[MEncoder-users] Audio sync problem

Owen Williams williams at dmu.ac.uk
Wed Sep 9 10:41:47 CEST 2009


Hello,
  I'm having a problem with audio sync.  I record Freeview in the UK.  I
want to convert everything to two formats mp4/h.264/aac formats:

o 1024x576 Main 3.1
o 640x480 Baseline 3.0

To be played primary through a flash player but also from
mplayer/vlc/quicktime or equivalent on a PC.

Freeview can/will have multiple aspect ratios in the recording so no
matter what which format I'd like to have the picture centered in the
image with appropriate black borders for that aspect ratio at that
moment in the stream.

I understand that this process is being developed for ffmpeg at the
moment but mencoder has it implemented using: 

expand=::0:0::16/9,scale=1024:576

This is my first pass for my high quality format :

/usr/local/bin/mencoder  ../Copy/copy.mpg -o /dev/null -mc 0 \
-ovc x264 -x264encopts \
bitrate=1500:pass=1:threads=16:turbo=1:level=31:frameref=6:\
partitions=+parti4x4+parti8x8+partp4x4+partp8x8\
+partb8x8:bframes=5:deblock=0,1:me_range=16:me=umh:\
deblock:subq=7:trellis=2:cabac \
-vf expand=::0:0::16/9,scale=1024:576,yadif,harddup \
-oac faac -faacopts mpeg=4:br=128:object=2 -channels 2

The audio is out of sync even though I'm using harddup and -mc 0.  I've
tried it with -noskip and every combination.

I got everything out out SVN again after I read that b-frames can cause
a problem so the software is less than a week old.  I've tried with and
without de-interlacing and and by putting the de-interlacer at the
beginning and the end of the filters.

Any suggestions as to what I can do to fix the audio sync?

Also, I get some strange results in the image like:

http://ocean.blue.dmu.ac.uk/~williams/16-9frameWith4-3image.jpg

from (only 11 minutes) :

http://ocean.blue.dmu.ac.uk/~williams/Film4.mpg

with the command above.

Any help would be very much appreciated.  So close...

Owen.



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