Trying to inject XMP-GSpherical TimeStamp to a MP4 LG-360 spherical video

[andresdevandelvira]

Hello, this is my first time in this Forum, I'm a very inexperienced user of Exiftool command line...  , usually using Exiftool Gui.

My OS: Windows 10 64 Bits
ExifTool version: 10.6.3.0

I'm trying to inject Xmp:TimeStamp metadata to a Spherical LG-360 Cam mp4 video.

The original Video has right date (Tag Xmp:TimeStamp), but the stitched video, injected with "Spherical Metadata Tool" has lost several metadata, including TimeStamp one.

If I export right original video metadata to xmp (using Exiftool GUI), the obtained file doesn't contains part of the metadata, including Xmp TimeStamp.

I'm trying to "reinject" these data with a command line,

exiftool.exe "-XMP-GSpherical:TimeStamp=2005:08:30 20:00:00" C:\20170829.mp4

but I always get the error:

Code Select Expand

Warning: Invalid date/time (use YYYY:mm:dd HH:MM:SS[.ss][+/-HH:MM|Z]) for XMP-GSpherical:TimeStamp
Nothing to do.
<-END-

This error appears also if I try to inject these metadata using Exiftool GUI.

Thanks,

[Phil Harvey]

This is a bug in ExifTool, but I don't think that fixing this bug will help because I believe that Google (for whatever reason) doesn't write the GSpherical XMP to the location specified by the XMP standard.  ExifTool will write this to the standard XMP location.

I will fix this bug (the tag's Writable format should be "integer" instead of "date"), but I don't want to get your hopes up too much.

- Phil

[andresdevandelvira]

Ok, I understand. 

Thanks for your impressive work.

[Phil Harvey]

Just a note:  ExifTool 11.54 or later (July 2019) writes GSpherical tags to the GSphericalXML of the video track.

- Phil

[Kajuna]

Hi. Lately YouTube has stopped reading these tags correctly. I'm not sure if this is a change in YouTube or in newer versions of Exiftool. The only difference I can see between tags written by the Google python tool (
https://github.com/google/spatial-media ) is the capitalization of True (Google) vs true (Exiftool) in the Spherical and Stitched tags.

(This is what the Google tool prints)
Google tags:

Code Select Expand

Loaded file...
        Track 0
                Spherical = true
                Stitched = true
                StitchingSoftware = Spherical Metadata Tool
                ProjectionType = equirectangular
        Track 1
Exiftool tags:

Code Select Expand

Loaded file...
        Track 0
                ProjectionType = equirectangular
                Spherical = True
                Stitched = True
                StitchingSoftware = Spherical Metadata Tool
        Track 1
Re-writing the tags with the Google tool does not fix the problem, but writing them with the Google tool to a file that hasn't had the tags previously seems to work well.

I have tried multiple ways to write the true value in lowercase but nothing seems to work. Was this a change in a recent version? Is there a way to force the tags to be lowercase? (I know they are supposed to be booleans, but...)

Thanks

Edit. I can write the tags as lowercase with the -n option, but YouTube still does not recognise the file as a 360 video

[StarGeek]

Try extracting and comparing the raw XMP from each file using
exiftool -b -XMP /path/to/files/

If the formatting is different, you might try the -api Compact option to make exiftool format the XMP such that Google will recognize it.  Though I think this is a long shot.

[Kajuna]

Try extracting and comparing the raw XMP from each file using
exiftool -b -XMP /path/to/files/

If the formatting is different, you might try the -api Compact option to make exiftool format the XMP such that Google will recognize it.  Though I think this is a long shot.

Thanks. -b -XMP doesn't print anything. This might be related:

XMP GSpherical Tags
Not actually XMP. These RDF/XML tags are used in Google spherical MP4 videos. These tags are written into the video track of MOV/MP4 files, and not at the top level like other XMP tags

Interestingly, if I add the tags with the Google tools the video is recognised as VR by YouTube. If I add ANY tag (even not related to spherical data) with ExifTool and the ALSO add the VR tags with the Google tool, YouTube fails to identify the video as VR.

[StarGeek]

Unfortunately, I can't really help on this.  Try searching these forum deeper, as I know there have been posts on the subject before.  Also search using Google search with Site:Exiftool.org as part of the querry.

[Kajuna]

Thanks anyway.

I'm just posting additional findings as I go, if that's ok. I'm comparing the data in the files, and files that work well seem to have the "XMP" data towards the end of the file:

https://imgur.com/a/880jiqi

While files that don't work have it at the beginning:

https://imgur.com/a/u0LPwVo

Also, the Google tool uses double quotes and exiftool uses single ones, plus google specifies the xml version at the beginning of the "XMP" data (<?xml version="1.0"?>). Although that does not seem to be the key of the problem.

Will try old versions of Exiftool next.

[Kajuna]

Old versions made no difference. What makes a difference is testing a very small file. Very small files are read correctly by YouTube. So my only hypothesis is this is a bug on YouTube's end, where the 360 metadata is only looked for within the last N bits of a file or stream. Since Exiftool writes the "XMP" data at the beginning, YouTube fails to find it in large files (obviously I could be completely wrong). Would there be a reason not to write the data at the end to work around this YouTube bug? I will report this to Google as well, but who knows if they will care enough

[Kajuna]

Should I post this as a separate feature request?

[StarGeek]

I don't think such a request will get much traction unless you can show that this is the actual problem.

Phil is away for a few weeks, so there wouldn't be an answer until then.

[Kajuna]

Here are samples to verify that, or to investigate the issue if the cause is different.

- Video with "XPM" tags injected with the Google tool: https://youtu.be/rENkZmz7nnQ (Plays in VR)
- Same video file with same "XMP" tags injected with Exiftool: https://youtu.be/hKekmx3jbk4 (Does not play in VR)
- Video processed with Exiftool AND with the "XMP" tags rewritten again with the Google tool: https://youtu.be/oC3qQf0CpIs (Does not play in VR)

Original files can be downloaded here: https://www.dropbox.com/scl/fi/oozbeljc3x6c8jmgpy8z5/clean_exiftool.zip?rlkey=ragpeaqe0iub0u2qfm6u32rff&dl=0

Differences I can see between Google and Exiftool versions:
1- Google has XML tag (<?xml version="1.0"?>)
2- Google uses double quotes vs single ones on Exiftool (xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#")
3- The "XMP" data is near the beginning of the file in Google's, but near the end in Exiftool's

Differences 1 and 2 are not present in the file that was processed with both tools, which does not play in VR, so difference number 3 seems to be the culprit.

Of course:
- It could be something else I'm not seeing
- There might be strong reasons why Exiftool is writing the data at the beginning
- This might be a bug on YouTube's end that Exiftool is not responsible for fixing.
- Etc.
So I'm just sharing my findings in case this all makes sense and helps solve the issue in future versions

[StarGeek]

I did find in my notes that I had this reddit page bookmarked.  Maybe it can help
https://reddit.com/r/Insta360/comments/10ii9r3/how_to_upload_360_videos_to_google_street_video/

[Kajuna]

I did find in my notes that I had this reddit page bookmarked.  Maybe it can help
https://reddit.com/r/Insta360/comments/10ii9r3/how_to_upload_360_videos_to_google_street_video/

It doesn't seem related. It shows a workflow for Google Street View, but no info on VR tags for YouTube