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Re: Pipe FFMPEG to GNUPlot on Windows

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squarebluesolutions@gmail.com wrote:

> I am trying to get the example given on the FFMPEG website (URL below)
> working on a Windows machine
> 
> https://trac.ffmpeg.org/wiki/Create%20a%20Waveform%20Image%20from%20an%20Audio%20Stream
> 
> The issue seems to come around the syntax for pipes on Windows. What
> research I have done shows that the more recent gnuplot builds support
> pipes - so my question is for the following Linux formatted command, what
> would be the correct Windows one...
> 
> ffmpeg -i in.wav -ac 1 -filter:a aresample=8000 -map 0:a -c:a pcm_s16le -f
> data - | \
>     gnuplot -p -e "plot '<cat' binary filetype=bin format='%int16'
>     endian=little array=1:0 with lines;"
> 
> When I run this - I get...
> 
> /bin/sh: cat: command not found
> 
> Presumably because the '<cat' is not valid as the pipe source on Windows.

Invocation of "cat" isn't needed under linux either.

I think in both cases you want 

     ... | gnuplot -p -e "plot '-' ..."

However you may have trouble piping binary files to gnuplot for some
plotting modes, particulary matrix data.  This is because gnuplot will
try to do lseek() within the file and that won't work for a pipe.

	Ethan

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Thread

Pipe FFMPEG to GNUPlot on Windows squarebluesolutions@gmail.com - 2015-02-26 13:44 -0800
  Re: Pipe FFMPEG to GNUPlot on Windows Ethan A Merritt <sfeam@users.sourceforge.net> - 2015-02-26 16:15 -0800
    Re: Pipe FFMPEG to GNUPlot on Windows James Gibson <squarebluesolutions@gmail.com> - 2015-03-07 17:03 -0800

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