I'm using SHM 12.2 to perform SNR (video quality scalability).

My GOP structure is something like IBBPBBP and I have an I frame every 96 frames.

So I have to define GOPSize equal to 3. But I get an error.

Error: GOP Size must be a multiple of 2, if GOP Size is greater than 1

Error: ref pic -5 is not available for GOP frame 1

Error: ref pic -9 is not available for GOP frame 1
Error: Invalid GOP structure given


My configuration file includes:
GOPSize : 3 # GOP Size (number of B slice = GOPSize-1)
# Type POC QPoffset CbQPoffset CrQPoffset QPfactor tcOffsetDiv2 betaOffsetDiv2 temporal_id #ref_pics_active #ref_pics reference pictures predict deltaRPS #ref_idcs reference idcs
Frame1: P 1 0 0 0 0.4624 0 0 0 4 4 -1 -5 -9 -13 0
Frame2: B 2 1 0 0 0.4624 0 0 0 4 4 -1 -2 -6 -10 1 -1 5 1 1 1 0 1


Is it possible to have odd number as GOPSize?