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 separated into "segments", and recorded with the odd lines in one segment followed by 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 to store, process and route 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 typically motion between the "fields".
Unlike normal television, the odd and even lines are from the same snapshot in time – exactly as film is shown today on 625/50 TV systems. This way the signal is more compatible (than normal progressive) for use with video systems, e.g. VTRs, SDTI or HD-SDI connections, mixers/switchers etc., which may also handle interlaced scans. It can also easily be viewed without the need to process the pictures to reduce 24-frame flicker.
PsF is not an alternative to Telecine 2:3 pulldown. Telecine 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 interlaced versions of those signals.