Wireshark is the world's foremost network protocol analyzer, and is the de facto standard across many industries and educational institutions. Deep inspection of hundreds of protocols, with more being added all the time Live capture and offline analysis Standard three-pane packet browser Multi-platform: Runs on Windows, Linux, OS X, Solaris, ...
Potplayer is a smooth media player with a great looking, minimalist user interface. The application has an extensive range of configurable options to choose from and lots of functionality. The application supports Bluray, DVD, Audio CD, and countless other media formats. It can be configured to work with various devices such as TV or HDTV, ...
Potplayer is a smooth media player with a great looking, minimalist user interface. It has an extensive range of configurable options to choose from and lots of functionality. The application supports Blu-ray, DVD, Audio CD, and countless other media formats. It can be configured to work with various devices such as TV or HDTV, and suppo...
Internet Download Manager is the choice of many, when it comes to increasing download speeds up to 5x. IDM has a clever download logic accelerator that features intelligent dynamic file segmentation and incorporates safe multipart downloading technology to increase the speed of your downloads. IDM reuses available connections without additional con...
Windows
(50)In 2007 I wrote about using PNGout to produce amazingly small PNG images. I still refer to this topic frequently, as seven years later, the average PNG I encounter on the Internet is very unlikely to be optimized.
For example, consider this recent Perry Bible Fellowship cartoon.
Saved directly from the PBF website, this comic is a 800 × 1412, 32-bit color PNG image of 671,012 bytes. Let's save it in a few different formats to get an idea of how much space this image could take up:
| BMP | 24-bit | 3,388,854 |
| BMP | 8-bit | 1,130,678 |
| GIF | 8-bit, no dithering | 147,290 |
| GIF | 8-bit, max dithering | 283,162 |
| PNG | 32-bit | 671,012 |
PNG is a win because like GIF, it has built-in compression, but unlike GIF, you aren't limited to cruddy 8-bit, 256 color images. Now what happens when we apply PNGout to this image?
| Default PNG | 671,012 | |
| PNGout | 623,859 | 7% smaller |
Take any random PNG of unknown provenance, apply PNGout, and you're likely to see around a 10% file size savings, possibly a lot more. Remember, this is lossless compression. The output is identical. It's a smaller file to send over the wire, and the smaller the file, the faster the decompression. This is free bandwidth, people! It doesn't get much better than this!
Except when it does.
In 2013 Google introduced a new, fully backwards compatible method of compression they call Zopfli.
The output generated by Zopfli is typically 3–8% smaller compared to
zlibat maximum compression, and we believe that Zopfli represents the state of the art in Deflate-compatible compression. Zopfli is written in C for portability. It is a compression-only library; existing software can decompress the data. Zopfli is bit-stream compatible with compression used in gzip, Zip, PNG, HTTP requests, and others.
I apologize for being super late to this party, but let's test this bold claim. What happens to our PBF comic?
| Default PNG | 671,012 | |
| PNGout | 623,859 | 7% smaller |
| ZopfliPNG | 585,117 | 13% smaller |
Looking good. But that's just one image. We're big fans of Emoji at Discourse, let's try it on the original first release of the Emoji One emoji set – that's a complete set of 842 64×64 PNG files in 32-bit color:
| Default PNG | 2,328,243 | |
| PNGout | 1,969,973 | 15% smaller |
| ZopfliPNG | 1,698,322 | 27% smaller |
Wow. Sign me up for some of that.
In my testing, Zopfli reliably produces 3 to 8 percent smaller PNG images than even the mighty PNGout, which is an incredible feat. Furthermore, any standard gzip compressed resource can benefit from Zopfli's improved deflate, such as jQuery:
Or the standard compression corpus tests:
| Size | gzip -9 | kzip | Zopfli | |
| Alexatop10k | 693mb | 128mb | 125mb | 124mb |
| Calgary | 3.1mb | 1017kb | 979kb | 975kb |
| Canterbury | 2.8mb | 731kb | 674kb | 670kb |
| enwik8 | 100mb | 36mb | 35mb | 35mb |
(Oddly enough, I had not heard of kzip – turns out that's our old friend Ken Silverman popping up again, probably using the same compression bag of tricks from his PNGout utility.)
But there is a catch, because there's always a catch – it's also 80 times slower. No, that's not a typo. Yes, you read that right.
gzip -9 |
5.6s |
7zip mm=Deflate mx=9 |
128s |
| kzip | 336s |
| Zopfli | 454s |
Gzip compression is faster than it looks in the above comparsion, because level 9 is a bit slow for what it does:
| Time | Size | |
gzip -1 |
11.5s | 40.6% |
gzip -2 |
12.0s | 39.9% |
gzip -3 |
13.7s | 39.3% |
gzip -4 |
15.1s | 38.2% |
gzip -5 |
18.4s | 37.5% |
gzip -6 |
24.5s | 37.2% |
gzip -7 |
29.4s | 37.1% |
gzip -8 |
45.5s | 37.1% |
gzip -9 |
66.9s | 37.0% |
You decide if that whopping 0.1% compression ratio difference between gzip -7and gzip -9 is worth the doubling in CPU time. In related news, this is why pretty much every compression tool's so-called "Ultra" compression level or mode is generally a bad idea. You fall off an algorithmic cliff pretty fast, so stick with the middle or the optimal part of the curve, which tends to be the default compression level. They do pick those defaults for a reason.
