Hi,

I am trying to code a GOP structure of 4 low-delay-P configuration, where frames 1,2,3 are non-reference frames and frame is 0 a reference frame. Below is the encoder configuration I use:

#======== Coding Structure =============
IntraPeriod : -1 # Period of I-Frame ( -1 = only first)
DecodingRefreshType : 0 # Random Accesss 0:none, 1:CDR, 2:IDR
GOPSize : 4 # GOP Size (number of B slice = GOPSize-1)
# Type POC QPoffset QPfactor tcOffsetDiv2 betaOffsetDiv2 temporal_id #ref_pics_active #ref_pics reference pictures predict deltaRPS #ref_idcs reference idcs
Frame1: P 1 2 0.4624 0 0 1 4 4 -1 -5 -9 -13 0
Frame2: P 2 2 0.4624 0 0 1 3 3 -2 -6 -10 1 -1 5 1 1 1 0 0
Frame3: P 3 2 0.4624 0 0 1 3 3 -3 -7 -11 1 -1 4 1 1 1 0
Frame4: P 4 1 0.578 0 0 0 3 3 -4 -8 -12 1 -1 4 1 1 1 0

Generated bitstream differs from the above specified structure in creating reference picture lists in the first two GOPs, frames 2,3,6 and 7. For these frames, the picture lists include additional reference frames. The rest of the bitstream is correct.

I'd appreciate your comments in case my configuration is the problem.

Below is an example of decoder log file:
POC 0 TId: 0 ( I-SLICE, QP 32 ) [DT 0.016] [L0 ] [L1 ] [:_{,(unk)]
POC 1 TId: 1 ( P-SLICE, QP 34 ) [DT 0.015] [L0 0 ] [L1 ] [:},(unk)]
POC 2 TId: 1 ( P-SLICE, QP 34 ) [DT 0.016] [L0 1 0 ] [L1 ] [:_{,(unk)]
POC 3 TId: 1 ( P-SLICE, QP 34 ) [DT 0.000] [L0 2 1 0 ] [L1 ] [:},(unk)]
POC 4 TId: 0 ( P-SLICE, QP 33 ) [DT 0.015] [L0 0 ] [L1 ] [:_{,(unk)]
POC 5 TId: 1 ( P-SLICE, QP 34 ) [DT 0.016] [L0 4 0 ] [L1 ] [:},(unk)]
POC 6 TId: 1 ( P-SLICE, QP 34 ) [DT 0.015] [L0 5 4 0 ] [L1 ] [:_{,(unk)]
POC 7 TId: 1 ( P-SLICE, QP 34 ) [DT 0.000] [L0 6 4 0 ] [L1 ] [:},(unk)]
POC 8 TId: 0 ( P-SLICE, QP 33 ) [DT 0.000] [L0 4 0 ] [L1 ] [:_{,(unk)]
POC 9 TId: 1 ( P-SLICE, QP 34 ) [DT 0.016] [L0 8 4 0 ] [L1 ] [:},(unk)]
POC 10 TId: 1 ( P-SLICE, QP 34 ) [DT 0.015] [L0 8 4 0 ] [L1 ] [:_{,(unk)]
POC 11 TId: 1 ( P-SLICE, QP 34 ) [DT 0.000] [L0 8 4 0 ] [L1 ] [:},(unk)]