To make an audio aac file from a downloaded youtube mp4 video:
I put this function in my .bash_profile:
vtoa () { /usr/bin/ffmpeg -i "$1" -vn -acodec copy "${1%.*}".aac }
To convert I just have to type vtoa videofilename.mp4
To convert folder of numbered pics to mp4: e.g.
ffmpeg -f image2 -r 15 -i /my/path/00%d.png -vcodec h264 -crf 15 test.mp4
(that’s 15 frames per second, filenames with 2 leading zeroes, starting with 000.png, constant rate factor 15 (lower is better)..)
That’s for filenames like 001.png, 00100.png, 001000 etc.
For 0-padded names, 001, 010, 100 etc use %03d.png
To convert image files in a folder to consecutive filenames, and convert to jpeg:
$ f=-1;for i in /my/path/* > do f=$((f+1)) > echo -n sips -s format jpeg "'"$i"'" > printf " --out /my/path2/%05d.jpg\n" $f > done > ex $ . ex