How to make ffmpeg write its output to a named pipe
Question: I know i can make `ffmpeg` put its output to `stdout` and `stderr` using
`pipe:1` and `pipe:2`, respectively, as `output_file` parameter.
([Docs](http://ffmpeg.org/ffmpeg-protocols.html#pipe))

But what about [named pipes](https://en.wikipedia.org/wiki/Named_pipe), can i
make it write to one?

If not, is there a way to redirect the data in `stdout` to a named pipe in Linux? (something like `ffmpeg <parameters> | pipe123`)

This question is a follow-up of [this
question](http://stackoverflow.com/questions/32563527/how-to-keep-piping-
output-of-a-program-to-a-python-script-if-the-program-is-res).


Answer: You could create a named pipe first and have `ffmpeg` write to it using the
following approach:

`ffmpeg` output to named pipe:

    
    
    # mkfifo outpipe
    
    # ffmpeg -i input_file.avi -f avi pipe:1 > outpipe
    FFmpeg version 0.6.5, Copyright (c) 2000-2010 the FFmpeg developers
      built on Jan 29 2012 17:52:15 with gcc 4.4.5 20110214 (Red Hat 4.4.5-6)
    ...
    [avi @ 0x1959670]non-interleaved AVI
    Input #0, avi, from 'input_file.avi':
      Duration: 00:00:34.00, start: 0.000000, bitrate: 1433 kb/s
        Stream #0.0: Video: cinepak, yuv420p, 320x240, 15 tbr, 15 tbn, 15 tbc
        Stream #0.1: Audio: pcm_u8, 22050 Hz, 1 channels, u8, 176 kb/s
    Output #0, avi, to 'pipe:1':
      Metadata:
        ISFT            : Lavf52.64.2
        Stream #0.0: Video: mpeg4, yuv420p, 320x240, q=2-31, 200 kb/s, 15 tbn, 15 tbc
        Stream #0.1: Audio: mp2, 22050 Hz, 1 channels, s16, 64 kb/s
    Stream mapping:
      Stream #0.0 -> #0.0
      Stream #0.1 -> #0.1
    Press [q] to stop encoding
    frame=  510 fps=  0 q=11.5 Lsize=    1292kB time=33.96 bitrate= 311.7kbits/s
    video:1016kB audio:265kB global headers:0kB muxing overhead 0.835379%
    

reading `outpipe` named pipe (`Python` example):

    
    
    # python -c "import os; fifo_read = open('outpipe', 'r', 0); print fifo_read.read().splitlines()[0]"
    RIFFAVI LIST<hdrlavih8j...
    ...
    

\-- ab1

