Video Acceleration

Linux offers access to video accelerators through programs like mplayer, VAAPI and vlc.

X-Video

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...

XvMC

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.

VAAPI

The Video Acceleration API, a vendor-independent replacement for XvMC.

VDPAU

NVIDIA's proprietary X.org video acceleration API, comparable to Microsoft's DXVA. It is independent from CUDA.