On 7/15/05, Eben King <eben1@tampabay.rr.com> wrote:
> > On Fri, 15 Jul 2005, Chuck Hast wrote:
> >
> > > On 7/15/05, Eben King <eben1@tampabay.rr.com> wrote:
> > > > So a correspondent sent me some images, encapsulated in a .PPT file.
> > > > (Naked JPEGs would have worked fine, but nooooo...) Is there any way, using
> > > > od, grep, dd, or maybe some tool I don't have yet, to get them out? I can
> > > > view it in Windows (I suppose Windows-in-VMware too) using MS*spit*'s free
> > > > "Powerpoint Viewer", but I can't do squat with it.
> > > >
> > > Did you try Open Office? I use it to open company PPT files all of the time,
> > > it should allow you to pull those images out.
>
> I found a way that does not involve OpenOffice. I wrote a scriptlet:
>
> for skipcount in `seq 2 1032700`; do
> echo -n "$skipcount "
> dd if=body_paint.ppt skip=$skipcount bs=1 2>/dev/null | file -
> done | grep -v ': *data$' > /tmp/file2
>
> (1032700 is a nice round number a little less than the file size in bytes)
>
> In /tmp/file2, there is lots of stuff like
>
> 71008 standard input: Sendmail frozen configuration - version þ?5ol÷þŸžqXÿ
> 71042 standard input: DBase 3 data file with memo(s) (16772103 records)
> 71178 standard input: shell archive or script for antique kernel text
>
> and most of it is total BS. But among the dreck, I found
>
> 537 standard input: JPEG image data, JFIF standard 1.01, resolution (DPI), 96 x 96
> and
> 49958 standard input: JPEG image data, JFIF standard 1.01, resolution (DPI), 96 x 96
>
> (so far) If I do
>
> dd if=filename.ppt skip=537 bs=1 | djpeg | xv -
>
> there is one of the images from the file! I can do the same with the other
> offset. Now, I don't know if they were JPEGs originally, or that's just
> what Powerpoint uses. And it's slow. Very slow. And (as you see) subject
> to misidentification by "file" -- I don't know but what the file's
> fragmented internally (a la "fast save" in Word), so I'd never retrieve the
> images this way. But it's a possibility, for users who don't have OO, and
> _do_ have lots of time, and who won't get too upset about missing images.
>
> --
Yes, that is a interesting work around, it would get you there. You would have
to follow things a bit more closely.
I will look and see if there are other ways to get them out using OO, seems like
someone needs to work on that one if not.
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