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{{Short description|Scheme to handle progressive scan video using interlaced equipment}}
'''Progressive segmented Frame''' (PsF, sF, SF) is a [[High-definition_television|High Definition]] mastering video format designed to acquire, store, modify and distribute [[progressive scan|progressive]] content using [[interlaced]] equipment and media. ▼
▲'''Progressive segmented
With PsF, a progressive frame is
The term ''progressive segmented frame'' is used predominantly in relation to [[high-definition video|high definition]] video. In [[standard-definition video]], which typically uses interlaced scanning, it is also known as ''quasi-interlace'',<ref name="POYNTON_DVANDHDTV_P62">{{cite book|url=https://books.google.com/books?id=ra1lcAwgvq4C&pg=RA1-PA62|title=Charles Poynton, Digital Video and HDTV: Algorithms and Interfaces|isbn=9781558607927|last1=Poynton|first1=Charles|year=2003|publisher=Morgan Kaufmann }}</ref> ''progressive recording''<ref name="DCR-HC36/HC46/HC96 OG PR">{{cite web|url=http://www.docs.sony.com/release/DCRHC36-46-96.pdf |title=DCR-HC36/HC46/HC96 Operating Guide |publisher=Sony Corporation |year=2006 |accessdate=2010-08-11}}</ref> or ''movie mode''.<ref name="WSS">{{cite web |last=Hosgood |first=Steven |date=1995 |title=All You Ever Wanted to Know About PALplus but were Afraid to Ask |url=http://stoneship.org.uk/~steve/palplus.html |url-status=dead |archive-url=https://web.archive.org/web/20120807001557/https://stoneship.org.uk/~steve/palplus.html |archive-date=2012-08-07 |website=All You Ever Wanted to Know About PALplus but were Afraid to Ask}}</ref> Other names for PsF used by electronic equipment manufacturers include ''progressive recording'' (Sony), ''progressive scan mode'' (Sony), ''progressive shutter mode'' (Sony), ''frame shutter mode'' (Sony), ''frame mode'' (Panasonic and Canon), ''Digital Cinema'' (Panasonic), ''Pro-Cinema'' (Panasonic) and ''Cinema mode'' (Canon).
== History ==
Not everyone welcomed the PsF standard, however. Some industry observers maintained that native 24p processing would have been a better and cleaner choice. [[Charles Poynton]], an authority in digital television, made 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 name="POYNTON_DVANDHDTV_P62"/> William F. Schreiber, former Director of the Advanced Television Research Program at [[Massachusetts Institute of Technology|MIT]], suspected that the continued advocacy of interlaced equipment originated from consumer electronics companies that were trying to get back the substantial investments they had made in obsolete technology.<ref>{{cite web|url=http://www.cinemasource.com/articles/hist_politics_dtv.pdf|title=The history and politics of DTV}}</ref>
▲With PsF, a progressive frame is sliced into two "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 electronic circuitry that is used to store, process and route interlaced video. Technically, progressive segments are equivalent to interlaced fields, but unlike native interlaced video, there is no motion between the two segments that make up the video frame. Both fields represent the same instant in time.
Despite the criticism, PsF quickly became a de facto standard for high-quality film-to-video transfer. One of the documented examples of PsF usage is the 2003 transfer of the film "[[Terminator 2: Judgment Day]]" to [[DVD]], performed by [[Artisan Entertainment]] and [[THX]]. The original 24 frame/s movie was converted to PsF format and recorded to [[D5 HD|HD-D5]] videotapes. This allowed for the creation of a [[digital master]] that was nearly identical to the original film, and made it possible to edit digitally at the native frame rate.<ref>{{cite web|url=http://www.dtvforum.info/lofiversion/index.php/t16581.html|title=Terminator 2: Extreme Edition|url-status=dead|archiveurl=https://web.archive.org/web/20080531060116/http://www.dtvforum.info/lofiversion/index.php/t16581.html|archivedate=2008-05-31}}</ref> The same digital master appears to be used for the 2006 [[Blu-ray Disc]] transfer of the movie.<ref>{{cite web |last=Bracke |first=Peter M. |date=June 27, 2006 |title=Terminator 2: Judgment Day (Blu-ray) |url=http://bluray.highdefdigest.com/terminator2.html |url-status=dead |archive-url=https://web.archive.org/web/20071018035700/https://bluray.highdefdigest.com/terminator2.html |website=Hi-Def Digest|archive-date=2007-10-18 }}</ref>
PsF has been recognized by [[Rec. 709#Frame rates|Recommendation ITU-R BT.709]] as a legitimate way to transport progressive frames within an interlaced system. 25PsF and 30PsF rates have been added to the specification in addition to the more established 24PsF. "Fractional" frame rates, having the above values divided by 1.001, are also permitted; the resulting 23.976PsF and 29.97PsF rates are used in 59.94 Hz systems. No change from 59.94 Hz systems to 60 Hz (although provided for and anticipated) has occurred, allowing display on analog NTSC color televisions and monitors after down-conversion and encoding.
