Spherical tags being stripped while editing unrelated tags

[zeevs]

Hi!

I'm trying to use exiftool to work around an annoyance of LG's 360 stitching software - the files it creates don't retain the original (unstitched) video's creation/modification timestamps, but the meaningless point in time when the video was stitched.

I created a simple script to do that using exiftool - but noticed that the files were no longer recognized as 360 files.

Diffing the metadata before and after exiftool operated on it, I noticed it removes a bunch of tags, which I'm pretty sure is the reason the resulting files are no longer recognized as 360 videos:

C:\Incoming\360\tmp>diff -u res1 res2
@@ -15,7 +15,6 @@
Movie Data Size                 : 3442389
Movie Data Offset               : 32
Movie Header Version            : 0
-Create Date                     : 2017:09:16 09:48:27
Modify Date                     : 2017:09:16 09:48:27
Time Scale                      : 48000
Duration                        : 2.05 s
@@ -47,12 +46,7 @@
Compressor Name                 : \012AVC Coding
Bit Depth                       : 24
Video Frame Rate                : 30.001
-Spherical                       : true
-Stitched                        : true
-Stitching Software              : LGE::Spherical Tool
-Projection Type                 : equirectangular
-Source Count                    : 2
-Time Stamp                      : 2017:08:19 16:28:35
+XMP Toolkit                     : Image::ExifTool 10.61
Matrix Structure                : 1 0 0 0 1 0 0 0 1
Media Header Version            : 0
Media Create Date               : 2017:09:16 09:48:27
@@ -66,6 +60,7 @@
Audio Channels                  : 2
Audio Bits Per Sample           : 16
Audio Sample Rate               : 48000
+Create Date                     : 2017:09:16 12:48:27+03:00
Avg Bitrate                     : 13.4 Mbps
Image Size                      : 2560x1280
Megapixels                      : 3.3

(I generally use -TagsFromFile and copy all the different timestamps from the original unstitched video to the stitched one - but for this sample I simply used exiftool "-CreateDate<FileCreateDate" filename.mp4 to see if it exhibits the same behavior - and it does)

It seems exiftool is stripping these tags for some reason.  I tried to search the archives to see if this is expected, and managed to find references to exiftool not being able to update these tags (e.g. Spherical), but I didn't find references to it stripping them.  Is this expected behavior?  Is there some other way to achieve what I'm trying to do while retaining these 360 tags?

Oh, and I should note to Phil - absolutely amazing job on this tool.  Thanks!!

Zeev

[StarGeek]

This will probably require Phil's attention but it may be a while as he's currently on vacation.

[zeevs]

Thanks for the heads up!

In the meantime, I uploaded a small sample with which one can reproduce the problem:

https://www.dropbox.com/s/8ji771wx0xpfmly/Result_20170819_192832.mp4?dl=1

Simply run
exiftool "-CreateDate<FileCreateDate" Result_20170819_192832.mp4

and diff the exiftool output before and after.

[Phil Harvey]

Thanks for the sample.  I am able to reproduce this problem.

You can avoid the problem by avoiding writing of XMP tags to this video with a command like this:

exiftool "-quicktime:createdate<filecreatedate" FILE

The problem is that ExifTool is writing the spherical video XML as if it were XMP, which destroys the spherical video tags you mentioned.  This will be fixed in the next release.

- Phil

[zeevs]

Thank you - for the workaround, the upcoming fix and the awesome tool you created!

[Phil Harvey]

This was fixed in version 10.62, which was released on Sept 28.  (And we're already on to version 10.63 now.)

- Phil

[zeevs]

Great, I've been off on vacation since Sep 19...  Looking forward to trying it out soon.