[libcamera-devel] [PATCH v4 2/2] android: jpeg: Support an initial set of EXIF metadata tags
Umang Jain
email at uajain.com
Fri Aug 28 08:57:40 CEST 2020
Create a Exif object with various metadata tags set, just before
the encoder starts to encode the frame. The object is passed
directly as libcamera::Span<> to make sure EXIF tags can be set
in a single place i.e. in CameraDevice and the encoder only has
the job to write the data in the final output.
Signed-off-by: Kieran Bingham <kieran.bingham at ideasonboard.com>
Signed-off-by: Umang Jain <email at uajain.com>
Reviewed-by: Kieran Bingham <kieran.bingham at ideasonboard.com>
---
src/android/camera_device.cpp | 18 +++++++-
src/android/jpeg/encoder.h | 3 +-
src/android/jpeg/encoder_libjpeg.cpp | 9 +++-
src/android/jpeg/encoder_libjpeg.h | 3 +-
src/android/jpeg/exif.cpp | 62 ++++++++++++++++++++++++++++
src/android/jpeg/exif.h | 9 ++++
6 files changed, 100 insertions(+), 4 deletions(-)
diff --git a/src/android/camera_device.cpp b/src/android/camera_device.cpp
index de6f86f..54ca9c6 100644
--- a/src/android/camera_device.cpp
+++ b/src/android/camera_device.cpp
@@ -24,6 +24,7 @@
#include "system/graphics.h"
#include "jpeg/encoder_libjpeg.h"
+#include "jpeg/exif.h"
using namespace libcamera;
@@ -1434,7 +1435,22 @@ void CameraDevice::requestComplete(Request *request)
continue;
}
- int jpeg_size = encoder->encode(buffer, mapped.maps()[0]);
+ /* Set EXIF metadata for various tags. */
+ Exif exif;
+ /* \todo Set Make and Model from external vendor tags. */
+ exif.setMake("libcamera");
+ exif.setModel("cameraModel");
+ exif.setOrientation(orientation_);
+ exif.setSize(cameraStream->size);
+ /*
+ * We set the frame's EXIF timestamp as the time of encode.
+ * Since the precision we need for EXIF timestamp is only one
+ * second, it is good enough.
+ */
+ exif.setTimestamp(std::time(nullptr));
+ exif.generate();
+
+ int jpeg_size = encoder->encode(buffer, mapped.maps()[0], exif.data());
if (jpeg_size < 0) {
LOG(HAL, Error) << "Failed to encode stream image";
status = CAMERA3_BUFFER_STATUS_ERROR;
diff --git a/src/android/jpeg/encoder.h b/src/android/jpeg/encoder.h
index f9eb88e..cf26d67 100644
--- a/src/android/jpeg/encoder.h
+++ b/src/android/jpeg/encoder.h
@@ -18,7 +18,8 @@ public:
virtual int configure(const libcamera::StreamConfiguration &cfg) = 0;
virtual int encode(const libcamera::FrameBuffer *source,
- const libcamera::Span<uint8_t> &destination) = 0;
+ const libcamera::Span<uint8_t> &destination,
+ const libcamera::Span<const uint8_t> &exifData) = 0;
};
#endif /* __ANDROID_JPEG_ENCODER_H__ */
diff --git a/src/android/jpeg/encoder_libjpeg.cpp b/src/android/jpeg/encoder_libjpeg.cpp
index 977538c..510613c 100644
--- a/src/android/jpeg/encoder_libjpeg.cpp
+++ b/src/android/jpeg/encoder_libjpeg.cpp
@@ -180,7 +180,8 @@ void EncoderLibJpeg::compressNV(const libcamera::MappedBuffer *frame)
}
int EncoderLibJpeg::encode(const FrameBuffer *source,
- const libcamera::Span<uint8_t> &dest)
+ const libcamera::Span<uint8_t> &dest,
+ const libcamera::Span<const uint8_t> &exifData)
{
MappedFrameBuffer frame(source, PROT_READ);
if (!frame.isValid()) {
@@ -204,6 +205,12 @@ int EncoderLibJpeg::encode(const FrameBuffer *source,
jpeg_start_compress(&compress_, TRUE);
