Writing multimedia applications with Grilo
static void_g_digicam_manager_class_init (GDigicamManagerClass
*klass){ GObjectClass *object_class = (GObjectClass*) klass;
g_assert (G_DIGICAM_IS_MANAGER_CLASS (klass));
parent_class = g_type_class_peek_parent (klass);
g_type_class_add_private (klass, sizeof
(GDigicamManagerPrivate));
/* Override virtual functions */ object_class->finalize =
_g_digicam_manager_finalize;
/** * GDigicamManager::focus-done: * @manager: the gdigicam
manager
Juan A. Surez [email protected]
Writing multimedia applications with Grilo
Opening
Sources
Sources
Grilo
Framework focused on making discovery and browsing easy for
application developersA single, high-level API for all the
sources
PluginsProvides access to multimedia content
Extendable
Grilo
SOURCESOURCESOURCESOURCESOURCEMEDIASOURCESOURCEMETADATAKEYS
creates
contains
provides
YoutubeJamendoFlickrIMDB...
AudioVideoImage...
TitleArtistAlbum...
Totem
Totem
Requirements
Define what we needType of contentAny kind?
Only video? Music?
Metadata keysURL
Title
Thumbnail
... 55 metadata keys
Content to show
Ignore any source that does not provide Videos
In browse view, ignore any source that does not support
browsing
In search view, ignore any source that does not support
searching
Information to show
- Title- Author- Duration- Thumbnail- URL- Title- Author-
Duration- Thumbnail- URLBrowseSearch
Invoke Grilo
- Title- Author- Duration- Thumbnail- URL- Title- Author-
Duration- Thumbnail- URLBrowseSearch
Problems
Two problems to solveSource not handling some keys
Too much expensive to retrieve some keys
Totem
Flags to control content retrievalNormal: provides the known
requested contentGRL_RESOLVE_NORMAL
Fast only: provides the known requested content that does not
penalize the operation in terms of
performanceGRL_RESOLVE_FAST_ONLY
Full: provides the known requested content using all the
available sourcesGRL_RESOLVE_FULL
Reduce the problems
Request content in chunks
Request fast only in first iteration
While current chunk is visibleAsk for each visible media element
the discarded keys (using full flag)
URL key case: slow key and not shown in the UIRequest it when
user wants to play
GNOME Music
GNOME Music
Cover Art
GNOME Music
Music defines its own structure
Grilo's one is different
Does not have concept of Artist or AlbumThey are boxes
Needs to sort the results
GNOME Music
Approaches
Request content from Tracker directlyCreate Grilo Media elements
to add missing information (Cover Art)
Instruct Grilo's Tracker plugin how to construct the mediasUse
query() function
Very specific to the plugin
In case of Tracker plugin, use SPARQL to make the queryFirst
column is the media to build
Use alias to map each SPARQL column to specific metadata
keys
GNOME Photos
Tracker
MinerMinerMinerGrilo-basedMiner
hello
Closing
Other use-cases
Application to upload audio/video content to web servicesstore()
function
Mediaplayer with auto-resumeplayback-interrupted-time key
store_metadata() functionMetadata Store source handles it
Show me a code
Resources
Wikihttp://live.gnome.org/Grilo
Source codegit://git.gnome.org/grilo
git://git.gnome.org/grilo-plugins
IRC#grilo at irc.gnome.org
Mailing
listhttp://mail.gnome.org/mailman/listinfo/grilo-list