PNGout was not exactly fast to begin with, so imagining something that's 80 times slower (at best!) to compress an image or a file is definite cause for concern. You may not notice on small images, but try running either on a larger PNG and it's basically time to go get a sandwich. Or if you have a multi-core CPU, 4 to 16 sandwiches. This is why applying Zopfli to user-uploaded images might not be the greatest idea, because the first server to try Zopfli-ing a 10k × 10k PNG image is in for a hell of a surprise.
However, remember that decompression is still the same speed, and totally safe. This means you probably only want to use Zopfli on pre-compiled resources, which are designed to be compressed once and downloaded millions of times – rather than a bunch of PNG images your users uploaded which may only be viewed a few hundred or thousand times at best, regardless of how optimized the images happen to be.
For example, at Discourse we have a default avatar renderer which produces nice looking PNG avatars for users based on the first letter of their username, plus a color scheme selected via the hash of their username. Oh yes, and the very nice Roboto open source font from Google.
 |
 |
 |
We spent a lot of time optimizing the output avatar images, because these avatars can be served millions of times, and pre-rendering the whole lot of them, given the constraints of …
… isn't unreasonable at around 45,000 unique files. We also have a centralized https CDN we set up to to serve avatars (if desired) across all Discourse instances, to further reduce load and increase cache hits.
Because these images stick to shades of one color, I reduced the color palette to 8-bit to save space, and of course we run PNGout on the resulting files. They're about as tiny as you can get. When I ran Zopfli on the above avatars, I was super excited to see my expected 3 to 8 percent free file size reduction and after the console commands ran, I saw that saved … 1 byte, 5 bytes, and 2 bytes respectively. Cue sad trombone.
(Yes, it is technically possible to produce strange "lossy" PNG images, but I think that's counter to the spirit of PNG which is designed for lossless images. If you want lossy images, go with JPG or another lossy format.)
The great thing about Zopfli is that, assuming you are OK with the extreme up front CPU demands, it is a "set it and forget it" optimization step that can apply anywhere and will never hurt you. Well, other than possibly burning a lot of spare CPU cycles.
If you work on a project that serves compressed assets, take a close look at Zopfli. It's not a silver bullet – as with all advice, run the tests on your files and see – but it's about as close as it gets to literally free bandwidth in our line of work.
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MediaInfo provides you with a quick access to the inner values of your audio and video files. Whether you want to glance at the set-up of tracks included in a file or you want to know all the precise details about the codecs used, MediaInfo will offer the suitable view. You can choose between a graphical user interface to quickly select the appr...
The report, entitled, Kaspersky Security Bulletin 2015, Overall statistics for 2015, shows some worrying trends. Highlights of the report show that in 2015, there were:
*These figures only show computers and devices protected by Kaspersky software
Distribution of exploits used in cyberattacks, by type of application attacked, 2015
Finance:
Kaspersky Lab solutions blocked attempts to launch malware capable of stealing money via online banking on 1,966,324 computers, this year, a growth of 2.8% from 2014.2014. The peak months for attacks on financial institutions was between February and April.
Ransomware:
2015 also proved to be an “interesting year for Ransomware.” Ransomware has come a long way in a very short space of time since the emergence of Cryptolocker in 2013. Encryption based ransomware also made its presence felt on Android OS as well, and was responsible for 17% of known infections to the Google operating system. But it wasn’t just Android that took a hit. 2015 also saw the first instance of ransomware on Linux, but due to an inception error by the malware authors, Linux users were able to decrypt their files without handing over cash.
Countries most at risk of online infection for users:
Well it’s bad news if you live in Russia. Russians faced the highest risk in the world of online infection, with almost 50% of “unique” users facing some form of infection from internet related activity. However, 34.2% of computers globally faced an attack at least once while users were actively online.
Web Developers:
Kaspersky notes that 2016 might not all doom and gloom, despite the advancement of encryption based ransomware. Kaspersky notes that web-browser developers have begun to take active steps themselves to protect their users from malware and online attacks, closing loopholes and instigating their own defenses against web attacks of all kinds.
Main trends of 2015:
In an effort to avoid prosecution, Kaspersky has identified a trend whereby cyber criminals are switching from direct malware attacks and are instead resorting to the aggressive use of adware, to make it harder for law enforcement agencies to track them. At the same time, hackers have also mastered other non-Windows based platforms, diversifying their attacks for maximum effectiveness.
Kaspersky expects the major trend in 2016 by cyber-criminals will be continue to develop and launch encryption based ransomware that will continue to target non-windows based operating systems, such as Linux and Android, and that Apple will also experience its own custom designed ransomware.
The post Kaspersky Looks Back At Cyber Security Stats For 2015 appeared first on TechBeat.
Windows
(299)
The Instagram for Chrome extension is a really useful tool if you happen to like viewing your favorite image packed social media outlet whilst sat at your desktop. The extension is both lightweight and powerful, with a slick, but familiar interface. With Instagram for Chrome installed you will be able to gain access to your Instagram feed, your ...
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