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Progressive segmented frame
Progressive segmented frame
Progressive segmented frame
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Progressive segmented frame (PsF, sF, SF) is a scheme designed to acquire, store, modify, and distribute progressive scan video using interlaced equipment.

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. In standard-definition video, which typically uses interlaced scanning, it is also known as quasi-interlace,[1] progressive recording[2] or movie mode.[3] 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

[edit]

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.[4] Brought to life by the movie industry in the end of the 1990s, the original PsF specification was focused on 24 frame/s content resulting in existing interlaced equipment having to be modified for 48 Hz scanning rate in order to work properly with 24 frame/s content.

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."[1] William F. Schreiber, former Director of the Advanced Television Research Program at 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.[5]

Usage

[edit]

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 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.[6] The same digital master appears to be used for the 2006 Blu-ray Disc transfer of the movie.[7]

PsF has been recognized by 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 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 2, and by Alexander Sokurov for creating Russian Ark fully in the digital domain.

Similar technologies

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2:2 pulldown (TV broadcast)

[edit]

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)

[edit]

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").[3]

Video recorders

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PsF is utilized in some DV, HDV and AVCHD camcorders 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:

Note on the progressive recording mode
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.[2]

The booklet for the 50 Hz ("PAL") Sony DSR-PD175P camcorder describes its progressive recording mode as follows:

Progressive Scan Mode
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.[8]

The operating instructions for the 60 Hz ("NTSC") Panasonic PV-GS500 camcorder describe its progressive recording mode as follows:

Pro-Cinema function
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.[9]

The HDV Progressive Primer whitepaper mentions Progressive Segmented Frame mode:

Progressive Scan Mode
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.[10]

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 2:3 pulldown.

Most video formats including professional ones utilize chroma subsampling to reduce amount of chroma information in a video, taking advantage of the human visual system's lower acuity for color differences than for luminance.[11] 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 interlaced artifacts being noticeable on colored objects.[12]

Variants

[edit]
  • 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 that transcends continental boundaries, an area previously reserved for film.[13]
  • 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.[14][15] 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

[edit]
Revisions and contributorsEdit on WikipediaRead on Wikipedia

Progressive segmented frame

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Progressive segmented frame (PsF), also known as segmented frame (sF) or SF, is a digital video encoding scheme that transmits video over interlaced interfaces by dividing a single progressive frame into two segments—comprising the odd and even lines, respectively—each capturing the same instant in time, thereby mimicking an interlaced signal while preserving progressive characteristics. This format ensures that both fields of the "interlaced" output represent identical temporal content, avoiding motion artifacts associated with true interlacing and maintaining full vertical resolution for a filmic appearance. Developed in the late to bridge the gap between emerging progressive high-definition production workflows and legacy interlaced equipment, PsF facilitates the acquisition, storage, editing, and distribution of progressive content without requiring full infrastructure overhauls. It is standardized primarily in SMPTE ST 274M, which defines the image sample structure and specifies the segmented frame interface in Annex A for progressive signals, including mappings for over serial digital interfaces (SDI). Additional guidelines appear in SMPTE RP 211, outlining implementations for frame rates such as 24sF, 25sF, and 30sF, and in SMPTE ST 425-1 for 3G-SDI Level A mapping supporting formats like 1080PsF at 23.98, 24, 25, 29.97, and 30 Hz with 4:2:2 or 4:4:4 color sampling and 10- or 12-bit depth. PsF is commonly employed in professional broadcast and , particularly for cinematic frame rates (e.g., 24 Hz) in high-definition workflows, allowing cameras to output progressive video as an interlaced signal for compatibility with SDI cables and monitors that lack native progressive support. This approach minimizes artifacts during but requires careful handling to align frames for and switching, as the format introduces specific timing considerations in vertical blanking intervals. While effective for HD resolutions like 1920 × 1080, PsF has seen declining use with the widespread adoption of fully progressive infrastructures, though it remains relevant in hybrid environments and for archival purposes.

