Opened 3 years ago

Last modified 3 years ago

#1287 new defect

Encoder: sps_max_dec_pic_buffering_minus1 may be set too low

Reported by: ksuehring Owned by:
Priority: minor Milestone:
Component: HM Version: HM-14.0
Keywords: Cc: fbossen, ksuehring, davidf, jct-vc@…, rickard

Description

With non-CTC GOP configurations the value set for sps_max_dec_pic_buffering_minus1 may be set too low.

sps_max_dec_pic_buffering_minus1 is currently based independently on the number of reference frames and the number of frames required for reordering. In GOP structures where different pictures are required for reference and reordering, the resulting value is too low. (e.g. a hierarchical GOP that only uses tid0 pictures as reference)

No error is output while encoding, and the reconstructed YUV file contains all pictures in input order. In combination with #1286 this results in encoder-decoder mismatch without any reported error in either encoder or decoder.

Possible solutions:

1) improve detection of required sps_max_dec_pic_buffering_minus1

2a) check ordering constraint and give an error, when ascending POC cannot be achieved
2b) allow the user to increase/specify the value of sps_max_dec_pic_buffering_minus1 (which might be complicated because the values exists per temporal ID)

Change History (2)

comment:1 Changed 3 years ago by DefaultCC Plugin

  • Cc fbossen ksuehring davidf jct-vc@… added

comment:2 Changed 3 years ago by ksuehring

  • Cc rickard added
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  • David Flynn(Subscriber, Always)
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  • Karsten Suehring(Reporter, Subscriber, Participant, Always)
  • Rickard Sjoberg(Subscriber)