[MEncoder-users] mencoder to PSP -> strange results

[Nigel]

Hi all,

Ive seen the other posts regardhing encoding to PSP mp4 using mencoder, but 
I have a strange problem
using mencoder precompiled binaries for Win32 from 
http://oss.netfarm.it/mplayer-win32.php

I'm trying to encode to a MPEG4-SP PSP format and in general it works, but 
sometimes the PSP just shows the files as incompatible data. (PSP fw 2.5 / 
2.6 / 2.71).

ie. Chapter 1 from the DVD, shows incompatible data, Chapter 2 is ok and 
plays fine
I then get mixed results depending on what DVD I use, some chapters are OK 
as above, some show as incompatible data

example command lines

mencoder-amd dvd://1 -dvd-device E:\ -chapter 01-01 -srate 24000 -af 
volume=10 -aspect 16:9  -of lavf -lavfopts 
format=psp:i_certify_that_my_video_stream_does_not_use_b_frames -oac 
lavc -ovc lavc -lavcopts 
aglobal=1:vglobal=1:vcodec=mpeg4:acodec=aac:vbitrate=515:abitrate=128 -vf 
scale=368:208,harddup -info name="TEST1" -ofps 30000/1001 -o M4V70001.MP4 
<< doesn't play, shows as incomptible data

mencoder-amd dvd://1 -dvd-device E:\ -chapter 02-02 -srate 24000 -af 
volume=10 -aspect 16:9  -of lavf -lavfopts 
format=psp:i_certify_that_my_video_stream_does_not_use_b_frames -oac 
lavc -ovc lavc -lavcopts 
aglobal=1:vglobal=1:vcodec=mpeg4:acodec=aac:vbitrate=515:abitrate=128 -vf 
scale=368:208,harddup -info name="TEST1" -ofps 30000/1001 -o M4V70002.MP4 
<< From the same DVD, works fine, plays A-OK on the PSP

I'm baffled, any ideas on where to start..

Thanks