Technical Fundamentals

Definition

A progressive segmented frame (PsF) is a video format designed to acquire, store, transmit, and distribute progressively scanned images using equipment and interfaces originally intended for interlaced scanning. In PsF, a single progressive frame—capturing all lines of the image at the same instant—is divided into two segments, typically referred to as fields, where one segment contains the odd-numbered lines and the other contains the even-numbered lines. This segmentation enables the progressive content to be transported over interlaced digital interfaces, such as those compliant with (SDI) standards, while maintaining compatibility with legacy interlaced display and processing systems. The "segmented" aspect of PsF distinguishes it from true interlaced scanning, where the two fields of a frame are captured at temporally distinct moments, often separated by 1/60th or 1/50th of a second to exploit motion. In contrast, both segments in a PsF are derived from the same progressive frame captured simultaneously, avoiding the temporal offset and associated artifacts like motion judder inherent in interlaced formats. This approach maps the odd lines onto the line positions of the first field (e.g., total lines 21–560 in a 1125-line structure) and even lines onto the second field (e.g., total lines 584–1123), utilizing the same line numbering as an interlaced picture for seamless integration into existing workflows. PsF is closely related to video, serving as a transport mechanism (often denoted as P/sF or similar) that preserves the full vertical resolution and temporal unity of progressive content without introducing interlacing artifacts. Common notations include PsF for "progressive segmented frame," sF for "segmented frame," and SF as an abbreviation, all referring to this method of conveying progressive images in a segmented structure that emulates interlaced transport but lacks interlaced characteristics.

Encoding Mechanism

The encoding process for Progressive Segmented Frame (PsF) starts with the capture of a complete progressive frame using a single scan, which serves as the source material for the format. This frame is then divided into two distinct fields without introducing temporal offset: the first field comprises all odd-numbered active lines (e.g., lines 1, 3, 5, ..., up to 1079 in a 1080-line frame), while the second field includes all even-numbered active lines (e.g., lines 2, 4, 6, ..., up to 1080). This segmentation preserves the progressive nature of the original image, as both fields represent the same instant in time, unlike true interlaced scanning where fields capture different moments. The resulting fields are formatted and transmitted over an interlaced-compatible interface, such as the 1125-line structure defined for high-definition television, with odd lines mapped to total lines 21 through 560 and even lines to 584 through 1123. To ensure compatibility with interlaced equipment while signaling the progressive intent, the segmented fields are stored and transmitted in a manner mimicking an interlaced signal, but with specific metadata to indicate PsF mode. In uncompressed serial digital interfaces (SDI), identification relies on the Video Payload Identifier (VPID) packet per SMPTE ST 352, embedded in the space, which explicitly codes the as progressive with segmented frame (e.g., byte 3 bit patterns denoting "sF" scanning). For compressed streams like , the (GOP) facilitates PsF indication by encoding the paired fields as a single logical frame, often using flags such as progressive_sequence=1 combined with field-based coding to maintain the lack of inter-field motion. Additionally, the vertical blanking interval (VBI) carries packets, including timecode per SMPTE RP 188, where identical timestamps for both fields confirm their origin from the same progressive frame; film transfer descriptors may also appear at the VBI start to further denote segmented progressive content. Decoding PsF involves recombining the received fields into the original progressive frame, a process handled by compatible equipment that detects the PsF flags or metadata. Since the fields share the same and exhibit no relative motion, the decoder interleaves the odd and even lines sequentially—placing line 1 from Field 1, line 2 from Field 2, line 3 from Field 1, and so on—to reconstruct the full frame without applying artifacts like combing. Specialized deinterlacers recognize PsF via VPID or VBI data and perform straightforward weaving, ensuring the output remains true to the source . This mechanism allows seamless integration with legacy interlaced workflows while delivering progressive quality. For clarity, the frame split can be visualized as follows for a representative 1080-line progressive frame:
ComponentLines IncludedLine CountTransmission Role
Field 1 (Odd)1, 3, 5, ..., 1079540First field in interlaced-like sequence
Field 2 (Even)2, 4, 6, ..., 1080540Second field in interlaced-like sequence
This division ensures each field carries half the vertical resolution, enabling transmission within standard interlaced bandwidth constraints.

