View Source

MediaPipeline

Create

@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

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

Destroy

@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


Cobalt            ->  Starboard:        SbPlayerDestroy(player_session)
Starboard         ->  GStreamer_client: Destroy Rialto Client Gst pipeline
activate GStreamer_client
note right of GStreamer_client
As each rialto sink is freed it will decrement the
ref count to its media player (via the TBD unique
pipeline ID). When the ref count reaches zero the
destructor is triggered.
end note
GStreamer_client  ->  rialtoClient:     ~IMediaPipeline()
deactivate GStreamer_client
rialtoClient      ->  rialtoServer:     ~IMediaPipeline()
rialtoServer      ->  GStreamer_server: Destroy rialto server pipeline
GStreamer_server  --> rialtoServer:
rialtoServer      --> rialtoClient:     
rialtoClient      --> GStreamer_client: 
GStreamer_client  --> Starboard
Starboard         --> Cobalt:

@enduml

MediaKeys

Check Supported Key Systems - indicative use of Rialto

@startuml

autonumber

box "Container" #LightGreen
participant Client
participant rialtoClient
end box

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


alt Client should check if the required key system is supported
Client       ->  rialtoClient:  supportsKeySystem(key_system)
rialtoClient ->  rialtoServer:  supportsKeySystem(key_system)
rialtoServer ->  Ocdm:          opencdm_is_type_supported(key_system, "")
Ocdm         --> rialtoServer:  result
rialtoServer --> rialtoClient:  result
rialtoClient --> Client:        result
else Or find the supported key systems then choose its preferred
Client       ->  rialtoClient:  getSupportedKeySystems()
rialtoClient ->  rialtoServer:  getSupportedKeySystems()
loop For each key system supported by Rialto
rialtoServer ->  Ocdm:          opencdm_is_type_supported(key_system, "")
Ocdm         --> rialtoServer:  result
opt If key_system supported
rialtoServer ->  rialtoServer:  Add key_system to array of supported keys systems
end
end
rialtoServer --> rialtoClient:  key_systems
rialtoClient --> Client:        key_systems
end


@enduml

Get DRM Version - Netflix/native Rialto

@startuml

autonumber

box "Container" #LightGreen
participant Netflix
participant DPI
participant rialtoClient
end box

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


Netflix      ->  DPI:           getDrmVersion()
DPI          ->  rialtoClient:  getSupportedKeySystemVersion("com.netflix.playready")
rialtoClient ->  rialtoServer:  getSupportedKeySystemVersion(key_system)
rialtoServer ->  Ocdm:          opencdm_create_system(key_system);
note right: This temporary media keys does not count towards\nany quota allocated by Rialto Server Manager
Ocdm         --> rialtoServer:  media_keys
rialtoServer ->  Ocdm:          opencdm_system_get_version(media_keys)
Ocdm         --> rialtoServer:  version
rialtoServer ->  Ocdm:          opencdm_destruct_system(media_keys)
Ocdm         --> rialtoServer:  status
opt Key system version retrieved successfully
rialtoServer --> rialtoClient:  rv=true, version
else Error querying supported key system version
rialtoServer --> rialtoClient:  rv=false, version=""
end
rialtoClient --> DPI:           rv, version
DPI          --> Netflix:       rv, version

@enduml

Create - Cobalt/OCDM

@startuml

autonumber

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

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


Cobalt       ->  Starboard:     SbDrmCreateSystem(key_system)
Starboard    ->  ocdmProxy:     opencdm_create_system(key_system)
ocdmProxy    ->  rialtoClient:  createMediaKeys(key_system)
rialtoClient ->  rialtoServer:  createMediaKeys(key_system)
rialtoServer ->  Ocdm:          opencdm_create_system(key_system)
Ocdm         --> rialtoServer:  handle
rialtoServer ->  rialtoServer:  Store Media Keys instance handle
note right
This stored handle is only needed for deleting any
MediaKeys objects that the client fails to destroy
when moved out of the Running state.
end note
rialtoServer --> rialtoClient:  media_keys_handle
rialtoClient --> ocdmProxy:     media_keys_handle
ocdmProxy    --> Starboard:     handle
Starboard    --> Cobalt:        handle

@enduml

Create - Netflix/native Rialto

@startuml

autonumber

box "Container" #LightGreen
participant Netflix
participant DPI
participant rialtoClient
end box

