GopherProxy

	tIndent code with spaces - adamsgaard.dk - my academic webpage
	git clone git://src.adamsgaard.dk/adamsgaard.dk
	Log
	Files
	Refs
	README
	LICENSE
	---
	commit d37bc1b2ef006b946ae2337b44f5c18a4c9954f8
	parent dd1fafe054a5b921d85668cb7a09a05eafe4bbe3
	Author: Anders Damsgaard <[email protected]>
	Date: Mon, 23 Mar 2020 07:50:39 +0100

	Indent code with spaces

	Diffstat:
	M pages/004-screencasts.txt \| 130 ++++++++++++++++-------------…

	1 file changed, 65 insertions(+), 65 deletions(-)
	---
	diff --git a/pages/004-screencasts.txt b/pages/004-screencasts.txt
	t@@ -15,42 +15,42 @@ laptop audio. I want to keep the fan noise low during rec…
	by applying minimal compression and encoding. The following shell
	script serves the purpose of starting and stopping recording:

	-#!/bin/sh
	-lockfile=/tmp/screenrecord.pid
	-
	-startrecording() {
	- out="$HOME/screenrecord-$(date '+%Y-%m-%d_%H:%M:%S').mkv"
	- ffmpeg -y \
	- -f x11grab \
	- -framerate 60 \
	- -s "$(xdpyinfo \| grep dimensions \| awk '{print $2}')" \
	- -i $DISPLAY \
	- -f sndio -i default \
	- -r 30 \
	- -c:v libx264rgb -crf 0 -preset ultrafast -c:a flac \
	- "$out" >/dev/null 2>&1 &
	- printf '%s' "$!" > "$lockfile"
	-
	- sleep 1
	- if [ ! -f "$out" ]; then
	- echo 'error: ffmpeg recording did not start' >&2
	- notify-send -u CRITICAL "${0##*/}" 'ffmpeg recording did not s…
	- rm -f "$lockfile"
	- exit 1
	- fi
	-}
	-
	-stoprecording() {
	- kill "$(cat "$lockfile")"
	- rm -f "$lockfile"
	- notify-send "${0##*/}" 'recording ended'
	-}
	-
	-if [ -f "$lockfile" ]; then
	- stoprecording
	-else
	- startrecording
	-fi
	+ #!/bin/sh
	+ lockfile=/tmp/screenrecord.pid
	+
	+ startrecording() {
	+ out="$HOME/screenrecord-$(date '+%Y-%m-%d_%H:%M:%S').mkv"
	+ ffmpeg -y \
	+ -f x11grab \
	+ -framerate 60 \
	+ -s "$(xdpyinfo \| grep dimensions \| awk '{print $2}')" \
	+ -i $DISPLAY \
	+ -f sndio -i default \
	+ -r 30 \
	+ -c:v libx264rgb -crf 0 -preset ultrafast -c:a flac \
	+ "$out" >/dev/null 2>&1 &
	+ printf '%s' "$!" > "$lockfile"
	+
	+ sleep 1
	+ if [ ! -f "$out" ]; then
	+ echo 'error: ffmpeg recording did not start' >&2
	+ notify-send -u CRITICAL "${0##*/}" 'ffmpeg recording did not start'
	+ rm -f "$lockfile"
	+ exit 1
	+ fi
	+ }
	+
	+ stoprecording() {
	+ kill "$(cat "$lockfile")"
	+ rm -f "$lockfile"
	+ notify-send "${0##*/}" 'recording ended'
	+ }
	+
	+ if [ -f "$lockfile" ]; then
	+ stoprecording
	+ else
	+ startrecording
	+ fi

	On Linux systems, the sound driver sndio should be replaced by alsa
	in the above ffmpeg(1) command. I have bound the above script to
	t@@ -60,13 +60,13 @@ in my X session.
	On OpenBSD I can show the webcam video feed with the [2]video(1)
	command. The following script toggles the video feed:

	-#!/bin/sh
	-# remember to `chown $USER /dev/video0`
	-if pgrep video >/dev/null 2>&1; then
	- pkill video
	-else
	- nohup video -s 320 >/dev/null 2>&1 &
	-fi
	+ #!/bin/sh
	+ # remember to `chown $USER /dev/video0`
	+ if pgrep video >/dev/null 2>&1; then
	+ pkill video
	+ else
	+ nohup video -s 320 >/dev/null 2>&1 &
	+ fi

	On Linux, the command mpv /dev/video0 can take place of the video(1)
	command above. I have the above script bound to the keybinding Alt+v
	t@@ -77,37 +77,37 @@ file to save bandwidth during upload. The following script…
	all input files and reduces file size to roughly 15% without
	concievable loss in quality:

	-#!/bin/sh
	+ #!/bin/sh

	-encode() {
	- ffmpeg -y -i "$1" \
	- -c:v libx264 -threads 0 -preset faster -pix_fmt yuv420p \
	- -c:a aac -crf 10 \
	- "${1%.*}_out.mp4"
	-}
	+ encode() {
	+ ffmpeg -y -i "$1" \
	+ -c:v libx264 -threads 0 -preset faster -pix_fmt yuv420p \
	+ -c:a aac -crf 10 \
	+ "${1%.*}_out.mp4"
	+ }

	-for f in "$@"; do
	- encode "$f"
	-done
	+ for f in "$@"; do
	+ encode "$f"
	+ done

	If there is a delay between video and audio, this can also be
	adjusted using ffmpeg(1). I correct for a 0.3 s delay that I
	encounter when recording on my laptop:

	-#!/bin/sh
	+ #!/bin/sh

	-synchronize() {
	- ffmpeg -y -i "$1" \
	- -itsoffset 0.300 \
	- -i "$1" \
	- -map 0:v -map 1:a \
	- -c copy \
	- "${1%.}_out.${1##.}"
	-}
	+ synchronize() {
	+ ffmpeg -y -i "$1" \
	+ -itsoffset 0.300 \
	+ -i "$1" \
	+ -map 0:v -map 1:a \
	+ -c copy \
	+ "${1%.}_out.${1##.}"
	+ }

	-for f in "$@"; do
	- synchronize "$f"
	-done
	+ for f in "$@"; do
	+ synchronize "$f"
	+ done

	[3]Example screen recording using ffmpeg(1) and video(1) with the
	above scripts.