IEC International iso Standard ISO/IEC 21122-2 Third edition Information technology JPEG 2024-08 Xs low-latency lightweight image coding system - Part 2: Profiles and buffer models Technologies de I'information - Systeme de codage d'images léger a faible latence JPEG XS - Partie 2: Profils et modeles tampons Reference number ISO/IEC 21122-2:2024(en) @ISO/IEC2024 IS0/IEC 21122-2:2024(en) COPYRIGHT PROTECTED DOCUMENT @IS0/IEC2024 All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below or Iso's member body in the country ofthe requester. ISO copyright office CP 401 : Ch. de Blandonnet 8 CH-1214 Vernier, Geneva Phone:+41227490111 Email: [email protected] Website: www.iso.org Published in Switzerland @ IS0/IEC 2024 - All rights reserved ii IS0/IEC 21122-2:2024(en) Contents Page Foreword. iv Introduction. Scope 1 1 2 Normative references 1 3 Terms and definitions 1 4 Abbreviated terms 4 5 Symbols. 4 6 Conventions 7 6.1 Conformance language 6.2 Operators Arithmetic operators 6.2.1 7 6.2.2 Logical operators 6.2.3 Relational operators. 7 6.2.4 Other operators 7 6.2.5 Precedence order of operators 8 6.2.6 Mathematical functions 8 7 Buffer model 8 7.1 General system block diagram 8 7.2 Influencing variables on the required buffer sizes 9 7.3 Role of the buffer model .10 8 .10 Interpretation of Bayer data 9 Conformance .11 Annex A (normative) Profiles, levels, sublevels and frame buffer bandwidth levels .12 Annex B (normative) Packet-based JPEG XS decoder model .35 Annex C (normative) Packet-based constant bit rate buffer model ..41 Annex D (informative) Encoder model, latency bounds and codestream conformance properties 47 for the packet-based constant bit rate buffer model .52 Annex E (informative) JPEG XS latency analysis Bibliography 61 @ IS0/IEC 2024 - All rights reserved iii