History and Development

Origins in Film-to-Video Conversion

The development of progressive segmented frame (PsF) emerged in the early 2000s, driven by the motion picture industry's need to transfer 24 frames per second (fps) cinematic content to 60 Hz video systems without introducing motion artifacts associated with traditional 3:2 pulldown techniques. This approach allowed for high-quality digital archiving and distribution of film scans onto tape formats, preserving the progressive nature of the source material while leveraging existing interlaced infrastructure for transmission and display. Key challenges addressed by early PsF implementations included facilitating global video exchange between 50 Hz PAL and 60 Hz regions, as well as mitigating judder effects that occurred when displaying progressive content on interlaced equipment. By segmenting each progressive frame into two fields containing identical temporal information—odd lines in one field and even lines in the other—PsF enabled compatibility with standard interlaced monitors and (SDI) chains without requiring full progressive hardware upgrades. Interlaced equipment limitations served as the primary compatibility driver, allowing transfers to maintain visual fidelity across diverse broadcast and workflows. The movie industry was a key proponent of PsF for achieving superior quality in film-to-video transfers, with early implementations appearing in DVD authoring processes.

Standardization and Adoption

PsF was first formally defined in SMPTE ST 274M (1998), which specifies the segmented frame interface in Annex A for progressive signals over serial digital interfaces (SDI). The formal standardization of progressive segmented frame (PsF) began with its recognition in Recommendation BT.709-5, published in 2002, which included PsF modes as a method for transporting progressive high-definition video within interlaced systems, specifying parameters for 1080-line formats at both 50 Hz and 60 Hz field rates. This recommendation established PsF as a legitimate format for professional production and international programme exchange, enabling compatibility with existing HD infrastructure while preserving progressive image quality. Subsequent updates, such as those in ITU-R BT.1700 (2005), extended related video signal characteristics to support both standard-definition and high-definition contexts, facilitating broader integration of PsF in analogue and digital workflows. In the , PsF saw significant industry adoption through integration into professional recording formats, notably Sony's HDCAM and later systems, which supported PsF recording for high-definition production starting around 2000 with the introduction of the HDW-F900 . This timeline marked PsF's transition from experimental use in film-to-video transfers to mainstream application, exemplified by its employment in major films such as Star Wars: Episode II – Attack of the Clones (2002), where footage was captured and recorded on HDCAM tape using PsF to maintain progressive frame integrity during . Similarly, (2002) utilized the Sony HDW-F900 for its groundbreaking single-take digital shoot, recording 25p output in PsF format to a hard disk recorder suitable for European broadcast standards. Early equipment support for PsF emerged in professional camcorders like the HDW-F900 (introduced in 2000) and telecine machines such as those from DFT Digital Film Technology, which output PsF signals for seamless film-to-HD video transfers without introducing interlacing artifacts. The Blu-ray Disc specification further embedded PsF compatibility by including 1080p24 modes, allowing professional PsF masters to be authored for consumer playback while preserving the 24 fps film cadence. Globally, standards bodies advanced PsF interoperability through SMPTE RP 188 (1999, with updates), which defined metadata flagging for timecode in serial digital interfaces, enabling precise identification and handling of PsF signals in packets. PsF evolved to fully support both 50 Hz (25PsF) and 60 Hz (30PsF/29.97PsF) systems as outlined in BT.709, accommodating regional broadcast infrastructures in , , and while minimizing bandwidth overhead compared to native progressive transport.

