Last Week on My Mac: In search of the missing HEIF

Apart from Apple’s new file system, APFS, the features I was most looking forward to in High Sierra were its new image and movie formats, HEIF (for still images) and HEVC (for video). Having worked through the various installation and related problems with High Sierra, I felt that I was at last ready to try out these new features.

The odd thing is that the only way that I can is using free third-party transcoding. As far as I can tell, this first release of High Sierra and Apple’s apps has almost no support for HEIF or HEVC.

I am also bitterly disappointed that my one-year-old iPad Pro, with last year’s best-ever chipset won’t apparently ever be able to write HEIF or HEVC files. So much for it being a ‘pro’ tool – but that’s another story.

As someone who shoots all their photos in Camera RAW format, whenever possible, my first test was simple: convert some of the images that I took from our visit to the Outer Hebrides this summer from their 16 MB originals to what Apple promises is “up to 2x better compression than JPEG”. I could then compare those images against the originals and JPEG-compressed versions, and establish whether this claim is fair.

I have a big interest in the efficiency of compressed images. I keep both original and prepared versions of all the images for this blog, and probably tens of thousands of others, on this iMac. Although my own photos start in RAW format, the overwhelming majority of those other images are in JPEG. Halving the space that they occupy would be a task worth considering, even though I would still have to transcode them to JPEG for uploading here.

I am a great fan and frequent user of GraphicConverter, which remains the master image conversion tool for macOS. I had already noted that version 10 includes HEIF/HEIC format in its long list of supported formats, but when run on Sierra points out that High Sierra is required for its support. So I tried to save one of my RAW images as a shiny new .heic file.


I wasn’t prepared for this response, nor for the discovery that none of the apps on my Mac was able to write an image as a .heic file, using HEIF format.

I was clearly doing something wrong, or using old apps which hadn’t been fully updated for High Sierra, so cast the net wider by asking in a tweet. I expected to face a barrage of replies berating me for my ignorance, and pointing me in the right direction. Instead, the answer was that no app appeared able to write such image files, yet.

Obviously, I didn’t reach the right people. Searching the web didn’t help either, although a few people seem to have asked the same question, only to be told that it isn’t supported yet.

So I went back to the original presentations from Apple’s WWDC in June. Sure enough, according to those, all macOS systems running High Sierra can decode and encode HEIF content, although only those with the most recent chipsets will benefit from hardware acceleration. I looked at the macOS 10.13 developer release notes, which simply state that “macOS 10.13 adds HEVC and HEIF decode capability.” There is no mention of encoding at all.

It took Alex Karahalios to come up with a solution, which converts JPEG images to HEIF/HEIC format. As macOS 10.13 doesn’t ship with a codec to support HEIF/HEVC, his ingenious script uses two free command tools, ffmpeg and writerapp. At present, ffmpeg seems the only way to write HEIF/HEIC or HEVC encoded images or movies, and it works equally well on Sierra.

I suppose it’s possible that Apple just forgot to deliver the HEVC codec as part of High Sierra. With so many complex features to cater for, it could easily happen. But when Apple’s publicity for High Sierra still lists “HEVC The new standard for video” as its second most important feature only after APFS, I feel entitled to wonder why the content-development products on my Macs don’t support that new standard, and why Apple hasn’t explained this situation.

As of macOS 10.13 and iOS 11, then, HEIF and HEVC are not the wonderful advances which they have been touted as, nor are they Apple’s new standard formats for still images and movies. The evidence points to their being no more than a marketing ploy for its latest iPhones and iPads. And like most marketing ploys, once you cut through the layers of hype, you reach a void which Apple has yet to consider.

If Apple really wanted to establish these new highly-efficient codecs as standard across its computers and devices, it would surely be making them as widely available to Mac and iOS users as possible. This isn’t like APFS, it’s not something which takes time to get right. If a free tool like ffmpeg can encode in HEIF and HEVC, then High Sierra could. And so could my iPad Pro.

It’s only Apple that is standing in the way.