[MPlayer-users] mencoder doesn't work with -vf remove-logo ?

Peter Daum gator_ml at yahoo.de
Sat Nov 14 18:18:54 CET 2009


... actually, I am pretty confident, that given the context "does not work"
is pretty clear, meaning: all that mencoder does is emit said messages.

I also think that most people would interpret phrases like "incompatible
with this codec", "Unsupported Pixel format" ... as indications of some
sort of error, except that they are also printed when everything seems
to work as expected.

I didn't quote the command line, because the details didn't seem to matter -
as said, the same filter chain for playing is ok, the same command line
with the "remove-log" left out also works ("works" in this case meaning,
that it takes slightly longer and I eventually have a file that wasn't
there before ;-)

However, as I meanwhile found out, there is one detail that _does_ matter:
The problem only seems to occur when using the x264 encoder, while the
same thing using for example "xvid" also works. So the shortest command
line to reproduce what I am talking about would be something like:

mencoder -vf remove-logo=logo.pgm -ovc x264 -oac copy -o /dev/null infile

I created the logo mask by playing the file with '-aspect 1.25' and
taking a screen shot (without the -aspect the width of the screen shot
is too big), editing it with gimp until I had a completely black background
with a white logo on it, blurring it and then saving it to a raw ppm file.
(If somebody knows a better solution, this would be great; I couldn't find
anything about how exactly the mask should look like; the result is still
pretty awful, particularly if the background contains many details and the
camera moves, but was the best, that I found; with a sharp mask for example
the result looks worse ...)

Oliver Seitz wrote:

> Err, sorry, but "does not work" is a bit vague as an error description.
> 
> Try something like
> 
> No output file created
> Mencoder hangs
> Mencoder crashes
> It takes hours for every frame
> Output file not playable
> Output file still contains the logo
> Output file has the logo replaced by a purple banana
> Picture quality is bad
> Output file is all black
> ...
> 
>> mencoder emits some error messages, but because I also get
>> similar error messages if everything works fine, they are
>> probably not significant:
>>
>>  > Trying filter chain: remove-logo expand x264
>>  > Could not find matching colorspace - retrying with -vf scale...
>>  > Opening video filter: [scale]
>>  > SwScale params: -1 x -1 (-1=no scaling)
>>  > Trying filter chain: scale remove-logo expand x264
>>  > The selected video_out device is incompatible with this codec.
>>  > Try appending the scale filter to your filter list,
>>  > e.g. -vf spp,scale instead of -vf spp.
> 
> I can see no "error" messages. I just see that the "scale" filter has been
> automatically inserted to do colorspace conversion. That's pretty ok.
> 
> 
>> Is this a problem with the "remove-logo" filter or am I doing
>> something wrong?
> 
> That's hard to say as long as you don't say what you're doing.
> 
> A full command line might be helpful, along with information on how you
> created the bitmap you passed to the remove-logo filter.



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