MediaBox finally supports UPnP MediaRenderer Output

The Fremantle version of MediaBox Media Center is coming along nicely. The latest development version (2009.11.1) is now in extras-devel, so if you're brave enough to test out hot fresh unstable stuff directly from extras-devel, you're invited to give it a try (installing just MediaBox from extras-devel should be pretty safe).

The big news with the latest development version is UPnP MediaRenderer support. If you have a compatible (GUPnP-Media-Renderer has been tested to be compatible so far) UPnP MediaRenderer in your network, you can have MediaBox play on that renderer instead of your phone.

If the MediaRenderer supports it, you can even play local files from your phone on it, not only stuff hosted on another UPnP/DLNA server.

Eventually, this cool stuff will be available for N8x0 users, too, of course.

Update on the N900 FM Radio

Success! We can receive FM radio on the N900 now.

Controlling the FM radio in the N900 is tricky stuff. At first, the hardware is disabled for power saving reasons. Bluetooth has to be powered up, the I2C communication bus has to be powered up, and only then, the FM radio driver will actually load.

I have created a package n900-fmrx-enabler for this task. The FMRX-Enabler is a D-Bus service that takes care about enabling the FM radio hardware on request and powering it down again when no application are using it.

After the driver has been loaded by the FMRX-Enabler, the FM radio provides two interfaces for controlling. A classic Video4Linux2 interface featuring only the basic stuff such as setting the frequency and muting/unmuting it, and a sysfs interface where you can read and write into file-like objects to control the radio.

Another tricky part is getting to hear sound from the radio. Unlike the N800, the FM radio doesn't output to the speakers directly. You have to capture the sound from the PGA line and play it back. A simple GStreamer pipeline such as

gst-launch pulsesrc ! pulsesink

does the job, after enabling PGA line2 and PGA capturing in the mixer.

I have uploaded an application package fmradio for the FM radio to extras-testing. Testers are encouraged to test this, too.

One drawback with the FM radio is that due to constant capturing and replaying, the FM radio is kinda demanding on the battery. There's no safe way around that. The unsafe way around that can damage your speakers, so capturing/replaying is a must.

I'm gonna put up some developer documentation for the FM radio stuff.

MediaBox on the N900

The popular NIT media center MediaBox is coming to the N900. Thanks to lots of user feedback the UI has been further simplified and optmized and of course "fremantlized". :)





The upcoming release for the N900 will be the first version to provide suport for portrait and landscape orientations. Browsing your music feels great in portrait mode!





MediaBox will support playing FM radio on the N900 as well (the N900 device specs don't list the FM radio, but there is one, on the Bluetooth chip).

Media indexing is now driven by tracker, the native indexer of the Fremantle OS. And if you don't like indexing you can of course browse the file system as before.

When you start MediaBox you will see the dashboard. This is where you can access your playlists, browse the device and your UPnP/DLNA servers, and access your indexed music, videos, and pictures. You can even put shortcuts to your stuff onto the dashboard for quick access, e.g. songs or albums you like, or folders with photos. No matter how deep within folders and subfolders you are, the dashboard is only one finger-tap away.

Another new feature is the folder history where you can see the folders where you recently were and go back.

If you have Tuomas Kulve's ogg-support installed, you will also be able to play Ogg Vorbis and FLAC music.

MediaBox still uses its own lightweight UPnP subsystem instead of gupnp that comes with Fremantle. My experience shows that the UPnP subsystem of MediaBox is still more compatible with the servers out there than gupnp is right now.

MediaBox is currently in the extras-devel repository for Fremantle and it's marked as an incomplete beta version. I expect to upload the full release later this month, after which it moves on to the extras-testing repository for community Q&A. Then it should only be a matter of time until it will appear in the extras repository.
The beta version in extras-devel is now updated frequently.

The new version will also be available for Diablo after the release for Fremantle. Portrait mode will be supported on Diablo, too, if you have rotation-support installed.

