Deinterlacing Rate

For all deinterlacing algorithms except weave, a choice may be made to call NvMediaVideoMixerRenderSurface for either each decoded field, or every second decoded field. If NvMediaVideoMixerRenderSurface is called for every decoded field, the generated post-processed frame rate is equal to the decoded field rate. Put another way, the generated post-processed nominal field rate is equal to 2x the decoded field rate. This is standard practice. If NvMediaVideoMixerRenderSurface is called for every second decoded field (say every top field), the generated post-processed frame rate is half to the decoded field rate. This mode of operation is thus referred to as "half-rate ".

Concatenation of past/current/future surface lists forms a window into the stream of decoded fields. To achieve standard deinterlacing, the window slides through the list of decoded fields, one field at a time, and a call is made to NvMediaVideoMixerRenderSurface for each movement of the window. To achieve half-rate deinterlacing, the window slides through the list of decoded fields, two fields at a time, and a call is made to NvMediaVideoMixerRenderSurface for each movement of the window.