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Guest
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Hi folks,
I'm using mencoder to convert videos to MPEG1 format, but setting the
GOP length does not seem to produce the right GOPs. Examples:
GOP length of 15 (keyint), max. of 2 consecutive B frames
(vmax_b_frames):
IBBPBB|IBBPBBPBBPBBPBB|IBBPBBPBBPBBPBB|...
-> The first GOP contains only 6 frames.
GOP length of 15, max. of 3 consecutive B frames:
IBBBPBBBPBBBPBBB|IBBBPBBBPBBB|IBBBPBBBPBBB|...
-> Only the first GOP contains 15 frames.
Why does this happen? How to get a real GOP length of 15 frames?
The used command line is (using a MVCD matrix):
mencoder -oac twolame -ovc lavc -of mpeg -mpegopts format=xvcd -vf
scale=352:288,harddup -srate 44100 -twolameopts br=128:mode=jstereo -
lavcopts
vcodec=mpeg1video:vrc_buf_size=327:vrc_minrate=300:vbitrate=888:vrc_maxrate=2400:intra_matrix=8,10,16,20,25,28,33,44,10,10,14,26,27,29,34,47,16,14,18,27,29,34,37,48,20,26,27,31,36,37,38,50,25,27,29,32,37,40,48,58,28,33,36,42,45,50,58,68,33,37,39,44,48,56,66,79,37,39,45,48,56,66,79,83:inter_matrix=16,18,20,22,23,27,32,40,18,20,22,24,26,32,36,42,20,22,24,26,33,38,42,44,22,24,26,34,38,42,44,46,23,26,33,38,42,44,46,48,27,32,38,42,44,46,48,50,32,36,42,44,46,48,50,52,40,42,44,46,48,50,52,58:keyint=15:vmax_b_frames=2:aspect=4/3:vstrict=0
-ofps 25 -o outputfile inputfile
Hints from anyone?
Max |
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