Re: GZIP of pre-zipped output

On Sun, Mar 21, 2010 at 8:46 PM, Craig Ringer
<craig@postnewspapers.com.au> wrote:
> On 22/03/2010 1:04 AM, Dave Crooke wrote:
>>
>> If you are really so desparate to save a couple of GB that you are
>> resorting to -Z9 then I'd suggest using bzip2 instead.
>>
>> bzip is designed for things like installer images where there will be
>> massive amounts of downloads, so it uses a ton of cpu during
>> compression, but usually less than -Z9 and makes a better result.
>
> bzip2 doesn't work very well on gzip'd (deflated) data, though. For good
> results, you'd want to feed it uncompressed data, which is a bit of a pain
> when the compression is part of the PDF document structure and when you
> otherwise want the PDFs to remain compressed.
>
> Anyway, if you're going for extreme compression, these days 7zip is often a
> better option than bzip2.

There's often a choice of two packages, 7z, and 7za, get 7za, it's the
later model version.