| Message ID | 20200504070425.5972-1-laurent.pinchart@ideasonboard.com |
|---|---|
| State | Accepted |
| Commit | 3ed0fced1f22bcdb9a0f05bbbc1e3b87017ac8c2 |
| Headers | show |
| Series |
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| Related | show |
Hi Laurent, Thanks for your fix, libtiff is fun. On 2020-05-04 10:04:25 +0300, Laurent Pinchart wrote: > The EXIF IFD is incorrectly chained to IFD 0 in addition to being a > referenced as a sub IFD through the EXIFIFD tag. While the libtiff API > doesn't clearly document why this happens, inspection of the > TIFFWriteDirectory() source code show that the function treats the IFD > being written as containing an image, which isn't correct for the EXIF > IFD. Use TIFFWriteCustomDirectory() instead, which fixes the problem. > The resulting DNG file can now be opened with darktable in addition to > rawtherapee. > > Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Reviewed-by: Niklas Söderlund <niklas.soderlund@ragnatech.se> > --- > src/qcam/dng_writer.cpp | 4 +--- > 1 file changed, 1 insertion(+), 3 deletions(-) > > diff --git a/src/qcam/dng_writer.cpp b/src/qcam/dng_writer.cpp > index ea4616f63d8e..cbd8bed3e6d0 100644 > --- a/src/qcam/dng_writer.cpp > +++ b/src/qcam/dng_writer.cpp > @@ -316,9 +316,7 @@ int DNGWriter::write(const char *filename, const Camera *camera, > TIFFSetField(tif, EXIFTAG_EXPOSURETIME, exposureTime); > } > > - TIFFCheckpointDirectory(tif); > - exifIFDOffset = TIFFCurrentDirOffset(tif); > - TIFFWriteDirectory(tif); > + TIFFWriteCustomDirectory(tif, &exifIFDOffset); > > /* Update the IFD offsets and close the file. */ > TIFFSetDirectory(tif, 0); > -- > Regards, > > Laurent Pinchart > > _______________________________________________ > libcamera-devel mailing list > libcamera-devel@lists.libcamera.org > https://lists.libcamera.org/listinfo/libcamera-devel
Hi Laurent, On 04/05/2020 08:04, Laurent Pinchart wrote: > The EXIF IFD is incorrectly chained to IFD 0 in addition to being a > referenced as a sub IFD through the EXIFIFD tag. While the libtiff API > doesn't clearly document why this happens, inspection of the > TIFFWriteDirectory() source code show that the function treats the IFD > being written as containing an image, which isn't correct for the EXIF > IFD. Use TIFFWriteCustomDirectory() instead, which fixes the problem. > The resulting DNG file can now be opened with darktable in addition to > rawtherapee. Nice! Sounds like it was more painful to fix than it should have been. Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com> > > Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> > --- > src/qcam/dng_writer.cpp | 4 +--- > 1 file changed, 1 insertion(+), 3 deletions(-) > > diff --git a/src/qcam/dng_writer.cpp b/src/qcam/dng_writer.cpp > index ea4616f63d8e..cbd8bed3e6d0 100644 > --- a/src/qcam/dng_writer.cpp > +++ b/src/qcam/dng_writer.cpp > @@ -316,9 +316,7 @@ int DNGWriter::write(const char *filename, const Camera *camera, > TIFFSetField(tif, EXIFTAG_EXPOSURETIME, exposureTime); > } > > - TIFFCheckpointDirectory(tif); > - exifIFDOffset = TIFFCurrentDirOffset(tif); > - TIFFWriteDirectory(tif); > + TIFFWriteCustomDirectory(tif, &exifIFDOffset); > > /* Update the IFD offsets and close the file. */ > TIFFSetDirectory(tif, 0); >
diff --git a/src/qcam/dng_writer.cpp b/src/qcam/dng_writer.cpp index ea4616f63d8e..cbd8bed3e6d0 100644 --- a/src/qcam/dng_writer.cpp +++ b/src/qcam/dng_writer.cpp @@ -316,9 +316,7 @@ int DNGWriter::write(const char *filename, const Camera *camera, TIFFSetField(tif, EXIFTAG_EXPOSURETIME, exposureTime); } - TIFFCheckpointDirectory(tif); - exifIFDOffset = TIFFCurrentDirOffset(tif); - TIFFWriteDirectory(tif); + TIFFWriteCustomDirectory(tif, &exifIFDOffset); /* Update the IFD offsets and close the file. */ TIFFSetDirectory(tif, 0);
The EXIF IFD is incorrectly chained to IFD 0 in addition to being a referenced as a sub IFD through the EXIFIFD tag. While the libtiff API doesn't clearly document why this happens, inspection of the TIFFWriteDirectory() source code show that the function treats the IFD being written as containing an image, which isn't correct for the EXIF IFD. Use TIFFWriteCustomDirectory() instead, which fixes the problem. The resulting DNG file can now be opened with darktable in addition to rawtherapee. Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> --- src/qcam/dng_writer.cpp | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-)