MediaBox Media Center 0.96.5 with New Features

After several weeks of development, I have now released version 0.96.5 of MediaBox Media Center. Lots of user feedback helped shape the new version.

Most notably the user interface looks a bit different now as it has been tidied up for a more consistent look & feel and much better performance with reduced memory footprint.

Quick Scrolling and Search

The item lists have a thumbable scrollbar and a index letter display helps you find your way while quick scrolling.



While searching for an item with the onscreen-keyboard or a hardware-keyboard, you can skip to the previous and next search results by pressing up or down on the D-pad.

Falling Asleep and Waking Up with Music

If you like to fall asleep with music or want to wake up with music, you will love the new sleep timer. Simply set the time when MediaBox should start or stop playing in the preferences viewer and select the media you want to have played. The sleep timer simulates PLAY and STOP actions so it can be used with virtually any media. For instance, you can have MediaBox wake you up with FM radio on the N800. With this feature, my N800 finally earned a steady place next to my bed.



Timed Karaoke Lyrics

Do you like lyrics? MediaBox displays song lyrics in LRC format. LRC lyrics files need to match the file name of the song file, e.g. "Song.mp3" and "Song.lrc".
LRC is a popular file format in China, and you can find lots of lyrics on various lyrics servers. Since LRC files are text files, you can also create them yourself.
I plan on making a LRC editor for MediaBox in the near future, too.

As always, MediaBox is available for N800 and N810 in the maemo-extras repository.
Nokia 770 users can retrieve MediaBox from the SVN repository or manually pull the
deb packages from the Chinook maemo-extras repository server.

A full list of what's new can be found in the release notes.

Mer plays videos with MediaBox

Another milestone has been reached in the Mer project on its way to eventually replace Maemo on the N8x0 devices. It will be possible to play videos with Mer 0.13. The current SVN version of MediaBox supports Mer and uses the libxine backend for video playback.

After installing libxine and MediaBox SVN version on Mer, you will need to install the D-Bus-Xine service. D-Bus-Xine is a simple D-Bus service for embedding libxine in applications. It was originally written for enabling DVD playback
with MediaBox on PCs.

A version compiled for Mer-ARMEL can be found here. If you want to compile D-Bus-Xine yourself, you can also download its source code.

I haven't built deb packages for D-Bus-Xine yet, so you'll have to manually extract the tarball in the root directory (/) on Mer.

After having started MediaBox, you should enter its preferences view
and set the media backends to Xine for all filetypes that you want to be able play.
However, there is no sound support yet in Mer 0.13, so don't expect too much.

EDIT: see the comments for how to get sound

MediaBox Media Center 0.96.4 released

Hilights of the new MediaBox release:

The overall performance of the user interface has been improved again and the lists now feature transition effects and remember the position where you where standing in the parent folder when you go back. This is especially handy when browsing UPnP/DLNA servers.



The mplayer backend has been optimized and mplayer now plays videos generally a lot smoother than before. Playback of higher resolution videos (e.g. 640 x 480) is now also smoother by automatic downscaling.

Media indexing has been improved and runs faster. And if you don't like indexing of ID tags, you can always browse the filesystem to play your media, of course.



Music can now also be browsed by genre, additional to browsing by artist, by album, and by folder.



MediaBox can now be told to keep the display lit while playing media. Stop playing, and the device may enter powersaving mode again.

If you use the Nokia headset that came with the device, you can now use the headset button to pause/play and skip to the next or previous track. Do this by pushing the button once, twice, or three times, respectively. Do not press the button to quickly because the headset is bad at detecting consecutive actions, though. Half a second between clicks is just right.

Extending MediaBox: Creating a Simple Component

Note: If you're reading this article in a feed aggregator like planet.maemo.org, it might be truncated. Please click the link to the original feed to read the full article.

Get your text editor ready because this time I'm showing you the basics of plugin development for MediaBox.