Applications and Usage

High-Definition Production and Broadcast

In production, progressive segmented frame (PsF) has been employed by professional cameras to capture progressive-scan content while maintaining compatibility with interlaced workflows. Sony's HDW-F900 camera, used for the 2002 film —a single-take production shot entirely in the —recorded in using a hard disk recorder attached to the camera, enabling the unbroken 96-minute single take. Similarly, Sony's HDC series cameras, such as the HDC-3500 and HDC-5500, support PsF output through optional software licenses like HZC-PSF50, allowing capture of 1080-line progressive signals segmented into fields for transmission over standard HD-SDI links. These cameras have facilitated PsF use in television production and documentaries, where the format provides motion clarity benefits in live events by avoiding interlacing artifacts, without necessitating a complete overhaul to native progressive systems. In broadcast applications, PsF enables efficient HD transmission within 50 Hz and 60 Hz networks, particularly for progressive content. The European Broadcasting Union (EBU) has endorsed 1080PsF/25 as one of the primary HDTV formats for broadcasting alongside 1080i/25 and 720p/50, supporting progressive material like film transfers over existing interlaced infrastructure. European broadcasters have utilized this for HD content delivery, where 1080PsF/25 minimizes bandwidth demands while preserving vertical resolution. In specialized fields like security and surveillance, Dallmeier systems from 2011 onward incorporate PsF for data transmission, segmenting progressive frames to reduce distortion in analog-to-digital conversions and ensure clear imaging over long cable runs. As of 2020–2025, PsF's role in HD production and broadcast remains limited but persistent in legacy workflows, particularly for compatibility in older HD-SDI pipelines and ATSC 1.0 systems that continue to air content. Its adoption has declined with the shift to native 4K progressive formats, though it endures in transitional setups for maintaining without full equipment upgrades.

Consumer Media Formats

In consumer media formats, progressive segmented frame (PsF) facilitates the distribution of progressive video content through interlaced-compatible systems, particularly on optical discs and early media. This approach allows film-originated material to be encoded without traditional pulldown patterns, preserving frame integrity for during playback on progressive-capable devices. DVDs can include progressive content flagged within or streams for compatible players to output deinterlaced video. Film masters are often transferred as 23.976p to maintain timing compatibility, enabling players to reconstruct full progressive frames and avoid judder from 3:2 pulldown. A representative example is the 2003 Terminator 2: Judgment Day Extreme Edition DVD, where the source master was created at 24PsF resolution prior to downconversion, ensuring high-quality SD delivery with potential for progressive playback. Blu-ray discs support PsF for 1080p24, 1080p25, and 1080p30 content using MPEG-2 or H.264/AVC encoding, where 25p and 30p modes are segmented into 50i or 60i signals for , while 24p can use native progressive. This is common for transfers from broadcast production, allowing seamless to progressive output on modern displays. PsF also appears in consumer recording formats like DV, HDV, and on camcorders, providing progressive capture in interlaced wrappers for editing and playback. Canon models, for instance, use PF30 (30PsF) and PF24 (24PsF) modes at 28 Mbps for 1080-resolution video, embedding full frames across fields in H.264 streams. These legacy formats ensured compatibility with early digital workflows. Post-2010, streaming services shifted from PsF-inclusive legacy encoding to native progressive formats, aligning with device capabilities and bandwidth efficiency. Platforms like Netflix now mandate progressive frame structures for all content submissions, marking the decline of PsF in digital distribution. In 4K UHD Blu-ray, PsF is rarely implemented, as the specification prioritizes native progressive scanning at 24, 25, 50, and 60 fps to optimize HDR10+ dynamic metadata and high-frame-rate content without segmentation overhead.

