Related to #943, the change in bold is proposed (still relevant in L0030-v3). This extra condition should not affect decision to WPP synchronize (availability check makes it redundant). But it does allow DS synchronization to behave as described in #943.

The context variables of the arithmetic decoding engine are initialized as follows.

– If the coding tree unit is the first coding tree unit in a tile, the initialization process for context variables is invoked as specified in subclause 9.2.1.1. – Otherwise if entropy_coding_sync_enabled_flag is equal to 1, PicWidthInCtbsY is greater than 1 and CtbAddrInRS % PicWidthInCtbsY is equal to 0, the following applies

In a few places, collocated_from_l0_flag is referred to as collocated_from_l0, i.e. the "_flag" suffix missing.

Hello,

actually, variable firstGreater1ScanPos is derived as followed :

firstGreater1ScanPos = -1 ... if (coeff_abs_level_greater1_flag[n] && firstGreater1ScanPos == -1)

firstGreater1ScanPos = n

This means that firstGreater1ScanPos is the first coefficient read from the bitstream having absolute value greater than 1 when we scan from high frequency to low frequency.

The prefix first is used rather for the LAST element in a scan from high frequency to low frequency. This is the case for firstSigScanPos.

I am wondering if we should call it lastGreater1ScanPos instead of firstGreater1ScanPos in order to respect the prefix convention in the spec.

Also, could you please point me to a discussion or study on the use of firstGreater1ScanPos?

Best regards, Phuong Nguyen.