Last time, I have explained the component system of MediaBox. If you haven't read this article yet, please do so as it will help you understand what's going on.
Now we're going to write a simple plugin that displays a short notification when the application has started.

As I have told you before, a plugin is a directory with some components in it. MediaBox looks for the plugin directories in its components directory. So we put a new directory in there with two empty files __init__.py and StartupNotifier.py in it:

  mediabox
    |
    +-- components
          |
          +-- my_first_plugin
                |
                +-- __init__.py
                |
                +-- StartupNotifier.py

Every plugin needs the __init__.py file. This is the place where components are loaded and messages are defined. In this example, we will only load our StartupNotifier component, though.

Put the following code into __init__.py:

  def get_classes():
  
      from StartupNotifier import StartupNotifier
      return [StartupNotifier]

The function get_classes is called by MediaBox to load the components. This function must return a list of the classes (not instantiated objects) of your components.

Now we are going to fill StartupNotifier.py with life. It is a simple component, so we derive StartupNotifier from the Component baseclass:

  from com import Component, msgs
  
  class StartupNotifier(Component):
  
      def __init__(self):
      
          Component.__init__(self)


      def handle_message(self, msg, *args):
      
          if (msg == msgs.CORE_EV_APP_STARTED):
              self.call_service(msgs.NOTIFY_SVC_SHOW_INFO,
                                "Application Startup Complete")

That's all. This simple form of a component is called a mediator component, because it just listens for and emits messages. When a component wants to listen to the message bus, it simply overrides the method handle_message and checks for the message types it's interested in. The call_service method on the other hand sends a service call to the message bus.

When you now start MediaBox, you will be greeted by your new plugin.

Next time will be a bit more theoretical again. Then I'll talk about the different types of components and what they do in MediaBox.

Extending MediaBox: The Component System Explained

I am going to write a bit about extending MediaBox with new plugins. Let's start with the basics of the component system first. I will show you some code examples in a later article.

Since version 0.96 MediaBox uses a component system for extensions. It is essential to understand this system when implementing plugins.

Components in MediaBox are independent objects connected to a message bus, where they can send messages or listen to messages from other components. Every component gets connected to the bus automatically when created. You don't have to take care about this step.

A plugin is a collection of one or more components grouped into a directory. The YouTube plugin, for instance, consists of a YouTube device component and a component for the preferences dialog.

Plugins can also add new messages to the vocabulary of messages that can be sent across the message bus.

Here's a little ASCII-art to summarize this all.

           consist of                 connect to
  Plugins -------------> Components ---------------> Message Bus
     |                    |      |                        |
     |               emit |      | listen for             |
     |                    |      |                        |
     |                    |      |                        |
     |     define         v      v          transports    |
     +------------------> Messages <----------------------+

Let's take a closer look at the message stuff now.
As explained above, the vocabulary of messages that can be sent across the message bus is defined by the plugins. Most of the messages are defined by the "core" plugin (which is not really a plugin but contains many of the core components of MediaBox).

Some messages are of type event. They are used to notify other components about something that has just happened, e.g. that a new UPnP device has been discovered.
Some messages are of type action. They are used by components to trigger actions in other components.
There are also messages of type service call. While events and messages may be handled by any component that listents for these messages, a service call is only sent to one component and not visible to others. The message bus remembers which component can handle a particular service call and will route all subsequent calls for the same service to the same component again.

To sum it up with ASCII-art:

                              +------> Event
            is either of type |
   Message -------------------+------> Action
                              |
                              +------> Service Call

When a plugin defines a new message, it has to give it a name. The name is all uppercase and consists of a domain name, the message type, and some descriptive name.
The domain name helps to avoid name clashes of messages defined by different plugins. It should be the name of your plugin.
The message type tells programmers about the type of message. It is one of EV for events, ACT for actions, and SVC for service calls.

