[libcamera-devel] [PATCH v4 3/8] android: jpeg: exif: Add functions for setting various values
Jacopo Mondi
jacopo at jmondi.org
Mon Jan 25 12:30:26 CET 2021
Hi Paul,
On Mon, Jan 25, 2021 at 04:14:39PM +0900, Paul Elder wrote:
> 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>
> Reviewed-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
>
Seems like I mostly have cosmetic comments
> ---
> Changes in v4:
> - change type of subsec to std::chrono::milliseconds
>
> Changes in v3:
> - merge setting subsec into setting the main timestamp
>
> Changes in v2:
> - some cosmetic and precision changes
> - use the new setString
> ---
> src/android/jpeg/exif.cpp | 178 +++++++++++++++++++++--
> src/android/jpeg/exif.h | 39 ++++-
> src/android/jpeg/post_processor_jpeg.cpp | 4 +-
> 3 files changed, 205 insertions(+), 16 deletions(-)
>
> diff --git a/src/android/jpeg/exif.cpp b/src/android/jpeg/exif.cpp
> index 204a237a..0f2c2d95 100644
> --- a/src/android/jpeg/exif.cpp
> +++ b/src/android/jpeg/exif.cpp
> @@ -7,7 +7,10 @@
>
> #include "exif.h"
>
> +#include <chrono>
You include <chrono> in the header file in this patch. You can drop it
here.
> +#include <cmath>
> #include <map>
> +#include <tuple>
> #include <uchar.h>
>
> #include "libcamera/internal/log.h"
> @@ -151,6 +154,16 @@ 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);
> @@ -267,7 +280,7 @@ void Exif::setSize(const Size &size)
> setLong(EXIF_IFD_EXIF, EXIF_TAG_PIXEL_X_DIMENSION, size.width);
> }
>
> -void Exif::setTimestamp(time_t timestamp)
> +void Exif::setTimestamp(time_t timestamp, std::chrono::milliseconds msec)
> {
> struct tm tm;
> localtime_r(×tamp, &tm);
I guess the fact we use localtime there, and gmtime in gmtime in
setGPSDateTimestamp is intentional (you're not on GMT, so you would
have noticed if CTS does not like this)
> @@ -282,19 +295,123 @@ void Exif::setTimestamp(time_t timestamp)
>
> /* Query and set timezone information if available. */
> int r = strftime(str, sizeof(str), "%z", &tm);
> - if (r > 0) {
> - 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);
> - }
> + if (r <= 0)
> + return;
> +
> + std::string tz(str);
> + tz.insert(3, 1, ':');
> + setString(EXIF_IFD_EXIF,
For my education: why don't you need to create entries for these
fields ?
> + 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::string subsec = std::to_string(msec.count());
> +
> + 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 */
> + ExifEntry *entry =
> + createEntry(EXIF_IFD_GPS,
Fits on the previous line
> + 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]);
In the previous function you have an empty line here
> + 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
You can align to the left
> + */
> +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_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, method, Unicode);
> }
>
> void Exif::setOrientation(int orientation)
> @@ -333,6 +450,39 @@ 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));
> +}
> +
> /**
> * \brief Convert UTF-8 string to UTF-16 string
> * \param[in] str String to convert
> diff --git a/src/android/jpeg/exif.h b/src/android/jpeg/exif.h
> index 8b84165b..b0d61402 100644
> --- a/src/android/jpeg/exif.h
> +++ b/src/android/jpeg/exif.h
> @@ -7,6 +7,7 @@
> #ifndef __ANDROID_JPEG_EXIF_H__
> #define __ANDROID_JPEG_EXIF_H__
>
> +#include <chrono>
> #include <string>
> #include <time.h>
>
> @@ -26,6 +27,27 @@ 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,
> + };
Do these come from the Exif spec ? are there no types defined for this
already ?
> +
> + enum WhiteBalance {
> + Auto = 0,
> + Manual = 1,
> + };
> +
Same question
As I've said, it's mostly cosmetic stuff
Reviewed-by: Jacopo Mondi <jacopo at jmondi.org>
Thanks
j
> enum StringEncoding {
> NoEncoding = 0,
> ASCII = 1,
> @@ -39,7 +61,18 @@ public:
> void setSize(const libcamera::Size &size);
> void setThumbnail(libcamera::Span<const unsigned char> thumbnail,
> Compression compression);
> - void setTimestamp(time_t timestamp);
> + void setTimestamp(time_t timestamp, std::chrono::milliseconds msec);
> +
> + 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);
>
> libcamera::Span<const uint8_t> data() const { return { exifData_, size_ }; }
> [[nodiscard]] int generate();
> @@ -49,6 +82,7 @@ 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,
> @@ -56,6 +90,9 @@ private:
> StringEncoding encoding = NoEncoding);
> 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_;
> diff --git a/src/android/jpeg/post_processor_jpeg.cpp b/src/android/jpeg/post_processor_jpeg.cpp
> index 436a50f8..c29cb352 100644
> --- a/src/android/jpeg/post_processor_jpeg.cpp
> +++ b/src/android/jpeg/post_processor_jpeg.cpp
> @@ -7,6 +7,8 @@
>
> #include "post_processor_jpeg.h"
>
> +#include <chrono>
> +
> #include "../camera_device.h"
> #include "../camera_metadata.h"
> #include "encoder_libjpeg.h"
> @@ -97,7 +99,7 @@ int PostProcessorJpeg::process(const FrameBuffer &source,
> * Since the precision we need for EXIF timestamp is only one
> * second, it is good enough.
> */
> - exif.setTimestamp(std::time(nullptr));
> + exif.setTimestamp(std::time(nullptr), std::chrono::milliseconds(0));
>
> std::vector<unsigned char> thumbnail;
> generateThumbnail(source, &thumbnail);
> --
> 2.27.0
>
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