External program to pipe raw video to

Question

I don't have ffmpeg installed on my raspbian OS, because it does not seem to be used in debian anymore. The fork 'libav-tools' is available though. I would like to encode the video stream with this external encoder. The motion.conf has the example line of code [1]

The syntax to use libav-tools (avconv) should be something like [2]

Alternatively I could use 'gpac', the syntax should be something like [3]

but that does not work. How do I reference the 'input' (What does this mean: "Generally, use '-' for STDIN..."???)

The excerpt of my 'motion.conf' is in [4]

[1]
;extpipe mencoder -demuxer rawvideo -rawvideo w=320:h=240:i420 -ovc x264 -x264encopts bframes=4:frameref=1:subq=1:scenecut=-1:nob_adapt:threads=1:keyint=1000:8x8dct:vbv_bufsize=4000:crf=24:partitions=i8x8,i4x4:vbv_maxrate=800:no-chroma-me -vf denoise3d=16:12:48:4,pp=lb -of avi -o %f.avi - -fps %fps
[2]
avconv -r 30 -i input.h264 -vcodec copy output.mp4
[3]
MP4Box -fps 30 -add input.264 output.mp4
[4]
...
############################################################
# External pipe to video encoder
# Replacement for FFMPEG builtin encoder for ffmpeg_output_movies only.
# The options movie_filename and timelapse_filename are also used
# by the ffmpeg feature
#############################################################

# Bool to enable or disable extpipe (default: off)
use_extpipe on

# External program (full path and opts) to pipe raw video to
# Generally, use '-' for STDIN...
;extpipe mencoder -demuxer rawvideo -rawvideo w=320:h=240:i420 -ovc x264 -x264encopts bframes=4:frameref=1:subq=1:scenecut=-1:nob_adapt:threads=1:keyint=1000:8x8dct:vbv_bufsize=4000:crf=24:partitions=i8x8,i4x4:vbv_maxrate=800:no-chroma-me -vf denoise3d=16:12:48:4,pp=lb -of   avi -o %f.avi - -fps %fps
;extpipe MP4Box -fps 30 -add rawvideo %f.mp4
extpipe avconv -r 30 -i rawvideo -vcodec copy %f.mp4 
...

Environment

Motion version:	3.2.12
ffmpeg version:	none
Libraries:	libav-tools, gpac
Server OS:

-- RicardoBirwe - 14 Nov 2016

Answer