... One of these factors is how the client application uses VDPAU; i.e. the number of surfaces allocated for buffering, order of operations, etc. ... At a bare minimum, the application must allocate one video surface for each reference frame that the stream can use (2 for MPEG or VC-1, a variable stream-dependent number for H.264) plus one surface for the picture currently being decoded. However, if this minimum number of surfaces is used, performance may be poor. ... Performance Levels . ...

... 2.3 Data acquisition Spectra generated by the Multibeam correlator contain the usual structure seen in spectra from other H i instruments: a bandpass spectrum which is the sum of the sky , ground and receiver temperatures multiplied by the product of the filters in the receiver chain; superimposed on this is a noise ... Note also that sources extended much beyond ,40 arcmin can be imaged poorly in HIPASS images because of the bandpass sidelobe effect described in Section 3.3. ...