Variants and Frame Rates

Standard Variants

The standard variants of progressive segmented frame (PsF) are defined within high-definition television (HDTV) frameworks, where progressive-scan images are captured and transported as two segments—odd and even lines—over interlaced interfaces to maintain compatibility with existing systems. These variants adhere to the parameter values for 1,920 × 1,080 active pixels and 1,080 active lines, with square-pixel sampling ( 1:1) and a 16:9 image , as specified for HDTV production and international programme exchange. The 24PsF variant operates at 24 frames per second (or 24/1.001 Hz), resulting in 48 fields per second (or 47.952 Hz), and serves as the primary format for transporting 24 fps content within 60 Hz interlaced systems. Similarly, 25PsF runs at 25 frames per second, yielding 50 fields per second, tailored for regions using 50 Hz infrastructure. For NTSC-derived systems, the 30PsF variant provides 30 frames per second with 60 fields per second, while 29.97PsF adjusts to 29.97 frames per second (or 30/1.001 Hz) with 59.94 fields per second to align with legacy broadcast timings. These variants are typically implemented at 1080-line resolutions, such as 1080i50 carrying 25PsF or 1080i60 carrying 30PsF/29.97PsF, enabling progressive content to utilize standard interlaced line numbering (e.g., active lines 1 to 1,080 mapped to total lines 42 to 1,121). The foundational specifications, including and signal parameters, derive from BT.709, ensuring consistent handling across production workflows.
VariantFrame Rate (Hz)Field Rate (fields/s)Typical Transmission FormatPrimary Application Context
24PsF24 (or 24/1.001)48 (or 47.952)1080i6024 fps film in 60 Hz systems
25PsF25501080i5025 fps in 50 Hz regions
29.97PsF29.97 (or 30/1.001)59.94 (or 60/1.001)1080i59.94NTSC-derived ~30 fps video
30PsF30601080i60~30 fps video

Fractional and Regional Variants

Fractional variants of progressive segmented frame (PsF) adapt the format to non-integer frame rates for compatibility with legacy broadcast standards, particularly in regions using color timing. The 23.976 PsF (equivalent to 24/1.001 PsF) operates at 23.976 frames per second with 47.952 fields per second (or 48/1.001 Hz) to align with NTSC's color subcarrier requirements, facilitating the transfer of 24 fps film content to video without introducing artifacts from speed adjustments. This rate is commonly employed in professional workflows for encoding film-originating material onto formats like HDCAM-SR tapes before distribution to DVD authoring or broadcast, preserving progressive timing while using interlaced infrastructure. Regional adaptations of PsF reflect differences in frequencies and historical broadcast norms, ensuring compatibility across global standards. In 50 Hz regions such as , 25 PsF is standard, transmitting 25 progressive frames per second as segmented fields to match PAL/SECAM-derived systems and avoid flicker on CRT displays. Conversely, North American 60 Hz territories utilize 29.97 PsF (30/1.001 PsF), aligning with NTSC's fractional timing to support 59.94 interlaced fields per second for broadcast and production. These variants maintain the core PsF mechanism of dividing each progressive frame into identical temporal fields while accommodating regional needs. Signaling for HD PsF formats, including both integer and fractional rates, is defined in SMPTE ST 274, which specifies the 1920 × 1080 image sample structure and Annex A for progressive segmented interfaces. This standard enables payload identification and timing for 4:2:2 or sampling at 10- or 12-bit depths, supporting rates like 23.976 PsF, 25 PsF, and 29.97 PsF over serial digital interfaces. In post-2020 hybrid workflows, these fractional and regional PsF variants persist in and conversion software for legacy compatibility, though adoption is declining with the shift to native progressive formats. Applications of PsF at higher resolutions, such as 2160p (4K UHD), have been explored in early trials but lack formal standardization in core ITU recommendations. While ITU-R BT.2020 (updated 2015) outlines UHDTV parameters including fractional frame rates like 23.976p and 50p/59.94p for compatibility with existing infrastructure, it does not explicitly define PsF transport; however, as of 2025, PsF is used in some UHD delivery workflows, such as 2160p25 PsF over 2160i50 for progressive content in interlaced systems.