These are some examples of actual messages defined by components belonging to MediaBox:

• CORE_EV_APP_IDLE_BEGIN (event: MediaBox is announcing to go idle in order to save battery)


• CORE_EV_APP_IDLE_END (event: MediaBox is announcing to wake up from idle state)


• NOTIFY_SVC_SHOW_MESSAGE (service call: show a short message)


• HWKEY_EV_UP (event: user pressed up on the d-pad)


• HWKEY_EV_DOWN (event: user pressed down on the d-pad)


• HWKEY_EV_LEFT (event: user pressed left on the d-pad)


• HWKEY_EV_RIGHT (event: user pressed right on the d-pad)


• UI_ACT_SELECT_VIEWER (action: select a viewer)

Some messages take parameters. NOTIFY_SVC_SHOW_MESSAGE, for instance, takes as parameter the text of the message to show. Some service calls even have a return value.

These are the basics of the component system. Next time I will show you how components are integrated in MediaBox, and how to create a simple plugin.

Making Themes for MediaBox

Today I'm showing you how to make new themes for MediaBox.

Every theme is a subdirectory in /usr/lib/mediabox/theme or in ~/.mediabox/themes (MediaBox 0.96.2 or higher).
You can test your themes in ~/.mediabox/themes and when distributing the theme as an installer package, it will install into /usr/lib/mediabox/theme.

There are a two files that are absolutely necessary for a theme to work, and every theme must include them.

The one is PREVIEW.png, which is a PNG image of size 112 x 67 pixels, showing a preview image of your theme. This is the icon that the users will see in the theme selector.

The other file that is necessary is a simple text file called info. This file describes the theme and looks like this:

name:        MyTheme
description: My example theme for MediaBox
author:      Your Name

Of course, with only these two files, your theme will be pretty empty. Actually, MediaBox will load everything that it doesn't find in the current theme from the default theme. Thus, every theme inherits from default.

When you look into the directory of the default theme (/usr/lib/mediabox/theme/default), you will see a lot of images in PNG format. These are the theme elements. Your theme can override any of these images by providing a PNG image of the same name and the same size. I have to stress that it is absolutely necessary that the theme elements provided by your theme are exactly the same size as the ones in the default theme! For instance, the element mb_panel.png is of size 64 x 64 pixels. If your theme provides mb_panel.png, it must be of size 64 x 64 pixels, too.

A theme can have a bunch of .def files, which are text files containing font and color definitions. The name and number of the .def files is not important. Below are example entries of a .def file:

#
# Virtual Keyboard
#
color_mb_vkb_background: #000000
color_mb_vkb_text: #dddddd
font_mb_vkb: Nokia Sans Cn bold 20

Empty lines and lines starting with a # symbol are ignored by MediaBox and can be used for adding comments and making the file better readable.
The other lines contain key-value pairs, where key and value are separated by a : symbol. If the key name starts with color_, then MediaBox treats it as a color definition. If the key name starts with font_, then MediaBox treats it as a font definition.

Color values are given in hexadecimal RGB (6 digits) or RGBA (8 digits) notation, prepended by a # symbol. Most color keys take RGB values only.

Font definitions are given in Pango syntax, containing the font name, optionally a style (bold or italic), and the font size in points. Although the Nokia internet tablets have a screen resolution of 225 dpi, the system renders fonts with 96 dpi.

Any keys defined in the .def files of the default theme can be overriden by your theme in .def files.

Once your theme is ready, you may want to distribute it as a installer package for the application manager. I have created a build script for this task. If you have upload permission for the maemo-extras repository, you can then upload your theme with the Maemo Extras Assistant web site and promote it to the extras repository, so that other users can enjoy it, too.

Theme packages always depend on mediabox-compat-theme with a certain version number. For MediaBox 0.96 and some following releases, this version number will be 1.0. So as long as MediaBox provides mediabox-compat-theme, version 1.0, your theme will remain compatible. At a later point some minor changes or extensions to your theme may be necessary to fully restore compatibility again.