Choosing JPEG 2000 Several Reasons Exist As to Why It Should Be the Master Compression Format

NEW MEDIA NETWORKS SYSTEMS INTEGRATION Choosing JPEG 2000 Several reasons exist as to why it should be the master compression format. BY JEAN-BAPTISTE LORENT

roadcasters, film studios in the future? Various options are process concerned with the impacts of and post-production hous- possible, and organizations have to changing technologies, whether it is the es are currently facing a decide carefully. support of new media and data formats B major challenge in that the Today’s broadcasters understand or a changing user community. “Long volume of generated video material is the industry’s keywords: highest im- term” may extend indefinitely. increasing dramatically. The result is age quality, flexible delivery formats, To standardize digital preservation a significant increase in the need for interoperability and standardized practices and provide a set of recom- storage and archive capability. profiles for optimal preservation. mendations for preservation pro- Broadcasters and video archivists They also have a vested interest gram, the Reference Model for are also looking for long-term digital in a common high-end format an Open Archival Information System (OAIS) was developed. OAIS is concerned with all tech- Pre- Wavelet Rate Data Codestream Image processing transform Compression control ordering nical aspects of a digital object’s life cycle: ingest into and storage in a preservation infrastructure, data man- LL 2 HL 2 agement, accessibility and distribution. L 1 LL1 HL 1 HL 1 Continued interoperability is strategic; LH 2 HH 2 LL 0 one needs easy and fast format conversion, as well as playback compatibility H 1 LH 1 HH 1 LH 1 HH 1 between manufacturers. For instance, a master file format must not be linked 1st decomposition 2nd decomposition to any specific application, production format or major user. Figure 1. JPEG 2000 is based on discrete wavelet transformation, scalar quantization, • Use open, well-documented industry context modeling, arithmetic coding and post-compression rate allocation. standards — no proprietary formats. preservation. In most cases, the source to store, preserve and commercialize Ideally, focus on standards recog- material is not digital. Instead, it is on the avalanche of video footage gener- nized and used for archiving applica- film that needs to be scanned or high- ated globally. JPEG 2000 is the grow- tions. Open-file formats are published quality analog video tape. ing choice for master file format. specifications, usually maintained by A production and digital archive standards organizations, which can compression format, with no conces- Digital storage keys therefore be used and implemented by sions in video content quality and the There are three keys to digital stor- anyone. For example, an open format actual fabrication process, is the obvi- age preservation: can be implemented by both propri- ous choice — one that reduces storage • Ensure continuous access to content etary and free/open-source softwares, costs compared to uncompressed vid- over time. Archive and storage covers using both types of software licenses. eo, while still maintaining indefinite all activities necessary to ensure con- Open formats are also called free-file protection from loss or damage. Such tinued access to digital materials for as formats if they are not burdened by a format should preserve original long as necessary. This includes strat- any copyrights, patents, trademarks or quality, while also easily enabling the egies to ensure access to reformatted other restrictions. Anyone may use it generation of most of the commonly and digitally-born content, regardless at no cost for any desired purpose. used formats. of the risks of media failure and tech- Several questions are frequent nological changes. Quality preserva- JPEG 2000 in OP1a MXF when selecting a format. What is the tion is crucial. A conversion system JPEG 2000 is based on discrete wave- best physical long-term storage me- of archived items is important for dis- let transformation (DWT), scalar quan- dia for video content? What is a good semination or distribution. tization, context modeling, arithmetic candidate for a digital preservation? • Everything that belongs together fits in coding and post-compression rate al- Can digital content be interpreted one package. Archiving is an enduring location. (See Figure 1.) JPEG 2000

