Unlike NVIDIA's VDPAU hardware video decoding API, Open Software projects never adopted VIA's proprietary hardware video decoding API. The Open Source VIA Xorg driver (openchrome) does the XvMC-VLD API for hardware video acceleration. However, the Open Source world is moving to APIs that support more advanced decoding, e.g. VDPAU and VAAPI. For example, MythTV 0.25 will not support either XvMC or XvMC-VLD.
In addition, graphical interfaces are increasingly making use of OpenGL video acceleration. This is this is true of MythTV as well. Unfortunately, while many Open Source Mesa OpenGL drivers are being kept current with the latest kernel and Xorg APIs, the VIA driver (unichrome) is not. As a result, as of Mesa 8.0, the driver is no longer supported.
As a result, once MythTV 0.25 is released, MiniMyth will remove support for VIA graphics hardware.
In addition, once MythTV 0.25 is released, MiniMyth will remove support for VIA C3 and VIA C3-2 compile time optimization.