[FFmpeg-user] audio delay while converting flv to avi

[access-dev ml]

  this command line produces and audio delay of 2-3 seconds
>
>  /usr/bin/ffmpeg -loglevel 0 -i 202.flv -ar 44100 -b 700k -sameq -f 
> avi  -ab
> 160k 202.avi

 Check with "async" option:

 ffmpeg -loglevel 0 -async 1 -i 202.flv -f avi -b 700k -sameq -ab 160k
 -ar 44100 202.avi

 see also "shortest" option -- finish encoding when the shortest input
 stream ends.

 Thank you, the audio has perfect sync now.
 But I wonder why this requires an option, in most cases, users want the 
 audio to be synced with the video isnt't it ?

 Also , it's the first time I encounter  this problem and I really want 
 to know why this happens.

 Thanks,

 Nicolas