Sunday, May 10, 2009

UPnP DevSprint in Paris


Hi from Paris, where together with [ade], dev, erwan, philn and lightyear I'm at the Coherence/KDE developer sprint focused on UPnP.
Yesterday, after struggling with QtDBUS (specifically the under-documented qdbusxml2cpp) I managed to the signals from Coherence and call functions. So now I can discover the devices on the network.

The signals are connected to a UPnPCollectionFactory that should create a new collection for each mediaserver (containing music) on the network.

Next step will be to really talk to the devices themselves. That will require some XML parsing, which can get a bit complicated. With any luck I'll find a Qt based DIDL-lite parsing library. Consider that a lazyweb questions :).

A bientôt,
Bart

Friday, February 13, 2009

UPnP support in KDE and Amarok

During FOSDEM [ade] and I met with Frank Scholz, the lead developer of Coherence. We discussed DLNA/UPnP and how Coherence can be used in KDE and Amarok. The conclusion of this meeting was that we should use Coherence as our base for supporting UPnP services in KDE. The first implementation will be a KIO slave for browsing media stored on remote devices.

UPnP is a network technology using a combination of SSDP, XML and SOAP, with some GENA thrown in for eventing. A group of UPnP services called the UPnP A/V Architecture has been picked up by an industry organization called the Digital Living Network Alliance. DLNA specifies device classes which have to implement specific services and support a minimal set of filetypes and codecs.

Coherence is a framework, written in Python but it exposes a DBUS API, that allows an application to participate in the "Digital Home Network". For the moment this means mainly UPnP, but support for Ampache is available and Apple's DAAP is also considered. It's published under the MIT license and is multiplatform.

In Amarok we have been planning to integrate UPnP for a long while. But except for a failed Google Summer of Code project last year not a lot of effort has been spend. Thanks to Coherence this will quickly change: in relative short term (read 2.2) we will introduce a UPnP Collection that will list and enable playback of music stored on a DLNA Digital Media Server.

We could even consider publishing the content in the local Collection, basically making Amarok a DMS. Amarok can then track plays on remote devices and use it in the scoring algorithm.
Even more advanced functionality would be to control one or more Digital Media Renderes, such as
the Philips Streamium, from Amarok.

A few mails have been going back and forth between interested developers about discovery of network services in general. In order to simplify using technologies as UPnP, zeroconf, Samba, etc I'm wondering if we can integrate this in Solid. Only the discovery part obviously, using the services would be the task of separate frameworks, such as Coherence. With this functionality in Solid it should be trivial to show a kind of "Network Map" to the user with all the services per device.

As you can tell, plenty of cool things to keep a few people busy for a year or 3.

Bart

Monday, February 02, 2009

Amarok Junior Job: Auto-download new podcasts

A recent comment by progmanos on the post of the 2.0.1.1 release reminded that I still have to implement Podcast episode auto-downloading. In the hurry to get 2.0 released I did add the config option, but forgot to add the actual code to make it work.


In Amarok 2 Podcasts are implemented in classes derived from PodcastProvider. There can be mutliple providers, which allows for instance podcast syncing between Amarok and an iPod.
The default provider is SqlPodcastProvider. This is where the auto-download function should get implemented.

This is a nicelly contained and not to steep introduction to Amarok development. So it's an excelent Junior Job.
If progmanos or anyone else would like to have a go at it, contact me on #amarok on irc.freenode.net. My nickname is Stecchino.

Tuesday, November 04, 2008

Amarok podcasting 2.0 and post-2.0 plans

Hey fellow developers and users,

In Juli 2007, at Akademy Glasgow I started implementing podcasting support in Amarok2. Since then I was sidetracked a little, as you may be aware.

The little time I did manage to spend designing and implementing was short and far from focused. So a lot of features are not finished or just plainly missing. The framework I created underneath suffered from the same lack of focus and is need of a good review. I'm aware there is probably some overdesign and some parts might be to complex. If you feel you can help in that area I suggest you take a look at extragear/multimedia/amarok/src/podcasts . Send questions, comments and suggestions to amarok-devel@kde.org .

The 3rd beta from Amarok 2.0 is already out the door and podcasting support is still not finished. In order to make it I had to reduce some goals I had set for myself during those rainy summer days in Scotland. Here's the plan:

Amarok 2.0:
The focus ATM is on finishing the SqlPodcastProvider, Podcastmodel and PodcastCategory (GUI).
SqlPodcastProvider uses tables in the standard SQL database, adds and updates the feeds using PodcastReader and downloads to disk using the regular KIO-jobs.
To make the podcasting fully functional though we'll need to reintroduce:
  • Autoscan the feed for updates
  • Download when available
  • Episode purging (delete downloaded episodes automatically)
The settings dialog for this exists, next up is using them :).
The GUI currently shows all episodes ever read from the feed, which obviously needs to be addressed.
The GUI for 2.0 should be very similar, if not identical to Amarok 1.4, probably minus folder tree grouping support since that is better handled generically for all Playlists (which PodcastChannel is in our class diagram).

If anyone has a bit of Qt Model/View experience and would like to see podcasting in Amarok 2.0 I suggest you send a mail to amarok-devel@kde.org or ping me on irc (Stecchino on #amarok).
Without help we might have to drop it's from 2.0 completely because it's a bit much for me alone to complete and stabilize.

Amarok > 2.0:
I do have a plan for a complete GUI overhaul post-2.0. I'll get some art and usability advice in another blog post when the time comes.

