This talk will focus on Grilo, a framework which purpose is to provide media application developers with proper tools to access online and offline multimedia. More specifically, Grilo provides: - A single, high-level API that abstracts the differences among various media content providers, allowing application developers to browse and search content from various services and sources with little work on the application side. - A collection of plugins for accessing content from various media providers. Developers can share efforts and code by writing plugins for the framework that are application agnostic. - A flexible API that allows plugin developers to write plugins of various kinds. Today, Grilo is already being used by various GNOME applications, such as Totem, Rhythmbox or MediaExplorer and it will have even more relevance in the future of the platform, where it is expected to be a key component of the new multimedia applications. During this talk we will look at the current version of Grilo, and we will cover the new features that are coming for the 0.2 release: new API aimed to be extensible, new capabilities for filtering, a new design of plugins architecture, support for declarative plugin development, and, of course, the new plugins. Talk from GUADEC 2012.

1. Grilo: present and future
Juan A. Suárez Romero <jasuarez@igalia.com>

2. Outline
● Why Grilo?
● What is Grilo?
● Next coming

3. Playing Content
Fetch Multimedia Play
application

4. Playing Content
Format? ogg, mkv, avi
Fetch Multimedia Codec? mp3, h264, theora
application

5. Playing Content
Fetch Multimedia Gstreamer
.
application Plugins

6. Fetching Content
GVFS/GIO/POSIX Multimedia Gstreamer
.
application Plugins

7. Fetching Content
Online/offline content
Different protocols
Different APIs
Multimedia Gstreamer
.
application Plugins

8. Fetching Content

9. Fetching Content
Grilo Multimedia Gstreamer
. .
Plugins application Plugins

10. Grilo Key Components
Plugin
registers Registry registers
Metadata
Metadata
Metadata enriches Key
Metadata
Source 1..*
Source
Source
Data contains Low level API
Media
Media Media
Media provides 1..*
Source
Source
Source High level API
Audio Video Image Box
Provided by plugins

11. Grilo Sources
● Provides the multimedia content
● Plugins
– Dynamic loaded libraries
– Each plugin provides one or more sources
● Two types of sources:
– Media Sources
– Metadata Sources

12. Grilo Sources
GrlMediaSource GrlMetadataSource
GrlYoutubeSource GrlJamendoSource GrlUpnpSource
GrlUpnpSource GrlGravatarSource GrlLasfmSource
GrlUpnpSource
libgrlyoutube.so libgrljamendo.so libgrlupnp.so libgrlgravatar.so libgrllastfm-albumart.so

13. Grilo Sources
● Source can declare new metadata keys
● Trade-off between application and plugin
developers
● Operations
– Media source: browse, search, metadata,
remove, store, notify changes
– Metadata source: resolve, store specific
metadata

14. Grilo Sources
● Cooperation between sources (full resolution)
search (tracker, “offspring”, search (tracker, “offspring”,
url, lyrics,
lyrics url, lyrics,
title, thumbnail,
thumbnail title, thumbnail, Media Source
album) album, artist)
artist
Application Grilo core API GrlTrackerMedia
send creates
GrlMedia
GrlMedia
GrlMedia
Metadata Source Metadata Source
lyrics thumbnail
GrlLyricsSource GrlLastfmSource

15. What's coming?

16. XML Plugins

17. Caps/Opts
● How to filter results?
– Filter by type
– Filter by specific key
● Problems
– Support in sources
– Too many parameters in function signature

18. Caps/Opts
search (GrlMediaSource *source,
const gchar *text,
const GList *keys,
guint skip,
guint count,
GrlMetadataResolutionFlags *flags,
GrlMediaSourceResultCb callback,
gpointer user_data);

19. Caps/Opts
● Capabilities (GrlCaps)
– Defines what the source can do
– Currently, different types of filtering
● Filter by media type
● Filter by key
● Filter by range
– Extend for other capabilities
● Sorting

20. Caps/Opts
● Options (GrlOperationOptions)
– Defines what the application want to do
– Matches the source capabilities
– Simplifies the function signature
search (GrlMediaSource *source,
const gchar *text,
const GList *keys,
GrlOperationOptions *options,
GrlMediaSourceResultCb callback,
gpointer user_data);

21. Plugins Hierarchy
GrlMediaPlugin
GrlMetadataSource GrlLastfmAlbumartSource
GrlMediasource GrlJamendoSource

22. Plugins Hierarchy
1..*
GrlPlugin GrlSource
GrlMetadataSource GrlMediasource
GrlLastfmAlbumartSource GrlJamendoSource

23. Plugins Hierarchy
1..*
GrlPlugin GrlSource
GrlLastfmAlbumartSource GrlJamendoSource

24. Improved full resolution algorithm
● Several metadata sources solving the same
key
– If one fails, try the next one
● Dependency not provided by media source
– Chain the resolution

25. Resources
● Wiki
– http://live.gnome.org/Grilo
● Source code
– git://git.gnome.org/grilo
– git://git.gnome.org/grilo-plugins
● IRC
– #grilo at irc.gnome.org
● Mailing list
– http://mail.gnome.org/mailman/listinfo/grilo-list

26. Credits
● Television Icon by The Noun Project (CC Attribution)
http://www.iconspedia.com/icon/television-icon-19995.html
● Icon Mobile Phone by Jean Victor Balin http://openclipart.org/detail/29119
● Hard Disk Icon by Mazenl77 (CC Attribution) http://www.iconspedia.com/icon/hard-disk-1600.html
● Memory Card Icon by Custom Icon Design Studio
http://www.gettyicons.com/free-icon/103/pretty-office-2-icon-set/free-memory-card-icon-png/
● Vimeo, Flickr, Jamendo, YouTube and UpnP logos under copyright of their own brands
● Option by rofltosh (CC BY-NC 2.0) http://www.flickr.com/photos/atomicbartbeans/71575328/
● Hold on by Andrew Pescod (CC BY-NC-SA 2.0) http://www.flickr.com/photos/andrewpescod/175668680/
● Train by Andifeelfine (CC BY-NC-ND 2.0) http://www.flickr.com/photos/andifeelfine/235779841/