[MEncoder-users] a/v desync when encoding combined 24000/1001 30000/1 fps NTSC DVD

[Sergey Kovalev]

belcampo wrote:
> Sergey Kovalev wrote:
>> But when I encode audio reducing abitrate, I do two-pass encoding with 
>> a shell script:
>> 
>> mencoder dvd://1 -chapter 3-3 -aid 129 \
>>      -ofps 24000/1001 -oac lavc -o $fname -ovc lavc -lavcopts \
>>      vcodec=mpeg4:vbitrate=1152:mbd=2:trell:v4mv:autoaspect:vpass=$i \
>>      -vf pullup,softskip,crop=656:352:32:64
>> 
>> where $fname and $i are shell variables with corresponding values.
>> The resulting avi shows enormous a/v desync:
>> A:15869.7 V:  25.9 A-V:15843.711 ct:  2.590 622/622  5%  1%  0.6% 0 0
>> if I understand A:, V: and A-V: numbers correctly. Seeking on audio 
>> stream is almost impossible. And forward seeking often leads to warnings:
>>
>> Badly interleaved AVI file detected - switching to -ni mode...
>>
>> Besides ct: value is always growing. That leads to the actual desync 
>> which can only be avoided by using -mc 0 while playing.
> I think you'll endup by dividing video and audio encoding then remuxing 
> to what you  want.
> In the end your sources are time x of video and time x audio. If you get 
> a/v sync at the beginning it will be there at the end.

I made some more testing and found out that when I encode audio with 
"-oac lavc", the afore-mentioned desync appears, but whan I use "-oac 
mp3lame -lameopts cbr:bitrate=224" syncing is done right.
Is it a bug or I've missed some option?

Also I don't understand what options "-vf pullup,softskip" do (which I 
took from documentation as advised), because without them I don't see 
any glitches in encoded video as with them.
Probably my original video is not telecined. I don't know what to 
suppose else.