Pulldown and Cadence Methods

Pulldown methods, such as and 3:2 pulldown, are temporal duplication techniques used to adapt progressive film content at 24 frames per second to broadcast standards, either by repeating fields or frames to match field rates like 50 Hz for PAL or 60 Hz for . These approaches inherently introduce motion artifacts because they create fields from different instants in time, leading to judder or combing effects during playback, particularly on progressive displays. In contrast, progressive segmented frame (PsF) maintains the integrity of each progressive frame by dividing it into two fields captured at the same instant, without any frame or field duplication across time, thus preserving smoother motion representation as defined in SMPTE ST 274 Annex A. The 2:2 pulldown process converts 24 fps film to 50 Hz PAL by first accelerating the film to 25 fps and then duplicating each frame into two identical fields, resulting in 50 fields per second but with repeated content that causes visible judder in scenes with motion. This duplication differs fundamentally from PsF, where a single progressive frame is segmented into top and bottom fields without repetition, avoiding judder by ensuring both fields represent the exact same temporal moment and allowing seamless reconstruction on compatible equipment. While 2:2 cadence is sometimes loosely associated with PsF in processing workflows, true PsF avoids the temporal redundancy of pulldown, providing a cleaner transmission path for progressive sources over interlaced infrastructure. Similarly, 3:2 pulldown adapts 24 fps to 60 Hz by distributing four film frames across five video frames, where three fields come from one frame and two from the next, creating a repeating that introduces combing artifacts and judder, especially noticeable during slow-motion playback or on progressive monitors. PsF circumvents these issues by eschewing any cross-frame field creation, instead segmenting each 24 fps progressive frame into paired fields with identical timestamps, thereby upholding the original without the motion discontinuities inherent in 3:2 duplication. This makes PsF particularly advantageous for high-definition workflows where artifact-free motion is critical. In the PALplus system, mode employs field repetition alongside vertical compression and helper signals to deliver enhanced 16:9 content within the standard 625-line PAL framework, repeating fields from frames to achieve compatibility while supporting options on receivers. However, this repetition-based approach, similar to 2:2 pulldown, can degrade motion fluidity compared to PsF, which offers a purer progressive alternative by segmenting frames without temporal repetition, enabling higher vertical resolution and reduced artifacts in transmissions. Progressive recording in formats like DV and HDV provides a related but distinct method, where true progressive frames are captured and stored without segmentation in digital streams, though HDV often outputs them as PsF for tape compatibility to leverage existing interlaced DV infrastructure. Unlike pulldown techniques that duplicate content for rate matching, DV/HDV progressive modes maintain non-segmented frame integrity during acquisition, but PsF's segmentation facilitates transmission over legacy systems without the judder from field repetition.

Native Progressive and Interlaced Alternatives

Native progressive formats, often denoted by 'p', capture and transmit the entire video frame in a single sequential scan, delivering full vertical resolution simultaneously without any field segmentation. This approach excels in compatibility with modern progressive displays, such as LCD and panels, by avoiding the need for processes that can introduce artifacts. However, native progressive signals demand specialized hardware and interfaces optimized for full-frame handling, rendering them incompatible with traditional interlaced workflows and . In contrast, interlaced formats, marked by 'i', divide each frame into two temporally offset fields—odd lines in one and even lines in the other—to reduce bandwidth demands by approximately half compared to progressive scanning. This temporal separation enables efficient transmission over limited channels but generates motion blur and combing artifacts during fast movement, as the fields represent slightly different moments in time. Progressive segmented frame (PsF) emulates this interlaced field structure for transmission purposes but segments a single progressive frame without any time offset between segments, thereby preserving the original progressive capture's integrity and mitigating the motion-related drawbacks of true interlacing while leveraging existing interlaced infrastructure. Contemporary codecs, including with its MPEG-4 AVC/H.264 compression and HEVC (H.265), predominantly adopt native progressive formats for their streamlined processing and alignment with progressive-only consumer devices, such as smartphones and streaming platforms. These standards support resolutions like and in true progressive mode, favoring direct frame delivery over segmented methods. PsF persists as a transitional in hybrid production environments, where progressive content must interface with legacy interlaced systems like older switchers or monitors. The fundamental distinction of PsF lies in its hybrid design, which enables seamless integration into interlaced pipelines—such as SDI chains—for progressive-sourced material, unlike pure progressive formats that necessitate full system upgrades to avoid signal mismatches.

