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Signaling of "Clean" Random Access Positions Joint Video Team (JVT) of ISO/IEC MPEG & ITU-T VCEG (ISO/IEC JTC1/SC29/WG11 and ITU-T SG16 Q.6) 3rd Meeting: Fairfax, Virginia, USA, 6-10 May, 2002 Document: JVT-C083 Filename: JVT-C083.doc Title: Signaling of “Clean” Random Access Positions Status: Input Document to JVT Purpose: Proposal Author(s) or Contact(s): Miska M. (...) Introduction Instantaneous decoder refresh refers to “clean” random access, where no data prior to the random access position is referred to in the decoding process. (...) Then, it can reset the multi-picture buffer. 2. Many times random access positions are aligned with scene cuts.
Language:English
Score: 1434103.7 - https://www.itu.int/wftp3/av-a...e/2002_05_Fairfax/JVT-C083.doc
Data Source: un
If A is a pixel in the source picture and B is the spatially corresponding pixel in the current slice, the pixel resulting from the cross-fade operation shall be equal to (A x opacity + (256 – B) x opacity) / 256, where / is division by truncation. 2.3 Random Access to Scene Transitions Scalable scene transitions are coded according to JVT-B042, whereas non-scalable ones do not require other changes than described in the previous section. (...) Otherwise, scalable transitions should be used. Scalable scene transitions typically provide a random access point, as the part of the transition lying in the enhancement layer can be safely disposed. (...) Alternatively, component pictures can be coded and transmitted in ascending order of display time. In any case, a random access to a scene transition may result into a situation where pictures from the previous non-decoded scene are received.
Language:English
Score: 1429974.6 - https://www.itu.int/wftp3/av-a...deo-site/0201_Gen/JVT-B043.doc
Data Source: un
If A is a pixel in the source picture and B is the spatially corresponding pixel in the current slice, the pixel resulting from the cross-fade operation shall be equal to (A x opacity + (256 – B) x opacity) / 256, where / is division by truncation. 2.3 Random Access to Scene Transitions Scalable scene transitions are coded according to JVT-B042, whereas non-scalable ones do not require other changes than described in the previous section. (...) Otherwise, scalable transitions should be used. Scalable scene transitions typically provide a random access point, as the part of the transition lying in the enhancement layer can be safely disposed. (...) Alternatively, component pictures can be coded and transmitted in ascending order of display time. In any case, a random access to a scene transition may result into a situation where pictures from the previous non-decoded scene are received.
Language:English
Score: 1429974.6 - https://www.itu.int/wftp3/av-a...te/2002_01_Geneva/JVT-B043.doc
Data Source: un
. · Taking a burst of photos and · browsing the images within one burst · building joint representations of the photos · Capturing multiple representations of the same scene with · different exposures · different focus · different view-points · Imaging “trick modes” · animating parts of the image area · adding animated effects on the sequence Currently there are basically two options to enable these use cases. (...) Without wishing to break the compatibility with HEVC that both these options offer, it is noted that both approaches are problematic for reasons including the following: · Storing as a sequence of still pictures · Massive file size requirements · No standardized framework for describing the relationship of individual frames · Storing as a video · Limited random access possibility to individual frames · Fixed playback order, no looping indications · Typical OS considers the file as traditional video and sends these to video player for playback In order to efficiently support the use cases considered, the best solution appears to be definition of a format based on HEVC for storing image sequences, with the following characteristics: · Significantly better compression than existing single-image formats · ”Random access” to all pictures to be able to · Show selected picture with minimal delay · Modify pictures without the need to recompress the rest of the sequence · Signaling of the preferred playback · Playback in selected order and be able to modify the order easily · Be able to loop the playback (also forward-backwards) · Indicate if the sequence is not to be played back but user is to browse the pictures · Player needs to easily identify the file is not a traditional image or a video clip · Legacy players should preferably just show a single cover picture 3 Proposal We propose to define a format based on HEVC version 1 and its file format (in ISO/IEC 14496-15) without adding any new tools so that the existing HEVC version 1 decoders can decode image sequences embedded in the new format. The work to enable this is expected to be quite minimal and include: · Definition of indication for the image sequence format · Definition of applicable encoding restrictions (e.g. to limit the random access delay) · Definition of relevant meta-data to enable the use-cases described above (residing either in the file format or in the video bitstream (e.g. as SEI messages), whichever suits the use cases better) We further propose to finalize the requirements in the July 2013 meeting based on the draft requirement provided in Annex B of this document and to coordinate the work between VCEG, MPEG and JPEG as feasible.
Language:English
Score: 1291683 - https://www.itu.int/wftp3/av-a...eo-site/1304_Inc/VCEG-AU11.doc
Data Source: un
It was suggested that scenes with the following feature may be explored and added if foind suitable: · fast random motion (for CIF and QCIF) · scene change with fading · scene with objects transition from blurred to non-blurred (verse versa) 1.2 Coding Conditions for Anchor: The exact conditions described in this document shall be used when encoding anchor material. (...) It was suggested that scenes with the following feature may be explored and added if found suitable: · fast random motion (for CIF and QCIF) · scene change with fading · scene with objects transition from blurred to non-blurred (verse versa) · What about SD progressive?
