media_editing

setup

pip install media_editing

Markdown_to_HTML.py

This script recursively converts Markdown files at a specified directory to HTML files, with options to include numbered sections, table of contents, CSS and to output commands only, not execute.

Example usage with CSS specified is as follows:

cd my_writing_files_in_Markdown

CSS="https://raw.githack.com/wdbm/style/master/SS/bluescale.css"
Markdown_to_HTML.py --CSS="${CSS}"

images_to_video.py

This script converts a list of image files to a video with the options of specifying the image extension, a soundtrack file, an output filename and a framerate.

text_to_QR_code.py

This script converts specified text to a QR code of specified scale and filepath and optionally displays the resulting QR code image using the default image viewer.

vidgif.py

This script converts a video to an animated GIF, with the option to output commands only, not execute.

OCR of region of display

sudo apt install imagemagick scrot tesseract-ocr

tmp="$(mktemp)"
scrot -s "${tmp}".png -q 100 
mogrify -modulate 100,0 -resize 400% "${tmp}".png 
tesseract "${tmp}".png "${tmp}" &> /dev/null
cat "${tmp}".txt

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High Dynamic Resolution (HDR)

Luminance HDR

setup

sudo apt update
sudo apt install luminance-hdr

settings used to combine a darker and a lighter image 2019-02-24

• tonemap
  • operator: Reinhard '05
  • brightness: -10
  • chromatic adaptation: 0
  • light adaptation: 1
• process
  • pre-gamma: 0.86

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recording internal audio: audio-recorder

setup

sudo dpkg -i audio-recorder_1.7-5~xenial_amd64.deb

usage

audio-recorder

• Under "Audio settings.", select the source as something like "Clear Chat Comfort USB Headset (Audio output)".
• Select "Start recording".

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FFmpeg

trim video using start and stop times without reencoding

Note the ordering of the command line arguments and options.

filepath_1="Star.Wars.1977.Despecialized.720p.x264.AC3.5.1.mkv"
filepath_2="out.mkv"
start="01:40:33"
stop="01:54:48"

time ffmpeg -y -i "${filepath_1}" -ss "${start}" -to "${stop}" -c copy "${filepath_2}"

remove audio from video

The -an flag is used.

ffmpeg -i in.mkv -c copy -an out.mkv

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ImageMagick

change quality of directory of JPEG images

mogrify -quality 95 *.jpg

strip/remove an image of all profiles and comments using ImageMagick

convert -strip image_1.png image_2.png

mogrify -strip *.jpg

create an image of specified width, height and color using ImageMagick

Width is specified before height.

convert -size 100x100 xc:#000000 out.png

convert -size 100x100 xc:rgba\(255,0,0,0.4\) out.png

width_pixels="3495"
height_pixels="2160"
color="#eeeeee"
filepath="out.png"
convert -size "${width_pixels}"x"${height_pixels}" xc:"${color}" "${filepath}"

width_pixels="3107"
height_pixels="1920"
color="#eeeeee"
filepath="background.png"
convert -size "${width_pixels}"x"${height_pixels}" xc:"${color}" "${filepath}"

overlay one foreground image on the center of a background image using ImageMagick

convert background.png -coalesce -gravity center -draw 'image over 0,0,0,0 "foreground.png"' out.png

filepath_foreground="foreground.png"
filepath_background="background.png"
filepath_output="out.png"

# not working, under development:
# time convert "${filepath_background}" -coalesce -gravity center -draw 'image over 0,0,0,0 \"${filepath_foreground}\"' "${filepath_output}"

The option -layers flatten may be worth considering.

reduce quality of images at working directory in batch, making new images at new directory

mkdir new
mogrify -path new -quality 80 -format jpg *.jpg

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Inkscape

set up palettes for Inkscape

/usr/share/inkscape/palettes

convert bitmap to vector using Inkscape

• https://www.youtube.com/watch?v=SjCFRI3knhE

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Calibre

setup 2019-01-24T0350Z

sudo -v && wget -nv -O- https://download.calibre-ebook.com/linux-installer.sh | sudo sh /dev/stdin

view ebook

ebook-viewer book.epub

convert EPUB to MOBI using ebook-convert

ebook-convert book.epub book.mobi

convert LaTeX to HTML to EPUB

mk4ht htlatex book.tex 'xhtml,charset=utf-8,pmathml'
ebook-convert book.html book.epub

convert Markdown to EPUB

ebook-convert book.md book.epub

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music

some music software and tools

• Audacity
• Hydrogen
• MidiEditor
• MusE
• MuseScore
• Online Sequencer

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