vpx: VP8 and VP9 Encoder

The vpx codec supports both VP8 and VP9 formats. However, VP9 is disabled in versions before 0.15 because it was too slow to be useful.

Please also note that VP8 currently only supports YUV420P colour subsampled data, which leads to some visual degradation, especially with text.

Build and installation

When building xpra from source, vpx support is included by default.

For encoding and decoding support, you should install libvpx. You will need libvpx 1.4 for full VP9 support.

For decoding support only (client) it is possible to use the dec_avcodec or dec_avcodec2 modules if ​ffmpeg (or ​libav if you use this fork) were built with vpx support.

Links

• ​libvpx - The WebM Project
• ​wikipedia VP8

The following wiki pages are also relevant:

• wiki/WindowRefresh - when and how the screen updates are processed
• wiki/Encodings - all the picture encodings available
• wiki/CSC - the Colourspace conversion step

Tickets:

• #455 vpx improvements: vp9 support, zero copy, VBR, speed and quality
• #464 libvpx 1.3: vp9, scaling, lossless modes..