2000 prevents error propagation over multiple frames and allows video sig- nal edition at any given time. Two wavelet filters are included: the irre- versible 9/7 and the fully reversible 5/3. The 5/3 wavelet filter offers a pure Figure 2. JPEG 2000 can be fully lossless or bit-to-bit reversible. Also, the intra-frame mathematically lossless compression, quality of the future-proof codec prevents error propagation over multiple frames. allowing an average 60-percent re- provides random access (i.e., involving frame-by-frame has made it popular in duction in storage, while still allowing minimal decoding) to the block level in the digital intermediate space in Hol- the exact original image information each sub-band, thus making it possible lywood. If the purpose of compression to be recovered. (See Figure 2.) The to decode a region, a low resolution or a is the distribution of essence, and no 9/7 wavelet filter still performs visual- low-quality image version without de- further editing is expected, long-GOP ly lossless encoding. JPEG 2000 offers coding the whole picture. MPEG will typically be preferred. uncompressed quality, with no con- Functionally, JPEG 2000 is a true JPEG 2000 brings a storehouse cession in video content quality and improvement that provides lossy and of features to the broadcast process, an important reduction in bandwidth lossless compression, progressive and whether ingest, transcoding, caption- and storage consumption. parseable code streams, error resil- ing, quality control or audio-track Additionally, its scalability fea- ience, region of interest, proxies, ran- management is requested. Its inher- tures a “create once, use many times” dom access and other features in one ent properties fully qualify it for approach for a wide range of plat- integrated algorithm. high-quality, intermediate creation and forms. Easy transcoding of the co- In the video domain, JPEG 2000 is masters archives. JPEG 2000 supports dec appeals to high-end applications conceived as an intra-frame codec, so every resolution, color depth, num- where workflows vastly benefit from it closely matches the production work- ber of components and frame rates; in transcoding to an intermediate ver- flow in which each video frame is treat- short, the codec is future-proof. sion. JPEG 2000 ensures a clean, ed as a single unit. Its ability to compress The intra-frame quality of JPEG quick operation when bit-rate is at a premium. (See Table 1.) Programs JPEG 2000 compression Correctly transcoded HD1080p SD programs “Math lossless” — at average bit rate JPEG 2000 files compressed at of 100Mb/s 100Mb/s have been labeled “visually Common TV HD programs “Visually lossless” — at average bit identical” to the 2K original footage rate of 200Mb/s by professional viewers. Further- more, the wavelet-based JPEG 2000 High end » HD productions or film “Math lossless” — at average bit rate compression does not interfere with of 450Mb/s the final — usually DCT-based — Table 1. Shown here are typical profiles in use for the JPEG 2000 MXF OP1a master broadcast formats. for preservation. Post-production workflows consist

Adoption for Robustness Open Quality 4:2:2 10 I-frame archiving Lossless to multi- vs. proprietary preservation sampling only app. generation MPEG-2 Long GOP N/A Royalties Limited N/A No N/A Poor H.264 Long GOP N/A Royalties Limited N/A No N/A Poor MPEG-2 intra Adopted Royalties Limited N/A Yes N/A Poor H.264 AVC intra Adopted Royalties Good Yes Yes N/A Good JPEG 2000 visually Most adopted License-free Excellent Yes Yes N/A Excellent lossless (9/7) and royalty- and more free JPEG 2000 lossless Most adopted License-free Perfect Yes Yes Perfect Perfect (5/3) and royalty- and more free

Table 2. Looking at different parameters, JPEG 2000 appears to be ideal as a mezzanine file format.

This article originally appeared in the April 2013 issue of Broadcast Engineering magazine. Copyright 2013, Broadcast Engineering. Reprinted with permission. NEW MEDIA NETWORKS SYSTEMS INTEGRATION of several encoding/decoding cycles. in detail, how JPEG 2000 video data Library of Congress, France’s Institut JPEG 2000 preserves the highest qual- should be encapsulated in the widely National de l’Audiovisuel and several ity throughout this process, without adopted MXF. Hollywood studios, such as 20th Cen- any blocking artifacts creation. More- Finally, a non-technical feature tury Fox, have selected the codec for over, all common bit depths, whether makes the JPEG 2000 open standard storage and preservation. it is 8-bit, 10-bit, 12-bit or 16-bit, even more attractive for long-term JPEG 2000 is a codec like no oth- are supported. projects; it is license- and royalty-free. ers. It gives users a superior quality, Uniquely matching current indus- control and a unique flexibility of the try needs, standardized broadcast pro- Other codecs image processing chain. The grow- files were adopted in 2010 (JPEG 2000 Most other codecs are proprietary. ing use of JPEG 2000 to archive and Part 1 Amd 3 – Profiles for Broadcast Some have compliancy issues and create mezzanine files, and the on- Application - ISO/IEC 15444-1:2004/ several limitations to support any vid- going standardization process of the Amd3), ensuring this wavelet-based eo formats or resolutions. (See Table IMF based on JPEG 2000, are just a codec its benchmark position in con- 2.) The MPEG family is ideal for last- few of its advantages. BE tribution, while fulfilling the industry- mile content delivery to viewers, but Jean-Baptiste Lorent is product manager, wide request for compression stan- not for production and storage, since intoPIX. dards to archive and create mezzanine pictures have to be post-processed. formats. A variety of media distribu- The following are available on the tion channels can be transcoded. The Conclusion Broadcast Engineering website: ongoing standardization process of the JPEG 2000 has gained significant Interoperable Master Format (IMF) by attraction as a mezzanine format. • JPEG 2000, from master to archive SMPTE, focused on JPEG 2000 pro- Open and well-documented, the co- • JPEG 2000 over IP files, brings the adoption full-closure. dec is future-proof and extendable. • Ultra High Definition Television The SMPTELYNX-CHD1812-pickhit+anniv.ai standards also 1 11/3/2012 specify, 2:24:27 That PM said, it is not surprising that the gains global standard status

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