Wednesday 11th July 2007

I just tried sending an email from my GMail account but I got a response back pretty quick saying that delivery had failed; I was pretty certain the email address was valid.

Looking at the response in greater detail I noticed that it had failed because a relay somewhere along the chain had blocked the message coming from GMail; you can see why here.

Technical details of permanent failure:
PERM_FAILURE: SMTP Error (state 16): 550-gmail.com 
is in the AHBL (rhsbl.ahbl.org).  For more info see:
550-http://www.ahbl.org/tools/lookup.php?ip=gmail.com
550 gmail.com - trelane - Google GMail, relaying 
child pornography spam

According to the response that I got, it appears that GMail has somehow got itself on an abusive hosts lists for apparently “relaying child pornography spam”. Strange! Anybody else having this problem?

Whatever happened to “don’t be evil” 🙂

Tagged PDF

Alfresco uses Open Office to convert documents to PDF but by default it doesn’t generate tagged PDF. This note describes how to configure Alfresco so that it does produce tagged PDF.

So what is a tagged PDF? Well, it’s a PDF that contains structural information about the content, e.g reading order, the presence of tables etc. This allows screen-readers to read the PDF document – it makes the PDF accessible. In order to get the most out of the conversion process, as much structural information as possible needs to be present in the original document. I came across these recently when doing some work for a local authority that is using Alfresco.

So how do you configure Alfresco to produce tagged PDF? Open up the file ‘openoffice-document-formats.xml’, which is located in <tomcat_home>/webapps/alfresco/WEB-INF/classes/alfresco/mimetype/, locate the Portable Document Format document format section (it should be at the top of the file) and modify it so it looks like this:


<document-format><name>Portable Document Format</name>
<mime-type>application/pdf</mime-type>
<file-extension>pdf</file-extension>
<export-filters>
 <entry><family>Presentation</family><string>impress_pdf_Export</string></entry>
 <entry><family>Spreadsheet</family><string>calc_pdf_Export</string></entry>
 <entry><family>Text</family><string>writer_pdf_Export</string></entry>
</export-filters>
<export-options>
  <entry><string>EnableTextAccessForAccessibilityTools</string><boolean>true</boolean></entry>
  <entry><string>UseTaggedPDF</string><boolean>true</boolean></entry>
</export-options>
</document-format>

Restart Alfresco. That’s it! The next time you convert a document to PDF it should be tagged. You can test that the conversion worked (on the Mac) by using Adobe Reader 8.0. Open up the PDF file. Go to Document -> Security -> Show Security Properties. Click on the ‘Description’ tag. The ‘Tagged PDF’ entry should be set to ‘Yes’ if the conversion worked correctly. You can also check the document for accessibility by clicking on Document -> Accessibility Quick Check.

You can download the modified configuration file here.

Thursday 7th June 2007

BBC News: “But they all maintain their innocence and lawyers observing the trial have suggested acquittals may be more likely than convictions because while turning Swissair’s $3bn cash balance into multi-million dollar debts in just a few years may be very stupid, it isn’t necessarily a crime.”

Converting to PDF with Alfresco

Brief note that explains how to set-up Alfreso to transform various document formats to PDF. I am writing this because I didn’t find it particularly easy to track down how to do it; it involves a lot of digging around in the wiki. Hopefully, this note will make it easier to set-up.

By default Alfresco will convert PDF, Word documents etc to plain text but if you want to go the other around, e.g. transform plain text to PDF, you need to start Open Office from the command line – a version of Open Office comes bundled with Alfresco. It’s easy really: just run the start_oo.sh script, which you will find in the Alfresco home directory. Once you have done this you should be able to transform documents to PDF.

You can check that Open Office is running by executing the command lsof -i | grep 8100. If you start Open Office manually, note that Alfresco expects Open Office to be running on port 8100.

There’s a whole page on starting Open Office from the command line on the Alfresco wiki. Not sure why the page needs to be so long. I just ran the start_oo.sh script and Open Office started up without any problems. Maybe I got lucky!

Tuesday 5th June 2007

This just has to be seen: Darth Vader Rap.

