[Mp4-tech] Question regarding reference list in B Slice

[Ye-Kui.Wang nokia.com]

Hi Eric,
1. For temporal scalability. The reason is that temporal enhancement layers may contain reference pictures and they may not be present in the bitstream after stream thinning. 
2. I think the latter is correct: the encoder has to make it impossible to have non-existing pictures being included in the lists. 
3. POC is needed in constructing the initial reference picture lists for B slices and is also needed in the operation of output order DPB (C.4.1-C.4.5).
BR, YK
________________________________
	From: mp4-tech-bounces lists.mpegif.org [mailto:mp4-tech-bounces lists.mpegif.org] 
	Sent: 2006$BG/(B2$B7n(B22$BF|(B 2:18
	To: garysull windows.microsoft.com; mp4-tech lists.mpegif.org
	Subject: [Mp4-tech] Question regarding reference list in B Slice
	Dear experts,
	In standard, it mentions the non-existing reference frame would be put into DPB when frame number gap is allowed. I have 3 questions about this.
	1.       What$B!G(Bs the usage of frame_num gap ? Why it$B!G(Bs introduced in standard ? Is there any document on the reason ?
	2.       When constructing reference list for B Slice, the standard describes that reference pictures marked as non-existing are not included in RefList0 or RefList1, is this exclusion operaton is done specially by decoder, or encoder has make it impossible to happen by using reference picture list reordering ?
	3.       Since non-existing reference picture cannot be put into RefList0 or RefList1 in B slice, why standard specifies the default value of delta_pic_order_cnt[0] and delta_pic_order_cnt[1] to them in section 8.2.5.2. Is there any place to reference the POC of non-existing pictures ?
	Thanks in advance,
	Eric
-------------- next part --------------
An HTML attachment was scrubbed...
URL: /pipermail/mp4-tech/attachments/20060224/0f23adcb/attachment.html