PsF
==
===2:2 pulldown (TV broadcast)===
[[Telecine#2:2 pulldown|2:2 pulldown]] is widely used in 50 Hz interlaced television systems to broadcast progressive material recorded at 25 frame/s, but is rarely used in 60 Hz systems. The 2:2 pulldown scheme had originally been designed for interlaced displays, so fine vertical details are usually filtered out to minimize ''[[interline twitter]]''. PsF has been designed to transport progressive content and, therefore, does not employ such filtering.
===PALplus film mode (TV broadcast) ===
[[PALplus]] utilizes a digital stream embedded in the interlaced [[analog TV]] signal called [[widescreen signaling]], which, among other data, describes whether the signal should be treated as interlaced ("camera mode") or progressive ("film mode").<ref name="WSS"/>
===Video
<!-- Deleted image removed: [[File:Sony-PSF-workflow.jpg|thumb|300px|right|Video capture, edit and delivery workflow using progressive segmented frame technique (Sony)]] -->
PsF is utilized in some [[DV (video format)|DV]], [[HDV]] and [[AVCHD]] [[camcorder]]s for 25-frame/s and 30-frame/s progressive-scan recording. To achieve this, the camera acquires 30 ([[NTSC]]) or 25 ([[PAL]]) independent images per second. These images are output as 60 (NTSC) or 50 (PAL) interlaced fields. The result is a progressive-scan content, which is compatible with traditional interlaced scanning systems.
24PsF (48sF, 1080sf24, 1920x1080/24/1:1SF) is the original PsF specification, which is used exclusively in professional equipment for film-to-video transfer, mastering and exchange between networks. This may be the first universal video standard which transcends continental boundaries, an area previously reserved for film.<ref>{{cite web|url=http://www.filmmaking-careers.com/film-production.html|title=Steve Wiedemann, 24/P HDTV: The Fall of Film Production}}</ref>▼
This is how Sony described the progressive recording mode in the operating guide for a 60 Hz ("NTSC") Sony DCR-HC96 camcorder:
{{quotation|'''Note on the progressive recording mode'''<br/>In a normal TV broadcast, the screen is divided into 2 finer fields and these are displayed in turn, every 1/60 of a second. Thus, the actual picture displayed in an instant covers only half of the apparent picture area. In progressive recording, the picture is fully displayed with all the pixels.<ref name="DCR-HC36/HC46/HC96 OG PR"/>}}
▲== 25PsF ==
The booklet for the 50 Hz ("PAL") Sony DSR-PD175P camcorder describes its progressive recording mode as follows:
25PsF (1080sf25, 1920x1080/25/1:1SF) is used in 50i systems for production that originates on video and is targeted for television distribution. ▼
{{quotation|'''Progressive Scan Mode'''<br/>The 25p image captured by the sensor system is recorded as an interlaced signal by dividing each frame into two fields. This enables compatibility with current editing and monitoring equipment that only accept interlaced signals, while maintaining the quality of the 25p image.<ref>{{cite web|url=http://www.sony.co.uk/biz/pdf/GeneratePDF.action?product=DSR-PD175P&site=biz_en_GB|title=DSR-PD175P: 1/3-inch 3 Exmor CMOS professional DVCAM camcorder}}</ref>}}
The operating instructions for the 60 Hz ("NTSC") Panasonic PV-GS500 camcorder describe its progressive recording mode as follows:
== 30PsF ==▼
{{quotation|'''Pro-Cinema function'''<br/>In addition to the effects when the Wide function is used, images can also be recorded at a rate of 30 frames a second with a strobe-like effect.<ref>{{cite web|url=http://ftp.panasonic.com/camcorder/om/pv-gs500_mul_om.pdf|title=Panasonic PV-GS500: operating instructions}}</ref>}}
