MPEG-2 encoder, GOP and B frames

[jreinaleon]

I have a problem. I encode a video using MPEG-2 video encoder with GOP fixed to 8 and B-frames fixed to 4. The video encoded hasn't these values. The result is something like M=5 N=5.

I'm using avidemux 2.6.21, 32-bits and 64-bits. I tried 2.7.0 version, 32-bits and 64-bits and I have the same problem.

What's the problem? am I doing something wrong?

This is the content of project file:

#PY  <- Needed to identify #
#--automatically built--

adm = Avidemux()
adm.loadVideo("C:/Users/Jose/Documents/UOC/Plataformas de distribución de contenidos/PAC1/clip-02.mp4")
adm.clearSegments()
adm.addSegment(0, 0, 12545000)
adm.markerA = 0
adm.markerB = 12545000
adm.videoCodec("ffMpeg2", "params=CQ=2", "lavcSettings=:version=2:MultiThreaded=2:me_method=5:_GMC=False:_4MV=False:_QPEL=False:_TRELLIS_QUANT=True:qmin=2:
qmax=31:max_qdiff=3:max_b_frames=4:mpeg_quant=1:is_luma_elim_threshold=1:luma_elim_threshold=0:
is_chroma_elim_threshold=1:chroma_elim_threshold=0:lumi_masking=0.050000:is_lumi_masking=1:dark_masking=0.010000:
is_dark_masking=1:qcompress=0.500000:qblur=0.500000:minBitrate=0:maxBitrate=9500:user_matrix=1:gop_size=8:interlaced=False:bff=False:widescreen=True:mb_eval=2:vratetol=8000:
is_temporal_cplx_masking=False:temporal_cplx_masking=0.000000:is_spatial_cplx_masking=False:
spatial_cplx_masking=0.000000:_NORMALIZE_AQP=False:use_xvid_ratecontrol=False:bufferSize=224:
override_ratecontrol=False:dummy=0"
, "matrix=0")
adm.addVideoFilter("resampleFps", "mode=1", "newFpsDen=1000", "newFpsNum=25000")
adm.addVideoFilter("swscale", "width=720", "height=576", "algo=2", "sourceAR=1", "targetAR=1")
adm.audioClearTracks()
adm.setSourceTrackLanguage(0,"unknown")
adm.audioAddTrack(0)
adm.audioCodec(0, "LavAC3");
adm.audioSetResample(0, 48000)
adm.audioSetDrc(0, 0)
adm.audioSetShift(0, 0,0)
adm.setContainer("ffPS", "muxingType=2", "acceptNonCompliant=False", "muxRatekBits=11000", "videoRatekBits=9800", "bufferSizekBytes=224")

Thanks!

P.S.: I know my english is very bad.

[AQUAR]

I think with M=5 then N has to be either 5 or 10.
IBBBBPBBBBI N=10
IBBBBI N=5