Hello,
I have done some searching here and in the ExifTool help with no luck.
Has someone figured out if Canon has a specific tag for recording the information about "Movie Cropping" from the EOS R5 camera?
I extracted the metadata for 2 different mp4 files (one with cropping and the other one without) and could not find a tag that would indicate this recording feature.
I also tried a web search with no luck.
Thank you.
If it was known, then there probably would be a tag for it.
Try running exiftool on two files with and without the "Movie Cropping" option set and include the -u (unknown) option (https://exiftool.org/exiftool_pod.html#u--unknown).
exiftool -G1 -a -s -U with.mp4 without.mp4
And compare the unknown tags to see if you can find a difference. If you can, then it would be helpful to make samples available and Phil probably will try to add it.
Thank you @StarGeek for your quick response!
Great suggestion, I am going to try to run exiftool with your parameters.
Looking at the current tags, I was hoping to find the cropping pixel sizes, just like we have the sensor size (horizontal & vertical). There are two other tags, Image Source size and Image Size. I was hoping one of them would give me the cropping size but not available. It looks like they are redundant information.
Now I am even wondering if Canon keeps track (a flag somewhere?) when we are shooting Movie Cropping: when reviewing the clip info directly from the camera I cannot find any display information telling me one way or the other.
Do we know if Canon publishes somewhere any tags they are using for their cameras?... or is it thanks to Phil and people like you that we are able to get this kind of information?
Thanks again and I will report about my finding.
Quote from: tordenver on April 15, 2022, 12:14:34 PM
Now I am even wondering if Canon keeps track (a flag somewhere?) when we are shooting Movie Cropping: when reviewing the clip info directly from the camera I cannot find any display information telling me one way or the other.
If there is, it's most likely in the MakerNotes, which is where camera makers usually put camera setting data.
QuoteDo we know if Canon publishes somewhere any tags they are using for their cameras?... or is it thanks to Phil and people like you that we are able to get this kind of information?
They do not. I don't think any camera makers make such information public, though I could be wrong. And it's not thanks to me, but thanks to Phil and a few other people such as greybeard in these forums and other open source projects such as DCRaw (https://www.dechifro.org/dcraw/).
None of the large camera manufacturers publish a metadata specification. A long while back, Sigma published one, but that quickly became obsolete and they haven't ever updated it.
- Phil
Thank you Phil.
@StarGeek - as you suggested I ran the exiftool command to find out the differences between the mp4 file with and without "movie cropping" setting.
Attached is an xls file with the selection of the tags that have different values for each file (in green color in my xls file). They are from the Canon group of tags. I am not sure what they corresponds to.
I kept in yellow, tags that seem to need more extractions to find out if the values are different or not. Do we know what to what information they correspond to?
I also kept some tag information with no color just for reference.
What would be my next troubleshooting to find out if these different values have any correlation with the "Movie cropping" setting?
Thank you
Can you send me two short videos, on cropped and one not, so I can take a look at the differences in the binary data? My email is philharvey66 at gmail.com
- Phil
Yes certainly Phil. Let me upload them to my Dropbox and send you a link for these 2 videos.
Thanks!
Hello Phil,
Here it is:
https://www.dropbox.com/sh/jv7ro55phx8cnna/AADHMNUliH9kesxG09qqRHW0a?dl=0 (https://www.dropbox.com/sh/jv7ro55phx8cnna/AADHMNUliH9kesxG09qqRHW0a?dl=0)
You will find the following EOS R5 camera recorded files:
. FAM_1387_4K-D-Fine_all-I.MP4 - this is a 4K DCI movie recording with no cropping (from 8K sensor to 4K DCI scale down recording)
. FAM_1388_4K-D_Crop_all-I.MP4 - this is a 4K DCI movie recording with cropping (from 8K sensor cropping to 4K DCI recording)
Each file is around 650MB. If it is too large for your download let me know and I can make you smaller ones.
Thanks again for looking into it.
This looks interesting to me, but you would have to try it on more videos to see if it is related to the crop settings:
> exiftool ~/Desktop/FAM* -Canon_0x4049 -u
======== /Users/phil/Desktop/FAM_1387_4K-D-Fine_all-I.MP4
Canon 0x4049 : 8 0 0 0
======== /Users/phil/Desktop/FAM_1388_4K-D_Crop_all-I.MP4
Canon 0x4049 : 8 1 0 1
- Phil
Thanks Phil. Are you thinking that the Canon_0x4049 is some kind of tag for the movie crop setting? does the 8000 or 8101 mean anything particular... or just a flag?
If this is the case, would you suggest I generate other videos with and without the movie crop setting and see if the flag is consistent with my observation? anything else you would suggest I test?
Thanks again.
David
Hi David,
0x4049 is the tag ID, but this tag is currently unknown so the -u option is needed to extract it.
Yes, run some more tests to see if this (or any other unknown tag) correlates with the crop settings. If you discover something, then I can give the tag a name and extract it without needing -u.
- Phil
Thanks for correcting me regarding the unknown tag. I will generate more files and let you know if this is consistent with your finding.
Best,
David