Language:English
Score: 1290694.2 - https://www.itu.int/wftp3/av-a...-site/0510_Nic/VCEG-AA10d1.doc
Data Source: un
ERROR PROTECTION FOR STORAGE AND TRANSPORT METHODS <07> a) Bit error resilience (random and burst) X X X b) Cell/packet loss resilience X c) Graceful degradation for severe cases X X d) Recovery of synchronization after an X<36> X<36> arbitrary point <08> 9. (...) TRICK MODE a) Fast playback (forward, backward) X b) Normal reverse playback c) Slow motion 14. RANDOM ACCESS / CHANNEL HOPPING X X X<38> 15. REAL TIME ASPECT RATIO CHANGES <12> a) Pan/scan X b) Letter box changes X ------------------------------------------------------------------------------- Notes <01> The standard should be flexible enough to cover a range of picture quality corresponding to a range of bit rates. <02> Clarification is needed in the light of note <01>. <03> 16:9 picture can contain one full size 4:3 picture with three additional 1/9 sized 4:3 pictures. <04> In case of ATM network, this network constriction is called Usage Parameter Control. (...) Temporal scalability may be eventually achieved if H.261 uses reduced frame rate in low bit rates. <36> This may eventually be achieved by the random access and channel hopping requirement. <37> Editing materials for data base etc. <38> Continuous presence multipoint videoconferencing.
Language:English
Score: 1266035.2 - https://www.itu.int/wftp3/av-a.../Report_texts/AVC-0206R_a2.txt
Data Source: un
Syntax and Semantics are included in this contribution.” 101 JVT-C144 [Walker+] Generic Adaptation Layer for JVT Video 102 JVT-C054 [Suzuki+, Sony] Study of Random Access for JVT “In this contribution, further study on random access for JVT codec is reported. (...) The paper proposes slice header syntax and semantics to signal the presence of sync pictures.” 102 JVT-C083 [Hannuksela, Nokia] Signaling of "Clean" Random Access Points “A ‘clean’ random access point is such that no data prior to the point is referred to in the decoding process. (...) We show that it is advantageous to use isolated regions instead of intra pictures to provide random access points in error-prone environments.” 103 JVT-C075 [Wang, TUT] Coding of Masked Scene Transitions Using Isolated Regions “This contribution proposes to code masked scene transitions using isolated regions.
Language:English
Score: 1257633.2 - https://www.itu.int/wftp3/av-a...05_Fairfax/JVT-C-Agenda_r0.doc
Data Source: un
Isolated regions provide an elegant solution for many applications, such as gradual random access, error resiliency/recovery, picture in picture functionality, and coding of masked video scene transitions. (...) Some of the specific techniques applying isolated regions are proposed in the accompanying contributions: JVT-C073 presents the error resiliency/recovery applications; JVT-C074 addresses the application of gradual random access; and JVT-C075 describes the solution for coding of masked scene transitions using isolated regions. 2. isolated regions 2.1 Motivation / Applications Independently decodable regions are needed or desirable in many applications. For example: · Coding of intra frames has been a conventional solution for coding of random access points. Recently, it was suggested to allow random access capabilities at non-intra frames [JVT-B063].
Language:English
Score: 1245980.4 - https://www.itu.int/wftp3/av-a...e/2002_05_Fairfax/JVT-C072.doc
Data Source: un
One is the peak at every intra refresh frame and the other is the peak at almost every scene change. 3.1 I and EI not at the Same Frame EMBED Excel.Sheet.8 Intra refresh is required to help random access and to cut error propagation. (...) The proposed technique works worse at random access than the normal encoding, since image of normal quality cannot be recovered before a decoder meets both I and EI. The proposed technique can not lower peaks at scene changes as shown at Frame 61 in Figure 5. 3.2 Peak at Scene Change Since most macro blocks of the first picture at each scene change are encoded in intra mode, number of bits at the picture becomes a peak if there is no proper rate control.
Language:English
Score: 1229663.3 - https://www.itu.int/wftp3/av-a...video-site/9807_Whi/q15e30.doc
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PICTURE QUALITY <01> a) High quality - pre-processing - temporal prediction - motion estimation - non transform coding - rate control - etc. b) Graceful degradation for critical scenes - rate control mechanism c) Minimum coder-decoder combination should provide targeted performance <02> 3. (...) ERROR PROTECTION FOR STORAGE AND TRANSPORT METHODS <07> a) Bit error resilience (random and burst) - video multiplex structure b) Cell/packet loss resilience such as slice design and absolute MB address - leaky prediction /46/ - demand refresh - error concealment - packetization - layered coding - use of FEC/CRC cells - use of two CLP's /28/ See /20/ for general info. on cell loss resilience. c) Graceful degradation for severe cases - layered coding d) Recovery of synchronization after an - GOP start code arbitrary point <08> 9. (...) TRICK MODE a) Fast playback (forward, backward) - regularly spaced I pictures - use of scalable features b) Normal reverse playback c) Slow motion 14. RANDOM ACCESS / CHANNEL HOPPING - regularly spaced I pictures 15.
Language:English
Score: 1215046.4 - https://www.itu.int/wftp3/av-a.../Report_texts/AVC-0206R_a3.txt
Data Source: un