JVET-AN0157 AHG17: Valgrind complexity analysis on CfE encoder run time targets [S. Hong, Y. Tokumo, T. Ikai (Sharp)]

In standard development, decoder execution time has long been recognized as unreliable due to various noise factors. As part of AHG7's mandate, there is a request to “Develop methodology of more reliable runtime measurement.”. Experimental results indicate a strong correlation between decoder execution time and instruction references. This contribution asserts that the Valgrind based operation count is more reliable measure. Although the Valgrind decoding is roughly 60 times than usual decoding, this contribution suggests using Valgrind operation count can be beneficial to obtain a more reliable measurement of decoding operation in specific classes.

It was commented that the decoder run time is also highly dependent on memory accesses, cache misses, and in case of multi-core how many instructions can be performed in parallel.

It was asked why for instruction counting not better performance counter would be used, as this does not increase run time.

JVET-AO0131 AHG3/7: Reference software extension for instruction counting [J. Sauer, Y. Zhao, Y. Sun, E. Alshina (Huawei)]

This document reports findings on instruction counting using special CPU hardware registers. Similar results can be obtained as shown in JVET-AN0119 or JVET-AN0157, but without a runtime performance penalty. It is shown, that instruction count is more stable than measuring runtime. The contribution proposes that reporting instruction count should be allowed as an alternative to reporting runtimes or even to be used instead. Other hardware counters that may also be of interest to AHG19 are cache-misses and branch-misses.

It was claimed that one advantage compared to runtime measurement might be that the instruction count is independent of homogeneity of cluster, SIMD availability, etc.

When using virtual machines, it may not be possible to access the hardware registers.

It was also commented that admin privileges might be necessary.

Some concern was raised to completely replace runtime by instruction count, or make the choice optional. It might be useful as additional information.

It was asked if comparability would still be given when different compilers (even compiler updates) or different degree of compiler optimization was used. SIMD would also be counted as only one instruction.

It was commented that for completely different algorithms, this would not be a good basis for comparison.

Further study was recommended – using additional data might be useful in the context of future standard development.

Traditional tools for profiling can deliver the...

JVET-AN2041 Preliminary Announcement of JVET AHG17 Meeting in Aachen, DE, during 23-27 February 2026 [J.-R. Ohm, M. Wien] (2025-10-27)

Meeting will be hybrid.

Experts requesting for Schengen visa might want to contact J.-R. Ohm and M. Wien as soon as possible.

Future meeting plans, expressions of thanks, a.o.b., and closing of the meeting

The draft of the WG 5 recommendations (see Annex C) was reviewed and approved in JVET at 1030–1100 on Saturday 11 October. In an update discussed on Sunday, the following changes (which had not yet been included in the version that was presented for information in the MPEG WG’s information exchange meeting on Saturday) were approved:

• The following recommendation was deemed necessary to be added: “WG 5 notes that action appears to not yet have been taken on some previous requests for public availability of ISO/IEC deliverables without cost, and kindly requests that ISO/IEC 23008-5:2017 (Ed. 2), ISO/IEC 23008-5:2017/Amd.1:2017, ISO/IEC 23008-8:2018 (Ed. 2), ISO/IEC 23008-8:2018/Amd1:2019, and ISO/IEC 23091-2:2025 (Ed. 3) be made freely available, considering that equivalent publications are freely available elsewhere from ITU-T as editions of ITU-T H.265.2, ITU-T H.265.1, and ITU-T H.273.” Experts were also asked to inform J.-R. Ohm and G. J. Sullivan if relevant standards were missing from this list, as far as they would be expected to be made publicly available.
• The responsible person for delivering 23090-3 is to be changed to Y.K. Wang.
• Some additions are also necessary to the resolutions of thanks, relating to multi-layer testing and...