compress - Dave's Blog


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2015 Sep 19, 1:08
Designing the least JPG compressible fabric pattern: …. This is the anti @ericlaw

HTTP Compression Documentation Reference

2012 Jun 13, 3:08
There's a lot of name reuse in HTTP compression so I've made the following to help myself keep it straight.
HTTP Content Coding Token gzip deflate compress
An encoding format produced by the file compression program "gzip" (GNU zip) The "zlib" format as described in RFC 1950. The encoding format produced by the common UNIX file compression program "compress".
Data Format GZIP file format ZLIB Compressed Data Format The compress program's file format
Compression Method Deflate compression method LZW
Deflate consists of LZ77 and Huffman coding

Compress doesn't seem to be supported by popular current browsers, possibly due to its past with patents.

Deflate isn't done correctly all the time. Some servers would send the deflate data format instead of the zlib data format and at least some versions of Internet Explorer expect deflate data format instead of zlib data format.

PermalinkCommentscompress compression deflate gzip http http-header technical zlib

Mothereffing animated gif

2012 Feb 17, 7:31

Client side animated GIF creator web app.

PermalinkCommentstechnical javascript gif animated compression html5

Download A Piece of Internet History | The Changelog

2010 Apr 29, 11:53"I wrote Gopherbot, a spidering archiver for Gopherspace. I ran it in June 2007, and saved off all the documents and sites it could find. That saved 40GB of data, or about 780,000 documents." Now available as a compressed 15GB torrent.PermalinkCommentstorrent gopher internet web technical history archive

Encode-O-Matic: Guess Encoding

2010 Apr 4, 2:02

I've just updated Encode-O-Matic with a Guess Input Encoding feature. When you start Encode-O-Matic or when you use the 'Guess Input Encoding' menu item from the 'Tools' menu, Encode-O-Matic will try out various combinations of encodings and guess at which set seem to apply to your input. For instance given the following text, Encode-O-Matic will correctly guess that it is percent encoded, base64 encoded, deflate compressed text:

It should work fairly well for simple things but I did pick 'Guess' for the name of the feature to intentionally lower expectations. It doesn't currently apply to character encodings but that may be something to consider in the future.PermalinkCommentstechnical encodeomatic tool encoding

Encode-O-Matic Update: Compression, Hex View, Quick Show Output

2010 Mar 9, 9:08

I've just put up an update for Encode-O-Matic with the following improvements:

PermalinkCommentstechnical encodeomatic project

Coding Horror: You're Reading The World's Most Dangerous Programming Blog

2010 Jan 20, 8:28GZip vs Deflate execution speeds. Deflate found to be much faster in particular cases and about the same in the rest.PermalinkCommentsgzip deflate performance technical http compression programming development blog

RFC 1951 - DEFLATE Compressed Data Format Specification version 1.3

2009 Sep 3, 7:17"This specification defines a lossless compressed data format that compresses data using a combination of the LZ77 algorithm and Huffman coding." Also see RFC 1950 zlib, a wrapper compression format that can use deflate, and RFC 1952 gzip, a compressed file format that can use deflate.PermalinkCommentstechnical rfc ietf compression http deflate gzip zlib

Timefire: On Reducing the Size of Compressed Javascript (by up to 20%)

2009 Sep 1, 4:39"...what effect does the large-scale structure of the JS output code have on the DEFLATE algorithm of GZIP which is used to serve up compressed script?" Another instance of using knowledge of the specific file type to get gains in compression. Is there a web proxy running all this at which I can point my phone?PermalinkCommentsvia:kris.kowal performance javascript gzip deflate compression web technical

CSS minifier and alphabetiser – Barryvan

2009 Sep 1, 4:36"I’ve written a small Java application that will read in a CSS file and output its contents to stdout or another file in a format that’s optimised for gzipping." Cool!PermalinkCommentsvia:kris.kowal technical compression css web performance gzip java

Eat Pants - Interactive Fiction Sessions from my Server Logs

2009 Jun 29, 4:19

I've looked at my web server logs previously to see if anyone had used my Web Frotz Interpreter and until recently didn't realize that awstats (the web server log report generator) was truncating the query from my URL, so I couldn't tell that anyone was actually using it. But after grepping the logs manually I've pulled out the URLs of visitor's text adventure sessions. If you'll recall, my Web Frotz Interpreter stores the game state in the URL so its easy to see user's game states in the web server logs.

I've put some of the links up on the Web Frotz Interpreter page. Some of the interesting ones:

PermalinkCommentsserver-logs technical zork frotz pants interactive-fiction uri if

Compressed web phone calls are easy to bug - tech - 12 June 2008 - New Scientist Tech

2008 Jun 19, 1:00"The new compression technique, called variable bitrate compression produces different size packets of data for different sounds...VoIP streams are encrypted to prevent eavesdropping. However, a team ... has shown that simply measuring the size of packetsPermalinkCommentssecurity privacy phone compression encryption blog article

URI Addressable Text Adventure Games

2008 Mar 2, 9:18

This post is about creating a server side z-code interpreter that represents game progress in the URI. Try it with the game Lost Pig.

I enjoy working on URIs and have the mug to prove it. Along those lines I've combined thoughts on URIs with interactive fiction. I have a limited amount of experience with Inform which generates Z-Code so I'll focus on pieces written in that. Of course we can already have URIs identifying the Z-Code files themselves, but I want URIs to identify my place in a piece of interactive fiction. The proper way to do this would be to give Z-Code its own mimetype and associate with that mimetype the format of a fragment that would contain the save state of user's interactive fiction session. A user would install a browser plugin that would generate URIs containing the appropriate fragment while you play the IF piece and be able to load URIs identifying Z-Code files and load the save state that appears in the fragment.

But all of that would be a lot of work, so I made a server side version that approximates this. On the Web Frotz Interpreter page, enter the URI of a Z-Code file to start a game. Enter your commands into the input text box at the bottom and you get a new URI after every command. For example, here's the beginning of Zork. I'm running a slightly modified version of the Unix version of Frotz. Baf's Guide to the IF Archive has lists of IF games to try out.

There are two issues with this thought, the first being the security issues with running arbitrary z-code and the second is the practical URI length limit of about 2K in IE. From the Z-Code standard and the Frotz source it looks like 'save' and 'restore' are the only commands that could do anything interesting outside of the Z-Code virtual machine. As for the length-limit on URIs I'm not sure that much can be done about that. I'm using a base64 encoded copy of the compressed input stream in the URI now. Switching to the actual save state might be smaller after enough user input.

PermalinkCommentszork frotz interactive-fiction zcode if technical uri fragment


2006 Dec 20, 4:37Free compression application.PermalinkCommentssoftware zip compression opensource free
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