The HDV Progressive Primer whitepaper mentions Progressive Segmented Frame mode:
{{quotation|'''Progressive Scan Mode'''<br/>In this mode, the captured image is divided into two halves, then recorded or output as interlace signal. The halves are called segments, not fields, because there is no temporal difference between them. This method is also called as PsF (Progressive segmented Frame) recording. The Progressive Scan mode is suitable for the feature films, documentaries, music videos which have to be recorded as interlaced video for viewing on interlaced monitors, but want to offer “progressive-look” to their motion. Besides, the video taken in the Progressive Scan mode can be edited and output as true progressive video if needed.<ref>{{cite book | title = HDV Progressive Primer | publisher = Sony | page = 11 | url = http://www.sony-asia.com/microsite/professional/hdv/pdf/HDV_Progressive_Primer.pdf}}</ref>}}
Consumer camcorders as well as most professional camcorders do not use PsF to record 24-frame/s video; instead they either record it natively in progressive form or apply [[Telecine#23pulldown|2:3 pulldown]].
Most video formats including professional ones utilize [[chroma subsampling]] to reduce amount of [[Chrominance|chroma]] information in a video, taking advantage of the human visual system's lower acuity for color differences than for luminance.<ref>
{{cite book
| title = Vision models and applications to image and video processing
| chapter = Vision and Video: Models and Applications
| author = S. Winkler, C. J. van den Branden Lambrecht, and M. Kunt
| editor = Christian J. van den Branden Lambrecht
| publisher = Springer
| year = 2001
| isbn = 978-0-7923-7422-0
| page = 209
| chapter-url = https://books.google.com/books?id=_s2BlAeR66YC&pg=PA209
}}</ref> Such a reduction improves compression of the video signal, which is always desirable because of storage and transmission limitations. To ensure compatibility with interlaced-based systems, chroma information in PsF video is sometimes recorded in interlaced format, despite that the content is progressive. This may result in [[Chroma subsampling#Interlaced and progressive|interlaced artifacts]] being noticeable on colored objects.<ref>
{{cite web
| title = Review: Canon Vixia HF11 AVCHD camcorder
| author = Adam Wilt
| publisher = ProVideo Coalition
| date = 2009-01-12
| url = https://www.provideocoalition.com/review_canon_vixia_hf11_avchd_camcorder/
}}</ref>
▲* '''24PsF''' (48sF, 1080sf24,
▲* '''25PsF''' (1080sf25,
* '''29.97PsF''' (1080sf29, 1920×1080/29.97/1:1SF) formats are sometimes used in 60 Hz systems for sitcoms and music shows.<ref>{{cite web|url=http://www.avsforum.com/avs-vb/showthread.php?p=13998888#post13998888|title='Beside You in Time' by Nine Inch Nails was encoded as interlaced.|date=March 2005 }}</ref><ref>{{cite web |last=Deering |first=Kris |date=November 2008 |title=Sony BDP-S350 Blu-ray Player review |url=http://hometheatermag.com/discplayers/sony_bdp-s350_blu-ray_player/ |url-status=dead |archive-url=https://web.archive.org/web/20090219000355/https://www.hometheatermag.com/discplayers/sony_bdp-s350_blu-ray_player/ |website=Home Theatre|archive-date=2009-02-19 }}</ref> 29.97PsF as well as '''30PsF''' (30p, 1080sf30, 1920×1080/30/1:1SF) formats are gaining popularity as an acquisition format for Web video delivery, because most video hosting web sites cannot stream video with rates higher than 30 frame/s.
==References==
{{Reflist|30em}}
[[Category:Film and video technology]]
▲[[de:Progressive Segmented Frame]]
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