W3C home > Mailing lists > Public > public-media-capture@w3.org > March 2013

live, muted, enabled, and ready-state

From: Cullen Jennings (fluffy) <fluffy@cisco.com>
Date: Fri, 22 Mar 2013 13:17:12 +0000
To: "public-media-capture@w3.org" <public-media-capture@w3.org>
Message-ID: <C5E08FE080ACFD4DAE31E4BDBF944EB11342C922@xmb-aln-x02.cisco.com>

The draft is confusing to readers on the topic of what these all mean. Later in the email I will provide what meaning I can extract from the draft but first let me propose my suggestion to clean up this mess. 

1) remove the enabled attribute, you can get all the info from the readyState, or if you really want to keep this attribute, rename it to muted 

2) add a method to mute/unmute. Give some thought to if this needs to be asynchronous or not 

2) In the MediaStreamTrackState enum, change the name of "live" to "unmated". 

3) everywhere in the specification get rid of the word enable and live and replace them with muted / unmated concept 

So here is what I can find in the draft on the meanings of these today, and the above recommendation does not change the meanings from what they are, it just tries to clear up the working. Feel free to ignore the rest of this email, the important things is the above proposal to fix it 

The ready-state can be one of 

new - track type is new and has not been initialized

live - The track is active (the trackís underlying media source is making a best-effort attempt to provide data in real time). The output of a track in the live state can be switched on and off with the enabled attribute.

muted - The track is muted (the trackís underlying media source is temporarily unable to provide data).

ended - The track has ended (the track's underlying media source is no longer providing data, and will never provide more data for this track).

So looking at this, it looks like toggling the enable bit moves the state back and forth from live to muted. 

Then we have muted and unmated events and related callbacks that correspond to the state be muted and live.

We have the text 

Each track in a MediaStream object can be disabled, meaning that it is muted in the objectís output. All tracks are initially enabled.

The output of a MediaStream object must correspond to the tracks in its input. Muted audio tracks must be replaced with silence. Muted video tracks must be replaced with blackness.

Later we have text that implies "live" has to do with if it is coming from a file or not, and nothing to do with being the opposite of muted. 

As a side note I despise text like 

  The readyState attribute represents the state of the track. It must return the value to which the user agent last set it.

There is not a single bit of useful information in that paragraph for someone trying to implement this or someone trying to use it. 
Received on Friday, 22 March 2013 13:17:44 UTC

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