The 2.x releases should see more advanced features being introduced that the framework is already designed to support:
For the SqlPodcastProvider specifically:
  • Renaming and sorting individual episodes (popular request)
  • Purging based on episode age and/or total size on disk
  • Labeling of PodcastChannels (perhaps to replace traditional folder tree grouping)
More general
  • Mediadevice Podcast support: iPod being the most advanced implementation but also generic usb devices, music phones and Canola2, I'm sure the INdT guys could help us with that.
  • OPML import and export
  • Podcast Directory personal subscription list.
  • BashpodderProvider: to use bashpodder and Amarok in parallel with synchronized download status
  • ...
On to hacking.

Tuesday, October 21, 2008

Feature parity with KDE 3.5 ++: minimized windows

Yesterday the itching became to bad an I hacked a bit on plasma and kwin to restore the workflow I enjoyed with KDE 3.5.

  • The task applet in plasma can be configured to only show minimized windows since r874077.
And

So now KDE support my OSX inspired desktop configuration again. I would include screenshots but plasma is currently broken. Such is the life on the bleeding edge.

Monday, September 01, 2008

Drupal registration module for KDE summits

As you might have noticed, the registration page of the Akademy 2008 website is in fact a drupal site. The original concept for this was conceived by Niels van Mourik (who does drupal development as a day job) and further developed by Marijn Kruisselbrink and me.

It's a normal drupal installation so every person that registers gets a user account. After the login you are automatically redirected to the first page of the registration module where personal details have to be entered.
Next up is the accommodation and extra options reservation. We've used the extras this year for the social event and day trip which both had a 150 person limit and for inquiring about interest in bike rental. The N810 giveaway was also arranged with the options feature, with a limit of 100.

The 3th tab will summarize the selections made and the payment due to complete the registration. A payment ID is automatically generated to be used in a SEPA (EU bank transfer) form as comment to simplify manual processing of those payments. There is also a direct link to PayPal to make the transfer. Obviously all details were supplied to PayPal using it's API so the payment is only a few clicks away. The PayPal payments are automaticly processed using their Instant Payment Notification system.

Here are some of the most important features of the registration module you won't have noticed as a regular user:
* Registrants page: An overview of all registrations including name, email, payment ID, payment status, balance and a combobox to lock the registration forms. It also has a global lock to close registration and control new account creation.
* Accommodation Page: Here we can adjust the available spaces in the hostels that were arranged by the organization. It's also a convenient overview to check the status.
* Reports: SQL queries and results on the internal database. Output in HTML with adjustable links for each tuple and CSV. It also does parameterized queries.
This is really the most powerful feature and has allowed us to do just about anything we wanted with the information in the database. Some examples of that are the automatic generation of conference invite letters for visa applications and namebadges. This was achieved with TeX classes written by Bart Coppens.
The MAC addresses were downloaded and parsed by bash magic to be used in the pfsense portal that provided access to the internet and gave everyone a static IP lease.

The module was functional for Akademy yet it was missing some important features and needs refactoring:
Refactor:
* Change the name of the module
* Change the names of the database tables according to the event name
* Rename the functions to something generic instead of akademy_*

Absolutely needed features:
* Confirmation emails
* Automatic reminder emails

Workflow design:
* Timeline: phases in the registration to control which fields are possible to be edited by whom and deadlines
** Accommodation booking open -> deadline
** Registration open -> deadline
** During event: only certain fields can be adjusted
* Deletion of incomplete registration at the registration deadline

Optional participant features:
* Optional additional visa form with more privacy sensitive data
* Cancel registration by participant him/herself
* More payment options like Google Checkout

Back office features:
* Better "Accommodation" page
** Show free beds as well
** Adding and removing hostel
* Better "Payments" page and db table with dates, bank transfer numbers, etc.
** Deletion or correction of {payment} tuples after refunding
* Page for adding and editing extra options

Advanced back office features:
* Automatic visa invite generation using LaTeX
* Automatic payment receipt generation with support for company name
* Bank, PayPal, etc fee accounting included in the database tables. Needs to include date received and a summary of the booked accommodation and options
* Drag'n'Drop style room assignments using AJAX
* Option: integrate it into a larger community web 2.0'ish website
* Option: "arrived" field or {arrival} table
* Option: cmdline or GUI program to use at the reception desk for:
** marking arrivals
** print individual badge or all badges
In order for the registration module to be used for upcoming events the refactor and needed features has to be done first. After that, and possibly before the Summit in Gran Canaria, the rest can be implemented. Certainly the advanced back office features will be very much needed for a +500 people event.

This modules should not be used by KDE only though. In fact I plan to use it for a conference on our campus early next year (yeah, another one).

If you have PHP, drupal or HTML skills, just want to suggest something or want to help with testing, please join #kde-www or send a mail to kde-www@kde.org

Tuesday, August 19, 2008

The Akademy 2008 team

Niels already mentioned the core team. But Akademy 2008 had a lot more volunteers and helpers

My colleagues of the EmSys group:
* Tom Tierens
* Wim Dams
* Philip Van Pelt
* Johan Van Bauwel
* Lars Struyf
* Patrick Pelgrims
and one of our students: David Nelissen.

Without them the network and computer labs would never have been up, let alone running relatively stable.

Also helping us were with catering and booth duty:
* Bart Elsen
* José Millián Soto
* Ruben Dezeure

And the technical staff of the campus:
* Dirk Swiggers
* Alois Budts
For putting up with all those "geeks" "hacking" in the computer labs.

Leo Schoeters for getting us some exposure on a local TV-station.

Peter Mathijssen made the logo and banners for the website.

We've rented equipment for video recording and power which were kindly supplied to use at a very steep discount by Koen Buys of KB Design.

Lot's of people were involved in organizing Akademy 2008. I'm sure next years team will be even bigger and the quality and "glitch-free"-ness will be the proof of that.

Thanks to all of them for making Akademy 2008 a wonderful experience.