Advantages and Limitations

Key Benefits

Progressive segmented frame (PsF) offers significant compatibility with existing infrastructure, allowing progressive content to be transmitted and processed using standard 1080i pipelines without requiring full system upgrades. For instance, 1080p/25 material can be mapped directly into 1080i/25 delivery channels as 1080psf/25, ensuring seamless integration with broadcast equipment, switchers, and consumer displays designed for interlaced signals. This approach also supports coexistence with interlaced formats at frame rates like 25 Hz or 30 Hz, utilizing common digital interfaces and line numbering for and monitoring. In terms of quality preservation, PsF maintains the full vertical resolution of progressive scans—such as —while avoiding judder and artifacts associated with frame repetition methods like 3:2 pulldown. Unlike pulldown techniques, which introduce motion inconsistencies when converting 24 fps to 60-field , PsF segments each progressive frame into two fields captured at the same instant, preserving temporal uniformity and delivering undistorted motion portrayal. This results in enhanced detail and reduced motion-related resolution loss compared to traditional interlaced formats, particularly beneficial for and content where clarity is paramount. PsF enhances efficiency, especially for global distribution of 24 fps content, by serving as a universal intermediate format that simplifies conversions across regional standards without additional processing overhead. It enables efficient compression at lower bitrates than some true progressive alternatives in legacy systems, while mimicking interlaced signals (e.g., at 48 Hz for 24PsF) to leverage existing bandwidth and equipment for transmission. This facilitates easier adaptation for both 50 Hz and 60 Hz territories, reducing costs and complexity in pipelines.

Technical Drawbacks and Modern Relevance

One significant technical drawback of progressive segmented frame (PsF) is the risk of misinterpretation by algorithms as true , which can lead to motion artifacts or image degradation if the fields are processed assuming temporal separation between them. Since PsF transmits a single progressive frame as two temporally identical fields, improper —such as applying motion-adaptive blending designed for interlaced content—may introduce combing or blurring in dynamic scenes. This issue arises particularly in legacy equipment or software without explicit PsF flagging, where the signal is automatically treated as interlaced, potentially causing loss of sharpness and vertical resolution during conversion to progressive displays. Additionally, PsF incurs processing overhead due to the need for specialized handling and flagging to ensure correct interpretation, as many systems do not automatically detect it and default to interlaced or progressive assumptions. For instance, converting 24p content to 24PsF doubles the field rate to 48 fields per second but maintains the same data transmission bandwidth as native 24p over HD-SDI (1.485 Gbps), allowing compatibility without additional strain in legacy pipelines. This format is also suboptimal for high-resolution applications like 4K or HDR, where native progressive scanning is preferred to avoid additional conversion steps that could degrade quality. In contemporary video ecosystems as of 2025, PsF has largely become a legacy technology, supplanted by native progressive formats such as 4K at 60p in streaming services like and , which prioritize seamless delivery on progressive displays without segmentation. While it persists in some HD broadcast remnants for compatibility with older infrastructure and in editing software for handling legacy footage, its use has diminished significantly with the widespread adoption of UHD standards that favor direct progressive transmission.

