-#
-# potential improvement: sometimes I probably want to stream full height
-# window. I could add an option for that.
-
-# potential improvement: setup a function which automatically mutes after some time, or
-# after some time of no audio input.
-
-
-### begin background/development docs ###
-
-# zmq vs stdin commands:
-#
-# * zmq allows targeting a specific filter when there are duplicates.
-#
-# * if you type stdin command too slow, ffmpeg will die because it stops
-# doing normal work while it is waiting.
-#
-# * zmq returns a result to the calling process, rather than printing to
-# stdout.
-#
-# * the only simple zmq tool I found, zmqsend, requires compiling. I
-# used the latest ffmpeg 7.0.1. Build like so:
-#
-# p build-dep ffmpeg/aramo
-# ./configure --enable-libzmq # i already had libzmq3-dev installed
-# make alltools
-# cp tools/zmqsend /a/opt/bin
-#
-# * ffmpeg debug output was useful in testing zmq commands.
-#
-# * Important documentation for stdin commands is only found by typing
-# "c" into the stdin of ffmpeg and reading the output.
-#
-#
-#
-# stdin command docs, before I abandoned it for zmq:
-# mkfifo -m 0600 /tmp/iank-ffmpeg
-# # ffmpeg sits and waits until we do this. dunno why.
-# echo >/tmp/iank-ffmpeg &
-# ffmpeg ... </tmp/iank-ffmpeg |& while read -r line; do : check results; done
-# # example of working commands:
-# echo "cdrawbox -1 t 0" >/tmp/iank-ffmpeg
-# echo "cdrawbox -1 t fill" >/tmp/iank-ffmpeg
-# echo "cdrawtext -1 reinit text=''" >/tmp/iank-ffmpeg
-# echo "cvolume -1 volume=1" >/tmp/iank-ffmpeg
-
-
-# For testing: to show the number of audio channels in a resulting file
-# https://stackoverflow.com/questions/47905083/how-to-check-number-of-channels-in-my-audio-wav-file-using-ffmpeg-command
-#
-# ffprobe -i /tmp/out.wav -show_entries stream=channels -select_streams a:0 -of compact=p=0:nk=1 -v 0
-
-# for a right/left speaker test:
-# https://askubuntu.com/questions/148363/which-linux-command-can-i-use-to-test-my-speakers-for-current-talk-radio-output
-# p install alsa-utils
-# speaker-test -t wav -c 2 -l 1
-
-# There are 2 other options for audio, so I wanted to do a little
-# performance measurement of this method.
-# 1 is to combine the 2 audio sources in pulse,
-# https://unix.stackexchange.com/questions/351764/create-combined-source-in-pulseaudio .
-# 1 is to record mumble and combine in post processing.
-
-### benchmark / perf tests: these are pretty inaccurate.
-# 29 seconds cpu use. video bitrate 1500k, 8 fps, 2x keyframe interval.
-# * 64k vorbis: 69.7%
-# * 128k vorbis: 70.1% (used in subsequent tests)
-# * 1 audio input: 64.3%
-# * 0 audio inputs: 59.2%
-
-# how I did perf testing: add -to 00:00:30 to ffmpeg opts to
-# conveniently exit after measurement. Then run:
-#
-# ffmpeg "${opts[@]}" &
-# pid=$!
-# sleep 29
-# ps -p $pid -o %cpu
-# kill %%
-
-# filter for only 1 audio input:
-#-filter_complex "[0]azmq,volume=precision=fixed;[1]zmq='b=tcp\://127.0.0.1\:5557',drawbox=color=0x262626,drawtext=fontsize=90: fontcolor=beige: x=40: y=40: text=''"
-# filter with 0 audio input:
-# -filter_complex "[0]zmq='b=tcp\://127.0.0.1\:5557',drawbox=color=0x262626,drawtext=fontsize=90: fontcolor=beige: x=40: y=40: text=''"
-
-
-# When things weren't working, I did some checking on newer ffmpeg to
-# see if that helped. It never did. I compiled the latest ffmpeg release
-# tarball, 7.0.1, and tried the version in debian bullseye by schrooting
-# before running ffmpeg. Building was just configure; make, but then I
-# found some flags that were needed. gpl flags r just because I noticed them.
-# ./configure --enable-libzmq --enable-libpulse --enable-libvorbis --enable-gpl --enable-version3
-#
-
-### end background/development docs ###