Canon EOS R Movie Chroma

[dmbrown]

When I run 'exiftool -s /Path/to/file', the output includes YCbCrSubSampling: YCbCr4:2:2 (2 1). However, this camera records video at 4:2:0, not 4:2:2. I am hoping someone can explain the discrepancy. Mediainfo, on the other hand, reports the 'Chroma Subsampling' as 4:2:0, as expected.

In addition, when I run the same exiftool command as above, but also include the -verbose option, the parameter YCbCrSubSampling is not included in the output. I would appreciate a explanation.

Thank you.

exiftool 11.65; iMac Pro; macOS 10.14.6 with both Supplemental Updates

[StarGeek]

Can you provide an short example video that exhibits this behavior for us to check?

Additionally, try adding the -a (duplicates) option to your command, as there might be duplicate entries (see FAQ #3).

[dmbrown]

I would be happy to send you a file, but can not get one below your 1MB limit. The smallest I have is 2.2MB. Is there an email address to which I can send it, or other method?

I did use the -a option; there are no other relevant color entires (unless I am misunderstanding something.)

Thank you for looking into this.

[Hayo Baan]

You could use a file transfer service eg wetransfer.com.

[StarGeek]

I would be happy to send you a file, but can not get one below your 1MB limit. The smallest I have is 2.2MB

Even if you take a 1 second video with the lens cap on? 

Other options to what Hayo mentioned would be Google Drive, Dropbox, or similar services.

[dmbrown]

A file exhibiting the issue is at https://www.dropbox.com/preview/Public/HNC_0013.MP4?role=personal

[StarGeek]

Try clicking the Share button on the Dropbox website to get a sharable link. 

[dmbrown]

Dropbox's Share feature requires the recipients email address. Please try the following link; it was created with a different Dropbox feature than the first one.

https://www.dropbox.com/sh/4ple69qewo9yzt9/AABxp_4gtB5DOUQToXnSHxOBa?dl=0

I appreciate your perseverance.

[StarGeek]

You can create a direct link.
Click here


Then here


That will create a direct link.

[dmbrown]

That was the process I tried, on the Public Folder in which was the desired file, to get the second link. I used the process on the file itself, with the following result:

https://www.dropbox.com/s/y261m5tbnlh61za/HNC_0013.MP4?dl=0

I also shared it with Google Drive at https://drive.google.com/file/d/10BwuEg0RE7QDjjxa5TJgS5IHFB_ocCv1/view?usp=sharing

[StarGeek]

That works.

FFprobe shows it as yuvj420p, so this is probably something Phil is going to have to dig into.    The trouble is that he is either on vacation or just about to go on vacation.  Either way, it will probably be a couple weeks until this gets looked at.

[dmbrown]

Thank you for working on this. Let me know if I can help in any way.

[Phil Harvey]

ExifTool only extracts metadata, it doesn't decode the video stream to get the actual parameters.

The 4:2:2 is coming from the Canon CNTH ThumbnailImage:

Code Select Expand

> exiftool -ycbcrsubsampling -G5 test.mov
[MOV-Movie-UserData-CanonCNTH-JPEG-SOF0] Y Cb Cr Sub Sampling: YCbCr4:2:2 (2 1)

The metadata from the thumbnail is extracted as the first subdocument (ie. group 3 is "Doc1").

I don't know how to parse the video stream to get this for the video itself.

I'll have to look into why this doesn't appear in the -v output.

- Phil

[dmbrown]

Phil - thank you for the information. I'll report the issue to Canon; I'll let you know what I learn.

[Phil Harvey]

This isn't a problem.  The thumbnail is 4:2:2 as reported.

- Phil