ExifTool Forum

ExifTool => Newbies => Topic started by: Juggernaut on June 11, 2018, 01:17:40 PM

Title: .mp4 files - tag "UserData_enc"
Post by: Juggernaut on June 11, 2018, 01:17:40 PM
I've recorded a simple video .mp4 file using Bandicam.
After that - tried to remove all removable tags with -all= command.
But nothing happened.
OK, I looked at it, and found for example tag UserData_enc with info about Bandicam.

AudioSampleRate               : 48000
UserData_enc                    : Bandicam 4.1.4.1412 / GDI / Nvidia NVENC
AvgBitrate                         : 220 kbps
ImageSize                         : 496x408
Megapixels                        : 0.202
Rotation                            : 0


Tried to force remove it and got this:

exiftool video.mp4 -UserData_enc=
Warning: Tag 'UserData_enc' is not defined
Nothing to do.


Why is that? Why is it "not defined" for ExifTool ?
Title: Re: .mp4 files - tag "UserData_enc"
Post by: Phil Harvey on June 11, 2018, 01:20:51 PM
From the QuickTime tags documentation (https://exiftool.org/TagNames/QuickTime.html):

ExifTool currently has a very limited ability to write metadata in QuickTime-format videos. It can edit/create/delete any XMP tags, but may only be used to edit certain date/time tags and the video orientation in native QuickTime metadata.

- Phil
Title: Re: .mp4 files - tag "UserData_enc"
Post by: StarGeek on June 11, 2018, 02:44:48 PM
You might try Ffmpeg.  See this SuperUser (https://superuser.com/a/428039/314998) answer for a example command line.
Title: Re: .mp4 files - tag "UserData_enc"
Post by: Juggernaut on June 11, 2018, 08:53:46 PM
Quote from: StarGeek on June 11, 2018, 02:44:48 PM
You might try Ffmpeg.  See this SuperUser (https://superuser.com/a/428039/314998) answer for a example command line.

Wow, huge thanks! It does a great job!

BTW do you know what does -1 mean in ...

ffmpeg -i in.mov -map_metadata -1 -c:v copy -c:a copy out.mov

?

There is not a word in documentation or on the web about pair -map_metadata -1 and what does -1 in this case means.
Why people so lazy..... Everyone writes this "remove all" command, but no one can explain it letter by letter, digit by digit.
Title: Re: .mp4 files - tag "UserData_enc"
Post by: StarGeek on June 11, 2018, 09:16:54 PM
Ffmpeg docs are so convoluted and that's one of the main reasons I often don't deal with it if I can't find a previously listed command.  But on this occasion I did find an answer (I think).  Under 5.11 Advanced options (https://ffmpeg.org/ffmpeg.html#Advanced-options), section on -map_metadata, there is the line:
QuoteA negative file index can be used to create a dummy mapping that just disables automatic copying.
Title: Re: .mp4 files - tag "UserData_enc"
Post by: Phil Harvey on June 12, 2018, 07:22:08 AM
I'm in the process of thinking about an upgrade to the MP4/MOV writing capabilities.

It would be useful if you could post the output of exiftool -v3 for any "UserData_xxx" tags that you find so I can add support for these.

Thanks.

- Phil
Title: Re: .mp4 files - tag "UserData_enc"
Post by: Juggernaut on June 12, 2018, 11:39:50 AM
Quote from: StarGeek on June 11, 2018, 09:16:54 PM
Ffmpeg docs are so convoluted and that's one of the main reasons I often don't deal with it if I can't find a previously listed command.  But on this occasion I did find an answer (I think).  Under 5.11 Advanced options (https://ffmpeg.org/ffmpeg.html#Advanced-options), section on -map_metadata, there is the line:
QuoteA negative file index can be used to create a dummy mapping that just disables automatic copying.

Yeah, I think it is for disabling auto-copy. Thanks.

Quote from: Phil Harvey on June 12, 2018, 07:22:08 AM
I'm in the process of thinking about an upgrade to the MP4/MOV writing capabilities.

It would be useful if you could post the output of exiftool -v3 for any "UserData_xxx" tags that you find so I can add support for these.

Thanks.

- Phil

Thanks for improving ExifTool!

I've attached a .txt file

Take a look at it. Is that what you need?
Title: Re: .mp4 files - tag "UserData_enc"
Post by: Phil Harvey on June 12, 2018, 12:54:17 PM
That's great, thanks.  "UserData_enc" will be extracted as "EncoderID" in the next release.

- Phil