References

  1. https://www.oxfordreference.com/display/10.1093/oi/authority.20110803100348645
  2. https://tech.ebu.ch/docs/techreports/tr002.pdf
  3. https://www.vmix.com/knowledgebase/article.aspx/142/what-does-psf-mean
  4. https://standards.globalspec.com/std/1095006/smpte-st-274m
  5. https://www.ti.com/lit/pdf/snla196
  6. https://www.itu.int/dms_pubrec/itu-r/rec/bt/R-REC-BT.709-4-200003-S!!PDF-E.pdf
  7. https://www.itu.int/dms_pubrec/itu-r/rec/bt/r-rec-bt.709-6-201506-i!!pdf-e.pdf
  8. https://tech.ebu.ch/docs/techreports/tr005.pdf
  9. https://www.telestream.net/pdfs/technical/Guide-to-Standard-HD-Digital-Video-Measurements-25W147006.pdf
  10. https://www.xdcam-user.com/2013/03/04/what-is-psf-or-why-does-my-camera-output-interlace-in-progressive/
  11. https://www.itu.int/rec/R-REC-BT.1700/en
  12. https://pro.sony/s3/cms-static-content/uploadfile/15/1237494517315.pdf
  13. https://ia801403.us.archive.org/0/items/The_Revolution_In_Cinematography_Post_Production_And_Distribution_Brian_Mckernan/The_Revolution_In_Cinematography_Post_Production_And_Distribution_Brian_Mckernan.pdf
  14. https://www.provideocoalition.com/psf8217s_missing_workflow_part_4_file-based_hd_video_recorders/
  15. https://www.cnet.com/tech/home-entertainment/what-is-1080p24/
  16. https://pro.sony/s3/cms-static-content/file/82/1237485155882.pdf
  17. https://pro.sony/ue_US/products/software-licenses-and-upgrades/hzc-psf50---hzc-psf50m---hzc-psf50w
  18. https://www.sony-asia.com/microsite/professional/hdv/pdf/HDV_Progressive_Primer.pdf
  19. https://tech.ebu.ch/news/ebu-members-1080p50-and-4k-production-15jun11
  20. https://www.sourcesecurity.com/datasheets/dallmeier-df3000a-dn/co-527-ga/DF3000A-DN.pdf
  21. https://pro.sony/ue_US/products/4k-and-hd-camera-systems/hdc-3500
  22. https://www.ign.com/articles/2003/05/30/terminator-2-extreme-edition
  23. https://hometheaterhifi.com/technical/technical-reviews/dvd-benchmark-part-5-progressive-scan-dvd/
  24. https://partnerhelp.netflixstudios.com/hc/en-us/articles/7262346654995-Post-Production-Branded-Delivery-Specifications
  25. https://us.blu-raydisc.com/ultrahd-benefits/
  26. https://www.itu.int/dms_pubrec/itu-r/rec/bt/R-REC-BT.709-6-201506-I!!PDF-E.pdf
  27. https://assets.ctfassets.net/870j9u9p7ed7/5cHBa3mBP29ufuK4vKDOzt/7058d5d19a8dfe82b5162201f3c5ffac/ITV_AS11_PROGRAMME_DELIVERY_SPECIFICATION_Version_6.5_APRIL_2025.pdf
  28. https://www.webopedia.com/definitions/2-2-pulldown/
  29. https://wwwapps.grassvalley.com/docs/Application_Notes/media_processing_conversion/alchemist_file/Alchemist_File-How_to_Process_Low_Frame_Rate_Files.pdf
  30. https://ieeexplore.ieee.org/document/867925
  31. https://www.etsi.org/deliver/etsi_i_ets/300700_300799/300731/01_60/ets_300731e01p.pdf
  32. https://www.renesas.com/in/en/document/apn/an9764-palplus-overview
  33. https://www.aja.com/pdf/support/AJA_whitepaper_HDV.pdf
  34. https://vision.unipv.it/wmt/mat/Sony_AVCHD.pdf
  35. https://tech.ebu.ch/docs/tech/tech3328.pdf
  36. https://www.bbc.co.uk/blogs/bbcinternet/2008/11/bbc_hd_picture_quality_and_dol.html
  37. http://car.france3.mars.free.fr/Formation%20INA%20HD/Colorimetrie%20HD/STAGE_HD%20(E)/Divers/Bancroft.pdf
  38. https://www.ti.com/lit/pdf/snla232
  39. https://www.ni.com/docs/en-NL/bundle/video-measurement-suite/page/nivms/signals_digital.html
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