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'''Progressive segmented Frame''' (PsF, 24PsF, 48sF, 1080sf24, 1920x1080/24/1:1SF) is a [[High-definition_television|High Definition]] mastering video format
== History ==
With PsF, a progressive frame is separated 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 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". The signal is played back at [[1080i]] but when viewed, it is seen as true [[1080p]]▼
Originally, PsF was not meant neither for [[High-definition_television|broadcast]] nor for usage in home video devices. PsF was designed as a standard to simplify the conversion of cinematic content to different video standards, and as means for video exchange between networks and broadcasters worldwide.<ref>{{cite web|url=http://www.tech-notes.tv/Jim/Articles/24vs48sF.html|title=Jim Mendrala, "A discussion of 24p frame and the new 48sF frame format"}}</ref> Brought to life by the movie industry in the end of 1990-ies, the original PsF specification was focused on 24 fps content. Existing interlaced equipment had to be modified for 48i scanning rate in order to work properly with PsF video.
== PsF and 2:2 pulldown ==▼
▲With PsF, a progressive frame is separated 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 to store, process and route interlaced video.
Progressive segmented frame technique is equivalent to [[Telecine|2:2 pulldown]] pattern. It seems that "PsF" is used for material originated on video, while "2:2 pulldown" seems to be used for [[Telecine|telecine]] process, and in broadcast. ▼
Not everyone welcomed the PsF standard. Some industry observers maintained that native 24p processing would have been a better and cleaner choice. Others accused Sony Pictures in lobbying products of its parent company, Sony Corporation, which at that time was producing interlaced equipment. Charles Poynton, an authority in digital television, makes the following remark in his book: "Proponents of [PsF] scheme claim compatibility with interlaced processing and recording equipment, a dubious objective in my view."<ref>{{cite web|url=http://books.google.com/books?id=ra1lcAwgvq4C&pg=RA1-PA62&sig=8ZAl0RqzUYnyxQSmjxiIw4ZJDbE|title=Charles Poynton, "Digital Video and HDTV: Algorithms and Interfaces"}}</ref>
Progressive segmented frame technique is equivalent to [[Telecine|2:2 pulldown]] pattern, which is used in PAL/SECAM television for at least half a century. As Charles Poynton explains, "film is transferred to 576i video using 2:2 pulldown: Each film frame is scanned into two video fields (or frames); the film is run 4% fast."
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== 25PsF ==
25PsF (1080sf25, 1920x1080/25/1:1SF) is used in 50i systems for production that originates on video and is targeted for television distribution.
Along with many professional video cameras, this standard is supported by some consumer camcorders like European version of the Canon HV20, which has both interlaced 1080i50 (HDV) mode as well as progressive 1080PsF25 (HDV25) mode.
== 30PsF ==
30PsF (1080sf30, 1920x1080/30/1:1SF) gains increased popularity in 60i systems as progressive mastering standard as well as Web delivery format.
Along with many professional video cameras, this standard is supported by some consumer equipment like North American/Japanese version of the Canon HV30 camcorder, which has native interlaced mode (1080i60, HDV), progressive 24p mode with 2:3 cadence (1080p24, HDV24) as well as PsF mode (1080PsF30, HDV30) mode.
At present time 30PsF is not well suited for television distribution, because very few television sets are able to detect 2:2 cadence of 30PsF video. As such, these TV sets may try to deinterlace video by dropping one field of each frame, halving vertical resolution.
== Examples of using PsF for acquisition ==
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