Sequence Diagram For Loading a DVB stream using the http://www.websequencediagrams.com/.

SequenceDiagramForLoadingADVBStream.wsd

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# No errors on tslock or demux and dcr
title Sequence Diagram For Loading a DVB stream (No errors)
 
participant "Higher Layer (HTML page, JS)" as HigherLayer
participant "HTMLMediaElement" as MediaPlayer
participant "Video pipeline(Tuner, Demod, Demux, Decoder)" as VideoPipeline
 
note right of MediaPlayer
networkState: NETWORK_EMPTY
readyState: HAVE_NOTHING
end note
 
HigherLayer->MediaPlayer: load()
 
note right of MediaPlayer
networkState: NETWORK_NO_SOURCE
end note
 
note right of MediaPlayer
networkState: NETWORK_LOADING
end note
 
MediaPlayer->HigherLayer: loadstart
 
 
MediaPlayer->VideoPipeline: Lock to the frequency specified in the DVB url.
 
MediaPlayer-->HigherLayer: progress
 
note right of VideoPipeline
Tuner tslock to the given frequency. Everything it's ok with no problem.
end note
 
VideoPipeline->MediaPlayer: Ok tslocked to the frequency with no problem.
 
 
MediaPlayer->VideoPipeline: Can you use the demux and decoder to get the DVB stream?
 
MediaPlayer-->HigherLayer: progress
 
note right of VideoPipeline
Media Player uses demux and dcr to create the stream. 
*ASSUMPTION*: The size of the video is predefined, so we don't care \nif the decoder will decode the data in order to get the size.
Set the duration to infinite. It might return the first couple of frames. No issues here.
PSI tables were retrieved with no problem.
end note
 
VideoPipeline->MediaPlayer: The size and the duration are returned.
 
note right of MediaPlayer
readyState: HAVE_METADATA
end note
 
MediaPlayer->HigherLayer: loadedmetadata
 
VideoPipeline->MediaPlayer: A couple of frames are returned.
 
 
MediaPlayer->VideoPipeline: Now that the stream is decoded and have the metadata, can you send me emough data for playback?
 
MediaPlayer-->HigherLayer: progress
 
note right of VideoPipeline
Media Player uses dcr to create enough data for playback.
end note
 
VideoPipeline->MediaPlayer: Enough data returned for playback.
 
note right of MediaPlayer
readyState: HAVE_ENOUGH_DATA
end note
 
MediaPlayer->HigherLayer: loadeddata 
MediaPlayer->HigherLayer: canplay
MediaPlayer->HigherLayer: canplaythrough
 
HigherLayer->MediaPlayer: play()

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