DIfference in BamUtils and Samtools Flagstats

[sanchari24]

Hi,
I observed some difference between Samtools flagstats and BamUtils. I could be wrong. Could you pls explain the differences ?

bamUtils

Number of records read = 284514507

TotalReads(e6) 284.51
MappedReads(e6) 279.49
PairedReads(e6) 149.73
ProperPair(e6) 87.84
DuplicateReads(e6) 154.57
QCFailureReads(e6) 222.00

MappingRate(%) 98.23
PairedReads(%) 52.63
ProperPair(%) 30.87
DupRate(%) 54.33
QCFailRate(%) 78.03

TotalBases(e6) 43884.78
BasesInMappedReads(e6) 43162.32

samtools flagstats

62511098 + 222003409 in total (QC-passed reads + QC-failed reads)
0 + 0 secondary
8390816 + 17004107 supplementary
35431353 + 119142032 duplicates
62511098 + 216975520 mapped (100.00% : 97.74%)
0 + 140807928 paired in sequencing
0 + 61867283 read1
0 + 78940645 read2
0 + 85755058 properly paired (N/A : 60.90%)
0 + 127356567 with itself and mate mapped
0 + 8423472 singletons (N/A : 5.98%)
0 + 37244505 with mate mapped to a different chr
0 + 31112912 with mate mapped to a different chr (mapQ>=5)