u/AbbreviationsFit8147

I’m trying to understand which kinds of HEVC videos are more likely to contain reference picture list modification signaling (ref_pic_list_modification_flag_l0 / _l1 in the slice header).

From a practical standpoint (real encodes, not just the spec), what types of encodes tend to trigger list modification more often?

Examples I’m thinking about:

• hierarchical B / pyramid GOP (typical VOD)
• low-delay B (where both L0 and L1 come from past references)
• very high --ref / many active refs
• use of long-term references (LTR), etc.

Any pointers or real-world observations would be appreciated.

I’m looking for practical insight on HEVC reference picture list modification.

In HEVC, RefPicListTemp0/1 are derived from the active RPS and default list construction rules, but a slice can signal ref_pic_list_modification_flag_l0/l1 to reorder entries.

Questions:

1. In real-world HEVC bitstreams (e.g., VOD/streaming, Blu-ray, broadcast), how often do you see ref_pic_list_modification_flag_l0 or _l1 set to 1?
2. What are the most common triggers in practice (many refs, hierarchical B, low-delay B, long-term refs, scene cuts, etc.)?
3. Is there any expectation that L1 modifications occur more/less often than L0, or is it encoder- and GOP-dependent?

As a concrete example, for Netflix HEVC encodes (if anyone has inspected them), do you tend to see ref_pic_list_modification_flag_l0/l1 == 1 often, or is it relatively uncommon?

I’m trying to understand how often reference picture list modification is actually used in HEVC/H.265 bitstreams.

In HEVC, after the temporary reference picture lists (RefPicListTemp0/1) are derived using the default rules, the spec allows overriding/reordering them when lists_modification_present_flagis enabled.

In practice, for HEVC-encoded video, how common is it to see ref_pic_list_modification_flag_l0 == 1 and/or ref_pic_list_modification_flag_l1 == 1? Are these flags frequently set in real streaming/VOD encodes, or are they relatively rare?

Also, in what situations does list modification typically show up?

An AI assistant told me that it’s more likely with many reference pictures or hierarchical B (pyramid) GOP structures, and that L1 modifications are more common than L0. Is that actually correct? If not, what’s the more accurate way to think about it?

(As a note: the AI has given me incorrect answers a few times before, so I’d appreciate guidance from people with real bitstream/encoder experience.)