I\'m trying to convert a gif file to webm file using the below which works fine however I’m wondering is it also possible to reverse it as well using ffmpeg or would I need
From ffmpeg --help, you can see what codecs ffmpeg supports with ffmpeg -codecs. ffmpeg -codecs|grep -i gif on mine says it supports gif.
ffmpeg checks extensions to get file type if you don't override,
ffmpeg -i onoz.webm onoz.gif
does the trick just fine.
The script posted here might help you. This one seems to be in bash but ripping the commands should work on Windows as well. https://github.com/WhatIsThisImNotGoodWithComputers/ffmpeg-webm-scripts
These are the relevant lines of code (note that they need to edited for your setup):
ffmpeg -i "${INPUT_FILE}" -ss $START_TIME -to $TO_TIME -an -qscale 1 $TEMP_FOLDER/%06d.jpg
cat $(ls -r $TEMP_FOLDER/*jpg) | ffmpeg -f image2pipe -vcodec mjpeg -r 25 -i - -c:v libvpx -crf 20 -b:v $FRAMERATE $CROPSCALE -threads 0 -an $OUTPUT_FILE
You basically have to convert all stills to jpgs and then back into webm, but in reverse order.