ExifTool Forum

ExifTool => Bug Reports / Feature Requests => Topic started by: dmbrown on September 01, 2019, 12:49:43 PM

Title: Canon EOS R Movie Chroma
Post by: dmbrown on September 01, 2019, 12:49:43 PM
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
Title: Re: Canon EOS R Movie Chroma
Post by: StarGeek on September 01, 2019, 01:27:51 PM
Can you provide an short example video that exhibits this behavior for us to check?

Additionally, try adding the -a (duplicates) option (https://exiftool.org/exiftool_pod.html#a---a--duplicates---duplicates) to your command, as there might be duplicate entries (see FAQ #3 (https://exiftool.org/faq.html#Q3)).
Title: Re: Canon EOS R Movie Chroma
Post by: dmbrown on September 01, 2019, 04:13:42 PM
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.
Title: Re: Canon EOS R Movie Chroma
Post by: Hayo Baan on September 02, 2019, 01:07:07 AM
You could use a file transfer service eg wetransfer.com (http://wetransfer.com).
Title: Re: Canon EOS R Movie Chroma
Post by: StarGeek on September 02, 2019, 03:21:52 AM
Quote from: dmbrown on September 01, 2019, 04:13:42 PM
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.
Title: Re: Canon EOS R Movie Chroma
Post by: dmbrown on September 02, 2019, 02:02:39 PM
A file exhibiting the issue is at https://www.dropbox.com/preview/Public/HNC_0013.MP4?role=personal
Title: Re: Canon EOS R Movie Chroma
Post by: StarGeek on September 02, 2019, 02:09:53 PM
Try clicking the Share button on the Dropbox website to get a sharable link. 
(https://i.imgur.com/KKbJdkO.png)
Title: Re: Canon EOS R Movie Chroma
Post by: dmbrown on September 02, 2019, 02:21:42 PM
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.
Title: Re: Canon EOS R Movie Chroma
Post by: StarGeek on September 02, 2019, 02:43:44 PM
You can create a direct link.
Click here
(https://i.imgur.com/dwzz5rb.png)

Then here
(https://i.imgur.com/ciqQfQ9.png)

That will create a direct link.
Title: Re: Canon EOS R Movie Chroma
Post by: dmbrown on September 02, 2019, 02:47:52 PM
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
Title: Re: Canon EOS R Movie Chroma
Post by: StarGeek on September 02, 2019, 03:19:44 PM
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.
Title: Re: Canon EOS R Movie Chroma
Post by: dmbrown on September 02, 2019, 03:21:45 PM
Thank you for working on this. Let me know if I can help in any way.
Title: Re: Canon EOS R Movie Chroma
Post by: Phil Harvey on September 26, 2019, 11:19:04 AM
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:

> 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

Title: Re: Canon EOS R Movie Chroma
Post by: dmbrown on September 26, 2019, 02:42:52 PM
Phil - thank you for the information. I'll report the issue to Canon; I'll let you know what I learn.
Title: Re: Canon EOS R Movie Chroma
Post by: Phil Harvey on September 27, 2019, 06:48:25 AM
This isn't a problem.  The thumbnail is 4:2:2 as reported.

- Phil
Title: Re: Canon EOS R Movie Chroma
Post by: dmbrown on September 27, 2019, 02:45:21 PM
Thanks again. After posting my message, it occurred to me that might be the case.