MP4 metadata

[velezericn]

I have code to change the mediacreated date for mp4 meta data with the following code in python

    cmd = [exiftool_path, "-overwrite_original","-CreateDate={}".format(new_date), directory_file_name]

i noticed that sometimes that the media created in the file explorer details tab that it'll sometimes not be there. i verified using exiftool that the mediacreated date was changed successfully and uploaded to amazon photos and see that the date taken is the create date that i modified. Which is good.

But why can't i see it when i go to the file explorer properties details menu sometimes? how can i have it appear there or is there another tag that i can write to that will appear as well?

[StarGeek]

But why can't i see it when i go to the file explorer properties details menu sometimes? how can i have it appear there or is there another tag that i can write to that will appear as well?

This post lists what I was able to document about what tags Windows is reading.  With Win8 & Win10, Quicktime:CreateDate was the only tag I found that Windows read for "Media created".  I don't use Windows 11, so I haven't tested that.

But there are times when Windows choked on reading the metadata, especially if there was a lot of it.

The most surefire solution would be to remux (not recompress) the file, but that will lose any EXIF data as well as any GPS tracks.  This is the command I use with ffmpeg to do this
ffmpeg -i input.mp4 -c copy -map 0 -map_metadata 0 output.mp4

[velezericn]

ok so i did a test. i took the mp4 file on a computer that had windows 11 and could see the media created date when i set the create date with the python script on the windows 10 computer where i'm sometimes i'm unable to see the date.

I noticed that if i set the date and time to 1980:01:01 05:00:00 in the python script

python:1980:01:01 05:00:00
windows 10: 1/1/1980 12am
windows 11: 12/31/1979 9pm

python:1980:01:01 00:00:00
windows 10: 12/31/1979 7pm
windows 11: 12/31/1979 4pm

why does the time change? how can i make it show 12am without changing the date and time by itself?

when you say remux what exactly do you mean?

[velezericn]

btw i tried the ffmpeg command and i still can't see the mediacreated date on windows 10

[StarGeek]

why does the time change? how can i make it show 12am without changing the date and time by itself?

My standard copy/paste on this
Most video time stamps are supposed to be set to UTC and the program is supposed to adjust this to the local time zone when displayed (see 4th paragraph on the Quicktime tags page), with the most common exceptions being the Quicktime:CreationDate (not to be confused with the Quicktime:CreateDate) and the Quicktime:DateTimeOriginal.

If your computer is in the same time zone as where the video was shot, ignoring differences for Daylight/Summer time, then you can add the -api QuickTimeUTC option and exiftool will automatically adjust the time to UTC.  Otherwise, you either have to figure out the UTC yourself or use this -api option and include the correct time zone, e.g. "2023:02:03 04:05:06±07:00".

So for the Windows 10 results, I'm guessing you're in a -05:00 time zone?  Because I know that Windows 8/10 automatically and correctly adjusted the time stamp from UTC when it displays the time under Properties.

Is the Windows 11 machine properly set with the correct time zone?  Because that result indicates that the computer thinks it is in a -08:00 time zone.  Either that or something was broken in Win11.

when you say remux what exactly do you mean?

Muxing, short for multiplexing, is the process of combining video, audio, and possibly other streams (like subtitles) in to a single file.  When you play a video, your computer demuxes the stream into the separate parts and sends the data to the correct outputs, i.e. the video stream goes to the graphics card, the audio goes to the speakers, etc.

Remuxing means demuxing (separating) the streams and then recombining them.  It is a lossless operation, unlike recompressing.  The most common use is the convert the file to a different container.  For example, converting an MKV into an MP4 file.  Or converting an older AVI/Mpeg/ts file into MKV or MP4.

[StarGeek]

btw i tried the ffmpeg command and i still can't see the mediacreated date on windows 10

You would still have to set the time correctly with exiftool afterwards.  The -map_metadata 0 option  should copy the metadata over from the original file, but I don't know enough about ffmpeg to be completely sure.

[velezericn]

Ok so i found out something interesting in terms of the time for jpgs and mp4s.

jpgs it seems you need to give it your local time so the utc adjusted with an offset and then the mp4 if you give it the utc the computer will automatically adjust so that makes alot of sense for what i've been trying to do recently.

i think the data for a larger .mp4 is when windows has trouble showing the mediacreated in the details situation happens. i need more data to support this but when i originally made this post the problem mp4 was 300mb or so and i dont seem to notice that problem with mp4s that are much smaller.