iOS 11 and macOS High Sierra introduced support for these new, industry-standard media formats:
HEIF and HEVC offer better compression than JPEG and H.264, so they use less storage space on your devices and iCloud Photos, while preserving the same visual quality.
You are missing an audio codec or the audio is a format that is not supported. To check which audio codec your file is encoded with, see No audio or audio is distorted with DivX movie playback on a Mac for reference. Note: If your file is encoded with MPEG2 or AC3, see Missing Audio Codec for Mac for reference. K-Lite Codec by Codec Guide contains all major codecs necessary for playing videos on different platforms. Unfortunately, when you switch to Mac OS X, K-Lite Codec is no longer a solution. The list below will provide you with alternatives that can successfully replace K-Lite Codec for Mac. Download the latest version of the XviD codec, which is needed to play XviD videos. We offer free downloads for both Mac OS X and Mac OS 8/9 users.
To fully view, edit, or duplicate HEIF and HEVC media on your device, upgrade to the latest version of iOS 11 or later or macOS High Sierra or later.
When using iOS 11 or later, the following devices can capture media in HEIF or HEVC format. Other devices can view, edit, or duplicate this media with limitations, if using iOS 11 or later or macOS High Sierra or later.
Though capturing in HEIF and HEVC format is recommended, you can set these devices to capture media using the older formats, which are more broadly compatible with other devices and operating systems:
Support for HEIF and HEVC is built into iOS 11 and later and macOS High Sierra and later, letting you view, edit, or duplicate this media in a variety of apps, including Photos, iMovie, and QuickTime Player.
On some older devices, support for HEVC is affected by the resolution and frame rate (fps) of the video. Resolutions of 1080p or lower and frame rates of 60 fps or lower are more broadly compatible with older devices. To reduce the resolution and frame rate that your capture device uses for recording video, go to Settings > Camera > Record Video, as well as Settings > Camera > Record Slo-mo.
If you're using iCloud Photos with iOS 10 or macOS Sierra, you might see a warning icon in the upper-right corner of the photo or video, or you might see an alert message. To fully view, edit, or duplicate HEIF and HEVC media on your device, upgrade to iOS 11 or later or macOS High Sierra or later.
iCloud Photos preserves media in its original format, resolution, and frame rate. If your device can't fully view, edit, or duplicate HEIF or HEVC media in iCloud Photos, or displays it at a lower resolution, upgrade to iOS 11 or later or macOS High Sierra or later.
When you share media using other methods, such as AirDrop, Messages, or email, it might be shared in a more compatible format, such as JPEG or H.264, depending on whether the receiving device supports the newer media format.
You can convert HEIF and HEVC media by exporting to a different format from an Apple or third-party app. For example:
When you import HEIF or HEVC media from an attached iOS device to Photos, Image Capture, or a PC, the media might be converted to JPEG or H.264.
You can change this import behavior in iOS 11 or later. Go to Settings > Photos. In the TRANSFER TO MAC OR PC section, tap Keep Originals to prevent the media from being converted to JPEG or H.264 when importing.
Here you can download for free the Grass Valley HQX Codec Pack for Windows and Mac. With this Codec Pack you are able to work with the high quality HQX Codec, as well as decode and encode your material. You can use the codec without any limitations.
The codec supports 8 and 10bit color depth, alpha channel, resolutions up to 4K (SD, HD, 2K, but even any format like e.g. 120x540).
Grass Valley HQX Codec Pack for Win(Version: 8.50, exe, 37,9MB)
Grass Valley HQX Codec Pack for Mac(Version: 1.05, exe, 0,5MB)