Streaming vs Downloads

I have been thinking a lot recently about methods of delivering large media files, e.g. video, mp3 etc, and playing them online. Think YouTube. You can either stream the file or use HTTP (progressive) download. My question is this: why would you want to stream a file? It seems to me that, with a few exceptional cases, streaming files is unnecessary. I am trying to come up with a list of pros and cons for streaming (large) media files.

Pros

  • Can be used to broadcast time-sensitive events, e.g. a live concert.
  • Useful for devices with limited storage capacity, e.g. mobile phones
  • As the content is not stored locally, makes “recording” content difficult, e.g. DRM – I have seen this one cited in several places
Cons

  • Requires “special” server-side software to implement the streaming protocol, e.g. RTMP. Can be expensive.
  • Some streaming protocols, such as Flash video, are proprietary (related to the above point)
  • More (server) hardware required to support connections etc ??

Even though I have only come up with a few negatives I am not convinced that streaming files is necessary in the majority of cases. Podcasts are a good example where just downloading the file is sufficient. Thoughts? Feel free to add any comments.

Update: seems there are stream recorders out there that do allow you to save content that is streamed.

Monday 14th May 2007

Due to popular demand – well, one person asked for it – I have added (reverse) geocoding to my map application. In plain English, this means that you can enter your address and the application will zoom to that location on the map; hopefully, this will be less painful than having to get to your starting point by dragging/zooming around. Currently this only works for U.S. addresses as – as far as I am aware – the Google Maps API only supports U.S. addresses.

BBC News: Web 2.0 ‘distracts good design’

Check out some of the funky graphic animations on this guy’s web page – scroll down to the “Research” section; the animations start there.

Why Hotmail sucks

I decided to clean out my Hotmail account as I had accumulated 469 unread emails in it – mostly junk mail; I don’t actually use Hotmail that much now either. It was becoming irritating because every time I logged in to Hotmail using my mobile phone – it has an Internet connection – I had to subtract 469 from the total number of unread messages to figure out if I had any new email. Still, should be easy enough to do, or so I thought. Just ask Hotmail to show me all the unread messages then delete them right? Wrong! Seems you can’t do that and even if there is a way, I don’t want to know about it because I have just spent the last 40 minutes or so going through about 2000 emails looking for ones that were marked as unread; the interface only shows 50 emails at a time so you can imagine what a pain it is plus it kept breaking in Firefox so I had to switch to using IE. Something so simple is so broken that it’s no wonder Microsoft is getting it’s ass kicked by the likes of Google. I’m sure if I complained they would probably just tell me to use Outlook if I want “advanced” features! Ho hum.

DRM

Interesting essay by Steve Jobs about DRM.

“Through the end of 2006, customers purchased a total of 90 million iPods and 2 billion songs from the iTunes store. On average, that’s 22 songs purchased from the iTunes store for each iPod ever sold.

Today’s most popular iPod holds 1000 songs, and research tells us that the average iPod is nearly full. This means that only 22 out of 1000 songs, or under 3% of the music on the average iPod, is purchased from the iTunes store and protected with a DRM. The remaining 97% of the music is unprotected and playable on any player that can play the open formats.”

Birthday bonanza

As yesterday was my birthday, last night myself and some friends descended on Guanabara, a Brazilian bar located in the West End, for a couple of drinks (only a couple, honest) and some live music.

I was told by one of staff working the floor a couple of days previously that the live music started around 8pm. She must have meant 8pm in Rio de Janiero because it didn’t actually start until around 10.30pm. Still, when they got going they weren’t too bad. Not too great either but enjoyable enough. Then again, after far too many cocktails, a beer, tequila and some dodgy Brazilian spirit that resembled surgical spirit, anything would sound good! The schizophrenic lead singer was particularly entertaining: one minute he thought he was Jamiroquai; the next, James Brown. He also seemed to have a problem keeping his shirt on.

Then there was the guy in the crowd playing the air saxophone. I’ve seen plenty of people playing air guitars before but never a sax. Novel if nothing else, although rather than resembling a saxophone player he looked more as though he was sucking his thumb while scratching his balls.

Overall it was a really good night and a good way to celebrate a birthday. Highly recommended.