lf (maybe ranger too) media w3m-img preview script

readme.md

lf media preview script

lf (maybe ranger too) media w3m-img preview script
supports audio (aplay), video (thumbnails through ffmpeg), and, of course, images
based on github.com/gokcehan/lf/wiki/Previews script

installation

put pv.sh in ~/.config/lf/pv.sh
add to lfrc:
map i $~/.config/lf/pv.sh $f

usage

use i on supported media file to preview it
use i on folder to preview supported folder content
use h, j to scroll files back, k, l to scroll forward
use q to exit

enjoy!

pv.sh

#!/usr/bin/env bash

# based on github.com/gokcehan/lf/wiki/Previews
# thanks to dylanaraps for bash bible

# a margin in pixels needed to prevent image from overlapping top title
SAFE_MARGIN=56
# a threshhold for upscaling images, like pixelart or so
NOFILTER_THRESH=256

# dylan dirname fn
dirname() {
	local tmp=${1:-.}

	[[ $tmp != *[!/]* ]] && {
	    printf '/\n'
	    return
	}

	tmp=${tmp%%"${tmp##*[!/]}"}
	
	[[ $tmp != */* ]] && {
	    printf '.\n'
	    return
	}

	tmp=${tmp%/*}
	tmp=${tmp%%"${tmp##*[!/]}"}

	printf '%s\n' "${tmp:-/}"
}

clear_screen() {
	printf '\e[%sH\e[9999C\e[1J%b\e[1;%sr' \
			"$((LINES-2))" "${TMUX:+\e[2J}" "$max_items"
}

show_smth() {
	# print three dots while processing stuff
	clear
	printf '\e['$(($COLUMNS / 2 - 1))'C'...
	
	# process according to mime
	mime_type=$(file -bi "$1")
	case $mime_type in
		image/*)
			IMG=${CACHE:-$1}
			;;
		video/*)
			clear
			ffmpeg -hide_banner -y -i ${CACHE:-$1} -ss 00:00:01.000 -vframes 1 /tmp/thumb.png
			clear
			sleep 0.1
			IMG="/tmp/thumb.png"
			;;
		audio/*)
			clear
			shopt -s checkwinsize; (:;:)
			printf '\e['$(($COLUMNS / 2 - ${#1} / 2))'C'$1'\n\n\e[?25l'
			aplay ${CACHE:-$1} & read -N 1 KEY && kill $!
			clear
			printf '\e['$(($COLUMNS / 2 - 1))'C'...
			sleep 0.1
			return 1
			;;
		*) return 1
	esac
	
	w3m_paths=(/usr/{local/,}{lib,libexec,lib64,libexec64}/w3m/w3mi*)
	read -r w3m _ < <(type -p w3mimgdisplay "${w3m_paths[@]}")
	read -r LINES COLUMNS < <(stty size)
	
	# Get terminal window size in pixels and set it to WIDTH and HEIGHT.
	export $(xdotool getactivewindow getwindowgeometry --shell)
	
	# Get the image size in pixels.
	read -r img_width img_height < <("$w3m" <<< "5;$IMG")
	orwidth=$img_width
	orheight=$img_height
	
	# resize image to fit the one of bigger dims
	((HEIGHT > WIDTH)) && {
		((img_height=img_height*WIDTH/img_width))
		((img_width=WIDTH))
	}

	((WIDTH > HEIGHT)) && {
		((img_width=img_width*HEIGHT/img_height))
		((img_height=HEIGHT))
	}

	# if image is very long, avoid overdrawing
	((img_width > WIDTH)) && {
		((img_height=img_height*WIDTH/img_width))
		((img_width=WIDTH))
	}

	((img_height > HEIGHT)) && {
		((img_width=img_width*HEIGHT/img_height))
		((img_height=HEIGHT))
	}

	# safe margins for title showing
	((img_height > $SAFE_MARGIN*2 && img_width > $SAFE_MARGIN*2)) && {
		((img_width=img_width-$SAFE_MARGIN))
		((img_height=img_height-$SAFE_MARGIN))
	}

	# if we deal with smoll images, like pixelart, avoid blurry upscaling
	((orwidth < $NOFILTER_THRESH && orheight < $NOFILTER_THRESH)) && {
		convert $IMG -filter box -resize "$img_width"x"$img_height" /tmp/img.png
		IMG=/tmp/img.png
	}
	
	# variable needed for centering image.
	HALF_HEIGHT=$(expr $HEIGHT / 2)
	HALF_WIDTH=$(expr $WIDTH / 2)
	HALF_IMG_HEIGHT=$(expr $img_height / 2)
	HALF_IMG_WIDTH=$(expr $img_width / 2)
	X_POS=$(expr $HALF_WIDTH - $HALF_IMG_WIDTH)
	Y_POS=$(expr $HALF_HEIGHT - $HALF_IMG_HEIGHT)
	

	clear

	# debug positioning
	# echo $X_POS $Y_POS $img_width $img_height
	# sleep 1
	# clear

	# hide the cursor.
	printf '\e[?25l'
	
	# show the title
	shopt -s checkwinsize; (:;:)
	printf '\e['$(($COLUMNS / 2 - ${#1} / 2))'C'$1

	# display the image in subthread with delay to prevent blinking
	(sleep 0.1 && printf '0;1;%s;%s;%s;%s;;;;;%s\n3;\n4\n' \
	    ${X_POS:-0} \
	    ${Y_POS:-0} \
	    "$img_width" \
	    "$img_height" \
		"$IMG" | "$w3m" &>/dev/null) &
	
	# wait for input
	read -N 1 KEY
	
	# clear the image.
	printf '6;%s;%s;%s;%s\n3;' \
	    "${X_POS:-0}" \
	    "${Y_POS:-0}" \
	    "$WIDTH" \
	    "$HEIGHT" | "$w3m" &>/dev/null
	
	clear_screen
}

# get the arg basedir (or dir as arg) contents
DIR_PATH=$(dirname $1)
[ -d $1 ] && DIR_PATH=$1
FILES_RAW=($DIR_PATH/*)
FILES=()
# filter it to only supported mimes
for i in "${FILES_RAW[@]}"; do
	mime_type=$(file -bi "$i")
	case $mime_type in
		image/*|video/*|audio/*)
			FILES+=($i)
			;;
	esac
done
COUNT=${#FILES[@]}
for i in "${!FILES[@]}"; do
	if [[ "${FILES[$i]}" = "${1}" ]]; then
		POS="${i}"
	fi
done
[ -z $POS ] && POS=0
show_smth ${FILES[$POS]}

# cycle through contents array
while true
do
	case $KEY in
		"h"|"j")
			POS=$((POS-1))
			[ $POS -lt 0 ] && POS=$((COUNT-1))
			show_smth ${FILES[$POS]}
			;;
		"k"|"l")
			POS=$((POS+1))
			[ $POS -eq $COUNT ] && POS=0
			show_smth ${FILES[$POS]}
			;;
		*)
			exit 0
	esac
done