HAP Codecs

Information for Developers

HAP works by applying a lightweight secondary compressor to standard compressed texture formats. Playback involves retreiving frames from the container (demuxing) and decompressing them to their compressed texture data (decoding), which is then presented directly to OpenGL or Direct3D.

Below you can find information to help add support for HAP into your own software. In many cases you can simply use an existing framework or library to enable both playback and encoding. For more information you can also visit the HAP project page on GitHub.

Creative Coding Environments

The following addons enable HAP support in popular creative coding environments:

Custom Software

If you are already using AVFoundation, FFmpeg, LibAV, DirectShow or QuickTime for movie playback or encoding it is relatively easy to add native support for the HAP video codecs to your own applications. Additional information can be found in the sections below.

Playing HAP media files

The route you choose to achieve playback will depend on the platforms you target, and your existing codebase:

Use any general purpose demuxer and perform the decoding yourself — Using a demuxer such as libavformat from FFmpeg, acquire encoded frames from their container, then use the HAP reference decoder to decode frames to their compressed texture formats.
Use the HapInAVFoundation framework on macOS — HapInAVFoundation supports demuxing and decoding of HAP on macOS. For legacy 32-bit applications there is sample code and a codec installer for working with HAP through QuickTime.
Use the DirectShow codec on Windows — Although it does not support HAP Q Alpha, the HAP DirectShow codec can decode to compressed texture formats when they are requested.

HAP Q and HAP Q Alpha use a YCoCg colorspace and require a shader to perform colorspace conversion when drawn.

The following fragment shader performs YCoCg conversion and can be used for drawing HAP Q frames:

The following fragment shader performs YCoCg conversion and combines the colour and alpha planes for HAP Q Alpha frames:

Encoding HAP video within your application

For many applications, enabling playback is sufficient, and users can be directed to one of the available HAP codecs to encode their media.

If you want to perform encoding within your application, you must first of all encode your RGB(A) frames to the appropriate compressed texture format, and then encode that data to HAP frames.

A number of libraries are available to perform texture compression.

The following resources may help:

The HAP reference encoder encodes compressed texture data to HAP frames.
On macOS HapInAVFoundation supports the full encoding process and includes a CLI for transcoding media files.
The source for the HAP QuickTime Codec.
FFmpeg can be used to encode media to HAP from the command line. Additional information can be found on the Using HAP page of this website.

Further Information

If you have questions or problems, visit the GitHub issues page. The HAP codecs email list is used to make occasional announcements.