Universal Binary "Apple Silicon" and CR3

[JS]

Hi,

will  Universal Binary "Apple Silicon" be able to write GPS data to Cr3 files like before to CR2 files?

-John

[dennis]

We are investigating this.

It could be done (properly) by modifying Exif to add GPS table.  But this is tricky code due to the TIFF structure of Exif.  A lot of cameras write a blank GPS table (containing only version for example) but the table is at least present, and it "shouldn't" be too difficult to increase Exif block.

Or if basic GPS table isn't present we could put it into XMP.

Increasing the size of a box in the ISOBMFF format is tricky but we handle it anyway for HEIC/HEIF.  But remember, although CR3 is ISOBMFF like HEIC/HEIF, it IS a proprietary format from Canon.  CR2 files are formatted like many other formats (NEF, ORF, DNG) as a TIFF format.

Right now, we don't update XMP in CR3 - we force a sidecar.  But if we put XMP into CR3 then we could easily add GPS along for the ride.

--dennis

[JS]

Thanks Dennis for quick reply. I didn't understand all You wrote. Looks like world has become  a bit more complicated again.

-John

[JS]

BTW: Reverse Geocoding works well again!

[dennis]

Thanks Dennis for quick reply. I didn't understand all You wrote. Looks like world has become  a bit more complicated again.

It is always complicated 

Also, I really don't like modifying RAW formats because they are proprietary regardless what "format" they are based on (TIFF or ISOBMFF).  I knew how to modify TIFF-based RAW files (e.g. CR2) for a long time, but I refused to do it until I figured out how to undo any modifications to the proprietary format.  Hence we have the "revert" command for TIFF-based RAW.  Not so easy to pull this off with ISOBMFF.

The Canon CR3 format has been difficult for other reasons like generating previews.  All previous RAW formats use a JPEG as a preview but Canon chose not to do that with CR3 (the preview is HEVC or whatever and not a complete image).

--dennis

[JS]

Interesting. I never understood what the "Revert" command was for. Not that I ever needed it. With the CR3 files: If I photograph raw + Jpg. In Preview: Does PM show the separate Jpg or the enclosed HEVC? Is there an advantage for Canon to use a HEVC?

-John

[ahoward]

In Preview: Does PM show the separate Jpg or the enclosed HEVC?

First, let's clarify: Not *every* CR3 has an embedded HEVC. As far as I know (and this is just what I have learned from customers, as the newest SLR that I actually own is from 2008), CR3's will only get an embedded HEVC file when you choose the "HDR-PQ" mode on cameras that offer it and shoot images in that mode. When shooting in this mode, I believe (and again, I have never actually used one of these cameras) there is a setting similar to RAW+JPEG where it will record both the CR3, embedded with an HEVC, and a separate HIF file. Any other mode: your camera embeds a JPEG in the CR3 and creates a JPEG sidecar.

In the current versions of Photo Mechanic (as opposed to Photo Mechanic 5 or older), if there is a JPEG and RAW file of the same base file name in the same folder, when they are paired up into a single thumbnail, Photo Mechanic will show you the JPEG, or if there is a RAW and an HEIC/HEIF file, it will show the HEIC/HEIF file. In other words: it will always show you the sidecar file if there is one.

If there is a standalone CR3 file with an embedded HEVC, if RAW rendering has not been enabled in Photo Mechanic, then you will currently see no preview or thumbnail for that image. If RAW Rendering is enabled, you'll see the version rendered by the chosen RAW renderer, but it will be slow. We are also investigating how to improve this experience so it's not "all or nothing" in terms of RAW rendering, as it is now.

Is there an advantage for Canon to use a HEVC?

Maybe Dennis knows, but that's more of a question for the folks who make the format.

[JS]

Thanks for all explanations.
-John