Re: Script to conditionally find and compress files recursively

On Thu, 13 Jun 2024, Anssi Saari wrote:

J Newman <jenniferkatenewman@gmail.com> writes:
>

It's true that you cannot tell within the first 5 seconds what the
ultimate compression ratio will be, but it seems to me (from
compressing avi/mp4/mov files with lzma -9evv) that you can tell
within +/- 5% to a high degree of confidence, what the ultimate
compression ratio will be given the first 5 seconds.

>
Well then, I believe the solution was already posted. Grab 5% of your
files with dd and see how it compresses.
>
I'm a little curious, what kind of space savings do you expect to get by
doing this? And wouldn't it make more sense to re-encode for lower
bitrate if space saving is your goal?
>

If it's about space saving, don't forget deduplication, alternatively, depending on yoru file system of choice, you could maybe use file system functionality to save space as well, but caveat emptor, always have off site (or off machine) backups.