android/jpeg/exif.cpp
@@ -7,8 +7,10 @@
#include "exif.h"
+#include <cmath>
#include <map>
#include <uchar.h>
+#include <tuple>
#include "libcamera/internal/log.h"
#include "libcamera/internal/utils.h"
@@ -151,6 +153,16 @@ ExifEntry *Exif::createEntry(ExifIfd ifd, ExifTag tag, ExifFormat format,
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);
@@ -295,6 +307,102 @@ void Exif::setTimestamp(time_t timestamp)
}
}
+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, NoEncoding, tsStr);
+
+ /* Set GPS_TIME_STAMP */
+ ExifEntry *entry =
+ createEntry(EXIF_IFD_GPS,
+ static_cast<ExifTag>(EXIF_TAG_GPS_TIME_STAMP),
+ EXIF_FORMAT_RATIONAL, 3, 3 * sizeof(ExifRational));
+ if (!entry)
+ return;
+
+ ExifRational ts[] = {
+ { static_cast<ExifLong>(tm.tm_hour), 1 },
+ { static_cast<ExifLong>(tm.tm_min), 1 },
+ { static_cast<ExifLong>(tm.tm_sec), 1 },
+ };
+
+ for (int i = 0; i < 3; i++)
+ exif_set_rational(entry->data + i * sizeof(ExifRational),
+ order_, ts[i]);
+
+ exif_entry_unref(entry);
+}
+
+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)
+{
+ ExifEntry *entry = createEntry(ifd, tag, EXIF_FORMAT_RATIONAL, 3,
+ 3 * sizeof(ExifRational));
+ if (!entry)
+ return;
+
+ ExifRational coords[] = {
+ { static_cast<ExifLong>(deg), 1 },
+ { static_cast<ExifLong>(min), 1 },
+ { static_cast<ExifLong>(sec), 1 },
+ };
+
+ for (int i = 0; i < 3; i++)
+ exif_set_rational(entry->data + i * sizeof(ExifRational),
+ order_, coords[i]);
+ exif_entry_unref(entry);
+}
+
+/*
+ * \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
+ *
+ * \todo use std::array
+ */
+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, NoEncoding, 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, NoEncoding, deg >= 0 ? "E" : "W");
+ setGPSDMS(EXIF_IFD_GPS, static_cast<ExifTag>(EXIF_TAG_GPS_LATITUDE),
+ 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, Unicode, method);
+}
+
void Exif::setOrientation(int orientation)
{
int value;
@@ -331,6 +439,45 @@ void Exif::setThumbnail(Span<const unsigned char> thumbnail,
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));
+}
+
+void Exif::setSubsecTime(uint64_t subsec)
+{
+ setString(EXIF_IFD_EXIF, EXIF_TAG_SUB_SEC_TIME,
+ EXIF_FORMAT_ASCII, NoEncoding, std::to_string(subsec));
+}
+
/**
* \brief Convert UTF-8 string to UTF-16 string
* \param[in] str String to convert
@@ -359,6 +506,18 @@ std::u16string Exif::utf8ToUtf16(const std::string &str)
return ret;
}
+void Exif::setSubsecTimeOriginal(uint64_t subsec)
+{
+ setString(EXIF_IFD_EXIF, EXIF_TAG_SUB_SEC_TIME_ORIGINAL,
+ EXIF_FORMAT_ASCII, NoEncoding, std::to_string(subsec));
+}
+
+void Exif::setSubsecTimeDigitized(uint64_t subsec)
+{
+ setString(EXIF_IFD_EXIF, EXIF_TAG_SUB_SEC_TIME_DIGITIZED,
+ EXIF_FORMAT_ASCII, NoEncoding, std::to_string(subsec));
+}
+
[[nodiscard]] int Exif::generate()
{
if (exifData_) {
diff --git a/src/android/jpeg/exif.h b/src/android/jpeg/exif.h
index db98ba63..baab96ed 100644
--- a/src/android/jpeg/exif.h
+++ b/src/android/jpeg/exif.h
@@ -26,6 +26,27 @@ public:
JPEG = 6,
};
+ enum Flash {
+ /* bit 0 */
+ Fired = 0x01,
+ /* bits 1 and 2 */
+ StrobeDetected = 0x04,
+ StrobeNotDetected = 0x06,
+ /* bits 3 and 4 */
+ ModeCompulsoryFiring = 0x08,
+ ModeCompulsorySuppression = 0x10,
+ ModeAuto = 0x18,
+ /* bit 5 */
+ FlashNotPresent = 0x20,
+ /* bit 6 */
+ RedEye = 0x40,
+ };
+
+ enum WhiteBalance {
+ Auto = 0,
+ Manual = 1,
+ };
+
enum StringEncoding {
NoEncoding = 0,
ASCII = 1,
@@ -43,6 +64,21 @@ public:
Compression compression);
void setTimestamp(time_t timestamp);
+ void setGPSDateTimestamp(time_t timestamp);
+ void setGPSLocation(const double *coords);
+ void setGPSMethod(const std::string &method);
+
+ void setFocalLength(float length);
+ void setExposureTime(uint64_t nsec);
+ void setAperture(float size);
+ void setISO(uint16_t iso);
+ void setFlash(Flash flash);
+ void setWhiteBalance(WhiteBalance wb);
+
+ void setSubsecTime(uint64_t subsec);
+ void setSubsecTimeOriginal(uint64_t subsec);
+ void setSubsecTimeDigitized(uint64_t subsec);
+
libcamera::Span<const uint8_t> data() const { return { exifData_, size_ }; }
[[nodiscard]] int generate();
@@ -51,12 +87,16 @@ private:
ExifEntry *createEntry(ExifIfd ifd, ExifTag tag, ExifFormat format,
unsigned long components, unsigned int size);
+ void setByte(ExifIfd ifd, ExifTag tag, uint8_t item);
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,
StringEncoding enc, const std::string &item);
void setRational(ExifIfd ifd, ExifTag tag, ExifRational item);
+ std::tuple<int, int, int> degreesToDMS(double decimalDegrees);
+ void setGPSDMS(ExifIfd ifd, ExifTag tag, int deg, int min, int sec);
+
std::u16string utf8ToUtf16(const std::string &str);
bool valid_;
--
2.27.0
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