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"Pro-Cinema" was used by Panasonic for the PV-GS500: ftp://ftp.panasonic.com/camcorder/om/pv-gs500_mul_om.pdf , page 41 |
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{{Short description|Scheme to handle progressive scan video using interlaced equipment}}
'''Progressive segmented With PsF, a progressive frame is divided into two ''segments'', with the odd lines in one segment and the even lines in the other segment. Technically, the segments are equivalent to interlaced ''fields'', but unlike native interlaced video, there is no motion between the two fields that make up the video frame: both fields represent the same instant in time. This technique allows for a progressive picture to be processed through the same electronic circuitry that is used to store, process and route interlaced video.
The term ''progressive segmented frame'' is used predominantly in relation to [[high-definition video|high definition]] video. In
== History ==
PsF was designed to simplify the conversion of cinematic content to different video standards, and as a means of video exchange between networks and broadcasters worldwide.<ref>{{cite web |last=Mendrala |first=Jim |date=December 5, 1998 |title=A discussion of 24p frame and the new 48sF frame format |url=http://www.tech-notes.tv/Jim/Articles/24vs48sF.html |
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>
== Usage ==
Despite the criticism, PsF quickly became a de facto standard for high
PsF has been recognized by [[Rec. 709#Frame
PsF became a means of initial image acquisition in professional Sony video cameras. It is employed in [[HDCAM]] and [[XDCAM]] video cameras, including the HDW-F900 [[CineAlta]] camera which was used by [[George Lucas]] for creating [[Star Wars: Episode II – Attack of the Clones|Star Wars, Episode 2]], and by [[Alexander Sokurov]] for creating [[Russian Ark]] fully in the digital ___domain.
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===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
===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 recorders===
<!-- 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.
This is how Sony described the progressive recording mode in the operating guide for a 60 Hz ("NTSC") Sony DCR-HC96 camcorder:
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{{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:
{{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:
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| 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
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| publisher = ProVideo Coalition
| date = 2009-01-12
| url =
}}</ref>
== Variants ==
* '''24PsF''' (48sF, 1080sf24, 1920×1080/24/1:1SF) is the original PsF format, which is used in professional equipment for film-to-video transfer, for high definition mastering and for video exchange between networks. This may be the first universal video standard
* '''25PsF''' (1080sf25, 1920×1080/25/1:1SF) is used in 50 Hz systems for production that originates on video and is targeted for television distribution.
* '''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/ |
==References==
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