[MEncoder-users] Audio sync problem

[Grozdan]

2009/9/9 Owen Williams <williams at dmu.ac.uk>:
> 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.

-mc 0 completely disables MEncoder's synchronization and increases the
chance of sync problems. I've no idea why you use it for this
particular case. Try without it.

>
> 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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>