Progressive segmented Frame (PsF) is a High Definition video format used to store progressive content on interlaced media.
Each progressive frame is segmented into two interlaced segments fields without interfield motion, or "combing".
Use
Progressive segmented Frame is similar to interlaced video but lacking motion between the fields. Each "true" progressive frame is seperated into "segments", with the odd lines in one segment and the even lines in the other segment. This allows for a progressive picture to be processed through the same common electronic circuitry that is used with interlaced video. The primary difference between Psf and interlaced video is motion. In Psf there is no motion between the two segments that make up the "progressive" frame while in interlaced there is probably motion between the "fields".
PsF is not an alternative to 2:3 pulldown. 2:3 pulldown is a method of converting 23.976Psf to 59.94i for broadcast in NTSC.
Sony's CineAlta series of cameras are capable of recording directly to 23.976PsF, 24PsF and 25PsF on HDCAM tape along with the intleraced versions of those signals.