Linux offers access to video accelerators through programs like mplayer, VAAPI and vlc.
Offloads 2D scaling and YUV colorspace conversions. Use xvinfo to determine Xv support:
X-Video Extension version 2.2 screen #0 Adaptor #0: "NV17 Video Texture" number of ports: 32 port base: 313 operations supported: PutImage supported visuals: depth 24, visualID 0x21 depth 24, visualID 0x24 depth 24, visualID 0x25 depth 24, visualID 0x26...
MPEG-2 and MPEG-4 offloading (NVIDIA's closed driver only supports MPEG-2, prefering VDPAU) via motion compensation and iDCT offload. Extends the Xv extension, using XvPorts. The 1.0 API specification was introduced in 2000.
The Video Acceleration API, a vendor-independent replacement for XvMC. It has backends for both VDPAU and XvBA.
NVIDIA's proprietary X.org video acceleration API, comparable to Microsoft's DXVA. It is independent from CUDA. Builds atop NVIDIA's PureVideo. On Debian, I have to manually link libvdpau. From /usr/lib:
sudo ln -s vdpau/libvdpau_nvidia.so.260.19.29 libvdpau_nvidia.so sudo ln -s vdpau/libvdpau_trace.so.260.19.29 libvdpau_trace.so
ATI's answer to VDPAU, built atop ATI's Unified Video Decoder.