Commands

How do I add a custom thumbnail to a .mp4 file using ffmpeg Link

ffmpeg -i video.mp4 -i image.png -map 1 -map 0 -c copy -disposition:0 attached_pic out.mp4

Reducing filesize of video in Linux Link

ffmpeg -i inputfilename.mp4 -b 1000000 outputfilename.mp4

Extract all images from a PDF Link

pdfimages -j in.pdf /destination/prefix

Split PDF/Extract page from PDF Link

pdftk input.pdf cat 2-4 output out1.pdf

Merge PDFs Link

pdftk file1.pdf file2.pdf cat output output.pdf

or

pdfunite in-1.pdf in-2.pdf in-n.pdf out.pdf

Convert image to PDF Link

convert page.png page.pdf

or

img2pdf im1.png im2.jpg -o out.pdf