Monthly Archives: October 2006

What I learned about MHP …

Recently in Austria (this is were I’m living, and no: we do not have kangaroos here) the public broadcaster switched on a series of digital video broadcasting stations to start the transition from analogue TV to the digital age using DVB-T. As I’m kind of multimedia guy, I bought a reasonable USB DVB-T stick to do some recording and watching (the TerraTec Cinergy Hybrid T USB XS).

The Austrian public broadcaster started with 4 streams: ORF 1, ORF 2, ORF 2 local and ATV+. All of these come with their own videotext and EPG (Electronic Program Guide, the main big thing about DVB). In addition the broadcaster sends some so called Multimedia Home Platform (MHP) multitext mixed up into the streams.

So what’s that? MHP is kind of sending web pages (kind of XHTML) and Java (just google for Java TV) to client browsers. This can be used to add applications (games, quizzes) and information (schedule, background, images) to the current and scheduled broadcasts. More information can be found in wikipedia.

So why write about it if its good and usable? At a first thought this is a good thing. Why not using XHTML and Java (or some other interpreted language with a small VM) to add some features from the web to TV? This can be considered as good idea. What’s not so good about is, that an MHP browser makes DVB-T receivers more expensive. There’s a gap of 40 Euros between the cheapest receiver without and the cheapest receiver with such a browser. Where does this gap come from?

The MHP.org homepage from the DVB-Project provides an answer: They write at their Conformance & Licensing page “[…] entitled to use the MHP Mark, for which it pays a €10,000 initial royalty and an annual royalty […]”. Well that’s quite an amount of licensing fee, isn’t it. This little and unimposing part of a sentence also provides an explanation why open source projects do not implement MHP.

However this shows that there is still a market for non royalty free standards and people obviously can gain some revenue from it. This practice is (or was) also common within the MPEG standardization group. But due to success of W3C royalty free standards they also established a subgroup for free and open standards.

Report from the Semantic Web Atelier

Yesterday the 9th SWAt (Semantic Web Atelier) in Graz took place. As I would write a summary anyway I’m blogging it here and now:We two talks, the first one was from Peter Scheir about the performance of RDF databases and the second one was from Gisela Dösinger about the findings of a survey.

The RDF databases part was in general a lively discussion as there are not many good scientific evaluation results available on the internet. It is true for all databases that were tested (Sesame, Jena, Kowari, …) that inference and reasoning kills performance. Furthermore if the API instead of query languages for operations on the data is used the performance is much better. In general Sesame is faster than Jena, only performance of delete operation is dreadful within Sesame. The Sesame API and the processes inside suffer from missing documentation. Jena on the other side has enough docs and is therefore easier to use. SPARQL support is not very good in both cases. One essence of the discussion was that if it is possible (based on the use case) one should use a database, like for instance MySQL, for storing and retrieving the triples.

Gisela Dösinger presented the results of an interview and online survey done within the Sembase project. Many people from Austria, who are somewhat involved with IT and / or Semantic Web were questioned. One major finding can be summarized as follows: The interview results show for example that the Semantic Web lacks clear definitions of problems, results and benefits as well as best practice examples. More results and corresponding figures are available the presentation slides.

The slides of both presentations will be available here.

MPEG Cutters

cut.pngHaving something to do with multimedia one minds that there are a lot of tools around that cost a lot of money. One surprising functional and cheap (well basically its free) tool is Cut! It has a simple and intuitive interface and it basically does its job good without any annoying feedback dialogs or errors. Its part of the TerraTec Home Cinema Program and allows lossless cut of MPEG streams. TerraTec Home Cinema 4.75 can be obtained from the driver section of the TerraTec Homepage.

Pure Java JPEG Decoders?

As there are always some issues with loading images I recently checked if there is any pure & free2use Java implementation of a JPEG decoder. Well, obviously there isn’t any alternative to Sun’s javax.imageio package. However I found an interesting site summarizing libraries for de- and encoding raster images here.

As for my schedule: I plan to write some simple decoder for PPM, just a ppm to BufferedImage converter, which should be threaded to support parallel execution on the new double core systems. Doing the same with JPG would be quite a thing I think :)

CfP Content-Based Multimedia Indexing, CBMI-2007

Just received this weekend from an MPEG standardization group context (just to give a hint where to categorize this conference in a first shot :)

Following the four successful previous events of CBMI (Toulouse 1999, Brescia 2001, Rennes 2003 and Riga 2005), CBMI’2007 will be held on June 25 – 27 2007 in Bordeaux, France. CBMI’07 aims at bringing together the various communities involved in the different aspects of Content-Based Multimedia Indexing. Best papers will be published in a special issue of Signal Processing : Image Communication Journal, Elsevier.

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This email and any files transmitted ….

Imagine you are in mailing list (as I’m in both Lucene lists) … Imagine getting mail messages every day (as you surely do :) … Imagine you get a mail footer like this:

This e-mail and any files transmitted with it
are for the sole use of the intended recipient(s)
and may contain confidential and privileged
information.
If you are not the intended recipient, please
contact the sender by reply e-mail and destroy
all copies of the original message.
Any unauthorised review, use, disclosure,
dissemination, forwarding, printing or copying
of this email or any action taken in reliance
on this e-mail is strictly prohibited and may
be unlawful.

What shall we do? Should we send it back? Well I post this message here … although it may be unlawful? You’ll find the original mail here in the Lucene mailing list archive.