screen record

anonymous-gist.sh

#!/bin/bash

less_noisy='-hide_banner -y -loglevel error'
screengrab_cmd='x11grab'
framerate=10
screen_resolution=$(xdpyinfo | awk '/dimensions:/ { print $2 }')
monitor_location=':0.0'
audio_input='default'
color_format='yuv420p'
quality_level='33' # default 23, higher worse, lower better. Common range is 18-33
compression_speed='veryslow' # slower compression means a smaller output file at the same quality

tmp_file='/tmp/raw.mkv'

if [[ $# == 0 ]]; then
    now=$(date "+%Y%m%d%H%M%S")
    output_file="${HOME}/Videos/${now}.mkv"
else
    output_file="$1"
fi

function main {
    validate_input "$@"
    start_recording_noise &
    record "$@"
    end_recording_noise &
    compress "$@"
}

function test {
    record
    compress
    review
}

function record {
    ffmpeg $less_noisy \
	   -f $screengrab_cmd \
	   -framerate $framerate \
	   -s $screen_resolution \
	   -i $monitor_location \
	   -f alsa \
	   -i $audio_input \
	   -c:v rawvideo \
	   -c:a pcm_s16le \
	   -pix_fmt $color_format \
	   $tmp_file
}

function compress {
    # -crf 33 cuts the size by about half
    # -preset veryslow cuts the size by about 20%
    # -tune stillimage actually increase size by a bit, not sure if it has an effect on quality?
    ffmpeg $less_noisy \
	   -i $tmp_file \
	   -crf $quality_level \
	   -preset $compression_speed \
	   -tune stillimage \
	   $output_file
}

function review {
    xdg-open $output_file
    ffprobe -hide_banner $output_file
    ls -hl $output_file
}

function validate_input {
    if [[ $# > 1 ]]; then
	echo "This script takes zero or one parameter, not $#"
	exit 1
    fi
    if [[ $# == 1 && "$1" != *@(mkv|mp4) ]]; then
	echo "File suffix doesn't match one of the allowed types. They are: .mkv, .mp4"
	exit 2
    fi
}

function start_recording_noise {
    export XDG_RUNTIME_DIR="/run/user/1000"
    path_to_sound="$(dirname ${0})/sounds/click.mp3"
    mplayer $path_to_sound -volume 100 &> /dev/null
}

function end_recording_noise {
    export XDG_RUNTIME_DIR="/run/user/1000"
    path_to_sound="$(dirname ${0})/sounds/camera-click.wav"
    mplayer $path_to_sound -volume 100 &> /dev/null
}

main "$@"
# test

# maybe useful stuff
# -thread_queue_size 4096 \