JVET-R0288 AHG16: Reference samples for ISP [F. Bossen (Sharp)]
It is asserted that during the 15th JVET meeting it was incorrectly determined that the text included in VVC draft 6 and its corresponding software is equivalent to aspect 1 of JVET-O0364 that was intended to be adopted. It is proposed to include aspect 1 of JVET-O0364 (as originally proposed) in the final VVC specification such as to facilitate implementations that use a single reference sample buffer for all blocks within a CU that exercises the ISP mode.
Cross-checker confirms that the software and spec text were thoroughly checked and are aligned.
There is probably some “ugliness” in the current design, and the proposal would simplify the software implementation (avoiding unnecessary duplicate padding). On the other hand, there is nothing broken with the current design, and in hardware it does not seem to be a problem. In the interest of stability of the low level design, no action should be taken.