[MEncoder-users] wmv to avi

[Adrian Dusa]

Dear James,

Thanks for this feedback, I am slowly beginning to understand what is
going on, although I am not going to become a specialist (using this
only as a regular user).

I have no idea whether this is a variable framerate issue or not, all
I can tell is that my .wmv files can be easily converted to avi using
some Windows tools like Allok Video Converter.
The main reason why I wanted to use mencoder is (beside the obvious
using open-source tools), not having to switch back and forth to
Windows (even if this means opening a virtual machine, consuming
memory).

But... if this is not supported yet by mencoder, there's probably
nothing else to be done.
Best wishes,
Adrian

On Sat, Mar 12, 2011 at 03:37, James Hastings-Trew <jimht at shaw.ca> wrote:
> 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.
>
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Adrian Dusa
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