[FFmpeg-user] Can I change the image format from `showwavespic` to png?

[Marcin Borkowski]

Hi all,

I use the `showwavespic` filter to get an image of the waveform.
However, the default image format is jpg, and the only way I found I can
change it is by providing a suitable extension of the output file.
Trouble is, I need the output to be stdout.  Is it possible to output
png to stdout?  (Good thing is that I want to pass the output through
ImageMagick anyway, so I can use that to do the conversion -- but it
would be even better if no conversion and no lossy compression were
happening at all.)

TIA,

-- 
Marcin Borkowski
http://mbork.pl