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

Netflix      ->  DPI:           initialize(drmSystemCallback, provisioningEngine)
DPI          ->  rialtoClient:  createMediaKeys("com.netflix.playready")
rialtoClient ->  rialtoServer:  createMediaKeys(key_system)
rialtoServer ->  Ocdm:          opencdm_create_system(key_system)
Ocdm         --> rialtoServer:  handle
rialtoServer ->  rialtoServer:  Store Media Keys instance handle
note right
This stored handle is only needed for deleting any
MediaKeys objects that the client fails to destroy
when moved out of the Running state.
end note
rialtoServer --> rialtoClient:  media_keys_handle
rialtoClient --> DPI:           media_keys_handle
DPI          --> Netflix:       status

@enduml

Destroy - Cobalt/OCDM

@startuml

autonumber


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

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


Cobalt       ->  Starboard:     SbDrmDestroySystem(handle)
Starboard    ->  ocdmProxy:     opencdm_destruct_system(handle)
ocdmProxy    ->  rialtoClient:  ~IMediaKeys()
rialtoClient ->  rialtoServer:  destroyMediaKeys(media_keys_handle)
rialtoServer ->  Ocdm:          opencdm_destruct_system(handle)
Ocdm         --> rialtoServer:  status
rialtoServer ->  rialtoServer:  Remove stored MediaKeys handle
rialtoServer --> rialtoClient:  status
rialtoClient --> ocdmProxy:     status
ocdmProxy    --> Starboard:     status
Starboard    --> Cobalt:        status

@enduml

Destroy - Netflix/native Rialto

@startuml

autonumber


box "Container" #LightGreen
participant Netflix
participant DPI
participant rialtoClient
end box

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


Netflix      ->  DPI:           teardown()
DPI          ->  rialtoClient:  ~IMediaKeys()
rialtoClient ->  rialtoServer:  destroyMediaKeys(media_keys_handle)
rialtoServer ->  Ocdm:          opencdm_destruct_system(handle)
Ocdm         --> rialtoServer:  status
rialtoServer ->  rialtoServer:  Remove stored MediaKeys handle
rialtoServer --> rialtoClient:  status
rialtoClient --> DPI:           status
DPI          --> Netflix:       status

note over Netflix: To prevent leaks ~IDrmSystem() should call\n~IMediaKeys() if teardown() wasn't called

@enduml

Check, if server certificate is supported

@startuml
autonumber

box "Container" #LightGreen
participant Client
participant rialtoClient
end box

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

Client       ->  rialtoClient:  isServerCertificateSupported(key_system)
rialtoClient ->  rialtoServer:  isServerCertificateSupported(key_system)
rialtoServer ->  Ocdm:          opencdm_system_supports_server_certificate(key_system)
Ocdm         --> rialtoServer:  result
rialtoServer --> rialtoClient:  result
rialtoClient --> Client:        result
@enduml

IPC

Initialise Rialto Client

There doesn't seem to be any obvious trigger for initialising Rialto in Cobalt/Gst environment so do so on first API call that needs to use Rialto.

@startuml

autonumber


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

alt EME requires Rialto first
Starboard        ->  ocdmProxy:         Any API that requires Rialto call
opt if !rialtoInitialised
ocdmProxy        ->  rialtoClient:      init()
end
ocdmProxy        ->  rialtoClient:      API call

else MSE requires Rialto first
Starboard        ->  GStreamer_client:  Any API that requires Rialto call
opt if !rialtoInitialised
GStreamer_client ->  rialtoClient:      init()
end
GStreamer_client ->  rialtoClient:      API call
end

@enduml

init() API is not currently implemented. Rialto client currently automatically establishes IPC connection automatically during initialisation

Terminate Rialto Client

Terminating Rialto has an even less obvious trigger than initialisation, for the purposes of being able to test suggest that when player & CDM count reaches 0 that we terminate - this could possibly be improved by waiting, say, 10 seconds to see if another API call occurs. If app calls another API after termination then Rialto will be re-initialised.

@startuml

autonumber


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


Starboard        ->  GStreamer_client:  SbPlayerDestroy()
GStreamer_client ->  GStreamer_client:  num_pipeline_sessions--
opt if (num_media_keys == 0 && num_pipeline_sessions == 0)
GStreamer_client ->  rialtoClient:      term()
end


opt
Starboard        ->  ocdmProxy:         SbDrmDestroySystem()
ocdmProxy        ->  ocdmProxy:         num_media_keys--
opt if (num_media_keys == 0 && num_pipeline_sessions == 0)
ocdmProxy        ->  rialtoClient:      term()
end
end

@enduml

term() API is not currently implemented and there is no mechanism to shut down IPC connection other than terminating the process