Page History

@startuml
autonumber

box "Container" #LightGreen
participant Cobalt
participant Starboard
participant GStreamer_client
participant rialtoClient
end box

box "Platform" #LightBlue
participant rialtoServer
participant GStreamer_server
end box

== Create Media Pipeline ==

Cobalt            ->  Starboard:        SbPlayerCreate(media_keys_handle, video_info, audio_info)
Starboard         ->  GStreamer_client: Create Gst pipeline with Rialto sinks  
 
activate GStreamer_client
 
opt maxWidth 
Starboard         ->  GStreamer_client: Set PROP_MAX_VIDEO_WIDTH
end
opt maxHeight 
Starboard         ->  GStreamer_client: Set PROP_MAX_VIDEO_HEIGHT
end

note right of GStreamer_client
As the Gst pipeline is brought up the creation of
the first rialto sink for a pipeline triggers the
createMediaPipeline() call. Creation of additional
rialto sinks increments a ref count to the media
pipeline. To identify which pipeline a sink relates
to it will pass the parent bin object pointer to 
the pipeline root element.
end note    
 
note right of GStreamer_client  
If max width and max height are not set by the client
the mediaPipeline shall be created with videoRequirements 
set to 2160x3840.

If max width and max height are set, then rialto shall
assume the playback is secondary video.
end note   

GStreamer_client  ->  rialtoClient:     createMediaPipeline(client, videoRequirements)
rialtoClient      ->  rialtoServer:     createMediaPipeline(client, videoRequirements)
rialtoServer      ->  rialtoServer:     Check resource permissions that were granted to app and currently\nallocated pipelines allows creation of this new pipeline
note left: Currently this check is simply num_current_pipeline_sessions < max_playback_sessions

opt Permission check passed
rialtoServer      ->  rialtoServer:     Store video requirements
opt videoRequirements != 2160x3840 && westerossink
rialtoServer  	  ->  GStreamer_server: Set secondary video
end  
rialtoServer      --> rialtoClient:     pipeline_session
rialtoClient      --> GStreamer_client: pipeline_session

GStreamer_client  ->  rialtoClient:     load(pipeline_session, MEDIA_TYPE_MSE, ~"", ~""). 
rialtoClient      ->  rialtoServer:     load(pipeline_session, MEDIA_TYPE_MSE, ~"", ~"")
rialtoServer      ->  GStreamer_server: Create rialto server MSE pipeline
GStreamer_server  --> rialtoServer:
opt videoRequirements != 2160x3840 && westerossink
rialtoServer  	  ->  GStreamer_server: Set secondary video
GStreamer_server  --> rialtoServer:
end   
rialtoServer      -/  rialtoClient:     notifyNetworkState(pipeline_session, NETWORK_STATE_BUFFERING)
rialtoClient      -/  GStreamer_client: notifyNetworkState(pipeline_session, NETWORK_STATE_BUFFERING)
rialtoServer      --> rialtoClient:     
rialtoClient      --> GStreamer_client: 

opt video_codec != None
GStreamer_client  ->  rialtoClient:     attachSource(pipeline_session, video_source)
rialtoClient      ->  rialtoServer:     attachSource(pipeline_session, video_source)
rialtoServer      ->  GStreamer_server: Add video sink to pipeline
GStreamer_server  --> rialtoServer:
rialtoServer      --> rialtoClient:
rialtoClient      --> GStreamer_client:
end

opt audio_codec != None
GStreamer_client  ->  rialtoClient:     attachSource(pipeline_session, audio_source)
rialtoClient      ->  rialtoServer:     attachSource(pipeline_session, audio_source)
rialtoServer      ->  GStreamer_server: Add audio sink to pipeline
GStreamer_server  --> rialtoServer:
rialtoServer      --> rialtoClient:
rialtoClient      --> GStreamer_client:
end

rialtoClient       -> rialtoServer:      allSourcesAttached(pipeline_session)
rialtoServer      ->  GStreamer_server:  Setup and add app source
GStreamer_server  --> rialtoServer:
rialtoServer      --> rialtoClient:

deactivate GStreamer_client

GStreamer_client  --> Starboard
Starboard         --> Cobalt:



== Notify that Pipeline & network session is currently IDLE ==

rialtoServer       -/  rialtoClient:     notifyNetworkState(NETWORK_STATE_IDLE)
note right
Note that notification may occur before createMediaPipeline() call returns
end note
rialtoClient       -/  GStreamer_client: notifyNetworkState(NETWORK_STATE_IDLE)

rialtoServer       -/  rialtoClient:     notifyPlaybackState(PLAYBACK_STATE_IDLE)
note right
Note that notification may occur before createMediaPipeline() call returns
end note
rialtoClient       -/  GStreamer_client: notifyPlaybackState(PLAYBACK_STATE_IDLE)

else Permission check failed

rialtoServer      --> rialtoClient:     ERROR_DENIED
rialtoClient      --> GStreamer_client: ERROR_DENIED

end
@enduml