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29th Meeting: by teleconference, DE, January 2023 2023-01-13 22:47
MTT maximum depth correction for class B sequences at QP 22 in ECM
Authors: Guillaume Laroche Canon Patrice Onno Canon
Abstract
The purpose of this contribution is to correct an error introduced by one ECM-6.0 adoption related to the maximum tree depth of Multiple Type Tree (MTT) for Class A when QP=22 in Random Access (RA). Unfortunately, the software change related to this adoption also unexpectedly affected the Class B sequences by accidentally increasing (from 2 to 3) the maximum Multiple Type Tree (MTT) depth when the QP=22 in RA. The intention of this contribution is to correct this error and to return to the initial setting for Class B sequences at QP=22 for RA to save encoder runtime while maintaining the intended adoption for the ECM 6.0.
Meeting Notes
JVET-AC0123 MTT maximum depth correction for class B sequences at QP 22 in ECM [G. Laroche, P. Onno (Canon)]

The purpose of this contribution is to correct an error introduced by one ECM-6.0 adoption related to the maximum tree depth of Multiple Type Tree (MTT) for Class A when QP=22 in Random Access (RA). Unfortunately, the software change related to this adoption also unexpectedly affected the Class B sequences by accidentally increasing (from 2 to 3) the maximum Multiple Type Tree (MTT) depth when the QP=22 in RA. The intention of this contribution is to correct this error and to return to the initial setting for Class B sequences at QP=22 for RA to save encoder runtime while maintaining the intended adoption for the ECM 6.0.

The maximum MTT depth was introduced in JVET-AA0098 with the intent of maximum runtime reduction for class A sequences. Its application to class B had not originally been intended.

It was pointed out that the change also would apply to the VTM11-ecm6 anchor, and would also lead to a run time reduction of its encoding. This means the anchor bitstreams at least for class B@QP22 will change.

Decision (BF/SW): Adopt JVET-AC0123.

Cited:
JVET-AC0235 X
ARCHIVE :
JVET-AC0123_v1.0.docx JVET-AC0123_v1.0.pdf Results_JVET-AC0123_vs_ECM-7.0.xlsm Results_JVET-AC0123_vs_ECM-7.0_v2.xlsm
Decisions
adopted
Decision (BF/SW): Adopt JVET-AC0123.
Citation