SemanticMetadata.net

My Talk @ Florida Atlantic University

Just hours ago I finished my talk here at FAU, Boca Raton,FL, USA. I was talking about user intentions or what I call “the other end of the camera”. It was the first time I presented a whole overview on the “Intentions & Multimedia” thing I’m working on now for quite a long time, and I think it was very well recieved.

• Slides from the talk (PDF)
• Slides at Slideshare

SeMuDaTe 09 already started

I’m currently in Graz, chairing the first session of SeMuDaTe 09, a community workshop of the multimedia metadata community. I’m looking forward to a day full of interesting talks and discussions. Proceedings of the event are already available at ceur.ws. Our paper on Global vs. Local Feature in Video Summarization will be presented in the afternoon by my colleague Marian Kogler.

Links:

• http://CEUR-WS.org/Vol-539/
• Our paper: Global vs. Local Feature in Video Summarization

ACM Multimedia 2009: Project Natal in the Brave New Topics Session …

Yesterday the “brave new topics” session took place. Initially it was meant to present challenging ideas and new things without the demand for extensive evaluation or being picky or realistic. Hrvoje Benko from Microsoft presented a lot of things regarding new output and input interfaces and closed his presentation with the ad for Project Natal. While some of the audience were astonished I still have to point out that especially the multimedia research community has to get a bit closer to gaming. Many of the engineered solutions there can be applied to common problems in multimedia and the other way round. At GDC europe people said problem in game developments are streaming and asset management. On the other hand gaming provides us with cool I/O devices (Dualshock, Sixaxis, Wiimote, etc.) So get together guys

Caliph & Emir @ ACM MM – Presentation on Thursday

I’m currently attending the ACM Multimedia conference in Beijing (nice city by the way, one only has to survive traffic). Tomorrow is out big day for our user intent classification tool “Intent inside” and the day after Claiph and Emir are presented by myself. If you are also her, I’d be happy to meet & greet and talk about further developments, etc.

CfP 2nd International Conferences on Advances in Multimedia

MMEDIA 2010 aims to provide an international forum by researchers, students, and professionals for presenting recent research results on advances in multimedia, mobile and ubiquitous multimedia and to bring together experts from both academia and industry for the exchange of ideas and discussion on future challenges in multimedia fundamentals, mobile and ubiquitous multimedia, multimedia ontology, multimedia user-centered perception, multimedia services and applications, and mobile multimedia.

>> more information

Converting video for flash video players to H.264/AAC

Have you ever tried to put a video online? Well actually it is quite easy if you user YouTube. No matter what codec you use you have a good chance to get a decent result. If you want to host the video yourself you basically need a flash video player (assuming that flash is the most widely spread tool on multiple platforms) like the JW FLVPlayer. Finally you’ll need to get your video file to a format flash can play using progressive download (which means you can watch it while downloading, just like on YouTube).

Since Adobe Flash Player 9 Update 3Flash can play back MP4 files with H.264 video and AAC audio streams [see here], so we can just focus on this one. First step is to get a ffmpeg version compiled with libx264 and libfaac. You might check this on the command line, just execute ffmpeg without parameters:

FFmpeg version SVN-r16573, Copyright (c) 2000-2009 Fabrice Bellard, et al.
configuration: [...] –enable-libfaac –enable-libgsm –enable-libx264 [...]

The bold ones should be there to support the needed codecs. I used FFmpeg Revision 16537 from this page, which works fine.

If the libraries are there you can proceed to the next step:

ffmpeg -i <inputfile> -b 1024k -vcodec libx264 \\
-acodec libfaac -ab 160k <output.mp4>

This converts your input file to the needed mp4 file. You can also change the size of the file with the switch “-s”, like for instance “-s 320×240″. Take a close look on the switches “-b” and “-ab” which define video and audio bitrate. If the sum of both bitrates is too high for the network the user will not be able to watch the video smoothly.

One might think s/he’s finished, but no … unfortunately progressive download doesn’t work with too many mp4 files. The file index (an atom == “mp4 metadata unit”) containing the file index (== the description where the video and the audio stream are located in the file and how they are stored) is at the end of the MP4 file. So the flash player has to download the whole file before starting the playback, ka-ching!

Fortunately there is an ffmpeg tool called qt-faststart (linux users will find it in the tools folder of ffmpeg) moving the index from end to start. For windows user a precompiled binary can be found here. Use this to move the metadata:

qt-faststart <infile.mp4> <outfile.mp4>

Now you are done with the file. Use for instance the JW FLVPlayer setup wizard to create an HTML snippet. Note that in height you have to add 19 pixels to your video dimensions, as this is the height of the control bar of the player

Contribution @ I-KNOW 09 accepted!

The contribution of Christoph Kofler and me with the title “An exploratory study on the explicitness of user intentions in digital photo retrieval” has been accepted for publication and presentation at the I-Know ’09. Here is the abstract (the full paper will follow as soon as we have prepared the camera ready version):

Search queries are typically interpreted as specification of information need of a user. Typically the search query is either interpreted as is or based on the context of a user, being for instance a user profile, his/her previously undertaken searches or any other background information. The actual intent of the user – the goal s/he wants to achieve with information retrieval – is an important part of a user’s context. In this paper we present the results of an exploratory study on the interplay between the goals of users and their search behavior in multimedia retrieval.

This work has been supported by the SOMA project.

Links

• I-KNOW 09
• SOMA project

Self Organizing Multimedia Architecture (SOMA) – The Project

Currently we are working a lot on a research project funded by a Carinthian agency. The project goes on for 3 years (2.5 years left) and has enough funds to pay 4 PhDs and 1 post doc researcher. Here is the description and the link to the blog:

The project Self-organizing Multimedia Architecture (SOMA) aims to capture the whole life-cycle of multimedia content in a single architecture for large distributed multimedia information systems. In SOMA we focus on scenarios where events, which we understand as “limited time periods of special importance”, are a central concept. Examples for such scenarios are sports events stretching over time, where start, finish or critical parts of a race are possible events, or traffic monitoring, where events like traffic jams or accidents have to be reported and investigated.

via Project Description | Self Organizing Multimedia Architecture.

Packing my Bag for the Triple-I

Tomorrow morning I’m on the road to go to Graz, where the Triple-I (former I-Know) takes place Wednesday to Friday. I’ll be there to visit and present at the KASW workshop and to chair the session of the multimedia metadata community. I’m looking forward to meet my colleages there. I-Know is always productive and good fun.

Lire accepted for the Open Source Contest @ ACM MM

Although its quite some time ago that I got the acceptance mail I forgot to blog the good news: Lire (Lucene Image Retrieval) has been acccepted to be presented at the ACM Multimedia within the Open Source Contest track. As it is a contest I assume we have chances to win something?