.PAF/.POWER Testing
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Ok, great!
Shame could throw up some real keen testing enviroments. However, if i have anymore examples of files to compress i will post them here for you.
Thanks fella.
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More would be better… Real world examples…
You will obviously have it once it is ready for alpha testing.PDF, PNG, DOCX/PDTX/XLXX/OODT, etc.
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moved to general forums for more testing examples.
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How’s the speed of the compression engine for the new format – both compression and extraction?
Can we build self-extracting files from a .PAF archive?
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How’s the speed of the compression engine for the new format – both compression and extraction?
Can we build self-extracting files from a .PAF archive?
right now we are still working on codecs, speed for strongest mode (in results above) should be similar to 7zip strongest mode…
as to the SFX, SFX is just an small app that extracts archive inside, so it is possible.
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That’s very good news indeed. Obviously better compression is good. Nice to know, though, that compression and extraction are still speedy.
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That’s very good news indeed. Obviously better compression is good. Nice to know, though, that compression and extraction are still speedy.
it will have to be a bit slower but overall, it is still fast.
Extra compression is not due to utilizing slower compression methods (which exist and can be used, but are considerably slower to extract, up to 10x), but by doing better work on preparing data to be compressed.In this case, this is actually recompression of deflate codec, which is used to make PDF, PNG, DOCX, OODT files smaller. However, just like in zip, it is inferior compression codec and since it is compression codec after-all, you cant significantly compress it further. So what we had to do is create re-def codec that opens up this data so it can be compressed better.
Hard part is to put it back together lossless, and still maintain good compression ratio, and make it all fast and seamless experience to the end user.
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ok, so no tasty PDFs to test? C’mn guys… we have just finished with the sample that Richard sent over. We need more.
There is nothing magical here, just a LOT of work.
Once again, how everything works is that we recompress deflate codec, used in png, pdf, zip, docx, oodt, etc.
So (simplified):
1. Extract deflate tokens from file
2. Compress them with better method (plzma currently)
3. Store differences between our deflate implementation and original file so we can have 100% match.
4. done.Basically main “problem” here is that everyone uses different deflate implementation. You know that if you ever zipped something with PA, WZ, WR, 7z and any other tool, you will never end up with same file sizes.
This is the problem during “reflate” because you cant arrive at 100% same file, you have to use differentials, just like what patchbeam uses for instance to sees the difference between new and old file.
So we need more interesting examples so we can tune our detection models so there will be minimal amount of diffs, and file size will be as small as possible… Lots of diffs and then we gain no compression.
For instance, PartyLite.pdf that SirRichard sent:
Original: 51 MB
PLZMA: 46 MB
Ver1 of reflate: 44 MB
Perfect reflate: 38 MBSo our first versions of reflate had 6 MB of differentials needed to re-created PDF perfectly… We improved that so it ended being 100kb or so and now we do 38 MB on that file.
That is before pjpeg (another codec) that recompresses the jpegs inside that PDF, so it ends up being the great 33 MB.
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I have been asking, unfortunetly when it comes to work we dont have daft Large PDF’s that would benefit from Compression.
My Photo person doesnt use PNG either. However, my partner who does Partlite on the side as she likes the product so I can obtain many PDF’s containing many images if you woud like more I will post them on my LiveDrive?
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they dont have to be particularly big… 30% less is 30% less. Just authentic.
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here are the results from independent testing of our test versions of reflate, our first codec for paf.
http://www.squeezechart.com/reflate0rc1.html
http://www.squeezechart.com/reflate-pdf.htmlThis is without specific jpg codec included (so pdf’s that contain jpg will not be recompressed to smallest size), and without detection mode for level of recompression needed, which will correct those docx results for instance.
very encouraging :-)
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Indeed!! allot of promise there! looking forward to it being available for us Toolbox power users :)
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@Sir:
Indeed!! allot of promise there! looking forward to it being available for us Toolbox power users :)
lots of ground work left, but pa-reflate is showing good results for sure, and it is quicker than only competition - stuffit.
by the time we finish 1.0 for release, it should be better than StuffIt in every single case in there, or at least 95%. In fact, with few adjustments, it would already be better overall except for png’s and pdf’s that contain jpegs, because we still have to implement our new jpeg codec.
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Remember to keep windows phone in mind when building Engine :D:D
Just kidding… Keep up the good work.
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will the new paf format allow the same actions as zip meaning you can work with files inside a zip file and it will automatically update itself.
I would like to see recovery like they have with rar. A paf repair tool as well and encryption. sfx program for paf.
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will the new paf format allow the same actions as zip meaning you can work with files inside a zip file and it will automatically update itself.
I would like to see recovery like they have with rar. A paf repair tool as well and encryption. sfx program for paf.
It would be a poor state of development if they couldnt repair there own code. :) but very valid points, and if PA want users to use their new format then they will need to tick those standard boxes you get with competitors formats, would you not concur?
