id	summary	reporter	owner	description	type	status	priority	milestone	component	version	resolution	keywords	cc
1523	Wrong update of prevTid0Pic	kolya		"There is wrong update of POC in Void TDecTop::xCreateLostPicture(Int iLostPoc) line 370 of TDecTop.cpp caling xUpdatePreviousTid0POC.

When missing frame is after first POC MSB cycle, and that missing frame is coded as a LT reference with syntax delta_poc_msb_present_flag[i] == 0 and and used_by_curr_pic_lt_flag[i] == 1, the lost pic handling routine sets the POC of the missing pic by POC LSB only and full POC correct recovering is not possible in that case. Nevertheless, that is not the problem by itself and does not make the bitstream non-compliant with spec, but lost pic copying routine erroneously updates the common value of prevTid0Pic which is used for next POC derivation.

According to spec, prevTidOPic should be a value for the pic in decoding order, not for the lost pic.

The bug appears as POC number going crazy after first POC MSB cycle provided there is a referenced but lost pic in DPB.

N.Shlyakhov _at_ ieee -dot- org
"	defect	new	critical	HM-next	HM			longterm, prevTid0Pic, decoder	ksuehring karlsharman jvet@…