+ if (exifData.size())
+ /* Store Exif data in the JPEG_APP1 data block. */
+ jpeg_write_marker(&compress_, JPEG_APP0 + 1,
+ static_cast<const JOCTET *>(exifData.data()),
+ exifData.size());
+
LOG(JPEG, Debug) << "JPEG Encode Starting:" << compress_.image_width
<< "x" << compress_.image_height;
diff --git a/src/android/jpeg/encoder_libjpeg.h b/src/android/jpeg/encoder_libjpeg.h
index aed081a..1e8df05 100644
--- a/src/android/jpeg/encoder_libjpeg.h
+++ b/src/android/jpeg/encoder_libjpeg.h
@@ -22,7 +22,8 @@ public:
int configure(const libcamera::StreamConfiguration &cfg) override;
int encode(const libcamera::FrameBuffer *source,
- const libcamera::Span<uint8_t> &destination) override;
+ const libcamera::Span<uint8_t> &destination,
+ const libcamera::Span<const uint8_t> &exifData) override;
private:
void compressRGB(const libcamera::MappedBuffer *frame);
diff --git a/src/android/jpeg/exif.cpp b/src/android/jpeg/exif.cpp
index b49b538..3fbb117 100644
--- a/src/android/jpeg/exif.cpp
+++ b/src/android/jpeg/exif.cpp
@@ -157,6 +157,68 @@ int Exif::setString(ExifIfd ifd, ExifTag tag, ExifFormat format, const std::stri
return 0;
}
+int Exif::setMake(const std::string &make)
+{
+ return setString(EXIF_IFD_0, EXIF_TAG_MAKE, EXIF_FORMAT_ASCII, make);
+}
+
+int Exif::setModel(const std::string &model)
+{
+ return setString(EXIF_IFD_0, EXIF_TAG_MODEL, EXIF_FORMAT_ASCII, model);
+}
+
+int Exif::setSize(Size size)
+{
+ setShort(EXIF_IFD_0, EXIF_TAG_IMAGE_LENGTH, size.height);
+ setLong(EXIF_IFD_EXIF, EXIF_TAG_PIXEL_Y_DIMENSION, size.height);
+
+ setShort(EXIF_IFD_0, EXIF_TAG_IMAGE_WIDTH, size.width);
+ setLong(EXIF_IFD_EXIF, EXIF_TAG_PIXEL_X_DIMENSION, size.width);
+
+ return 0;
+}
+
+int Exif::setTimestamp(const time_t timestamp)
+{
+ char str[20];
+ std::strftime(str, sizeof(str), "%Y:%m:%d %H:%M:%S",
+ std::localtime(×tamp));
+ std::string ts(str);
+ int ret = -1;
+
+ ret = setString(EXIF_IFD_0, EXIF_TAG_DATE_TIME, EXIF_FORMAT_ASCII, ts);
+ if (ret < 0)
+ return ret;
+
+ ret = setString(EXIF_IFD_EXIF, EXIF_TAG_DATE_TIME_ORIGINAL, EXIF_FORMAT_ASCII, ts);
+ if (ret < 0)
+ return ret;
+
+ ret = setString(EXIF_IFD_EXIF, EXIF_TAG_DATE_TIME_DIGITIZED, EXIF_FORMAT_ASCII, ts);
+ if (ret < 0)
+ return ret;
+
+ return ret;
+}
+
+int Exif::setOrientation(int orientation)
+{
+ int value = 1;
+ switch (orientation) {
+ case 90:
+ value = 6;
+ break;
+ case 180:
+ value = 3;
+ break;
+ case 270:
+ value = 8;
+ break;
+ }
+
+ return setShort(EXIF_IFD_0, EXIF_TAG_ORIENTATION, value);
+}
+
int Exif::generate()
{
if (exifData_) {
diff --git a/src/android/jpeg/exif.h b/src/android/jpeg/exif.h
index 6c10f94..f15afb9 100644
--- a/src/android/jpeg/exif.h
+++ b/src/android/jpeg/exif.h
@@ -9,8 +9,10 @@
#include <libexif/exif-data.h>
+#include <libcamera/geometry.h>
#include <libcamera/span.h>
+#include <ctime>
#include <string>
class Exif
@@ -19,6 +21,13 @@ public:
Exif();
~Exif();
+ int setMake(const std::string &make);
+ int setModel(const std::string &model);
+
+ int setOrientation(int orientation);
+ int setSize(libcamera::Size size);
+ int setTimestamp(const time_t timestamp);
+
libcamera::Span<const uint8_t> data() const { return { exifData_, size_ }; }
int generate();
--
2.25.1
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