[MEncoder-users] wmv to avi

[James Hastings-Trew]

On 11-03-11 8:31 AM, Adrian Dusa wrote:
> Dear Andrew, dear Reimar,
>
> Thanks very much for your replies, and sorry for not responding sooner
> (I have this bad habbit of setting digest mode only for the multiple
> email lists I have subscribed).
>
> I tried both your suggestions, but I'm probably doing something wrong
> (I'm a rookie btw), because the result is still the same.
>
> My new syntax is:
> mencoder blah.wmv -ovc xvid -xvidencopts pass=1 -oac copy -vf harddup
> -noskip -of avi -o /dev/null
> mencoder blah.wmv -ovc xvid -xvidencopts pass=2:bitrate=1000 -vf
> harddup -of avi -noskip -o blah.avi
>
> (I even tried the second line with -ofps 25, same result)
>
> Thanks very much for your patience,
> Adrian
>
>
> On Thu, Mar 10, 2011 at 14:38, Adrian Dusa<dusa.adrian at gmail.com>  wrote:
>> Dear MEncoder users,
>>
>> I am trying to convert a .wmv file to .avi using mencoder. It works as
>> expected, but the output file has a time length 10 times shorter than
>> the input file.
>>
>> To be short, it is about a chess game with various pauses between two
>> consecutive moves. The output video file, however, simply shows the
>> moves without any pause, skipping the pauses. From a 10 minutes input
>> file, the output has only 1 minute.
>>
>> I tried a 2 pass encoding, under a Kubuntu Maverick distribution:
>>
>> mencoder blah.wmv -ovc xvid -xvidencopts pass=1 -oac copy -noskip -of
>> avi -o /dev/null
>> mencoder blah.wmv -ovc xvid -xvidencopts pass=2:bitrate=1000 -fps 25
>> -of avi -noskip -o blah.avi
>>
>> Any suggestion would be highly appreciated.
>> Thanks in advance,
>> Adrian
Two things come to mind:
1 - wmv allows for variable frame rate which mencoder does not support. 
You can try to specify an output framerate, but if the wmv really has 
only 1 frame representing several seconds of time, well, that's not 
going to be fixed by any amount of fussing around with -fps values in a 
mencoder command line.
2 - This is more just general mencoder advice: get whatever you are 
doing working with one pass encodes first before fussing around with 2 
pass encodes. And you definitely need to specify the same input and 
output frame rates for BOTH passes.

Google around for "converting variable frame rate video to avi" - you'll 
see that is a largely unsolved problem (with any tool chain - mencoder 
is not alone in this). Variable frame rate might be a neat video 
compression solution, but its hell on file convertability.